Isoamylase profile of mung bean seedlings treated with high temperature and gibberellic acid

Abstract

Heat stress is one of the common abiotic stresses and is the most harmful factor affecting the growth and productivity of any crop. Heat stress can reduce number of morphological and physiological properties of any living organism. Gibberellic acid (GA₃), a plant growth hormone is also known for resistance of number of abiotic stresses like heat stress. Effect of high temperatures and GA3 were evaluated in terms of amylase isozymes in four mung bean genotypes. Twenty four hours old seedlings of four mung bean genotypes (NM 19-19, NM 20-21, NM 121-123 and NCM 89) were exposed to lethal temperature (50°C), pretreated with 40°C prior to lethal temperature with and without 100 μM GA₃. Polyacryamide gel electrophoresis (7.5%) revealed five isoamylases all together in different samples; however, variations were seen among control and treated samples of different genotypes. It was observed that Amy 2 was present in all samples. A very light band of Amy 5 was seen only in treated samples of 0 h of all genotypes, similarly Amy 4 was specific to treated samples at 0 h harvest of NM 20-21 and NCM 89. Application of GA3 during unstressed condition (A1), showed no prominent induction in amylase activity for all genotypes except for NCM 89 at 24 and 72 h. However, the induction in amylase was seen when the pretreatment of 100 μM GA₃ was given during mild (B1or B2) or lethal temperature (C) for all genotype at some harvests.

Keywords: Gibberellic acid, heat stress, Isoamylase, mung bean

African Journal of Biotechnology Vol. 12(13), pp. 1495-1499