Plant acyl-CoA-binding proteins function in stress protection of transgenic plants

Abstract

Acyl-CoA-binding proteins (ACBPs) display conservation at the acyl-CoA-binding domain which facilitates binding to acyl-CoA esters. The genes encoding ACBPs in the model plants, Arabidopsis thaliana (thale cress) and Oryza sativa (rice), belong to gene families and six members have been reported in each of these species. It has been observed that several genes encoding ACBPs in both A. thaliana and O. sativa are induced by various forms of abiotic and biotic stresses, including drought, heavy metals, low temperature and phytopathogens. When some of the Arabidopsis ACBPs were overexpressed in transgenic plants, they were conferred stress protection. Studies using acbp knock-out mutants also supported the role of ACBPs in stress responses. Furthermore, a few of these ACBPs contain ankyrin repeats and kelch motifs, which enable interactions with protein partners. Interestingly, the protein partners of the ankyrincontaining AtACBP2 were demonstrated to be stress-responsive proteins, and were subsequently shown to enhance stress tolerance in transgenic plants. The role of AtACBPs in binding ligands and in stress protection will be discussed. Funded by the Research Grants Council of Hong Kong [HKU765813M & HKU17105615M]