Laboratory of Cell and Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, 310058, China,
Mol Genet Genomics. 2013 Nov;288(11):601-14. doi: 10.1007/s00438-013-0775-3. Epub 2013 Sep 3.
Pectate lyases (PL) depolymerize demethylated pectin (pectate, EC 4.2.2.2) by catalyzing the eliminative cleavage of α-1,4-glycosidic linked galacturonan. Pectate Lyase-like (PLL) genes are one of the largest and most complex families in plants. However, studies on the phylogeny, gene structure, and expression of PLL genes are limited. To understand the potential functions of PLL genes in plants, we characterized their intron-exon structure, phylogenetic relationships, and protein structures, and measured their expression patterns in various tissues, specifically the reproductive tissues in Brassica rapa. Sequence alignments revealed two characteristic motifs in PLL genes. The chromosome location analysis indicated that 18 of the 46 PLL genes were located in the least fractionated sub-genome (LF) of B. rapa, while 16 were located in the medium fractionated sub-genome (MF1) and 12 in the more fractionated sub-genome (MF2). Quantitative RT-PCR analysis showed that BrPLL genes were expressed in various tissues, with most of them being expressed in flowers. Detailed qRT-PCR analysis identified 11 pollen specific PLL genes and several other genes with unique spatial expression patterns. In addition, some duplicated genes showed similar expression patterns. The phylogenetic analysis identified three PLL gene subfamilies in plants, among which subfamily II might have evolved from gene neofunctionalization or subfunctionalization. Therefore, this study opens the possibility for exploring the roles of PLL genes during plant development.
果胶裂解酶（PL）通过催化α-1,4-糖苷键连接的半乳糖醛酸的消除性裂解来分解去甲基化果胶（果胶，EC 4.2.2.2）。果胶裂解酶样（PLL）基因是植物中最大和最复杂的家族之一。然而，关于 PLL 基因的系统发育、基因结构和表达的研究还很有限。为了了解 PLL 基因在植物中的潜在功能，我们对其内含子-外显子结构、系统发育关系和蛋白质结构进行了表征，并测量了它们在各种组织中的表达模式，特别是在 Brassica rapa 的生殖组织中。序列比对揭示了 PLL 基因的两个特征基序。染色体定位分析表明，46 个 PLL 基因中的 18 个位于 B. rapa 最少分裂亚基因组（LF）中，16 个位于中等分裂亚基因组（MF1）中，12 个位于更分裂亚基因组（MF2）中。定量 RT-PCR 分析表明，BrPLL 基因在各种组织中表达，其中大多数在花中表达。详细的 qRT-PCR 分析鉴定了 11 个花粉特异性 PLL 基因和几个具有独特空间表达模式的其他基因。此外，一些复制基因表现出相似的表达模式。系统发育分析鉴定了植物中 PLL 基因的三个亚家族，其中亚家族 II 可能是从基因新功能化或亚功能化进化而来的。因此，本研究为探索 PLL 基因在植物发育过程中的作用提供了可能性。
