Inositol synthesis in Sinorhizobium meliloti involved in salt tolerance

2015 Fiscal Year Final Research Report

• Project/Area Number: 26660067
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied microbiology
• Research Institution: Kobe University
• Principal Investigator: Yoshida Ken-ichi 神戸大学, (連合)農学研究科(研究院), 教授 (20230732)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: Sinorhizobium meliloti / inositol / salt stress / osmotic stress

Outline of Final Research Achievements

Sinorhizobium meliloti possesses ino1 encoding myo- inositol phosphate synthase, which is induced upon salt stress, implying the possibility that inositol derivatives might function in this bacterium as an osmoprotectant. On the other hand, this bacterium has several other osmoprotectants, including glutamic acid, N- acetyl Guru Tamil glutamine amides, betaines, and trehalose, and the effects of ino1 might not be so obvious. A series of mutant strains with various combinations of inactivated genes indicated that ino1 could affect osmoresistance, but its contribution had only auxiliary significance. Therefore, an attempt was made to examine if overexpressed ino1 might enhance the resistance. However, we failed to overexpress ino1 after multiple trials, and over-expression of ino1 might have some toxicity. In any case, S. meliloti could produce myo-inositol phosphate, which is induced in response to salt stress and involved in salt tolerance acquisition.

Free Research Field

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