The global problem of drought threatens agricultural production and constrains the development of sustainable agricultural practices. In plants, excessive water loss causes drought stress and induces early senescence. Severe water shortages restrict the expansion of rice production and hinder the irrigation of existing paddy fields. Recently, scientists from China National Rice Research Institute (CNRRI) of Chinese Academy of Agricultural Sciences (CAAS) have made progress on genetic mechanism of water loss in rice.

In this study, CAAS scientists isolated a rice (Oryza sativa.L) mutant, designated as early senescence 1 (es1-1), which exhibits early leaf senescence. The es1-1 leaves undergo water loss at the seedling stage (as reflected by whitening of the leaf margin and wilting) and display early senescence at the three-leaf stage. ES1 was cloned using map-based strategy, which encodes a SCAR-like protein 2, a component of the SCAR/WAVE complex involved in actin polymerization and function. Moreover, es1-1 mutants exhibited significantly higher stomatal density.

Phenotypes of wild-type and es1-1 plants

ES1 is a SCAR homolog