CaDIR1 Gene Regulates the Drought Stress Response in Pepper

Drought stress limits plant growth and development, leading to a reduction in crop productivity. Previously, several E3 ligases have been reported to regulate the drought stress response. Hyunhee Joo and Chae Woo Lim from Chung-Ang University in South Korea now reveal that the pepper (Capsicum annuum) Drought Induced RING type E3 ligase 1, CaDIR1, regulates the drought stress response via abscisic acid (ABA)-mediated signaling.

CaDIR1 contains a C3HC4-type RING finger domain in the N-terminal region, which functions during protein degradation via attachment of ubiquitins to the target proteins. The expression levels of the CaDIR1 gene were found to be suppressed by ABA and were induced by drought stress. The team conducted genetic studies to examine the function of CaDIR1 in response to ABA and drought stress.

CaDIR1-silenced pepper plants displayed a drought-tolerant phenotype while CaDIR1-overexpressing Arabidopsis plants exhibited an ABA-hypersensitive phenotype during the germination stage, but an ABA-hyposensitive phenotype exhibit this during the adult stage. Moreover, adult CaDIR1-overexpressing plants also exhibited a drought-sensitive phenotype.

These results indicate that CaDIR1 functions as a negative regulator of the drought stress response via ABA-mediated signaling.

For more on this study, read the full article in Frontiers in Plant Science.