Rice | 2021
G protein γ subunit qPE9-1 is involved in rice adaptation under elevated CO2 concentration by regulating leaf photosynthesis
Abstract
G protein γ subunit qPE9-1 plays multiple roles in rice growth and development. However, the role of qPE9-1 in rice exposed to elevated carbon dioxide concentration (eCO 2 ) is unknown. Here, we investigated its role in the regulation of rice growth under eCO 2 conditions using qPE9-1 overexpression (OE) lines, RNAi lines and corresponding WT rice. Compared to atmospheric carbon dioxide concentration (aCO 2 ), relative expression of qPE9-1 in rice leaf was approximately tenfold higher under eCO 2 . Under eCO 2 , the growth of WT and qPE9-1- overexpressing rice was significantly higher than under aCO 2 . Moreover, there was no significant effect of eCO 2 on the growth of qPE9-1 RNAi lines. Furthermore, WT and qPE9-1- overexpressing rice showed higher net photosynthetic rate and carbohydrate content under eCO 2 than under aCO 2 . Moreover, the relative expression of some photosynthesis related genes in WT, but not in RNAi3 line, showed significant difference under eCO 2 in RNA-seq analysis. Compared to WT and RNAi lines, the rbcL gene expression and Rubisco content of rice leaves in qPE9-1- overexpressors were higher under eCO 2 . Overall, these results suggest that qPE9-1 is involved in rice adaptation under elevated CO 2 concentration by regulating leaf photosynthesis via moderating rice photosynthetic light reaction and Rubisco content.