Chlorophyll and Protein Changes Observed Post Co-Cultivation of Explants with Agrobacterium Tumefaciens in Soybean (Glycine max L. Merr.)

Abstract

Although, Agrobacterium-mediated genetic transformation represents a major milestone in agricultural biotechnology for crop improvement against biotic and abiotic stresses. Further insights on the interactions between this bacterium and explants required for in vitro plant regeneration remain scant. This study investigated the changes in chlorophyll content and protein profiles of cotyledonary node explants co-cultivated with A. tumefaciens in soybean. Soybean seeds were germinated on MS medium supplemented with 4.0 mgL^-1 6-BA to develop seedlings used for explant preparation and infection with Agrobacterium. The results indicated that 6-BA decelerated germination, inhibiting normal seedling development and resulting in stout seedlings with stunted epicotyls and reduced primary roots without lateral roots. According to these results, Agrobacterium co-cultured explants gave the mean chlorophyll content (mg g^-1) ranging between 13.2±0.892 to 18.7±1.478 in all cultivars, compared to the controls at 14.2±0.113 to 50.5±18.04. Protein lysates derived from these explants contained a combination of high and low molecular weight proteins, in which expressed predominant protein concentration ranged between 10-100 kDa for control explants and 10-120+ kDa for Agrobacterium infected and co-cultured cotyledonary tissues. This study revealed changes in chlorophyll and protein profile post-co-cultivation of explants with Agrobacterium, thus, providing further insights on the role of this bacterium on explant response for subsequent in vitro genetic transformation in soybean.