Molecular Characterization and Differential Analysis of Salt Responsive Genes in Lentil (Lens Culinaris M.) Under Salt Stress

Abstract

Abiotic stresses negatively influence the crop production. Among the abiotic stresses, Salinity is considered in major abiotic stress creating constraints to plant growth and productivity. During the changing climate and seeing the vision of agriculture to fulfill the near future demand of increasing population it is necessary to take a step to develop tolerant genotypes to sustain agricultural productivity. The knowledge of tolerant genotypes and their variability is an important requirement for successfulness of any breeding programme. Therefore present study was attempted to screen salinity tolerance in ten lentil genotypes on the basis of their morphological, physiological, biochemical and yield attributes and their variability relationship was also studied using 19 SSR markers. The experiment was conducted in plastic pots in a randomly block design with three replication of each genotype for each control and two treatments (ECe= 4dSm-1 and ECe = 6dSm-1). The twenty seeds of each lentil genotype were sown in pots and after germination the thinning was done and only five plants were left in each pot. Plants were expose to salinity through saline water irrigation after 30 DAS and after 65 DAS data were recorded of each observation viz. morphological ( Plant height, leaf area, leaf area index), physiological (relative water content, membrane stability index, total chlorophyll content, sodium and potassium content), biochemical (proline, catalsae, ascorbate peroxidase and nitrate reductase activity) and yield attributes (pod plant--1, number of seed plant-1, yield plant-1 and 1000 seed weight). On the basis of experimental findings, the genotypes PDL1 were found to be highly tolerant and genotype PL07, PL04, IPL316, IPL406 was moderately tolerant whereas genotypes L4076, L4147, DPL62, DPL58 and K75 were found sensitive among studied genotypes under both salinity levels. However on the basis of yield attributes, the genotype PDL1 was found to be most tolerant among studied genotypes under both salinity levels. In diversity analysis, used SSR markers showed closely relationship and PIC values derived from allelic diversity and frequency found to be uniform among all genotypes studied. However, the primer SSR 124 was found to be highly polymorphic with PIC value (0.645). On the basis of morpho-physio-biochemical and yield attributes, one tolerant PDL1 and one sensitive L4076 lentil genotype were selected to analyze the differential expression pattern of Cu/Zn SOD and Mn SOD gene. Observed results of differential expression indicate a very low induction of SOD genes expression in sensitive genotype while, genotype PDL1 selectively induce higher expression of Cu/Zn SOD gene as compared to Mn SOD. The transcript level of both SOD genes was found to be more folds increase in shoot tissues. The overall performance of PDL1 under salt stress was found superior than among studied genotypes. The genotype PDL1 will be very beneficial for the farmer belong to area which is salt affected to achieve higher pulse production. These attributes can be used as screening tool for salinity tolerance in other cultivars as well.