Characterization of Oil Palm Acyl-CoA-Binding Proteins and Correlation of Their Gene Expression with Oil Synthesis

Abstract

Acyl-CoA-binding proteins (ACBPs) are involved in binding and trafficking acyl-CoA esters in eukaryotic cells. ACBPs contain a well-conserved acyl-CoA-binding domain. Their various functions have been characterized in the model plant Arabidopsis and, to a lesser extent, in rice. In this study, genome-wide detection and expression analysis of ACBPs were performed on Elaeis guineensis (oil palm), the most important oil crop in the world. Seven E. guineensis ACBPs were identified and classified into four groups according to their deduced amino acid domain organization. Phylogenetic analysis showed conservation of this family with other higher plants. All seven EgACBPs were expressed in most tissues while their differential expression suggests various functions in specific tissues. For example, EgACBP3 had high expression in inflorescences and stalks while EgACBP1 showed strong expression in leaves. Because of the importance of E. guineensis as an oil crop, expression of EgACBPs was specifically examined during fruit development. EgACBP3 showed high expression throughout mesocarp development, while EgACBP1 had enhanced expression during rapid oil synthesis. In endosperm, both EgACBP1 and EgACBP3 exhibited increased expression during seed development. These results provide important information for further investigations on the biological functions of EgACBPs in various tissues and, in particular, their roles in oil synthesis.

In silico Analysis of Acyl-CoA-Binding Protein Expression in Soybean

“…Their expression remained high during early maturation which was the beginning of seed-filling stage. Studies conducted on Class I ACBPs in Arabidopsis (Guo et al, 2019b), Helianthus annuus (sunflower) (Aznar-Moreno et al, 2016), rice (Guo et al, 2019a), Elaeis guineensis (oil palm) (Amiruddin et al, 2019), and B. napus (Yurchenko et al, 2009(Yurchenko et al, , 2014 suggested their involvement in seed oil biosynthesis. Comparative transcriptomic analysis followed by qRT-PCR on developing embryos and seed coats of B. napus, showed that the Class I BnACBP6 displayed the highest of all BnACBP expression throughout seed development suggesting it plays a potential role in oil accumulation (Liao et al, 2019).…”

“…Comparative transcriptomic analysis followed by qRT-PCR on developing embryos and seed coats of B. napus, showed that the Class I BnACBP6 displayed the highest of all BnACBP expression throughout seed development suggesting it plays a potential role in oil accumulation (Liao et al, 2019). In oil palm and sunflower, the expression of their Class I ACBPs in the seeds was highest during the oil accumulation period (Aznar-Moreno et al, 2016;Amiruddin et al, 2019). In transgenic rice, the overexpression of Class I OsACBP2 increased grain size and oil content (Guo et al, 2019a).…”

Crystal structure of the rice acyl‐CoA‐binding protein OsACBP2 in complex with C18:3‐CoA reveals a novel pattern of binding to acyl‐CoA esters

“…Expression of a BnACBP cDNA in Arabidopsis developing seeds caused an increase in polyunsaturated FAs at the expense of eicosenoic acid (20:1 cis Δ11) and saturated FAs in seed oil [41]. Elaeis guineensis (oil palm) ACBPs are highly expressed during fruit development, implying significant roles in oil synthesis [42]. All these examples support the notion that ACBPs perform important physiological roles in binding acyl‐CoA esters in many plant species and relate the significance of our current structural work to ACBP function in planta .…”

Plant Acyl-CoA-Binding Proteins—Their Lipid and Protein Interactors in Abiotic and Biotic Stresses

“…Following the discovery of BnACBP, similar 10-kDa ACBPs emerged in Arabidopsis thaliana [ 95 ], Gossypium hirsutum (cotton) [ 96 ], Ricinus communis (castor bean) [ 97 ], Digitalis lanata Ehrh. (Wolly Foxglove) [ 98 ], Oryza sativa (rice) [ 89 ], Vernicia fordii (tung tree) [ 99 ], Vitis vinifera (grape) [ 100 ], Helianthus annuus (sunflower) [ 101 ], Elaeis guineensis (oil palm) [ 102 ], Zea mays (maize) [ 103 ] and Glycine max (soybean) [ 104 ].…”