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1 細胞生物學 : 葉綠體粒線體謝明勳副研究員中央研究院植物暨微生物學研究所

2 Energy flow and chemical recycling in ecosystems 葉綠體光合作用粒線體呼吸作用

4 葉綠體與粒線體都有自己的 DNA DNA in chloroplasts

5 阿拉伯芥 Arabidopsis thaliana: 當代分子遺傳研究最受歡迎的模式植物 - 生活周期短 : 約 6-8 周 - 植物體小 : 成株約 30 公分高 - 種子產量高 : 每棵植物可產生數千顆種子 - 基因體小 :5 對染色體, 約 1.25 x 10 8 鹼基對 (base pairs, bp) - 基因體已定序完成 : 約 2 萬 6 千個基因 - 知識技術發展迅速 : 研究者眾 - 大量的突變種可供研究 : 阿拉伯芥種源中心

6 以阿拉伯芥為例, 請問植物的葉綠體內約有多少個基因與蛋白質? 請問植物的粒線體內約有多少個基因與蛋白質?

7 以阿拉伯芥為例, 請問植物的葉綠體內約有多少個基因與蛋白質? 87 基因, >3,000 蛋白質請問植物的粒線體內約有多少個基因與蛋白質? 57 基因, >3,000 蛋白質

8 真核生物的起源 Endosymbiosis and The Origin of Eukaryotes Endosymbiosis theory 內共生假說 The mitochondria of eukaryotes evolved from a-proteobacteria (α- 變形菌 ) living within their host cell. The chloroplasts of eukaryotes evolved from endosymbiotic cyanobacteria ( 藍綠菌 ).

9 Genes of cyanobacterial origin and the intracellular targeting of their products in Arabidopsis Lots of genes have been transferred to the nuclear genome. Leister (2003)

10 請問人類的粒線體內有多少個基因?

Human Mitochondrial Genome 人類粒線體的基因體全長 16.5 kb, 只有 13 個可以轉譯成蛋白質的基因 The genome of human mitochondria contains 16,569 base pairs of DNA organized in a closed circle.

11 Human Mitochondrial Genome 人類粒線體的基因體全長 16.5 kb, 只有 13 個可以轉譯成蛋白質的基因 The genome of human mitochondria contains 16,569 base pairs of DNA organized in a closed circle. These encode: 2 ribosomal RNA (rrna) molecules 22 transfer RNA (trna) molecules 13 polypeptides 7 subunits that make up the mitochondrial NADH dehydrogenase 3 subunits of cytochrome c oxidase 2 subunits of ATP synthase cytochrome b 絕大部分的粒線體蛋白質, 都是在細胞質內合成, 然後運送到粒線體內

12 An overview of cellular respiration

13 Chemiosmosis couples the electron transport chain to ATP synthesis

14 Electron transport chain - oxidative phosphorylation kda Polypeptides Complex I NADH dehydrogenase (7) Complex II Succinate dehydrogenase Complex III Cytochrome C oxidoreductase (1) Complex IV Cytochrome C oxidase (3) Complex V ATP synthase (2)

15 Evolutionary trend towards reducing organelle gene content Genome Rikettsia prowazekii (alpha proteobacterium) Reclinomonas americana (protozoan) mitochondria Marchantia polymorpha (liverwort) mitochondria Arabidopsis thaliana mitochondria Homo sapiens mitochondria Protein coding genes Similar trend in the chloroplasts

16 The Chloroplast Genome The genome of the chloroplasts found in Marchantia polymorpha (a liverwort 苔蘚植物, one of the Bryophyta) contains 121,024 base pairs in a closed circle. These make up some 128 genes which include: 植物葉綠體的基因體大約有個基因

17 什麼基因還留在葉綠體內? I. Genes involved in plastid gene expression - rrnas, trnas - ribosomal proteins - RNA polymerase II. Genes involved in photosynthesis (electron transport chain) - 28 thylakoid proteins psa and psb subunits - ATP synthase subunits (atp) - NADH dehydrogenase subunits (nad) - Cytochrome b6f subunits (pet) III. RUBISCO large subunit (rbcl) Organized in operons; some gene orders conserved with bacteria

