フルテキストURL Plant_Cell_Physiol_57_6_1115.pdf Fig.pdf
著者 Yoshioka-Nishimura, Miho|
抄録 In chloroplasts, a three-dimensional network of thylakoid membranes is formed by stacked grana and interconnecting stroma thylakoids. The grana are crowded with photosynthetic proteins, where PSII-light harvesting complex II (LHCII) supercomplexes often show semi-crystalline arrays for efficient energy trapping, transfer and use. Although light is essential for photosynthesis, PSII is damaged by reactive oxygen species that are generated from primary photochemical reactions when plants are exposed to excess light. Because PSII complexes are embedded in the lipid bilayers of thylakoid membranes, their functions are affected by the conditions of the lipids. Electron paramagnetic resonance (EPR) spin trapping measurements showed that singlet oxygen was formed through peroxidation of thylakoid lipids, suggesting that lipid peroxidation can damage proteins, including the D1 protein. After photodamage, PSII is restored by a specific repair system in thylakoid membranes. In the PSII repair cycle, phosphorylation and dephosphorylation of the PSII proteins control the timing of PSII disassembly and subsequent degradation of the D1 protein. Under light stress, stacked grana turn into unstacked thylakoids with bent grana margins. These structural changes may be closely linked to the mechanisms of the PSII repair cycle because PSII can move more easily from the grana core to the stroma thylakoids through an expanded stromal gap between each thylakoid. Thus, plants modulate the structure of thylakoid membranes under high light to carry out efficient PSII repair. This review focuses on the behavior of the PSII complex and the active role of structural changes to thylakoid membranes under light stress.
キーワード FtsH protease Light stress PSII PSII repair cycle Photoinhibition Thylakoid membrane
備考 This is an Accepted Manuscript of an article published by Oxford University Press
発行日 2016-06-01
出版物タイトル Plant and Cell Physiology
57巻
6号
出版者 Japanese Society of Plant Physiologists
開始ページ 1115
終了ページ 1122
ISSN 0032-0781
NCID AA0077511X
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 https://creativecommons.org/licenses/by-nc-nd/4.0/deed.ja
論文のバージョン author
PubMed ID 27017619
DOI 10.1093/pcp/pcw050
Web of Sience KeyUT 000379752100001
関連URL https://doi.org/10.1093/pcp/pcw050
フルテキストURL Plant_Cell_Physiol_55_7_1255.pdf
著者 Yoshioka-Nishimura, Miho| Nanba, Daisuke| Takaki, Takashi| Ohba, Chikako| Tsumura, Nodoka| Morita, Noriko| Sakamoto, Hirotaka| Murata, Kazuyoshi| Yamamoto, Yasusi|
抄録  Under light stress, the reaction center-binding protein D1 of PSII is photo-oxidatively damaged and removed from PSII complexes by proteases located in the chloroplast. A protease considered to be responsible for degradation of the damaged D1 protein is the metalloprotease FtsH. We showed previously that the active hexameric FtsH protease is abundant at the grana margin and the grana end membranes, and this homo-complex removes the photodamaged D1 protein in the grana. Here, we showed a change in the distribution of FtsH in spinach thylakoids during excessive illumination by transmission electron microscopy (TEM) and immunogold labeling of FtsH. The change in distribution of the protease was accompanied by structural changes to the thylakoids, which we detected using spinach leaves by TEM after chemical fixation of the samples. Quantitative analyses showed several characteristic changes in the structure of the thylakoids, including shrinkage of the grana, outward bending of the marginal portions of the thylakoids and an increase in the height of the grana stacks under excessive illumination. The increase in the height of the grana stacks may include swelling of the thylakoids and an increase in the partition gaps between the thylakoids. These data strongly suggest that excessive illumination induces partial unstacking of the thylakoids, which enables FtsH to access easily the photodamaged D1 protein. Finally three-dimensional tomography of the grana was recorded to observe the effect of light stress on the overall structure of the thylakoids.
