Podcasts about Chloroplast

References Plant Physiology 2011. 157(4):1746-64 Methods Mol Biol. 2016; 1376: 175–194 J Biol Chem. 2018 Sep 21; 293(38):14786–14797 Mozart, WA. 1786. Voi che sapete" (from: Le nozze di Figaro, K492.) https://youtu.be/tH93uhBs5m8?si=GVfvA5r_QlrVJJgq --- Support this podcast: https://podcasters.spotify.com/pod/show/dr-daniel-j-guerra/support

In this episode, Jon Teater (Whitetail Landscapes) and Dan Kittredge (Bionutrient Food Association) discuss quality of the food, nutrient value, and health attributes of nutrient dense plants. Dan discusses what got him trying to improve his plants to repel going pest and disease pressure and how organic is not always the option. Dan explains how to create more yield and better production in our fields, food plots and forested land. Working with the bottom of the food chain to produce the best food on our land and in our forest. Dan discusses how to change our degraded ecosystem Principles of biological systems. Chloroplast, photosynthesis, sugar, and oxygen are all factors in supporting our plant health. The significance of soil and the microbes. Discusses the essentials of plant life, and how our soils have degraded over the years and what we can do to repair our environments. Why Dan does not add nitrogen or other fertilizers. New ways to amend your soil that most have not heard of before. Dan explains low-cost methods that will improve your land, improve mineral composition, and ultimately improve the food that is available to animals and build a healthier deer herd. Dan identifies how to remineralize your land and build higher complexed plants that attract more deer. Dan discusses the importance of inoculation, foliar sprays, seed quality and plant spacing.  Check out the Sportsmen's Empire Podcast Network for more relevant, outdoor content! Social Links Bionutrient Food Association https://www.youtube.com/channel/UCI99ERb9iBmwgrJPbv3iKdA https://whitetaillandscapes.com/ https://www.facebook.com/whitetaillandscapes/ https://www.instagram.com/whitetail_landscapes/?hl=en Learn more about your ad choices. Visit megaphone.fm/adchoices

In this episode, Jon Teater (Whitetail Landscapes) and Dan Kittredge (Bionutrient Food Association) discuss quality of the food, nutrient value, and health attributes of nutrient dense plants. Dan discusses what got him trying to improve his plants to repel going pest and disease pressure and how organic is not always the option. Dan explains how to create more yield and better production in our fields, food plots and forested land. Working with the bottom of the food chain to produce the best food on our land and in our forest. Dan discusses how to change our degraded ecosystem Principles of biological systems.Chloroplast, photosynthesis, sugar, and oxygen are all factors in supporting our plant health. The significance of soil and the microbes. Discusses the essentials of plant life, and how our soils have degraded over the years and what we can do to repair our environments. Why Dan does not add nitrogen or other fertilizers.New ways to amend your soil that most have not heard of before. Dan explains low-cost methods that will improve your land, improve mineral composition, and ultimately improve the food that is available to animals and build a healthier deer herd. Dan identifies how to remineralize your land and build higher complexed plants that attract more deer. Dan discusses the importance of inoculation, foliar sprays, seed quality and plant spacing. Check out the Sportsmen's Empire Podcast Network for more relevant, outdoor content!Social LinksBionutrient Food Associationhttps://www.youtube.com/channel/UCI99ERb9iBmwgrJPbv3iKdAhttps://whitetaillandscapes.com/https://www.facebook.com/whitetaillandscapes/https://www.instagram.com/whitetail_landscapes/?hl=en

Mr Jim's Puzzle Is Now AvailableYes, Mr Jim made a mystery puzzle where its up to you to solve who the mystery animal is! Each Puzzle includes a 54 piece jigsaw puzzle, a Mr Jim audio story, and the mystery animal toy from Schleich®.—> Buy It Now The Spy Starter Pack Birthday Shout Out Join the HEYMRJIM Family

Mr Jim's Puzzle Is Now AvailableYes, Mr Jim made a mystery puzzle where its up to you to solve who the mystery animal is! Each Puzzle includes a 54 piece jigsaw puzzle, a Mr Jim audio story, and the mystery animal toy from Schleich®.—> Buy It Now The Spy Starter Pack Birthday Shout Out Join the HEYMRJIM Family

Mr Jim's Puzzle Is Now AvailableYes, Mr Jim made a mystery puzzle where its up to you to solve who the mystery animal is! Each Puzzle includes a 54 piece jigsaw puzzle, a Mr Jim audio story, and the mystery animal toy from Schleich®.—> Buy It Now The Spy Starter Pack Birthday Shout Out Join the HEYMRJIM Family

AP Biology Cell Campaign Speech

This week before we take a hiatus we talk Clannad, Until Dawn and once again Will talks Murakami! If you do enjoy the show, share it with your friends! Tweet about us using the #whtb or word of mouth is great! If you want to further support the show, check out our Ko-fi page: https://ko-fi.com/whathasthisbecome Check out Lauren's website also: https://www.magpiedie.com/ https://www.etsy.com/shop/magpiedie Dwayne Trayne: https://open.spotify.com/show/1Xdn7dxRLRcHWgaRqTOz8A If you want to engage more with the show, check out our Twitter: https://twitter.com/whathasthisbec1 Find small clips from the pod & DT on our YouTube: https://www.youtube.com/channel/UCdDPApUvQMdgXJQrPtR74BA/featured Our Facebook: https://www.facebook.com/whathasthisbec1 Will: https://twitter.com/WilliamMarr4 Lauren: https://twitter.com/ElizaRumm Twitch: https://www.twitch.tv/elizarumm We have Instagram: https://www.instagram.com/whathasthisbec1/ And finally, Lauren's Redbubble: https://www.redbubble.com/people/elizarumm Will also has a Redbubble: https://www.redbubble.com/people/Chloroplast/shop?asc=u

