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Two chili cultivars, i.e., cv. Bullet and cv. Tejaswini, were evaluated on postharvest related ripening characteristics with varying durations under hydrogen peroxide, putrescine and silver treatments. The reducing sugar was inversely related to the maximum values at 7 days of ripening. Silver and putrescine were the most regulatory in terms of changing of the total carbohydrate content as compared to hydrolysis of the total reducing sugar. Regarding pectin methylesterase activity, both chilies were consistent, regardless of the number of days of incubation. Still, putrescine and silver were significant contributors to variations in cv. Bullet and cv. Tejaswani. For the pigment content, lycopene and chlorophyll increased in a linear manner, although these treatments significantly varied over time. Hydrogen peroxide and putrescine were responsible for the maximum accumulation of lycopene for both the cultivars, whereas, only cv. Tejaswani displayed maximum carotenoid for putrescine. Silver for both chili varieties was the most inhibitory for lycopene and carotenoid content. Superoxide had a good impact on the accumulation of lipid peroxides, irrespective of the chili variety. The maximum accumulation of lipid peroxide was recorded at seven days of treatment. Phenolics and flavonoids were in decreasing order for both the chili varieties, progressing through the days of the study period in a similar manner. Silver was the main contributor to variations in the phenolics and flavonoid contents in cv. Tejaswani. The solubilization of total carbohydrate into reducing sugar was in an inverse relationship, with the maximum values being reached at 7 days of ripening.

Rice genotype (cv. Swarna Sub1) was compared with cv. Swarna with respect to salinity stress. The modality of sub1A traits, which is primarily linked to submergence tolerance, was monitored as to its sensitivity to salinity. Proline and electrolyte leakage were not significantly changed in cv. Swarna Sub1 as compared to cv. Swarna. However, the effects of silver ions through individual, hydroponics and pre-treatment distinctly varied between two cultivars. Silver absorption distinctly varied with 45.01-fold rises in cv. Swarna against control, whereas for sodium cv. Swarna Sub1 scored the highest accumulation by 3.03-fold. Potassium depletion in plants recorded a significant down-regulation for both the genotypes, maximally under salinity by 43.78 and 22.33%, respectively. Plants exhibited a significant suppression of shoot and root length which finally manifested in dry matter accumulation by 93.95 and 89.24%, respectively, for cv. Swarna and Swarna Sub1 under pre-treatment. Chlorophyll content significantly varied among the treatments as well as between the cultivars. Carotenoids and lycopene though depleted but had not any significant variation between the cultivars. NADP(H)-oxidase was distinctly overexpressed for cv. Swarna Sub1 by 1.16-fold under salinity than cv. Swarna (1.22-fold). Still, pre-treatment with silver has maximally induced superoxide content establishing oxidative sensitivities with a peak rise of 3.07 and 2.44-fold for two genotypes. Therefore, the significant traits linked to sub1A QTL would be the selection markers or to overexpress in susceptible genotypes under the condition of salinity for better sustenance.

Hydroponic culture containing 200 mM NaCl was used to induce oxidative stress in seedlings of cultivars initially primed with 1 mM SNP and 10 µM ABA. Exogenous application of sodium nitroprusside (SNP – a nitric oxide donor) and abscisic acid (ABA) was well sensitized more in cv. Swarna Sub1 than cv. Swarna and also reflected in different cellular responses. The major effects of salinity, irrespective of the cultivar, were lowering the water relation, including relative water content and osmotic potential, and decreasing the compatible solutes like alanine, gamma-aminobutyric acid, and glycine betaine. The accumulated polyamines were reduced more in cv. Swarna with a concomitant decrease in photosynthetic reserves. NADP-malic enzyme activity, sucrose accumulation, ascorbate peroxidase, and glutathione S-transferase activities gradually declined under NaCl stress and the catabolizing enzymes like invertase (both wall and cytosolic forms) also declined. On the contrary, plants suffered from oxidative stress through superoxide, hydrogen peroxide, and their biosynthetic enzymes like NADP(H) oxidase. Moderation of Na+/K+ by both SNP and ABA were correlated with other salt sensitivities in the plants. The maximum effects of SNP and ABA were found in the recovery of antioxidation pathways, osmotic tolerance, and carbohydrate metabolism. Findings predict the efficacy of SNP and ABA either independently or cumulatively in overcoming NaCl toxicity in rice.

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