Involved in triacylglycerol (TAG) synthesis. Catalyzes the acylation of the sn-3 hydroxy group of sn-1,2-diacylglycerol using acyl-CoA. Can use oleoyl-CoA, linoleoyl-CoA and linolenoyl-CoA as substrates. Has substrate preference for linolenoyl-CoA or oleoyl-CoA compared to linoleoyl-CoA