Vote Chloroplast 2020

In this episode of the a16z bio Journal Club, bio deal team partner Judy Savitskaya and Lauren Richardson discuss research that aims to enhance the efficiency of photosynthesis and carbon fixation. These two processes are used by plants and other phototrophs (like algae) to convert light energy and carbon dioxide from the air into organic matter. The pathways took millions of years to evolve, but can scientists use advances in biochemistry and synthetic biology to increase their efficiency? The two discussed were both published in the journal Science and are both from the lab of Tobias Erb at the Max Planck Institute for Terrestrial Microbiology. The first article, published in 2016 develops a synthetic pathway for the fixation of carbon dioxide in vitro. The second article, which was published in May, combines this synthetic carbon fixation pathway with the natural photosynthetic pathway isolated from spinach to create an artificial chloroplast.This combination of natural and synthetic components to improve the efficiency of these pathways has a number of potential applications, including in engineering our crops to grow faster. We discuss these exciting applications, how evolution has restricted the efficiency of carbon fixation and how these engineered solutions get around that problem, and the use of microfluidics for vastly improved experimental design. "A synthetic pathway for the fixation of carbon dioxide in vitro" in Science (November 2016), by Thomas Schwander, Lennart Schada von Borzyskowski, Simon Burgener, Niña Socorro Cortina, Tobias J. Erb"Light-powered CO2 fixation in a chloroplast mimic with natural and synthetic parts" in Science (May 2020), by Tarryn E. Miller, Thomas Beneyton, Thomas Schwander, Christoph Diehl, Mathias Girault, Richard McLean, Tanguy Chotel, Peter Claus, Niña Socorro Cortina, Jean-Christophe Baret, Tobias J. Erba16z Journal Club (part of the a16z Podcast), curates and covers recent advances from the scientific literature -- what papers we’re reading, and why they matter from our perspective at the intersection of biology & technology (for bio journal club). You can find all these episodes at a16z.com/journalclub.

Hoy damos un repaso a los orígenes de la fotosíntesis entre las células con núcleo, mencionamos algunos de los principales tipos de algas (con muchos más que se nos quedan en el tintero, sobre todo unicelulares) y mencionamos a un organismo muy especial que tiene encantados a los estudiosos de la endosimbiosis. Aquí un ejemplo del tipo de estructuras donde ocurre la fotosíntesis en cianobacterias y cloroplastos: https://upload.wikimedia.org/wikipedia/commons/2/2b/Chloroplast_in_leaf_of_Anemone_sp_TEM_85000x.pngUna foto de Paulinella chromatophora con sus cianobacteriashttps://schaechter.asmblog.org/.a/6a00d8341c5e1453ef016767992d89970b-320wi

Naresh Loudya from Royal Holloway University of London discusses a recent paper published in the Philosophical Transactions of the Royal Society B entitled ‘Retrograde signalling in a virescent mutant triggers an anterograde delay of chloroplast biogenesis that requires GUN1 and is essential for survival‘. Apologies for the high background noise early in the recording. The post Naresh Loudya discusses nucleus-chloroplast signaling appeared first on Weeding the Gems.

