National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
BMC Plant Biol. 2022 Aug 3;22(1):388. doi: 10.1186/s12870-022-03771-x.
Multiple C2 domain and transmembrane region proteins (MCTPs) are evolutionarily conserved and important signaling molecules. However, the MCTP gene family has not been comprehensively analyzed in maize.
In this study, 385 MCTP genes were identified in all surveyed 38 species. Moreover, gene duplication mode exploration showed that whole genome duplication (WGD) mainly contributed to the expansion of MCTP genes in angiosperms. Phylogeny reconstruction with all surveyed species by the maximum-likelihood (ML) method showed five clades of MCTPs, Clades I to V. Each clade of MCTPs had conservative structures and motifs. Focusing on maize, 17 MCTPs were identified, and a neighborjoining (NJ) phylogenetic tree with only ZmMCTPs was also constructed. As expected, 17 MCTPs showed similar phylogenetic relationships in the neighbor-joining (NJ) tree with those in the maximum-likelihood (ML) tree and could also be divided into five subclades. Moreover, ZmMCTP members in different clades showed specific gene structure, conserved motif, and domain structure compositions. Intriguingly, most ZmMCTP genes were intronless. Analyses of isoelectric points (pIs) and grand averages of hydropathicity (GRAVYs) indicated that the N-terminus was more dispersive than the C-terminus. Further tissue-specific expression analysis indicated that duplicated ZmMCTP pairs involved in whole genome duplication (WGD) had similar expression trends. Finally, ZmMCTPs were transcriptionally altered under diverse abiotic stresses and hormone treatments.
Our results contribute to deciphering the evolutionary history of MCTPs in maize and other plants, facilitating further functional analysis of these factors, and provide a basis for further clarification of the molecular mechanism of stress responses.
多个 C2 结构域和跨膜区蛋白（MCTP）是进化上保守的重要信号分子。然而，MCTP 基因家族在玉米中尚未得到全面分析。
在本研究中，在所有调查的 38 个物种中鉴定出 385 个 MCTP 基因。此外，基因复制模式的探索表明，全基因组复制（WGD）主要导致被子植物 MCTP 基因的扩张。通过最大似然法（ML）对所有调查物种进行系统发育重建表明，MCTPs 分为五个分支，即 Clades I 至 V。每个 MCTP 分支都具有保守的结构和基序。以玉米为例，鉴定出 17 个 MCTP，还构建了仅包含 ZmMCTPs 的邻接（NJ）系统发育树。正如预期的那样，17 个 MCTP 在邻接（NJ）树中的系统发育关系与 ML 树中的相似，也可以分为五个亚分支。此外，不同分支中的 ZmMCTP 成员具有特定的基因结构、保守基序和结构域组成。有趣的是，大多数 ZmMCTP 基因是无内含子的。等电点（pI）和平均亲水性（GRAVY）分析表明，N 端比 C 端更分散。进一步的组织特异性表达分析表明，涉及全基因组复制（WGD）的复制 ZmMCTP 对具有相似的表达趋势。最后，ZmMCTPs 在多种非生物胁迫和激素处理下的转录发生改变。
我们的研究结果有助于解析玉米和其他植物中 MCTP 的进化历史，促进对这些因子的进一步功能分析，并为进一步阐明应激响应的分子机制提供基础。
