Esterifies the acyl-group from acyl-acyl carrier proteins (acyl-ACPs) to the sn-1 position of glycerol-3-phosphate. The physiological acyl donors in chloroplasts are acyl-ACPs, but acyl-CoAs are used as artificial donor for in vitro reactions (Probable). The enzyme from chilling-resistant plants discriminates against non-fluid palmitic acid and selects oleic acid whereas the enzyme from sensitive plants accepts both fatty acids. Squash is chilling-sensitive (Probable). Preferably utilizes oleoyl groups (18:1-ACP) and has lower affinity to palmitoyl (16:0-ACP) and stearoyl groups (18:0-ACP)