Today we celebrate the one year anniversary of the show and the man who wrote a flora of the Middle East. We'll learn about the German botanist who discovered mitosis and chloroplasts. We celebrate the 93rd birthday of an English-Australian gardener who learned to garden and survived during World War II. We'll honor the tremendous work of Kenya's garden activist and founder of the Green Belt Movement. Today's Unearthed Words feature words about April. We Grow That Garden Library™ with a book that was released 16 years ago today. And then, we'll wrap things up with the fascinating story of a whiskey baron who used his wealth to create an arboretum that is home to America's largest collection of Holly trees. But first, let's catch up on some Greetings from Gardeners Around the World and today's curated news.   Subscribe Apple | Google | Spotify | Stitcher | iHeart   Gardener Greetings Well, it's hard to believe that the show is already a year old. I started the show on April 1st because this month's name came from the Latin word aperio, meaning "to open [bud]," - so it was the perfect time to start something new. Plants outside and in are really beginning to grow now. Daisy and Sweet Pea are this month's birth flowers. To participate in the Gardener Greetings segment, send your garden pics, stories, birthday wishes and so forth to Jennifer@theDailyGardener.org And, to listen to the show while you're at home, just ask Alexa or Google to play The Daily Gardener Podcast. It's that easy.   Curated News In chaotic times, gardening becomes therapy | Cleveland.com "As spring's arrival in the Northern Hemisphere coincides with government stay-at-home orders, the itch to get outside has turned backyard gardens into a getaway for the mind in chaotic times. Gardeners who already know that working with soil is a way to connect with nature say it helps take away their worries, at least temporarily. "I love to see things grow," Lindsay Waldrop said. "It's incredibly therapeutic." Families, too, are discovering that gardening gives cooped-up kids something to do, builds their self-esteem and brings variety to what has suddenly become a lot of time spent together. This home-grown attitude goes back to World War II when millions of people cultivated victory gardens to protect against potential food shortages while boosting patriotism and morale. Hollie Niblett, who lives near Kansas City, Kansas, hopes the victory gardens come back. Niblett, who has a degree in horticultural therapy, tends to a kitchen garden near her backdoor, perennial flowers, flowering trees and shrubs, and upper and lower grassy yards connected by a path through an area left in its natural condition. "There are so many things about it that feed my soul," she said. "Right now, more than anything, my garden gives me hope, gives me purpose, and provides a sense of connection to something bigger than myself."   811 - Call Before You Dig - And, right now - Don't. Add 811 in your phone contacts. Save it under "Digging." In the notes, add a reminder to call at least three days before you dig. Alright, that's it for today's gardening news. Now, if you'd like to check out my curated news articles and blog posts for yourself, you're in luck, because I share all of it with the Listener Community in the Free Facebook Group - The Daily Gardener Community. There's no need to take notes or search for links - the next time you're on Facebook, search for Daily Gardener Community and request to join. I'd love to meet you in the group.   Important Events 1838  Today is the birthday of George Edward Post. We remember George because he wrote a Flora of the Middle East. Westerners were delighted because, for the first time, it was written in English, and they could understand it. George botanized in Syria, which is where he lived most of his life. He was in Syria, serving as a missionary and doctor. In his spare time, he would be off collecting plants and working on his Flora. George was a man who had tremendous energy and stamina. He worked long hours, and many colleagues acknowledged that he accomplished more than most folks in a 24-hour period. In his personal life, it turns out that George had the ability to fall asleep quickly, which no doubt helped him recharge on-demand and as needed. One account of George's tremendous lust for life and for plant collecting relayed that he would go off into the mountains on horseback. The story goes that George was such a good horseman, he could collect specimens without getting off his horse. He was allegedly able to lean below his saddle and reach way down to cut and collect a specimen. Then, he'd just sit back up and go on his way. At the end of his life, George was aware that his body was worn out, and he said something to that effect in the days before he died. Around that same time, he received a visitor who knew just how to revive his spirits. The guest placed a few pieces of ripe wheat in his hand as a symbol of the harvest and of the specimens George had spent a lifetime studying. It also served as a reminder of the treasured bible passage: "To everything, there is a season, and a time to every purpose under the heaven: A time to be born, and a time to die; a time to plant, and a time to pluck up that which is planted."   1805  Today is the birthday of the German botanist Hugo von Mohl. The greatest "botanist of his day," it said in one newspaper. A German botanist, he was the first to propose that new cells are formed by cell division. Mitosis was discovered by Hugo von Mohl. And, in 1837, he discovered chloroplasts - something von Mohl called Chlorophyllkörnen, which translates to "a grain a chlorophyll." Forty-seven years later, the Polish-German botanist Eduard Strasburger shortened the term Chlorophyllkörnen to Chloroplast. Von Mohl described chloroplasts as discrete bodies within the green plant cell. Today we know that chloroplasts are the food producers of the cell. Chloroplasts are only found in plant cells, and they convert light energy from the sun into sugar; so without chloroplasts, there would be no photosynthesis. In 1846, von Mohl described the sap in plant cells as "the living substance of the cell," and he also created the word "protoplasm."   1927  Today is the 93rd birthday of English-born Australian horticulturalist, conservationist, author, broadcaster, and television personality Peter Cundall. A Tasmanian gardener, Peter was the friendly host of the long-running TV show Gardening Australia - one of the first shows committed to 100% organic practices and practical advice. Peter inspired both young and old to the garden. In his epic "lemon tree episode," Peter got a little carried away and essentially finished pruning when the tree was little more than a stump. Thereafter, Cundallisation was synonymous with over-pruning. Peter learned to garden as a little boy. His first garden was a vegetable patch on top of an air raid shelter in Manchester, England. His family was impoverished. His father was an abusive alcoholic. Two of his siblings died of malnutrition. Through it all, the garden brought stability, nourishment, and reprieve. Of that time, Peter's recalls, "Lying in bed in the morning waiting for it to be light, so I could go out and get going in my garden. I used to think there was some gas given out by the soil that produced happiness."   1940  Today is the birthday of the Kenyan ecologist and first female Kenyan Ph.D. and professor Wangari Maathai ("One-Garry" - rhymes with starry - "Ma-TH-EYE") Wangari was the founder of the Green Belt Movement. She fought for environmental protection and women's empowerment by working with communities to plant "green belts" of trees. Today, the Green Belt Movement has planted "over 45 million trees across Kenya to combat deforestation, stop soil erosion, and generate income for women and their families." In 2004, Wangari became the first African woman to win the Nobel Peace Prize. The Nobel committee recognized "her contribution to sustainable development, democracy, and peace." Wangari authored four books: The Green Belt Movement, Unbowed: A Memoir; The Challenge for Africa; and Replenishing the Earth. Wangari died from ovarian cancer in 2011 at the age of 71. Wangari said, "We think that diamonds are very important, gold is very important, all these minerals are very important. We call them precious minerals, but they are all forms of the soil. But that part of this mineral that is on top, like it is the skin of the earth, that is the most precious of the commons." "Using trees as a symbol of peace is in keeping with a widespread African tradition. For example, the elders of the Kikuyu carried a staff from the thigi tree that, when placed between two disputing sides, caused them to stop fighting and seek reconciliation. Many communities in Africa have these traditions." "When we plant trees, we plant the seeds of peace and hope."   Unearthed Words Here are some poignant words about this time of year.   The first of April is the day we remember what we are the other 364 days of the year. — Mark Twain, American writer & humorist   "The first of April, some do say, Is set apart for All Fools' Day. But why the people call it so, Nor I, nor they themselves do know. But on this day are people sent On purpose for pure merriment." — Poor Robin's Almanac, 1790   The April winds are magical, And thrill our tuneful frames; The garden walks are passional To bachelors and dames." ― Ralph Waldo Emerson, American essayist and poet   Men are April when they woo,  December when they wed;  Maids are May when they are maids,  but the sky changes when they are wives. — Shakespeare, As You Like It, Act IV Scene 1   "[W] ell-apparell'd April on the heel Of limping winter treads…" — Shakespeare, Romeo and Juliet, Act 1 Scene 2    Grow That Garden Library On the Wild Side by Keith Wiley It's hard to believe that this book was published on this day already sixteen years ago in 2004. The subtitle to this book is "Experiments in the New Naturalism." Keith created his own wild garden in the early 2000s after being inspired by rural England. He also discovered an entire world of influence as he studied New England roadsides, the Colorado Rockies, Swiss Alpine Meadows, and the South African savannas. In this book, Keith strives to capture "only the spirit of wild plantings and never attempt to replicate exactly any landscape or combination of plants." Keith has learned to focus on form, color, and placement of plants. His attention to detail is what makes his approach work so well. Keith was an early advocate of grouping plants into plant communities. He loves it when plants self-seed - especially when they create beauty in unanticipated ways. Keith's book shares many of his favorite plants and plant groupings. He offers tons of advice and ideas for gardens. in this book, he's hoping to inspire us to get creative, "freeing your own creative inner spirit from the straitjacket of horticultural tradition." You can get a used copy of On the Wild Side by Keith Wiley and support the show, using the Amazon Link in today's Show Notes for under $8.   Today's Botanic Spark 1945  Today is the anniversary of the death of American businessman Isaac Wolfe Bernheim. Bernheim made a fortune selling and distilling whiskey - and in turn, he used some of his wealth to create the Bernheim Arboretum and Research Forest. In 1931, the Frederick Law Olmsted firm was asked to design the park. They created roadways, paths, and natural areas, planted trees, and turned the farmland back into meadows, lawns, and forest. Sparing no expense, Bernheim provided the capital to add lakes, rivers, and ponds for "an enlivening effect." Nineteen years later, in 1950, the Bernheim Forest officially opened and was ultimately given to the people of Kentucky in trust. Bernheim is the largest privately-owned natural area in Kentucky. Today, the arboretum's holly collection is among the best in North America, with more than 700 specimens representing over 350 individual species and cultivars. Love is like the wild rose-brier; Friendship like the holly tree. The holly is dark when the rose-brier blooms, But which will bloom most constantly? — Emily Brontë, author The holly collection features 176 American Holly (Ilex opaca), 44 Japanese Holly (Ilex crenata), over 50 deciduous hollies (Ilex decidua, Ilex verticillata, Ilex serrata, and hybrids), and 19 cultivars of Inkberry (Ilex glabra) - as well as many specialty hybrids. The arboretum is also home to maples, crab apples, conifers (including dwarf conifers), oaks, buckeyes, ginkgoes, ornamental pears and dogwoods. There is also a sun and shade trail, a quiet garden, and a garden pavilion. By 1994, the State of Kentucky made Bernheim the state's official arboretum. A true visionary, Bernheim wrote that "nothing is static in this world." He appreciated that the natural world was constantly going through continuous change. He believed that people needed to spend time connecting with nature. In August of 1939, Bernheim set up some conditions for his forest in a letter to the trustees, and he proposed the following rules for the forest: No discussion of religion or politics, no trading or trafficking. . . No distinction will be shown between rich or poor, white or colored. My vision embraces an edifice, beautiful in design,... It may be made of marble or of native stone. . . . Within it, there will be an art gallery . . . . Therein there will be busts in bronze of men and women whose names have risen to places of distinctive honor in Kentucky. A museum of natural history containing specimens of every animal … of this hemisphere... . . . a tall steel pole … will float the American Flag… [and] children… will be told the story of liberty. To all, I send the invitation to come . . . to re-create their lives in the enjoyment of nature . . . in the park which I have dedicated ... and which I hope will be kept forever free.  

