Expression of signalling and defence-related genes mediated by over-expression of JERF1, and increased resistance to sheath blight in rice



Sheath blight (SB) is one of the most destructive rice diseases that affect the yield and quality of rice. Jasmonate and Ethylene Response Factor 1, designated JERF1, can be induced by ethylene, methyl jasmonate (MeJA), abscisic acid (ABA) and salt stress. Previous research demonstrated that over-expression of JERF1 enhanced drought tolerance by regulating the expression of stress-related genes in rice. The present study reports that JERF1 could improve SB resistance of transgenic rice. At the molecular and physiological levels, JERF1 could up-regulate the expression of signalling and defence-related genes and increase the activities of lipoxygenase (LOX) and phenylalanine ammonia lyase (PAL). Analysis of cis-elements showed that there were several DRE/CRT (dehydration-responsive element/C-repeat) and/or GCC boxes in the promoters of these candidate genes, indicating that JERF1 might regulate the expression of defence-related genes via interaction with these cis-elements. These results suggest that JERF1 might improve SB resistance by modulating the expression of defence-related genes. This may prove to be a useful strategy for genetic engineering to improve SB resistance using transcription factor genes in rice.