Biochemical and metabolic responses involved in cold tolerance of Kabuli and Desi chickpeas

The study of physiological and biochemical processes involved in cold tolerance can help breeders to produce tolerant varieties. In this study, H2O2, carotenoid, chlorophyll and ascorbic acid contents and antioxidative activity of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX), and some their isozymic patterns in two chickpea (Cicer arietinum L.) genotypes, Kabuli Sel96Th11439 and Desi 4322 during control (23°C), acclimation phase (10°C), cold stress phase (4°C) in acclimated plants after two and four days, cold stress phase (4°C) in non-acclimated plants after two and four days were investigated. Analysis of variance showed that there were a significant difference between genotypes and thermal treatments in most studied traits. By transferring acclimated plants to cold stress phase (4°C), the activity of SOD, CAT, APX and GPX increased whereas in non-acclimated plants, the activity of this enzymes decreased. Such results were confirmed by molecular indices like number, migration and intensity of isozymic bands. Cold stress phase (4°C) caused an increase of chlorophyll and carotenoid contents and a decrease of H2O2 content in acclimated plants compared to non-acclimated plants. Therefore, decreased levels of damage indices and increased capacity of defence systems can considered as main factors of cold tolerance in Kabuli plants compared to Desi plants.