Vote Chloroplast!

On this week's The Sci-Files, your hosts Chelsie and Danny interview Anastasiya Lavell and Cameron De La Mora. Anastasiya is a fifth-year graduate student in the Biochemistry and Molecular Biology department. She is advised by Dr. Christoph Benning.  This summer she is working with an undergraduate student from Illinois State University, Cameron De La Mora, who came to MSU through our Plant Genomics REU program.Photosynthetic organisms are key to capturing carbon dioxide and reducing it back to a usable form for other organisms to consume. The process of capturing the energy from sunlight though is quite dangerous and complex. Protein complexes and other accessory molecules are distributed in and around the thylakoid membranes, and in plants these membranes are housed by the chloroplast. Thylakoids have a special composition of membrane lipids compared to the rest of the cell in plants and studying the way these lipids are made can inform us of their importance for the process of photosynthesis. Anastasiya is currently studying a gene in Arabidopsis thaliana, the protein product of which is found in the chloroplast. This protein seems to be important for maintaining the normal composition of acyl chains on the galactolipids found in the chloroplasts of Arabidopsis. Through traditional biochemistry and molecular biology approaches, Anastasiya is trying to pinpoint exactly how this protein is participating in chloroplast lipid biosynthesis.  Together, Anastasiya and Cameron are working to further the understanding of how this protein might act as an integral membrane protease.If you're interested in talking about your MSU research on the radio or nominating a student, please email Chelsie and Danny at scifiles@impact89fm.org. Check The Sci-Files out on Twitter @SciFiles89FM and Facebook!

Survival of the fittest is a famous anecdote but isn’t always the best way of describing natural selection. Who was Charles Darwin? Whose shoulders did he stand on? What is evolution? Let’s learn to be scientifically conversational. For all references and supplemental information, you can navigate to ascienceshow.com.  

SHOW NOTE พืชมงคล Special / 3 เหตุการณ์สำคัญแห่งประวัติศาสตร์วิวัฒนาการพืช / WiT Game เฉลย A E I O U + ปริศนาฝาหม้อ 0:00:00-00:06:50 เพลงเปิด กล่าวทักทาย เกริ่นนำวันพืชมงคล แนะนำผู้ร่วมจัดรายการ 0:06:51-0:14:36 เทปสัมภาษณ์คุณลุงสมชาย และคุณป้าโคนัน เกษตรโคนม ในพิธีจรดพระนังคัลแรกนาขวัญ ณ ท้องสนามหลวง 0:14:37-0:15:33 ผลการเสี่ยงทายของพระยาแรกนาในปี2558 0:15:34-0:18:16 ความสำคัญของวันพืชมงคล เกริ่นนำ Witcast พืชมงคล Special!! 0:18:17 – 0:26:33 วิวัฒนาการครั้งสำคัญของพืชครั้งที่ 1 /คลอโรพลาสต์ (Chloroplast) / จากสาหร่ายสีเขียวแกมน้ำเงิน ไซยาโนแบคทีเรีย (cyanobacteria) สู่คลอโรพลาสต์ 0:26:34-0:30:26 อธิบายเปรียบเทียบไมโตรคอนเดรียของคนกับคลอโรพลาสต์ของพืช/การแยกสายระหว่างพืชและสัตว์ 0:30:27-0:31:55 สรุปวิวัฒนาการของพืชครั้งที่ 1 0:31:56-0:36:20 เหตุการณ์สำคัญที่ 2 ในประวัติศาสตร์พืช /การยกพลขึ้นบกของพืช/มอส:พืชโบราณ 0:36:21: 0:37:35 เพลงพิลึก กึกกือ – มอส 0:37:36-0:38:47 การปรับตัวของพืชเมื่อขึ้นบก /สร้างสารเคลือบเพื่อป้องกันระเหยน้ำออก 0:38:48-0:41:25 ระบบท่อลำเลียง 0:41:26-0:42:07 ปากใบ 0:42:08-0:55:49 พืชเปลี่ยนแปลงการสืบพันธุ์ /แกมีโทไฟต์ (gametophyte) สปอร์โรไฟต์ (sporophyte)/ วงจรชีวิตแบบสลับ 0:55:50-1:02:25 กำเนิดเมล็ด /พืชยกพลขึ้นบกอย่างสมบูรณ์ 1:02:26-1:09:44 การปฏิวัติครั้งที่ 3 ของพืช /ดอกและผล 1:9:44-1:10:12 สรุปประวัติศาสตร์ของเหล่าพืช 1:10:13-1:10:09 เพลงดอกไม้ – บอย โกสิยพงษ์ 1:10:10-1:16:06 ช่วงเฉลยวิทย์เกม 1:16:07-1:20:19 คำถามวิทย์เกม /ปิดรายการ ------------------------------------------------------------- กำเนิด คลอโรพลาสต์ -1   วิวัฒนาการขึ้นบกของพืช -1 ,2,3 Fern sperm https://www.youtube.com/watch?v=NRppDo1fhtM https://www.youtube.com/watch?v=UAgouJS00t8 Moss sperm https://www.youtube.com/watch?v=ZZj0Mb5BydQ   วงจรชีวิตมอส, เฟิร์น, สน, พืชดอก  

Tue, 18 Nov 2014 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/18329/ https://edoc.ub.uni-muenchen.de/18329/1/Torabi_Salar.pdf Torabi, Salar Abu-Torab ddc:570, ddc:500, Fakultät für Biologie

