Investigation of expression pattern for some genes related to antioxidant activities in promising genotypes of barley under salinity stress conditions

Objective:

Salinity stress is one of the most important environmental stresses that significantlyhas negative effects on plant growth and crop production all over the world. Among cereal crops, barley (Hordeum vulgar L.) is the most tolerate cereal to abiotic stresses, especially to salinity stress. In the present study, to evaluate the molecular response of some promising genotypes of barley to salinity stress, the expression patterns of APX, GPX, SOD, Rbohf1, and Rbohf2 genes were assessed under two control and salt stress conditions.

Materials and methods:

In this study, the effect of salt treatment (200 mM NaCl) on relative expression patterns of APX, GPX, SOD, Rbohf1, and Rbohf2 genes in a set of six promising genotypes of barley along with a local cultivar as the reference genotype (cv. Mehr) was evaluated. The experiment was conducted in a randomized complete block design in two environments (normal and saline stress) under controlled glasshouse conditions using a hydroponic system. After seedling establishment and applying stress treatment (21-days), plants were subjected to sampling and the relative expression for targeted genes was estimated as proposed by Pfaffl (2001).

Results:

According to the results, a significant difference was observed between control and salt treatments, as well as, among tested barley genotype in terms of all investigated genes. Salt treatment significantly increased expression of Rbohf1, APX, GPX, Rbohf2, and SOD by 6.80, 4.51, 4.26, 2.76, and 2.72-fold compared to control treatment, respectively. A comparison of the expression patterns of studied genes revealed that promising genotypes G6 and G7 showed better tolerance against oxidative stress induced by salt treatment and revealed an acceptable tolerance to salinity stress.

Conclusions:

Our results revealed that the genotypes G6 and G7 due to their genetic background have a high potential to the regulation of their antioxidant system. Hence, these genotypes can be used as ideal candidates for supplementary studies and even participate in adaptability and stability trials to release as commercial cultivars tolerant to salt stress.