The mechanism of exogenous ABA and BR regulating cold tolerance of maize.

In order to explore the response mechanism of exogenous ABA and BR to improve the cold tolerance of maize seedlings and explore the related candidate genes of exogenous ABA and BR regulating the cold tolerance of cold-sensitive maize, exogenous ABA, BR and their combination were used to treat maize inbred lines with different cold tolerance. The effects of exogenous ABA, BR and their combination on the physiological characteristics of maize seedlings under 10 degrees Celsius low temperature stress were studied. Transcriptome analysis showed that the differentially expressed genes of Shen 137 were mainly enriched in hormone signal transduction, plant-pathogen interaction, carbon metabolism, starch and sucrose metabolism after low temperature or application of exogenous hormones. Four key candidate genes in response to exogenous ABA and BR under low temperature stress were screened by WGCNA. This provides further evidence for exploring the regulatory mechanism of exogenous ABA and BR on cold tolerance of maize and the interaction between ABA and BR under low temperature stress.