EARLY SENESCENCE1 Encodes a SCAR-LIKE PROTEIN2 That Affects Water Loss in Rice

Abstract

. In plants, excessive water loss causes drought stress and induces early senescence. In this study, we isolated a rice (Oryza sativa) mutant, designated as early senescence1 (es1), 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. We used map-based cloning to identify ES1, which encodes a SCAR-LIKE PROTEIN2, a component of the suppressor of cAMP receptor/Wiskott-Aldrich syndrome protein family verprolin-homologous complex involved in actin polymerization and function. The es1-1 mutants exhibited significantly higher stomatal density. This resulted in excessive water loss and accelerated water flow in es1-1, also enhancing the water absorption capacity of the roots and the water transport capacity of the stems as well as promoting the in vivo enrichment of metal ions cotransported with water. The expression of ES1 is higher in the leaves and leaf sheaths than in other tissues, consistent with its role in controlling water loss from leaves. GREEN FLUORESCENT PROTEIN-ES1 fusion proteins were ubiquitously distributed in the cytoplasm of plant cells. Collectively, our data suggest that ES1 is important for regulating water loss in rice.

Regulatory Role of OsMADS34 in the Determination of Glumes Fate, Grain Yield, and Quality in Rice

“…The pCA1301-C plasmid was transformed into Agrobacterium tumefaciens strain LBA4404 and the positive bacterial strains were introduced into the m34-z mutants using the A. tumefaciens -mediated transformation method (Rao et al, 2015). The primers used are listed in Supplementary Table 1 .…”

Rice TUTOU1 Encodes a Suppressor of cAMP Receptor-Like Protein That Is Important for Actin Organization and Panicle Development

“…Notably, the rice tut1 mutant shows a pleiotropic phenotype during its entire life cycle, including shorter roots, reduced plant height, degenerating leaves, and degenerating panicles, suggesting that TUT1 functions as a housekeeping gene during rice growth and development. A recent study revealed that EARLY SENESCENCE1 (ES1), identical to TUT1, plays an important role in regulating water loss (Rao et al, 2015), suggesting that TUT1/ES1 is involved in various developmental and physiological processes.…”

Characterization and fine mapping of a new early leaf senescence mutant es3(t) in rice

“…RLS1 encodes a previously uncharacterized nucleotide-binding site (NBS) containing protein with an armadillo (ARM) domain at its carboxyl terminus, and regulates rice leaf senescence through affecting chloroplast degradation (Jiao et al 2012). Rao et al found that the mutation of the gene encoding SCAR-like protein2 could cause drought stress and induce early senescence (Rao et al 2015). SCAR-like protein2 is a suppressor of cAMP receptor-like protein involved in actin polymerization and absolute ethanol.…”

“…The samples were then kept at 4 °C for 4 h. After fixation, they were rinsed with 0.1 M phosphate buffer (pH 7.0) and further fixed by 1 % osmium tetroxide for at least 1 h. The specimens were then dehydrated with a gradient of ethanol, embedded in small boxes and stained with lead citrate solution. The processed specimens were examined and photographed using a transmission electron microscope (Hitachi H-7650, Tokyo, Japan) (Gothandam et al 2005;Rao et al 2015).…”

“…During the reproductive development and grain filling stages, early leaf senescence is closely related to the poor performance of yield-related agronomic traits (Ray et al 1983;Bai et al 2015;Rao et al 2015). In contrast, appropriate timing of leaf senescence can panicle development in rice (Bai et al 2015;Rao et al 2015). PSD128/OsCDC48 encodes a putative AAA-type ATPase and is responsible for the premature senescence and death phenotype in rice.…”