The physiological, biochemical, and molecular modifications under
This experiment was carried out to evaluate the underlying mechanisms of
chickpea genotypes (MCC797; cold-tolerant and MCC505; cold-sensitive)
responses to freezing temperatures (-3, -6, -9, -12 ℃). The increment of
leaf malondialdehyde, H2O2, and electrolyte leakage due to freezing
stress was greater in the cold-sensitive genotype. The plant survival
was also dramatically decreased in the cold-sensitive genotype exposed
to freezing stress (20% at -12 ℃), while it remained constant (100%)
in the cold-tolerant genotype. The fv’/fm’ and fq’/fm’ was increased
sooner during the recovery period in the cold-tolerant (24 h after
stress) compare to the cold-sensitive genotype (48 h after stress).
Proline and enzymatic antioxidants activity, including APX, CAT, POD,
and SOD, were increased more rapidly in the cold-tolerant genotype. The
relative gene expression of catalase (cat), peroxidase (pod), and
proline were also more stimulated in the cold-tolerant genotype.
Freezing temperatures increased the expression of cat, pod, and proline
on average by 4, 3, and 6 folds, respectively, in the cold-sensitive,
while their upregulation was 16, 13, and 16 folds, respectively, in the
cold-tolerant genotype. The greater gene expression and, consequently,
the higher antioxidant content of leaves led to lower lipid peroxidation
after the cold adaptation in the cold-tolerant genotype.