2005 Fiscal Year Final Research Report Summary
Resarch of metabolic responses to environmental stress in halophyte and regulation by protein kinase
| Project/Area Number |
15380015
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Crop science/Weed science
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| Research Institution | Kobe University |
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Principal Investigator |
YASUDA Takeshi Kobe University, Faculty of Agriculture, Professor, 農学部, 教授 (20026553)
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| Co-Investigator(Kenkyū-buntansha) |
NANMORI Takashi Kobe University, Research Center for environmental genomics, Professor, 遺伝子実験センター, 教授 (00180555)
FUKAMI Yasuo Kobe University, Research Center for environmental genomics, Professor, 遺伝子実験センター, 教授 (00156746)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Atriplex / betain / environmental stress / halophyite / protein kinase / salt tolerance |
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| Research Abstract |
Glycinebetaine (betaine) highly accumulates as a compatible solute in certain plants and has been considered to play a role in the protection from salt stress. The betaine biosynthesis pathway of betaine-accumulating plants involves choline monooxygenase (CMO) as the key enzyme and phosphoethanolamine N-methyltransferase (PEAMT), which require S-adenosyl-L-methionine (SAM) as a methyl donor. SAM is synthesized by SAM synthetase (SAMS), and is needed not only for betaine synthesis but also for the synthesis of other compounds, especially lignin. We cloned CMO, PEAMT and SAMS isogenes from a halophyte Atriplex nummularia L. (Chenopodiaceous). The transcript and protein levels of CMO were much higher in leaves and stems than in roots, suggesting that betaine is synthesized mainly in the shoot. The regulation patterns of transcripts for SAMS and PEAMT highly resembled that of CMO in the leaves during and after relief from salt stress, and on a diurnal rhythm. In the leaves, the betaine con
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tent was increased but the lignin content was not changed by salt stress. These results suggest that the transcript levels of SAMS are coregulated with those of PEAMT and CMO to supply SAM for betaine synthesis in the leaves.
We have constructed a series of deletion mutants of Arabidopsis MAPK kinase kinase (AtMEKK1) and obtained a constitutively active mutant, AtMEKK1 Δ166, which lacks in self-inhibitory sequence of N-terminal 166 amino acids but still has substrate specificity. AtMEKK1 Δ166 predominantly phosphorylates AtMEK1, an Arabidopsis MAPKK, but not its double mutant (AtMEK1T218A/S224E), suggesting that Thr-218 and Ser-224 are the phosphorylation sites.
In wounded seedlings, AtMEKK1 was activated and phosphorylated its downstream AtMEK1. Furthermore, analysis using anti-AtMEKK1 and anti-AtMEK1 antibodies revealed that the interaction between the two proteins was signal dependent. These results suggest the presence of AtMEKK1-AtMEK1 pathway induced by wounding. Taking account of our previous data supporting the AtMEK1-ATMPK4 pathway, we provide here new data to complete the AtMEKK1-AtMEK1-AtMPK4 cascade that works under wounding of Arabidopsis seedling. Less
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[Journal Article] Transcriptional responses of glycinebetaine-related genes to salt stress and light in leaf beet.2006
Author(s)
Tabuchi, T., Okada, T., Takashima, Y., Azuma, T., Nanmori, T., Yasuda, T.
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Journal Title
Plant Biotechnology 23(In press)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Similar Regulation Patterns of Choline Monooxygenase, Phosphoethanolamine N-Methyltransferase and S-Adenosyl-L-Methionine Synthetase in Leaves of the Halophyte Atriplex nummularia L.2005
Author(s)
Tabuchi, T., Kawaguchi, Y., Azuma, T., Nanmori, T., Yasuda, T.
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Journal Title
Plant & Cell Physiology 46-3
Pages: 521-531
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Activation of Arabidopsis MAPK kinase kinase (AtMEKK1) and induction of AtMEKK1-AtMEK1 pathway by wounding.2005
Author(s)
Toto Hadiarto, Nanmori, T., Matsuoka, D., Iwasaki, T., Sato, K, Fukami, Y., Azuma, T., Yasuda, Y.
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Journal Title
Planta 223(internet on line)
Description
「研究成果報告書概要(欧文)」より
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