Analysis of soybean acyl-CoA-binding protein expression

Abstract

Acyl-CoA-binding proteins (ACBPs), found in all eukaryotes and some prokaryotes, play important roles in developmental and stress responses. They contain a highly-conserved domain of around 90 residues that can bind to acyl-CoA esters, which are the essential intermediates in lipid metabolism. Investigations on non-leguminous plants such as Arabidopsis thaliana (thale cress), Oryza sativa (rice), and Brassica napus (oilseed rape) have revealed that plant ACBPs can be classified according to size and the presence domain(s) adjoining the acyl-CoA-binding domain. Soybean (Glycine max) ACBPs, designated GmACBPs, are not well reported although this legume is a globally important crop cultivated for its high oil and protein content and plays a significant role in the food and chemical industries. In this study, in silico analysis of GmACBPs identified 11 members grouped into four classes: two members in each of Class I (small) and Class II (ankyrin repeats), four members in Class III (large) and three members in Class IV (kelch motif). Their domain architecture was predicted and compared to Arabidopsis and rice ACBPs. The subcellular localization of each GmACBP was also predicted and their putative expression profiles in various organs deduced. Data mining of RNA-sequencing analyses indicated high expression of some Class III GmACBPs in root nodules hinting on their involvement during nodulation, a role not previously encountered for the non-leguminous ACBPs. Root nodules are special organs in legume plants arising from their interaction with the soil bacteria Rhizobia in fixing atmospheric nitrogen. Interestingly, the sole member of Class III ACBP in each of non-leguminous Arabidopsis and rice had been previously identified in plant-pathogen interactions. Therefore, studies will focus on identifying the role of GmACBPs in nodulation.