キーワード FtsH protease Light stress Photosystem II Spinach chloroplast TEM Thylakoid
備考 This is an Accepted Manuscript of an article published by Oxford University Press
発行日 2014-07-01
出版物タイトル Plant and Cell Physiology
55巻
7号
出版者 Japanese Society of Plant Physiologists
開始ページ 1255
終了ページ 1265
ISSN 0032-0781
NCID AA0077511X
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 https://creativecommons.org/licenses/by-nc-nd/4.0/deed.ja
論文のバージョン author
PubMed ID 24891560
DOI 10.1093/pcp/pcu079
Web of Sience KeyUT 000339714800007
関連URL https://doi.org/10.1093/pcp/pcu079
フルテキストURL Plant_Cell_Physiol_57_8_1779.pdf img.pdf suppl.pdf
著者 Yin, Ye| Adachi, Yuji| Nakamura, Yoshimasa| Munemasa, Shintaro| Mori, Izumi C.| Murata, Yoshiyuki|
抄録 Methyl jasmonate (MeJA) induces stomatal closure. It has been shown that stomata of many ABA-insensitive mutants are also insensitive to MeJA, and a low amount of ABA is a prerequisite for the MeJA response. However, the molecular mechanisms of the interaction between ABA and MeJA signaling remain to be elucidated. Here we studied the interplay of signaling of the two hormones in guard cells using the quadruple ABA receptor mutant pyr1 pyl1 pyl2 pyl4 and ABA-activated protein kinase mutants ost1-2 and srk2e. In the quadruple mutant, MeJA-induced stomatal closure, H2O2 production, nitric oxide (NO) production, cytosolic alkalization and plasma membrane Ca(2+)-permeable current (ICa) activation were not impaired. At the same time, the inactivation of the inward-rectifying K(+) current was impaired. In contrast to the quadruple mutant, MeJA-induced stomatal closure, H2O2 production, NO production and cytosolic alkalization were impaired in ost1-2 and srk2e as well as in aba2-2, the ABA-deficient mutant. The activation of ICa was also impaired in srk2e. Collectively, these results indicated that OST1 was essential for MeJA-induced stomatal closure, while PYR1, PYL1, PYL2 and PYL4 ABA receptors were not sufficient factors. MeJA did not appear to activate OST1 kinase activity. This implies that OST1 mediates MeJA signaling through an undetectable level of activity or a non-enzymatic action. MeJA induced the expression of an ABA synthesis gene, NCED3, and increased ABA contents only modestly. Taken together with previous reports, this study suggests that MeJA signaling in guard cells is primed by ABA and is not brought about through the pathway mediated by PYR1, PYL1 PYL2 and PYL4.
キーワード ABA ABA receptors Arabidopsis thaliana Guard cells Methyl jasmonate OST1 protein kinase
備考 This is an Accepted Manuscript of an article published by Oxford University Press
発行日 2016-08-01
出版物タイトル Plant and Cell Physiology
57巻
8号
出版者 Japanese Society of Plant Physiologists
開始ページ 1779
終了ページ 1990
ISSN 0032-0781
NCID AA0077511X
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 https://creativecommons.org/licenses/by-nc-nd/4.0/deed.ja
論文のバージョン author
PubMed ID 27354421
DOI 10.1093/pcp/pcw102
Web of Sience KeyUT 000384717100015
関連URL https://doi.org/10.1093/pcp/pcw102
フルテキストURL Plant_Cell_Physiol_58_8_1583.pdf Fig.pdf suppl_fig.pdf
著者 Cai, Qingqing| Fukushima, Hiroko| Yamamoto, Mai| Ishii, Nami| Sakamoto, Tomoaki| Kurata, Tetsuya| Motose, Hiroyasu| Takahashi, Taku|
抄録 The acaulis5 (acl5) mutant of Arabidopsis thaliana is defective in the biosynthesis of thermospermine and shows a dwarf phenotype associated with excess xylem differentiation. SAC51 was identified from a dominant suppressor of acl5, sac51-d, and encodes a basic helix-loop-helix protein. The sac51-d mutant has a premature termination codon in an upstream open reading frame (uORF) that is conserved among all four members of the SAC51 family, SAC51 and SACL1-SACL3 This suggests that thermospermine cancels the inhibitory effect of the uORF in main ORF translation. Another suppressor, sac57-d, has a mutation in the conserved uORF of SACL3 To define further the function of the SAC51 family in the thermospermine response, we analyzed T-DNA insertion mutants of each gene. Although sacl1-1 may not be a null allele, the quadruple mutant showed a semi-dwarf phenotype but with an increased level of thermospermine and decreased sensitivity to exogenous thermospermine that normally represses xylem differentiation. The sac51-1 sacl3-1 double mutant was also insensitive to thermospermine. These results suggest that SAC51 and SACL3 play a key role in thermospermine-dependent negative control of thermospermine biosynthesis and xylem differentiation. Using 5' leader-GUS (β-glucuronidase) fusion constructs, however, we detected a significant enhancement of the GUS activity by thermospermine only in SAC51 and SACL1 constructs. Furthermore, while acl5-1 sac51-1 showed the acl5 dwarf phenotype, acl5-1 sacl3-1 exhibited an extremely tiny-plant phenotype. These results suggest a complex regulatory network for the thermospermine response in which SAC51 and SACL3 function in parallel pathways.
キーワード Arabidopsis Thermospermine Translation Xylem differentiation uORF
備考 This is an Accepted Manuscript of an article published by Oxford University Press
発行日 2016-08
出版物タイトル Plant and Cell Physiology
57巻
8号
出版者 Japanese Society of Plant Physiologists
開始ページ 1583
終了ページ 1592
ISSN 0032-0781
NCID AA0077511X
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
著作権者 http://creativecommons.org/licenses/by-nc-nd/4.0/
論文のバージョン author
PubMed ID 27388339
DOI 10.1093/pcp/pcw113
Web of Sience KeyUT 000384717100001
関連URL https://doi.org/10.1093/pcp/pcw113