Phytohormones Ameliorated the Physiological Changes During Post Germination Drought in Maize

Abstract

A pot experiment was conducted to find out effect of gibberellic acid (GA), salicylic acid (SA) and sodium nitroprusside as nitric oxide donor (NO) separately or in combination to mitigate the deviations in physiological parameters evaluated in maize while drought imposed post germination stage. Maize seeds after soaking in 10-4 M of above mention chemicals were sown in pots filled with soil. The leaves were sampled at post germination stage. Results indicated that under drought stress, carotenoid and anthocyanin contents increased significantly while chlorophyll a and chlorophyll b remained unchanged at 5% level of significance. Pre-treatment of solution comprising SA, GA and interaction of GA+SA enhanced the content of these pigments under drought stress. While sodium nitroprusside slightly increased chlorophyll a and b content under drought. Sugar and protein decreased due to drought stress and sugar enhanced due to effect of NO only but protein content did not increase by any one of applying hormones under drought stress. Likewise GA and SA enhanced accumulation of proline which acts as osmolyte and scavenger of free radical to defend cell injury against drought stress. Similarly activities of oxidative enzymes such as peroxidase and polyphenol oxidase increased under drought stress and responded differentially by GA, SA etc, while ascorbate peroxidase and catalase activities decreased due to drought stress which became increased by effect of NO. Results revealed that pretreatment of seeds with GA, SA, GA+SA and NO are effective to tolerate the effect of drought stress in maize at post germination stage.

Keywords: Drought, Enzymes, Maize, osmolyte, Pigments

DOI: 10.7176/JBAH/11-15-01

Publication date:August 31^st 2021