Revised phylogeny of the Cellulose Synthase gene superfamily: insights into cell wall evolution

First author: Alan Little; Affiliations: University of Adelaide (阿德莱德大学): Adelaide, Australia

Corresponding author: Geoffrey B. Fincher

Cell walls are crucial for the integrity and function of all land plants, and are of central importance in human health, livestock (牲畜) production, and as a source of renewable bioenergy. Many enzymes that mediate the biosynthesis of cell wall polysaccharides (多糖) are encoded by members of the large cellulose synthase (CesA) gene superfamily. Here, we analyzed 29 sequenced genomes and 17 transcriptomes to revise the phylogeny of the CesA gene superfamily in angiosperms. Our results identify ancestral gene clusters that predate the monocot-eudicot divergence and reveal several novel evolutionary observations, including the expansion of the Poaceae-specific cellulose synthase-like CslF family to the graminids and restiids and the characterisation of a previously unreported eudicot lineage, CslM, that forms a reciprocally (相反地) monophyletic eudicot-monocot grouping with the CslJ clade. The CslM lineage is widely distributed in eudicots, and the CslJ clade, which was previously thought to be restricted to the Poales, is widely distributed in monocots. Our analyses show that some members of the CslJ lineage, but not the newly identified CslM genes, are capable of directing (1,3;1,4)-β-glucan biosynthesis, which, contrary to current dogma, is not restricted to Poaceae.

细胞壁对于所有陆地植物保持完整和维持功能至关重要，同时也影响着人类健康、牲畜产量，还是非常重要的可再生生物能源。参与细胞壁多糖生物合成的许多酶是由纤维素合酶CesA这一大的基因家族成员所编码的。本文分析了29个测序植物基因组以及17个转录组，揭示了被子植物中CesA基因家族的系统演化。本文的结果鉴定了单、双子叶分化之前的古老基因类群，揭示了一些新的演化途径，包括禾本科特异的类纤维素合酶CslF亚家族扩增和先前未曾报道的双子叶CslM亚家族，该基因家族与CslJ各自形成了单、双子叶特有的单系基因家族。CslM亚家族在双子叶中广泛分布，而先前被认为只在禾本科中存在的CslJ亚家族也在单子叶中广泛分布。本文的分析显示CslJ亚家族的某些成员可能直接作用于(1,3;1,4)-β-葡聚糖的生物合成，而新鉴定的CslM亚家族则不具备这个能力，并且不局限于禾本科，与现在的主流观点不符。

通讯：Geoffrey B. Fincher (https://www.adelaide.edu.au/directory/geoffrey.fincher)

doi: https://doi.org/10.1104/pp.17.01718

Journal: Plant Physiology

First Published date: 20 May, 2018

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