Brassinosteroid-induced S-nitrosylation of fructose-1,6-bisphosphate aldolase increased ATP synthesis under low temperatures in mini Chinese cabbage seedlings.

Low temperature causes an imbalance in plant energy metabolism homeostasis. Brassinosteroids (BRs) are a class of hormones with important regulatory functions in plant responses to low temperature. S-nitrosylation of proteins is a key pathway for nitric oxide-mediated regulation of plant stress. In this study, we investigated whether S-nitrosylation proteins are involved in regulating energy metabolism in mini Chinese cabbage seedlings at low temperature. Low temperature inhibited the transcriptional accumulation of BrFBA2, BrGAPDH, BrPGK, and BrPK. However, applying exogenous BR and S-nitrosoglutathione significantly upregulated the transcription of these genes and accelerated the release of ATP. Exogenous BR significantly upregulated the S-nitrosylation level of fructose-1,6-bisphosphate aldolase 2 (FBA2) at low temperatures. FBA2 protein S-nitrosylation modification occurred in vitro at Cys-197. OE-BrFBA2 lines showed enhanced S-nitrosylation at low temperatures. Applying exogenous BR enhanced the S-nitrosylation of FBA2 and accelerated ATP release in TRV2-BrFBA2 lines. Exogenous BR treatment was conducive to maintaining the homeostasis of cell energy metabolism in mini Chinese cabbage seedlings at low temperature.