A Multiple Stress-Responsive Gene ERD15 from Solanum pennellii Confers Stress Tolerance in Tobacco

Abstract

Wild species often show more tolerance to environmental stress factors than their cultivated counterparts. An early responsive-to-dehydration gene was cloned from a drought- and salt-tolerant wild tomato Solanum pennellii (SpERD15). SpERD15 transcript accumulated differentially in different organs, and was remarkably induced by dehydration, salinity, cold and treatment with plant growth regulators. The protein encoded by SpERD15 was predominantly localized in the nucleus. Interestingly, we found that the majority of the transgenic tobacco plants were co-suppressed along with the overexpressing line. Overexpressing plants manifested stress tolerance accompanied by the accumulation of more soluble sugars and proline, and limited lipid peroxidation compared with co-suppression lines, which were more sensitive than the wild type. The differential contents of these compatible solutes in different transgenic lines were related to the changes in the expression of the genes involved in the production of some important osmolytes (P5CS and Sucrose synthase). Reduced lipid peroxidation over a broad range of stress factors was in agreement with increased expression of stress-responsive genes (ADH and GAPDH). Overexpression of SpERD15 increased the efficiency of PSII (F(v)/F(m)) in transgenic tobacco plants by maintaining PSII quinone acceptors in a partially oxidized form. The results show that SpERD15 augments stress tolerance by enhancing the efficiency of PSII through the protection of cellular membranes, as conferred by the accumulation of compatible solutes and limited lipid peroxidation.

Identification of Novel Loci Regulating Interspecific Variation in Root Morphology and Cellular Development in Tomato

“…The short root phenotype with a growth angle away from the gravity vector may have developed to facilitate growth in an environment with thin top soil and rocky terrain, as well as to enable efficient capture of water in the desert environment. S. pennellii is drought resistant (Pillay and Beyl, 1990;Easlon and Richards, 2009;Ziaf et al, 2011), and water restriction experiments with short root or angled ILs can certainly test this hypothesis. Furthermore, the identification of lines that were able to uncouple the root length phenotype from the growth angle phenotype can help determine the contribution of each trait to such a drought resistant phenotype.…”

Isolation and expression studies of the ERD15 gene involved in drought-stressed responses

“…Finally, plants will enact defense mechanisms against external stresses ). Presently, a total of 16 ERD genes have been cloned from A. thaliana, and many have also been obtained from the soybean, Solanum pennellii, B. napus, and C. annuum, among others (Chen et al, 2010;Ziaf et al, 2011;Alves and Fietto, 2013).…”

“…It accumulates in response to different stresses and helps plants to acclimate to changes in their environment. There are many genes that are characterized as positive or negative regulators of ABA; one of them has been termed the early response to dehydration (ERD) protein (Ziaf et al, 2011). Expression levels of ERD genes increase in response to drought, low temperature, high salt content, and ABA, which leads to a rapid and effective response mechanism (Taji et al, 1999).…”

“…ERD15 was originally characterized as a rapid drought-responsive gene (Kiyosue et al, 1994c) in Arabidopsis; recently, it has been reported as a negative regulator of ABA that can also be induced by salicylic acid (SA), wounding, and pathogenic infection to mediate cross-talk between abiotic and biotic stress responses (Kariola et al, 2006;Ziaf et al, 2011). As a transcription factor, ERD15 binds and activates expression of the endoplasmic reticulum stress-and osmotic stress-induced NRP-B promoter to transduce a stress-induced cell death signal (Alves et al, 2011).…”

EARLY RESPONSIVE to DEHYDRATION 15, a new transcription factor that integrates stress signaling pathways

“…The ERD15 homologs from Solanum licopersicum and from Solanum pennelli are 98% identical and belong to the same group as AtERD15, indicating a possible analogous function. 18 However, the tomato protein is clearly located in the nucleus and confers tolerance to freezing when ectopically expressed in transgenic tomato plants, which is in marked contrast to the phenotypes displayed by ERD15-overexpressing The chimeric BD-AtERD15 neither activates β-galactosidase gene expression nor induces His prototrophy, whereas BD-GmERD15 strongly activates the expression of both reporter genes, indicating that GmERD15, but not AtERD15, exhibits transactivation activity. The same results were observed when the reporter genes were under the control of the NRP-B promoter, and the chimeras AD-AtERD15 and AD-GmERD15 were used (Parts C and D) to demonstrate that AtERD15 does not bind to the NRP-B promoter.…”