Variations in Response Patterns among two Genotypes of Chickpea Against Ambient and Elevated UV-B: Antioxidative Enzyme Profile, Nitrogen Metabolism and Accumulation of Salicylic Acid and Jasmonic Acid

Abstract

There is limited information on genotypic variations against UV-B and the physiological and biochemical traits underlying these variations. Therefore, the objectives of this study were to identify the traits responsible for the differential response of cultivar (cv.) PUSA 302 and cv PUSA 264 of chickpea (Cicer arientinum L.) to UV-B. The field experiment was a split-plot design with two UV-B levels (ambient and ambient+3.6kJ m-2 d-1) as main plots and two genotypes as sub-plots. Measurements of nitrogen fixing ability, salicylic acid, jasmonic acid, flavonoids and reactive oxygen species, quercetin and kaempferol, SDS-PAGE and antioxidative enzyme profile with changes in growth and yield parameters were done. Elevated UV-B stimulated the leghaemoglobin contents in both the cultivars while nitrogenase activity increased only in cv PUSA 302. Salicyclic acid and jasmonic acid induced in both the cultivars under elevated UV-B with higher magnitude of increase in cv. PUSA 302. Both the manifestation and magnitude of major antioxidative enzymes increased in both the cultivars under elevated UV-B except APX. GR and POX showed more induction with more intense bands in cv. PUSA 302 whereas CAT, SOD and GPX increased more in cv PUSA 264 under elevated UV-B. Although, the amount of protein was less in cv PUSA 302 but the fold decrease upon UV-B exposure was more in cv PUSA 264. RuBisCo, larger subunit was majorly targeted by UV-B in both the cultivars, cv PUSA 264 being more vulnerable. The differences in the performances of the cultivars against UV-B was manifested in the form of variations in different growth and yield pattern; growth was promoted in both the cultivars except root length in cv PUSA 302 and shoot length in cv PUSA 264. Cv. PUSA 264 displayed more reduction in yield than cv PUSA 302 under elevated UV-B.