In order to sustain their structure and metabolism, chloroplasts and other plastid types must import the majority of their proteins from the cytosol across the envelope membrane. Translocation of these precursor proteins across the double envelope membrane is achieved by two multimeric complexes - the so-called TOC and TIC complexes (Translocon at the Outer envelope of Chloroplast and Translocon at the Inner envelope of Chloroplast, respectively). N-terminal transit peptides essential for import of the precursor proteins are cleaved after their entry into the stroma. It was thus far believed that all of the different cytosolic precursor proteins would enter the chloroplast through the same, jointly acting TOC/TIC machineries. Recent evidence, however, suggests that multiple, regulated import pathways exist in plastids that involve different import machineries. Different combinations of TOC and TIC proteins were shown to establish different import sites in Arabidopsis thaliana with specificity for either photosynthetic proteins (the general import pathway) or non-photosynthetic „housekeeping“ proteins. Moreover, numerous non-canonical import pathways such as the import of Tic32 and AtQORH mediated by the yet unknown novel import pathway and the import via the secretory pathway were shown to exist. Proteomics studies have revealed the presence of a large number of plastid proteins lacking predictable N-terminal transit sequences for import. The import mechanism for the majority of these proteins has not been determined yet. Examples of the transit sequenceless precursor proteins are the chloroplast envelope quinone oxidoreductase homologue, AtQORH and the chloroplast inner envelope protein 32, Tic32. Both proteins are imported into the inner plastid envelope membrane by a non-canonical pathway (Toc159- and Toc75-independent) and without any proteolytic cleavage. In the present study not only the import characteristic of nine tentative ‘non-canonical’ chloroplast precursor proteins but also the new interactions between these precursor proteins and the proteins at the organellar surfaces were analyzed. Moreover, a non-canonical precursor protein without the classical transit peptide, the iron superoxide dismutase (FSD1) could be identified. Biochemical crosslinking experiments revealed that FSD1 interacts with new members of the Toc159 family in pea, namely PsToc132 and PsToc120. Using deletion mutants as well as a peptide scanning approach, regions of the precursor protein, which are involved in receptor binding could be defined. These are distributed across the entire sequence; surprisingly only the extreme N-terminus as well as a C-proximal domain turned out to be essential for targeting and import. En route into the plastid FSD1 engages components of the general import pathway, implying that in spite of the ‘non-canonical’ targeting information and recognition by a specific receptor, this precursor protein follows a similar way across the envelope as the majority of plastid precursor proteins.

This episode: BacterioFiles teams up with The Plant Pathology Podcast to talk about how microbes living in plants sometimes team up with the plants, sometimes with plant pathogens! Download Episode (17.7 MB, 19.25 minutes)Show notes:Journal Paper Lee et al. 2009 paper: Fusarium sometimes prevents corn smut Other interesting stories: Deep-sea vent viruses sabotage cell storage Bacteria probably could survive accidental trip to Mars Microbes that survive in petroleum could do well in other harsh processes Many cyanobacteria produce potentially useful antifungal compounds (paper) (paper) Poor agricultural practices may reduce soil microbe diversity (paper) Post questions or comments here or email to bacteriofiles at gmail dot com. Thanks for listening! Subscribe at iTunes, check out the show at Twitter or Facebook

Thu, 26 Sep 2013 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/19354/ https://edoc.ub.uni-muenchen.de/19354/1/Tadini_Luca.pdf Tadini, Luca ddc:570, ddc:500, Faku

Thu, 5 Sep 2013 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/18674/ https://edoc.ub.uni-muenchen.de/18674/1/Angouri_Razeghi_Jafar.pdf Angouri Razeghi, Jafar ddc:570, ddc:5

The photosynthetic machinery inside plants is explained.

Mon, 27 Aug 2012 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/15788/ https://edoc.ub.uni-muenchen.de/15788/1/Li_Nannan.pdf Li, Nannan ddc:570, ddc:500, Fakultät für Biologie

Tue, 26 Jun 2012 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/16185/ https://edoc.ub.uni-muenchen.de/16185/1/Jeshen_Ingrid.pdf Jeshen, Ingrid Karin ddc:570, ddc:500, Fakultät für Biologie

Fri, 13 Jan 2012 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/15271/ https://edoc.ub.uni-muenchen.de/15271/1/Stoppel_Rhea.pdf Stoppel, Rhea ddc:570, ddc:500, Fakultät für Biologie 0

Transcript -- From sunlight to sparrow hawks - Professors David Streeter and Chris Perrins track a woodland food chain.

From sunlight to sparrow hawks - Professors David Streeter and Chris Perrins track a woodland food chain.

Transcript -- From sunlight to sparrow hawks - Professors David Streeter and Chris Perrins track a woodland food chain.

From sunlight to sparrow hawks - Professors David Streeter and Chris Perrins track a woodland food chain.

Genetic crosses between the dioecious Bryonia dioica Jacq. (Cucurbitaceae) and the monoecious B. alba L. in 1903 provided the first clear evidence for Mendelian inheritance of dioecy and made B. dioica the classic case of XY sex determination in plants. We use chloroplast (cp) and nuclear (nr) DNA sequences from 129 individuals representing all morphological species to study species relationships and distribution, sexual system evolution, and association of ploidy-level with dioecy in Bryonia. Chloroplast and nuclear trees mostly fit morphological species concepts; there are seven dioecious and three monoecious species, together ranging from the Canary Islands to Central Asia. Bryonia verrucosa, the morphologically most differing species from the Canary Islands is sister to all other species. Our data argue for the inclusion of the narrowly endemic Central Asian species B. lappifolia and B. melanocarpa in B. monoica. Conflicts between cp and nr topologies imply that the dioecious hexaploid B. cretica arose from hybridization(s) involving the diploid species B. dioica, B. syriaca, and/or B. multiflora. The tetraploid B. marmorata likely originated via autopolyploidy. The nr phylogeny implies at least two transitions between dioecy and monoecy, but no correlation between change in sexual system and ploidy level. Fossil-calibrated molecular clocks using family-wide rbcL data with a Bryonia-centered sampling suggest that the deepest divergence in Bryonia occurred ca. ten million years ago and that monoecious and dioecious species crossed in the classic studies are separated by several million years of evolution. Traits, such as annual regrowth from a tuberous rootstock and other adaptations to a seasonal climate, as well as species and haplotype abundance, point to an origin of Bryonia in the Middle East. Species and haplotype poverty north of the Alps together suggest recolonization there after the last glacial maximum. Most species of Bryonia have 10 chromosomes (as confirmed by my own counts), and there appears to be no morphologically distinct pair that would represent the sex chromosomes. However, we know from the crossings carried out by Correns and others that in B. dioica, sex shows monofactorial dominant inheritance, setting up the hypothesis that B. dioica may have a pair of chromosomes on which key sex-determining gene(s) and sexlinked genes have accumulated. To gain insight into the possible presence of such a pair of sex chromosomes in B. dioica, it is necessary to sequence a fairly long sex-linked region to study its substitution behavior and to eventually visualize its physical placement using FISH. As a first step towards this goal, I developed a sex-linked SCAR marker for B. dioica from AFLP bands and sequenced it for individuals representing the full distribution range of the species from Scotland to North Africa. The region north of the Alps harbours distinct Y and X alleles that differ in a 197-bp indel, with the Y allele being perfectly linked to the male sex. In southern Europe, however, the XY system appears to break down (to an extent that is not clear), and there are signs of recombination between the Y and X homologues. Population genetic analyses suggest that the sex-linked region I amplified (i.e., the SCAR marker) experienced different evolutionary pressures in northern and southern Europe. These findings fit the evidence from my phylogenetic and phylogeographic analyses that the XY system in Bryonia is evolutionarily labile. Overall, my work suggests that Bryonia may be a good, but very complex, system in which to study the early steps of plant sex chromosome evolution.

