Effects of salinity stress on proline content and expression ofΔ1-pyrroline-5-carboxylate synthaseandvacuolar-type H+subunit Egenes in wheat

Abstract

AbstractTo evaluate the responses of some important agronomic traits of 14 bread wheat cultivars, a split plot experiment was conducted based on a randomized complete block design under non-stress, moderate and severe salinity stress conditions. In this study, Backcross and Roshan were identified as the most salinity-tolerant cultivars, while Mihan and Shirudi were considered as the most salinity-sensitive cultivars. The proline content, as well asΔ1-pyrroline-5-carboxylate synthase(P5CS) andvacuolar-type H+-ATPase subunit E(W36) gene expression levels, were examined in these cultivars under normal, moderate and high salinity stress conditions. The proline content andP5CSgene expression level increased with a rise in NaCl concentration. Further, a direct relationship was observed between the proline content andP5CSgene expression in all samples. Our results showed thatW36gene expression in Backcross and Roshan cultivars, as the most resistant ones, strongly increased with elevation of the NaCl concentrations. On the other hand, in the sensitive cultivars such as Mihan and Shirudi, small changes were observed in the gene expression levels with rising salinity levels. Additionally, Backcross and Roshan cultivars had the highest proline content as well asP5CSandW36genes expression levels under moderate and high salinity stress levels.