The module consisting of transcription factor WRKY14 and thaumatin-like protein TLP25 is involved in winter adaptation in Ammopiptanthus mongolicus.

Abstract

Thaumatin-like proteins (TLPs) are conserved proteins involved in the defense and stress responses of plants. Previous studies showed that several TLPs were accumulated in leaf apoplast in Ammopiptanthus mongolicus in winter, indicating that TLPs might be related to the adaptation to winter climate in A. mongolicus. To investigate the roles of TLPs in winter adaptation, we first analyzed the expression pattern of TLP genes in A. mongolicus and then focused on the biological function and regulation pathway of AmTLP25 gene. Several TLP genes, including AmTLP25, were upregulated during winter and in response to both cold and osmotic stress. Overexpression of the AmTLP25 gene led to an increased tolerance of transgenic Arabidopsis to freezing and osmotic stress. Furthermore, the elevated AmWRKY14 transcription factor during winter activated AmTLP25 gene expression by specifically binding to its promoter. It is speculated that the AmWRKY14 - AmTLP25 module contributes to the adaptation to temperate winter climate in A. mongolicus. Our research advances the current understanding of the biological function and regulatory pathway of TLP genes and provides valuable information for understanding the molecular mechanism of temperate evergreen broad-leaved plants adapting to winter climate.