The molecular mechanisms of light dependent chloroplast movement could for a long time not be unravelled. But the recent discovery of a mutant deficient in chloroplast movement sparked new impulses in the field. This study investigates the molecular mechanisms of chloroplast movement based on the protein Chup1 and the interactions of Chup1 and cytoskeletal effectors. It is demonstrated that Chup1 is exclusively and directly targeted to the chloroplast surface in an N-terminus dependent manner. Analyzing a putative role of Chup1 as a linker between chloroplasts and the cytoskeleton, an interaction with actin is demonstrated which is independent on the filament status of actin. In accordance with this, binding of actin to the outer envelope of chloroplasts is demonstrated. Adding to the understanding of chloroplast movement, it is shown that Chup1 interacts with profilin. Furthermore, an enhancing effect of Chup1 on the interaction of profilin to actin could be demonstrated. As profilin is an actin binding protein and a potent modifier of the polymerisation status of actin filaments, a key role of profilin in chloroplast movement is suggested. For Chup1, an important role as a linker molecule in bridging chloroplasts to actin filaments and a regulatory function in actin polymerization is discussed. The investigation of the global expression profile revealed the effects of light treatment on chup1 mutant plants and the effects of blue light on wildtype plants. From cluster analysis, gene products participating in blue-light induced signalling are suggested. Furthermore, it is suggested, that gene expression is not involved in the regulation of chloroplast movement. A conclusive model of chloroplast movement can be presented.

Chloroplast Biogenesis and Auxin Signaling

Chloroplast Biogenesis

Chloroplast Biogenesis

Fri, 22 Jun 2007 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/10253/ https://edoc.ub.uni-muenchen.de/10253/1/Cho_Won_Kyong.pdf Cho, Won Kyong ddc:570

Precursor protein targeting toward surfaces of organelles is assisted by different cytosolic chaperones. The Toc translocon recognizes precursor proteins and facilitates their translocation across the outer envelope of chloroplasts. Toc64 is a subunit of the chloroplast protein import machinery. This work focuses on topological and functional properties of Toc64. The topological prediction of the protein by different programs revealed that Toc64 contains three transmembrane domains, which has been confirmed by the obtained biochemical an experimental results. It was demonstrated that the TPR domain of Toc64 is cytosolic exposed, whereas a second domain of about 30 kDa is exposed to the intermembrane space and protected by the chloroplast outer envelope, which is a part of the amidase and charged regions. Functional analysis demonstrated that Toc64 is a bi-functional preprotein receptor. First, the cytosolic exposed TPR is the docking site for Hsp90 bound precursor proteins. The Hsp90 is recognised by the clamp type TPR of Toc64. Hence, a novel mechanism in which chaperones are recruited for a specific targeting event by a membrane-inserted receptor is outlined. Second, the intermembrane space exposed domain allows the association of Toc64 with the Toc complex and is involved in precursor protein recognition and translocation across the intermembrane space. This domain also participates in the formation of the intermembrane space complex, which involves Toc12, isHsp70 and Tic22.

The nuclear-encoded preproteins destined for chloroplasts are phosphorylated at a serine or threonine residue in their transit peptides by a cytosolic protein kinase. A phosphorylation motif was proposed for these sites of phosphorylation. In the present study, the sites of phosporylation were investigated for the proteins APC1, HCF136, CAO of Arabidopsis thaliana and pea LHCP. In case of APC1 and LHCP, it was found that more than one site of phosphorylation exist in their transit peptides. For HCF136, the actual site of phosphorylation differred from the site determined by the proposed phosphorylation motif, whereas the transit peptide of CAO was not found to be phosphorylated at all. Further, it was tried to find the significance of this phosphorylation on the import process, in vivo. The second part of this work involved the study of the isoform of the ubiquitous housekeeping enzyme, the Nucleoside diphosphate kinase (NDPK2). The NDPK2 from pea had been earlier reported to have two forms in the chloroplast. The detailed biochemical characterisation of these forms was taken up here. No difference between their import behaviours and localisations within chloroplasts could be determined. They were both found to be in the stroma, associated with thylakoids and nucleoids. In recent years, a number of groups have reported the presence of the NDPK2 of Arabidopsis thaliana to be in the nucleus and cytosol which contradicts with earlier studies conducted with pea, spinach and Brassica campestris where this isoform was found to be in chloroplasts. The present work shows that NDPK2 from Arabidopsis thaliana is also localised within the chloroplasts.

