Amelioration of lead toxicity by ascorbic acid in sugarcane (Saccharum officinarum L.) under in vitro condition

Agricultural sites are polluted with various metal ions worldwide. Ascorbic acid (AA) plays diverse roles in plant growth, development, and the regulation of cellular mechanisms against environmental stress. This study provides the relationship between morphological and biochemical parameters involved in the amelioration of Pb toxicity in three sugarcane (Saccharum officinarum L.) genotypes (YT-53, CP-77-400, NSG-59) by using six concentrations of Pb(NO₃)₂ under in vitro conditions. Morphological and biochemical parameters of ascorbic acid pretreated and non-pretreated calli were compared at each Pb(NO₃)₂ concentration. Ascorbic acid-pretreated calli have better callus growth and regeneration potential than non-treated calli under increased Pb concentration. Biochemical parameters such as antioxidant enzyme activity (peroxidase (POD), superoxide dismutase (SOD), catalase (CAT)) increased under increased Pb concentration. Ascorbic acid pretreatment further enhanced the POD and SOD activity, while CAT activity and total soluble protein contents of pretreated calli did not change significantly. Ascorbic acid ameliorated the Pb toxicity morphologically but showed uneven behavior towards biochemical parameters. Different genotypic behaviors versus different treatments were also observed. In the future, information from this study can be used to develop the metal-resistant sugarcane genotype against metal stress under in vitro conditions.