Transcriptome analysis of a transgenic Arabidopsis plant overexpressing CsBCAT7 reveals the relationship between CsBCAT7 and branched-chain amino acid catabolism

The amino acids found in plants play important roles in protein biosynthesis, signaling processes, and stress responses, and as components in other biosynthesis pathways. Amino acid degradation helps maintain plant cells energy states under certain carbon starvation con- ditions. Branched-chain amino acid transferases (BCATs) play an essential role in the metabolism of branched-chain amino acids (BCAAs) such as isoleucine, leucine and valine. In this paper, we performed genome-wide RNA-seq analysis using CsBCAT7-overexpressing Arabidopsis plants. We observed significant changes in genes related to flowering time and genes that are germination-responsive in trans- genic plants. RNA-seq and RT-qPCR analyses revealed that the expression levels of some BCAA catabolic genes were upregulated in these same transgenic plants, and that this correlated with a delay in their senescence phenotype when the plants were placed in extended darkness conditions. These results suggest a connection between BCAT and the genes implicated in BCAA catabolism.