[P3] Abiotic Stress for Crop Production

[P3-02] Selection of Transcripts Relating to Chlorophyll Content of Rice Seedlings at Low Temperature Using RNA-Sequencing Data

^○Akari Fukuda¹, Tatsuro Hirose², Yoichi Hashida², Naohiro Aoki³, Atsuhi J. Nagano⁴ (1.Institute of Crop Science, National Agriculture and Food Research Organization, Japan, 2.Faculty of Agriculture, Takasaki University of Health and Welfare, Japan, 3.Graduate School of Agricultural and Life Science, The University of Tokyo, Japan, 4.Faculty of Agriculture, Ryukoku University, Japan)

The seedlings of an indica rice cultivar, Kasalath, showed chlorosis symptoms at 18℃; although the leaves of a japonica cultivar, Arroz da Terra, remained green at 18℃. In this study, transcripts relating to the chlorophyll content of rice seedlings at 18℃ were investigated using RNA sequencing (RNA-seq) data. Differential expression analysis revealed that the expression levels of photosynthetic genes were repressed in Kasalath seedlings at 18℃ compared to the seedlings grown at 25℃. However, stress-responsive genes were expressed at higher levels at 18℃ than at 25℃ in the Kasalath seedlings. Furthermore, the transcripts whose expression levels were related to chlorophyll content were statistically selected using the RNA-seq data of 21 F₂ plants derived from a cross between Arroz da Terra and Kasalath. For the regression models, frequently selected genes included photosynthetic and stress responsive genes. The expression levels of the photosynthetic genes in the high-frequently selected genes had significant positive correlations with chlorophyll content in 95 F₂ plants at 18℃. Contrastingly, the expression levels of stress-responsive genes had significantly negative correlations with chlorophyll content, suggesting that low temperature-sensitive lines expressed more stress-responsive genes than tolerant lines at 18℃.