CATALASE-DEFICIENT MUTANTS IN LENTIL (Lens culinaris MEDIK.): PERTURBATIONS IN MORPHO-PHYSIOLOGY, ANTIOXIDANT REDOX AND CYTOGENETIC PARAMETERS

Two catalase (CAT)-deficient mutants namely, catLc1 and catLc2 were isolated in EMS-induced (0.15% and 0.5%, 6 h) M2 population of lentil (Lens culinaris Medik.) var. VL 125. Leaf and root CAT activity was only about 22.53% and 9.16%, respectively, in catLc1, and was nearly 11.22% and 30.84% of mother variety in catLc2. Sharp differences were observed between the two mutants for morpho-physiological, antioxidant status and cytogenetic parameters. Compared to mother variety, root growth was affected in catLc1, while shoot growth was markedly reduced in catLc2 mutant. Significantly low redox status of ascorbate and glutathione under CAT-deficiency presumably crippled the H2O2scavenging capacity, resulting in abnormal accumulation of H2O2 and concomitantly, high rate of membrane lipid peroxidation and electrolyte leakage as the marks of oxidative stress in the two mutants with more severe effect in roots of catLc1 and leaves of catLc2. At controlled pot experiment under a range of irradiance (100-400 μmol m -2 s -1 ), CATdeficiency coupled with membrane damage increased in catLc2 plants, while catLc1 mutant was largely unaffected. Under CAT-deficiency, mitotic disruptions were severe in catLc1 roots while meiotic anomalies were very high in catLc2. CATdeficiency in lentil originated as recessive mutations by the action of two different non-allelic loci.