18 Gene content of tobacco chloroplast DNA

19 An overview of photosynthesis: cooperation of the light reactions and the Calvin cycle 光合作用 : 將光能轉變為化學能光反應碳反應 ( 暗反應 )

20 The light reactions and chemiosmosis: the organization of the thylakoid membrane 光反應

21 The transfer of electrons and protons in the thylakoid membrane is carried out vectorially by four protein complexes psb pet psa ndh atp rpl, rps, ycf, orf

22 什麼基因還留在葉綠體內? I. Genes involved in plastid gene expression - rrnas, trnas - ribosomal proteins - RNA polymerase II. Genes involved in photosynthesis (electron transport chain) - 28 thylakoid proteins psa and psb subunits - ATP synthase subunits (atp) - NADH dehydrogenase subunits (nad) - Cytochrome b6f subunits (pet) III. RUBISCO large subunit (rbcl) Organized in operons; some gene orders conserved with bacteria

23 碳反應 ( 暗反應 ) The Calvin cycle Rubisco: Ribulose-1,5- bisphosphate carboxylase oxygenase

24 澱粉與蔗糖的合成

25 Electron micrograph of a starch-containing chloroplast in an Arabidopsis leaf 澱粉粒

26 Chloroplast gene expression machinery Chloroplast DNA Transcription Chloroplast mrna Translation Chloroplast Protein Replication 轉錄轉譯複製葉綠體與粒線體內的基因表現機制, 比較類似原核生物

27 Mitochondria and chloroplasts are semiautonomous organelles Arabidopsis nuclear genome: 125 Mb; ~30,000 genes chloroplast genome: 154 kb; ~87 genes mitochondrial genome: 367 kb; ~57 genes

28 Mitochondria and chloroplasts are semiautonomous organelles 阿拉伯芥的細胞核基因體 :125 Mb; ~30,000 個基因阿拉伯芥的葉綠體內約有 3,500 種蛋白質阿拉伯芥的葉綠體基因體 (154 kb):~87 個基因阿拉伯芥的粒線體內約有 2,500 種蛋白質阿拉伯芥的粒線體基因體 (367 kb):~57 個基因

29 Chloroplast and mitochondria are highly dependent on nuclear genes -- 葉綠體與粒線體內,90% 以上的蛋白質是由細胞核內的基因所合成 -- 這些蛋白質在細胞質內合成之後, 再經由特定的運送途徑, 運送到葉綠體或粒線體內

30 Generalized scheme for protein synthesis, targeting, and turnover

31 Translocation into the chloroplast of a protein destined for the stroma Toc: translocase of the outer chloroplast envelope Tic: translocase of the inner chloroplast envelope

32 VAC1 transit peptide-gfp is localized to the chloroplast VAC1 protein TP TP GFP

33 The protein import apparatus of mitochondria TOM: translocase of the outer mitochondrial membrane TIM: translocase of the inner mitochondrial membrane

34 SLO1-GFP is localized to the mitochondrion SLO1-GFP Chlorophyll Merge

35 葉綠體在細胞內的運動 Arabidopsis NPL1: A Phototropin Homolog Controlling the Chloroplast High-Light Avoidance Response Takatoshi Kagawa, Tatsuya Sakai, Noriyuki Suetsugu, Kazusato Oikawa, Sumie Ishiguro, Tomohiko Kato, Satoshi Tabata, Kiyotaka Okada, Masamitsu Wada4

36 葉綠體的避光反應 Chloroplast distribution in photosynthesizing cells of the duck weed Lemna accumulation response avoidance response

37 Chloroplast movement Photoperception Phototropin a blue light receptor Signal transduction? Chloroplast movement Actin filaments

38 Light-induced chloroplast movements in leaves: seeing is believing

39 葉綠體的分裂 Electron micrograph of dividing plastids The position of the FtsZ ring is indicated by arrows. FtsZ proteins: related to the cytoskeletal component tubulin

40 Position of the FtsZ ring during sequential stages of chloroplast division WT ftsz mutant single giant chloroplast

41 阿拉伯芥與葉綠體分裂有關的突變種 WT ftsz mutant mind mutant single giant chloroplast irregular sizes of chloroplasts The positioning of contractile rings is determined by MIN proteins.

