1997 Fiscal Year Final Research Report Summary
Molecular Breeding of Plants by Gene Transfer of Chitinase and the Mechanism of Resistance to the Fungal Pathogens
| Project/Area Number |
08660051
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
植物保護
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| Research Institution | Ibaraki University |
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Principal Investigator |
AKUTSU Katsumi Ibaraki University Agriculture Professor, 農学部, 教授 (10151002)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Transgenic plant / Rice chitinase gene / Gray mold resistance / Cucumber plant / Botrytis cinerea |
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| Research Abstract |
A rice chitinase cDNA (RCC2) driven by the CaMV 35S promoter was introduced into cucumber (Cucumis sativus L.) through Agrobacterium mediation. More than 200 putative transgenic shoots were regenerated and grown on MS medium supplemented with 100mg/l kanamycin. Sixty elongated shoots were examined for the presence of the integrated RCC2 gene and subsequently confirmed to have it. Of these, 20 were tested for resistance against gray mold (Botrytis cinerea) by infection with the conidia : 15 strains out of the 20 independent shoots exhibited a higher resistance than the control (non-transgenic plants). Three transgenic cucumber strains (designated CR29, CR32 and CR33) showed the highest resistance against B.cinerea : the spread of disease was inhibited completely in these strains. Chitinase gene expression in highly resistant transgenic strains (CR32 and CR33) was compared to that of a susceptible transgenic strain (CR20) and a control. Different responses for disease resistance were observed among the highly resistant strains. CR33 inhibited appressoria formation and penetration of hyphae. Although CR32 permitted penetration of hyphae, invasion of the infection hyphae was restricted. Furthermore, progenies of CR32 showed a segregation ratio of 3 : 1 (resistant : susceptible). As the disease resistance against gray mold was confirmed to be inheritable, these highly resistant transgenic cucumber strains would serve as good breeding materials for disease resistance.
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