1993 Fiscal Year Final Research Report Summary
MICHANISMS OF SIGNAL TRANSDUCTION AND GENE EXPRESSION OF THE PLANT ACTIVE DEFENSE GENES IN PLANT MICROBE INTERACTION
| Project/Area Number |
04454062
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物保護
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
YAMADA Tetsuji Okayama Univ., Fac.Agri., Professor, 農学部, 教授 (00191320)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRAISHI Tomonori Okayama Univ., Fac.Agri., Professor, 農学部, 教授 (10033268)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Phenylalanine ammonia-lyase / PAL / chalcone synthase / CHS / pea / elicitor / suppressor / Mycosphaerella pinodes |
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| Research Abstract |
The object of this research is to elucidate the mechanisms of signal transduction and control of the genes involved in plant active defense responses. We have characterized the molecular basis for the signal transduction pathway and cis- and trans-acting factors involved in the activation and deactivation of plant active defense genes, particularly focused on the study of the effects of elicitor and suppressor produced by a pea pathogen, Mycosphaerella pinodes, on the signal tansduction and the regulation of the genes encodig PAL and CHS in in pea active defense responses. Details of the current status of the studies are,
1. The phosphorylation of PIP and PIP_2 by lipid kinase was stimulated by the treatment with elicitor, but it was distinctively suppressed in the concomitant presence of suppressor. Suppressor inhibits not only PM-ATPase but also the phosphorylation of PIP and PIP_2, which suggests that ATPase and PI-, PIP-kinases cross-talk each other and blocking PM-ATPase activity r
… More
esults in delaying the induction of the expression of PAL and CHS in a manner very similar to a fungal suppressor.
2. Structure and gene organization of the two members of PAL gene (PSPAL1 and PSPAL2) and two members of CHS gene (PSCHS1 and PSCHS2) in a small multigene family were determined. Sequentially deleted promoter fragment of PSPAL1 and PSPAL2 connected to a plant expression vector containing the reporter gene was introduced into pea protoplasts by electroporation, and induction by elicitor and suppression by suppressor was examined. Cis- element responsible for elicitor induction in both PSPAL genes contain consensus sequence motifs of box 2 and box 4, whereas both PSCHS genes contain box 2.
3. Trans-acting factor(s) and cis-regulatory elements responsible for elicitor-induction in PSPAL1 and PSPAL2 were defined by gel retardation assay and in vitro DNAse I-footprinting analysis. At least two nuclear binding proteins were found to be involved in elicitor-induction which recognize AT rich sequence motifs. Less
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