During evolution of photoautotrophic eukaryotes, the nucleus has gained a dominant role in the coordination of the integrated genetic system of the cell consisting of three specifically coevolved genetic compartments. The photosynthetic machinery is encoded by the chloroplast and nuclear genomes. Therefore, biosynthesis and assembly of stochiometric amounts of subunits as well as association of the proteins with corresponding cofactors need to be managed and precisely regulated. To identify novel nuclear-encoded factors involved in the regulation of chloroplast gene expression at different levels, 12 nuclear mutants with high chlorophyll fluorescence (hcf) phenotypes denoting quite diverse defects in the photosynthetic apparatus were selected. Three of them, hcf145, hcf109 and hcf101, were analysed and the affected genes were characterized in more detail. Spectroscopic, fluorimetric and immunological studies have revealed that hcf145 and hcf101 were predominantly affected in photosystem I (PSI), while hcf109 had pleiotropic deficiencies. Remarkably, the dramatic reduction of PSI core complex accumulation in hcf145 was not accompanied by corresponding deficiencies of the outer light-harvesting antenna complex. A comparison of stationary transcript levels with rates of transcription, as estimated by Northern and chloroplast run-on transcription analysis, revealed that the hcf145 mutant is primarily and specifically characterised by a reduced stability of tricistronic chloroplast psaA-psaB-rps14 transcripts. The corresponding operon encodes the two large PSI polypeptides PsaA and PsaB, which form the heterodimeric PSI reaction centre, and the ribosomal protein S14. Chloroplast translation inhibition experiments excluded translational defects as the primary cause of impaired mRNA stability. Defined intervals of the tricistronic transcript were quantified by real-time RT-PCR which established that the psaA region is less stable than the rps14 region in hcf145. Therefore, although up to date, no 5'-3' exoribonucleases have been found in eubacteria (including the ancestors of plants), factor HCF145 appears to be required for the protection of the psaA-psaB-rps14 mRNA against progressive ribonucleolytic degradation starting at the 5' end. In the hcf109 mutant, exclusively plastid transcripts containing UGA stop codons are unstable. The affected gene encodes the first described chloroplast peptide chain release factor AtprfB. Its full-length cDNA, introduced into hcf109 via Agrobacterium-mediated transformation, could functionally complement the mutant. Homology of AtprfB to eubacterial release factors indicates that processes of translational termination in chloroplasts resemble those in eubacteria. The mutant phenotype revealed that translation of all plastid mRNAs containing UGA stop codons is exclusively terminated by AtprfB. However, besides its peptide chain release function, AtprfB appears to acquire yet unknown roles in regulating the stability and translation of the chloroplast mRNAs containing UGA stop codons. These additional regulatory functions could reflect evolutionary constraints which keep the number of plastid TGA stop codons high in vascular plant organelles in contrast to those of algae, mosses and ferns. In contrast to hcf145, steady-state levels and translation of photosynthetic transcripts are not altered in the PSI mutant hcf101. Separation of thylakoid membrane complexes by sucrose gradient centrifugation has uncovered that, similar to hcf145, accumulation of the outer antenna of PSI is not changed in hcf101. Therefore, hcf101 is affected in the assembly of the PSI core complexes. Expression of the HCF101 full-length cDNA in the hcf101 genetic background functionally complemented the mutant. The HCF101 protein encodes a very ancient and universally conserved protein of P-loop ATPases. HCF101 is plastid-localised and represents the first described factor essentially required for the assembly of PSI and other [4Fe-4S]-containing protein complexes in the chloroplast. Relatives of HCF101 are divided into four classes present in all organisms and in all cellular compartments. The antiquity of HCF101 points to the importance of Fe-S cluster biogenesis during the earliest phases of cell evolution. The ubiquity of HCF101 indicates that it is essential for all free-living cells.

Chloroplast gene expression is predominantly regulated at the posttranscriptional levels of mRNA stability and translation efficiency. The expression of psbA, an important photosynthesis-related chloroplast gene, has been revealed to be regulated via its 5’- untranslated region (UTR). Some cis-acting elements within this 5’UTR and the correlated trans-acting factors have been defined in Chlamydomonas. However, no in vivo evidence with respect to the cis-acting elements of the psbA 5’UTR has been so far achieved in higher plants such as tobacco. To attempt this, we generated a series of mutants of the tobacco psbA 5’UTR by base alterations and sequence deletions, with special regard to the stem-loop structure and the putative target sites for ribosome association and binding of nuclear regulatory factors. In addition, a versatile plastid transformation vector pKCZ with an insertion site in the inverted repeat region of the plastid genome was constructed. In all constructs, the psbA 5’UTR (Wt or modified) was used as the 5’ leader of the reporter gene uidA under control of the same promoter, Prrn, the promoter of the rRNA operon. Through biolistic DNA delivery to tobacco chloroplasts, transplastomic plants were obtained. DNA and RNA analyses of these transplastomic plants demonstrated that the transgenes aadA and uidA had been correctly integrated into the plastome at the insertion site, and transcribed in discrete sizes. Quantitative assays were also done to determine the proportion of intact transplastome, the uidA mRNA level, Gus activity, and uidA translation efficiency. The main results are the following: 1) The insertion site at the unique MunI between two tRNA genes (trnR-ACG and trnNGUU) is functional. Vector pKCZ has a large flexibility for further DNA manipulations and hence is useful for future applications. 2) The stem-loop of the psbA 5’UTR is required for mRNA stabilisation and translation. All mutants related to this region showed a 2~3 fold decrease in mRNA stability and a 1.5~6 fold reduction in translation efficiency. The function of this stem-loop depends on its correct sequence and secondary conformation. 3) the AU-box of the psbA 5’UTR is a crucial translation determinant. Mutations of this element almost abolished translation efficacy (up to 175-fold decrease), but did not significantly affect mRNA accumulation. The regulatory role of the AU-Box is sequencedependent and might be affected by its inner secondary structure. 4) The internal AUG codon of the psbA 5’UTR is unable to initiate translation. An introduction of mRNA translatability from this codon failed to direct the translation of reporter uidA gene, overriding the mutation of the AU-Box. 5) The 5’end poly(A) sequence does not confer a distinct regulatory signal. The deletion of this element only insignificantly affected mRNA abundance and translation. However, this mutation might slightly disturb the conformation of the stem-loop, resulting in a moderate decrease in translation efficiency (~1.5 fold). 6) The SD(Shine-Dalgarno)-like RBS (ribosome binding site) of the psbA 5’UTR appears to be an indispensable element for translation initiation. Mutation of this element led to a dramatically low expression of the uidA gene as seen by Gus staining. 7) The 5’end structural sequence of the rbcL 5’UTR does not convey a high mRNA stabilising effect to the psbA 5’UTR in a cycling condition of the light and the dark. Their distinct roles appear to be involved in darkness adaptation. Furthermore, with respect to the overall regulatory function of the psbA 5’UTR, two models are proposed, i.e. dual RBS-mediated translation initiation, and cpRBPs-mediated mRNA stability and translation. The mechanisms for mRNA stabilisation entailed by the rbcL 5’UTR are also discussed. Direct repeat-mediated transgene loss after chloroplast transformation and other aspects related to the choice of insertion site and plastid promoter are also analysed.

The chloroplast outer envelope protein OEP86 functions as a receptor in precursor protein translocation into chloroplasts. Sequence analysis suggests that the precursor of OEP86 is directed to the chloroplast outer envelope by a cleavable, negatively charged, and unusually long amino-terminal peptide. This presequence is unlike other potential targeting signals and suggests the existence of another membrane insertion pathway. Insertion of precursor OEP86 required the hydrolysis of adenosine triphosphate and the existence of surface exposed chloroplast membrane components, and it was not competed by another precursor protein destined for the internal plastid compartments.

Sat, 1 Jan 1994 12:00:00 +0100 http://epub.ub.uni-muenchen.de/3461/ http://epub.ub.uni-muenchen.de/3461/1/3461.pdf Alefsen, H.; Waegemann, Karin; Soll, Jürgen Alefsen, H.; Waegemann, Karin und Soll, Jürgen (1994): Analysis of the chloroplast protein import machinery. In: Journal of Plant Physiology, Vol. 144: pp. 339-345. Biologie

We have studied the influence of phospholipase C treatment of intact purified chloroplast on the translocation of a plastid destined precursor protein. Under standard import conditions, i.e. in the light in the presence or 2 mM ATP translocation was completely abolished but binding was observed at slightly elevated levels. An experimental regime which allowed binding but not import of the precursor protein, i.e. in the dark in the presence of 10 μM ATP, demonstrated that translocation intermediates, normally detected at this stage, were missing in phospholipase treated chloroplasts. The precursor was completely sensitive to protease treatment, indicating that the transfer of the precursor from the receptor to the import apparatus was blocked by phospholipase treatment.

