Determining the role of castor lysophosphatidic acid acyltransferases (RcLPATs) provides information that aid in understanding the biosynthesis mechanism of castor oil (triacylglycerols, TAG), which contains 90 % ricinoleic acid (18:1OH), a hydroxy fatty acid (HFA) with numerous industrial applications. The entire family of seven RcLPATs was shown to encode functional enzymes using in vitro assays. Gene expression analysis suggested that RcLPATs play roles in various vegetative and reproductive organs by associating with membrane lipid and TAG biosynthesis. To identify isoforms of RcLPATs capable of acylating 18:1OH, individual RcLPATs were expressed in CL37, an Arabidopsis line containing approximately 17 % HFA in seed TAG. Transgenics expressing RcLPAT2, RcLPAT3B, or RcLPATB increased total HFA to 18.2 %–20.3 %. Furthermore, different accumulation levels of 18:1OH and densipolic acid (18:2OH) were detected among these three transgenic backgrounds. The mechanisms of substrate selectivity among RcLPAT2, RcLPAT3B, and RcLPATB are discussed.

确定蓖麻油溶血磷脂酸酰基转移酶（RcLPATs）的作用可提供有助于理解蓖麻油（三酰甘油，TAG）的生物合成机理的信息，蓖麻油含有90％蓖麻油酸（18：1OH），羟基脂肪酸（HFA）和多种工业应用。使用体外试验显示，七个RcLPAT的整个家族编码功能性酶。基因表达分析表明，RcLPAT通过与膜脂和TAG生物合成相关，在各种营养和生殖器官中发挥作用。为了鉴定能够将18：1酰化的RcLPAT的同工型，在拟南芥属CL37中表达了各个RcLPAT。种子TAG中含有约17％HFA的品系。表达RcLPAT2，RcLPAT3B或RcLPATB的转基因可使总HFA增至18.2％–20.3％。此外，在这三个转基因背景中检测到18：1OH和densipolic acid（18：2OH）的不同积累水平。讨论了RcLPAT2，RcLPAT3B和RcLPATB之间底物选择性的机制。