SpUSP, an annexin-interacting universal stress protein, enhances drought tolerance in tomato

Abstract

Universal stress protein (USP) appears to play an active role in the abiotic stress response, but their functions remain largely unknown in plants. A USP gene (SpUSP) was cloned from wild tomato (Solanum pennellii) and functionally characterized in cultivated tomato in the present study. The SpUSP transcript is abundantly accumulated in leaf stomata and its expression varied with the circadian rhythm. SpUSP was remarkably induced by dehydration, salt stress, oxidative stress, and the phytohormone abscisic acid (ABA) etc. This protein was predominantly localized in the nucleus and cell membrane. Overexpressing SpUSP increased drought tolerance of tomato in the seedling and adult stages. Under drought stress, the ABA content significantly increased in the SpUSP-overexpressing plants, which induced stomatal closure and reduced water loss, leading to the enhancement of drought tolerance. Based on the microarray data, a large number of chlorophyll a/b-binding proteins and photosystem-related genes were up-regulated in the SpUSP-overexpressing plants under drought conditions, which possibly enhanced the stomatal sensivitity to ABA and maintained the photosynthetic function. SpUSP overexpression also alleviated the oxidative damage accompanied by oxidative stress-responsive gene activation and osmolyte accumulation. Annexin (SGN-U314161) was found to interacte with SpUSP in the yeast two-hybrid method. This interaction was further confirmed by the bimolecular fluorescence complementation assay. The present study demonstrated that the annexin-interacting SpUSP plays important roles in the drought tolerance of tomato by influencing ABA-induced stomatal movement, increasing photosynthesis, and alleviating oxidative stress.

Overexpression of the OsERF71 Transcription Factor Alters Rice Root Structure and Drought Resistance

“…The stressinducible genes included 9-CIS-EPOXYCAROTENOID DIOXYGENASE, a key enzyme in ABA biosynthesis that can improve plant drought tolerance when overexpressed (Iuchi et al, 2001;Qin and Zeevaart, 2002). LATE EMBRYOGENESIS ABUBDANT PROTEIN and UNI-VERSAL STRESS PROTEIN also were found among the up-regulated genes, both of which have been shown to improve drought tolerance when overexpressed (Xu et al, 1996;Sivamani et al, 2000;Loukehaich et al, 2012). Among cell wall-associated genes, cell wall-loosening genes such as EXP and XTH are known to be involved in cell enlargement.…”

Genome-Wide Association Mapping Combined with Reverse Genetics Identifies New Effectors of Low Water Potential-Induced Proline Accumulation in Arabidopsis

“…These proteins are now annotated as "adenine nucleotide a-hydrolase-like superfamily protein," although whether all of them bind or hydrolyze ATP has not been reported. There is little functional information on these proteins in plants, although one recent transgenic study did suggest a role for a UspA protein in drought resistance (Loukehaich et al, 2012). The increased Pro accumulation in mutants of the nucleoside triphosphate hydrolase AT1G33290 also suggests a link of Pro accumulation to energy status; however, the functions of these proteins are even less understood than those of the UspA domain proteins.…”

Carbonylated proteins accumulated as vitality decreases during long-term storage of beech (Fagus sylvatica L.) seeds

“…In plants, the expression of USP can be induced by dehydration, salinity stress, oxidative stress and ABA. The overexpression of USP can result in increased desiccation tolerance in seedlings, young plants and at later developmental stages (Loukehaich et al 2012), which indicates that desiccation tolerance-associated USP proteins are critical for stress condition endurance beyond bacteria. Analyses of the appearance of USP-like proteins in dry stored beech seeds (Fig.…”