DURING photosynthetic CO2 fixation, fixed carbon is exported from the chloroplasts in the form of triose phosphate by the chloroplast phosphate translocator, which is the principal polypeptide (E29) from spinach chloroplast envelopes1. We have sequenced this nuclear-coded envelope membrane protein from both spinach and pea chloroplasts2,3. An envelope membrane protein, E30, has been identified as a possible receptor for protein import into pea chloroplasts using an anti-idiotypic antibody approach4–6; antibodies raised against purified E30 inhibited binding and import of proteins into chloroplasts7. The amino-acid sequence of E30 deduced from its complementary DNA7 turned out to be highly homologous to that of E29, assigned by us as the spinach phosphate translocator2, and was identical to the corresponding polypeptide from pea chloroplasts3. Differences in the binding properties to hydroxylapatite of £30 and the phosphate translocator suggested that E30 was not responsible for the chloroplast phosphate-transport activity but was the chloroplast import receptor7. Here we present evidence that argues against this and which identifies E30 as the chloroplast phosphate translocator.

A chloroplast outer envelope membrane protein was cloned and sequenced and from the sequence it was possible to deduce a polypeptide of 6.7 kDa. It has only one membrane-spanning region; the C terminus extends into the cytosol, whereas the N terminus is exposed to the space between the two envelope membranes. The protein was synthesized in an in vitro transcription-translation system to study its routing into isolated chloroplasts. The import studies revealed that the 6.7-kDa protein followed a different and heretofore undescribed translocation pathway in the respect that (i) it does not have a cleavable transit sequence, (ii) it does not require ATP hydrolysis for import, and (iii) protease-sensitive components that are responsible for recognition of precursor proteins destined for the inside of the chloroplasts are not involved in routing the 6.7-kDa polypeptide to the outer chloroplast envelope.

Chloroplast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is composed of two different subunits, GapA and GapB. cDNA clones containing the entire coding sequences of the cytosolic precursors for GapA from pea and for GapB from pea and spinach have been identified, sequenced and the derived amino acid sequences have been compared to the corresponding sequences from tobacco, maize and mustard. These comparisons show that GapB differs from GapA in about 20% of its amino acid residues and by the presence of a flexible and negatively charged C-terminal extension, possibly responsible for the observed association of the enzyme with chloroplast envelopes in vitro. This C-terminal extension (29 or 30 residues) may be susceptible to proteolytic cleavage thereby leading to a conversion of chloroplast GAPDH isoenzyme I into isoenzyme II. Evolutionary rate comparisons at the amino acid sequence level show that chloroplast GapA and GapB evolve roughly two-fold slower than their cytosolic counterpart GapC. GapA and GapB transit peptides evolve about 10 times faster than the corresponding mature subunits. They are relatively long (68 and 83 residues for pea GapA and spinach GapB respectively) and share a similar amino acid framework with other chloroplast transit peptides.

Fri, 1 Jan 1988 12:00:00 +0100 http://epub.ub.uni-muenchen.de/3505/ http://epub.ub.uni-muenchen.de/3505/1/3505.pdf Soll, Jürgen; Fischer, Irene Soll, Jürgen und Fischer, Irene (1988): Analysis of chloroplast envelope membranes using photoaffinity label. In: Journal of Plant Physiology, Vol. 132: pp. 631-635. Biologie

An ATP-dependent protein kinase was partially purified from isolated outer envelope membranes of pea (Pisum sativum L., Progress No. 9) chloroplasts. The purified kinase had a molecular weight of 70 kilodaltons, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It was of the cyclic nucleotide and Ca2+, calmodulin-independent type. The purification involved the detergent solubilization of purified outer envelopes by 0.5% cholate and 1% octylglycoside, followed by centrifugation on a linear 6 to 25% sucrose gradient. Active enzyme fractions were further purified by affinity chromatography on histone III-S Sepharose 4B and ion exchange chromatography on diethylaminoethyl cellulose. The protein kinase eluted at 100 millimolar and 50 millimolar NaCl, respectively. The protein kinase was essentially pure as judged by Western blot analysis. The enzyme has a KM of 450 micromolar for ATP and a Vmax of 25 picomoles of 32P incorporated into histone III-S per minute per microgram. Inhibition by ADP is competitive (Ki 150 micromolar).

Thu, 1 Jan 1987 12:00:00 +0100 http://epub.ub.uni-muenchen.de/3596/ http://epub.ub.uni-muenchen.de/3596/1/3596.pdf Schulze-Siebert, D.; Homeyer, U.; Soll, Jürgen; Schultz, Gernot Stumpf, Paul K. (Hrsg.) (1987): Synthesis of Plastoquinone-9, α-Tocopherol and Phylloquinone (Vitamine K1) and its integration in chloroplast carbon metabolism of higher plants. 17. Internat. Symposium on Plant Lipids, Univ. of California, Davis, July 27 - August 1,

A new protein kinase of the cAMP independent type was found to be bound to the outer envelope membrane of spinach chloroplasts. While stimulated by Mg2+ and inhibited by ADP, the enzyme showed no response to conventional protein substrates and was essentially independent of pH in the physiological (pH 7 to 8) range. The new protein kinase phosphorylated the mature form of the small subunit of ribulose 1,5- bisphosphate carboxylase/oxygenase and, to a lesser extent, an unidentified 24-kDa polypeptide, both of which were bound to the outer envelope membrane. The results suggest that phosphorylation of cytoplasmically synthesized protein constituents of chloroplasts is involved in their transport through the chloroplast envelope membrane barrier.

Sat, 1 Jan 1983 12:00:00 +0100 https://epub.ub.uni-muenchen.de/5373/1/Zimmermann_Wolfgang_5373.pdf Weissbach, Arthur; Zimmermann, Wolfgang; Siedlecki, Janusz

Fri, 1 Jan 1982 12:00:00 +0100 http://epub.ub.uni-muenchen.de/3599/ http://epub.ub.uni-muenchen.de/3599/1/3599.pdf Schultz, Gernot; Soll, Jürgen; Fiedler, Erich Wintermanns, F. G. J. M. (Hrsg.) (1982): The biosynthesis of isoprenoid compounds in the chloroplast from the compartmental view. 5. Internat. Symposium on the Biochemistry and Metabolism of Plant Lipids, June 7 - 10, 1982, Groningen, The Netherlands.