Plant epidermal cells express unique molecular machinery that juxtapose the assembly of intracellular lipid components and the unique extracellular cuticular lipids that are unidirectionally secreted to plant surfaces. In maize (Zea mays), mutations at the glossy2 (gl2) locus affect the deposition of extracellular cuticular lipids. Sequence-based genome scanning identified a new Gl2 homolog in the maize genome, namely Gl2-like. Both the Gl2-like and Gl2 genes are members of the BAHD superfamily of acyltransferases, with close sequence similarity to the Arabidopsis (Arabidopsis thaliana) CER2 gene. Transgenic experiments demonstrated that Gl2-like and Gl2 functionally complement the Arabidopsis cer2 mutation, with differential influences on the cuticular lipids and the lipidome of the plant, particularly affecting the longer alkyl chain acyl lipids, especially at the 32-carbon chain length. Site-directed mutagenesis of the putative BAHD catalytic HXXXDX-motif indicated that Gl2-like requires this catalytic capability to fully complement the cer2 function, but Gl2 can accomplish complementation without the need for this catalytic motif. These findings demonstrate that Gl2 and Gl2-like overlap in their cuticular lipid function, but have evolutionarily diverged to acquire nonoverlapping functions.

植物表皮细胞表达独特的分子机制，将细胞内脂质成分的组装和单向分泌到植物表面的独特的细胞外角质脂质并置。在玉米 ( Zea mays ) 中，glossy2 (gl2)基因座的突变会影响细胞外角质层脂质的沉积。基于序列的基因组扫描在玉米基因组中发现了一个新的GL2同源物，即GL2-like。Gl2 -like和Gl2基因都是酰基转移酶BAHD超家族的成员，与拟南芥( Arabidopsis thaliana ) CER2基因具有密切的序列相似性。转基因实验表明，Gl2-like和Gl2在功能上补充拟南芥cer2突变，对植物的角质层脂质和脂质组有不同的影响，特别是影响较长的烷基链酰基脂质，尤其是在32碳链长度处。假定的 BAHD 催化 HXXXDX 基序的定点诱变表明，Gl2 样需要这种催化能力来完全补充cer2功能，但GL2可以在不需要这种催化基序的情况下完成互补。这些发现表明，Gl2和类 Gl2在其角质层脂质功能上有重叠，但在进化上发生了分歧，以获得不重叠的功能。