Morphologically and genetically diverse forage pea (Pisum sativum var. arvense L.) genotypes under single and combined salt and drought stresses

Abstract

Salinity and drought stresses limit agricultural productivity of many crops including forage pea which is an important forage legume. Due to increasing importance of legumes in forage production, there is a clear need to investigate the underlying affects of salinity and drought stresses on forage pea. This study was designed to understand how single or combined salinity and drought stresses impact on physio-biochemical and molecular status of morphologically and genetically diverse forage pea genotypes. Firstly, yield-related parameters were determined under three-year field experiment. The results revealed that the agro-morphological features of the genotypes are significantly different. Afterwards, the sensitivities of the 48 forage pea genotypes were deter-mined against single and combined salinity and drought stresses by performing growth parameters, biochemical status, antioxidative enzymes, and endogenous hormones. Also, the salt and drought-related gene expressions were evaluated under normal and stressed conditions. The results collectively showed that the genotypes of O14, and T8 were more tolerant against combined stress compared to others, via activating antioxidative enzymes (CAT, GR, and SOD), endogenous hormones (IAA, ABA, and JA), stress-related genes (DREB3, DREB5, bZIP11, bZIP37, MYB48, ERD, RD22) and leaf senescence genes (SAG102, SAG102). These genotypes could be used to develop pea plants that tolerate salinity or drought stress conditions. To the best of our knowledge, the present study is the first detailed study in pea against combined salt and drought stresses.