open access

https://doi.org/10.14943/doctoral.k15123

https://hdl.handle.net/2115/87554

スサビノリの高温ストレス誘導性遺伝子発現を司る初期生理応答の研究

英語

2022-09-26

Hokkaido University

iii, 63p.

Heat stress responses are complex regulatory processes, including sensing, signal transduction, and gene expression. However, the exact mechanisms of these processes in seaweeds are not well known. We explored the relationship between membrane physical states and gene expression in the red alga Neopyropia yezoensis. To analyze heat stress-induced gene expression, we identified two homologs of the heat-inducible high temperature response 2 (HTR2) gene in Neopyropia seriata, named NyHTR2 and NyHTR2L. We found conservation of HTR2 homologs only within the order Bangiales; their products contained a novel conserved cysteine repeat we designated the Bangiales cysteine-rich motif. A quantitative mRNA analysis showed that expression of NyHTR2 and NyHTR2L was induced by heat stress. However, the membrane fluidizer benzyl alcohol (BA) did not induce expression of these genes, indicating that the effect of heat was not due to membrane fluidization. In contrast, expression of genes encoding multiprotein-bridging factor 1 (NyMBF1) and heat shock protein 70 (NyHSP70-1 and NyHSP70-2) was induced by heat stress and by BA, indicating that it involved a membrane fluidization-dependent pathway. In addition, dark treatment under heat stress promoted expression of NyHTR2, NyHTR2L, NyMBF1, and NyHSP70-2 but not NyHSP70-1; expression of NyHTR2 and NyHTR2L was membrane fluidization independent and that of other genes was membrane fluidization dependent. These findings indicate that the heat stress response in N. yezoensis involves membrane fluidization-dependent and -independent pathways.

2022-09-26

甲第15123号

博士(水産科学)

(主査) 教授 細川 雅史, 教授 水田 浩之, 教授 岸村 栄毅, 教授 三上 浩司 （宮城大学）

水産科学院（海洋応用生命科学専攻）

博士論文

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