Freezing tolerance of chickpea: biochemical and molecular changes at vegetative stage

The aim of this study was to find a correlation between the freezing tolerance of three chickpea (Cicer arietinum L.) cultivars (A degrees nci, IAYA +/- k-05, and SarA +/--98) and their wild relative C. echinospermum and physiological responses. Chickpea plants (15-d-old) were subjected to cold acclimation (CA) (10 A degrees C for 7 d), freezing (-3 or -5 A degrees C for 2 h), and subsequent rewarming (25 A degrees C for 7 d). In two separate experiments with three replications, we determined growth, water status, photosystem 2 photochemical activity, photosynthetic pigments, H2O2, malondialdehyde, and proline content, relative leakage ratio, antioxidant enzyme activities, and gene expressions in cultivars different in freezing tolerance. Freezing temperatures adversely affected all the physiological parameters of all cultivars. Rewarming did not lead to complete recovery. The cultivar A degrees nci was more tolerant to the freezing temperatures than others.