Srdx light or dark
For example, leaf senescence is involved in transferring and recycling the limited nutrients from senescent leaves to young developing leaves under stress conditions ( Himelblau and Amasino 2001). Several reports have suggested that senescence functions as an active defense response, which is regulated by genetic and physiological processes. Senescence is the final stage of development and is not only induced by aging but also by diverse environmental factors including unfavorable light intensity, temperature, water and nutrient states ( Lim et al.
Our results suggest that EPI1 functions as a negative regulator of the dark-induced and JA-stimulated senescence. In addition, we found that senescence-induced and -reduced genes are down- and upregulated, respectively, in the MeJA-treated transgenic plants under darkness. These transgenic plants additionally maintained a high level of chlorophyll, even after the methyl jasmonate (MeJA) treatment, which stimulated senescence in the dark. We found that EPI1 possesses transcriptional repression activity and that the transgenic plants overexpressing EPI1 and expressing its chimeric repressor, EPI1-SRDX, commonly suppressed the darkness-induced senescence in their excised aerial parts. In this study, we identified an ERF gene termed “ ERF gene conferring Postharvest longevity Improvement 1” (EPI1) as a possible regulator of senescence in Arabidopsis. Identification of the factors involved in the regulation of senescence and the analysis of their function are important for both a biological understanding of the senescence mechanism and the improvement of agricultural productivity.