42 Replication of tobacco plastid DNA - Plastid DNA replication is not linked to organelle division. - The number of genome copies present in plastids can vary during development. ~40 copies in shoot meristem cells, increases to ~600 copies in leaf primordia, decreases again in mature leaves -- 2 origins of replication (oria and orib) -- Displacement loop (D-loop): indicative of an origin of replication

43 粒狀線狀的胞器英文中的粒線體 (mitochodrion, 複數形式為 mitochondria ) 一詞是由希臘語中的線 ( μίτος 或 mitos ) 和顆粒 ( χονδρίον 或 chondrion ) 組合而成的

44 Embryonic Swiss Mouse Fibroblast Cells The extensive mitochondrial network and its physical relation to the cell... zeiss-campus.magnet.fsu.edu

45 A digital image of the mitochondrial network found in the ovarian tissue from a mountain goat relative, known as the Himalayan Tahr

46 Cellular roles of mitochondrial dynamics. Westermann B J. Biol. Chem. 2008;283: by American Society for Biochemistry and Molecular Biology

48 A review of photosynthesis 五碳糖三碳糖 C3 光合作用

49 Photorespiration 光呼吸作用 Rubisco: ribulose-1,5-bisphosphate carboxylase/oxygenase

50 Peroxisomes and mitochondria are often closely associated with chloroplasts in photosynthetic cells crystal of catalase

51 C3 光合作用 C4 光合作用 CAM 光合作用

52 C 4 leaf anatomy and the C 4 pathway C4 光合作用四碳糖

53 The basic C4 photosynthetic carbon cycle involves four stages in two different cell types 葉肉細胞維管束鞘細胞

54 C4 植物維管束鞘細胞的葉綠體沒有葉綠餅

55 The C4 photosynthetic pathway 葉肉細胞 4C 3C 維管束鞘細胞 The C4 cycle concentrates CO2 in bundle sheath cells

56 Some C4 crop plants Maize Sugarcane Sorghum Zea mays Saccharum officinarum Sorghum vulgare

57 C 4 and CAM photosynthesis compared 景天科 CRASSULACEAE crassulacean acid metabolism

58 Crassulacean acid metabolism (CAM) The CAM mechanism enables plants to improve water use efficiency

60 Supported by the Bill & Melinda Gates Foundation (11 millions), the project will involve a consortium of scientists who will work together to discover the cassette of plant genes responsible for the greatest known efficiency of solar energy conversion in plant photosynthesis. Rice is the most important crop in the world for human food. Over the past 40 years, its production has kept pace with the increase in population. However, it is clear that the gains of the first Green Revolution are largely exhausted. Rice with C4 photosynthesis could make a major contribution to a second Green Revolution. The objective of our research is to produce and test prototypes of rice that convert the maximum fraction of solar energy into the maximum amount of chemical energy in grain, using the smallest amount of land, water and fertilizer in the shortest possible time. We propose that only rice with supercharged, C4 photosynthesis is likely to provide this.

61 5S11

62 6a27

63 3a nm

64 U866

PowerPoint Presentation

PowerPoint Presentation 細胞生物學 : 粒線體葉綠體中央研究院植物暨微生物學研究所副研究員謝明勳 e-mail: ming@gate.sinica.edu.tw Energy flow and chemical recycling in ecosystems 葉綠體光合作用粒線體呼吸作用阿拉伯芥 Arabidopsis thaliana: 當代分子遺傳研究最受歡迎的模式植物 - 生活周期短 : 約 6-8 周