Influence of polyethylene glycol, sodium nitroprusside, and carbon sources on in vitro callus induction and regeneration in drought-tolerant and drought-sensitive rice (Oryza sativa L.).

The study investigates the impact of polyethylene glycol (PEG), sodium nitroprusside (SNP), and different carbon sources on the in vitro callus induction and regeneration of drought-tolerant and drought-sensitive rice (Oryza sativa L.) genotypes. PEG, a known osmotic agent, mimics drought conditions, thus providing insights into the plant's response mechanisms under stress. SNP, a nitric oxide donor, is evaluated for its role in modulating stress responses and promoting growth under adverse conditions. Various carbon sources are evaluated to determine their efficacy in supporting callus induction and subsequent regeneration. Results indicate differential responses between drought-tolerant and drought-sensitive rice genotypes, highlighting the potential for optimizing tissue culture protocols to enhance the resilience and regenerative capacity of rice under drought stress. While moderate PEG (5%) stimulated callus induction and regeneration, higher concentrations resulted in adverse effects, including reduced callus mass and regeneration potential. Morphological changes were also observed in response to PEG concentrations, highlighting genotype-specific responses. Meanwhile, combined effect of carbon sources such as maltose and sorbitol along with nitrogen sources "SNP" enhanced callus induction (> 90%) and regeneration (> 90%) under 20% PEG stress in both drought-tolerant and drought-sensitive rice. [ABSTRACT FROM AUTHOR]