University of Michigan, Department of Ecology and Evolutionary Biology, Ann Arbor, MI, U.S.A.
Mol Plant Microbe Interact. 2017 Jun;30(6):489-501. doi: 10.1094/MPMI-10-16-0218-R. Epub 2017 May 8.
Subtilases, a family of proteases involved in a variety of developmental processes in land plants, are also involved in both mutualistic symbiosis and host-pathogen interactions in different angiosperm lineages. We examined the evolutionary history of subtilase genes across land plants through a phylogenetic analysis integrating amino acid sequence data from full genomes, transcriptomes, and characterized subtilases of 341 species of diverse green algae and land plants along with subtilases from 12 species of other eukaryotes, archaea, and bacteria. Our analysis reconstructs the subtilase gene phylogeny and identifies 11 new gene lineages, six of which have no previously characterized members. Two large, previously unnamed, subtilase gene lineages that diverged before the origin of angiosperms accounted for the majority of subtilases shown to be associated with symbiotic interactions. These lineages expanded through both whole-genome and tandem duplication, with differential neofunctionalization and subfunctionalization creating paralogs associated with different symbioses, including nodulation with nitrogen-fixing bacteria, arbuscular mycorrhizae, and pathogenesis in different plant clades. This study demonstrates for the first time that a key gene family involved in plant-microbe interactions proliferated in size and functional diversity before the explosive radiation of angiosperms.
丝氨酸蛋白酶家族参与陆地植物的多种发育过程，也参与不同被子植物谱系中的互利共生和宿主-病原体相互作用。我们通过整合来自全基因组、转录组和 341 种不同绿藻和陆地植物的特征化丝氨酸蛋白酶以及来自其他 12 种真核生物、古菌和细菌的丝氨酸蛋白酶的氨基酸序列数据，对丝氨酸蛋白酶基因在陆地植物中的进化历史进行了分析。我们的分析重建了丝氨酸蛋白酶基因系统发育，并确定了 11 条新的基因谱系，其中 6 条以前没有特征化成员。两个在被子植物起源之前分化的先前未命名的大型丝氨酸蛋白酶基因谱系，占与共生相互作用相关的丝氨酸蛋白酶的大多数。这些谱系通过全基因组和串联重复扩张，通过新功能化和亚功能化产生与不同共生相关的旁系同源物，包括与固氮细菌、丛枝菌根和不同植物类群中的致病性的共生。这项研究首次表明，一个参与植物-微生物相互作用的关键基因家族在被子植物的爆发性辐射之前在大小和功能多样性上都得到了增殖。
