Ajayi Oyeyemi Olugbenga, Showalter Allan M
Department of Environmental and Plant Biology, Ohio University, Athens, 45701, USA.
Molecular and Cellular Biology Program, Ohio University, Athens, 45701, USA.
Sci Rep. 2020 Nov 25;10(1):20562. doi: 10.1038/s41598-020-72658-4.
Utilizing plant biomass for bioethanol production requires an understanding of the molecular mechanisms involved in plant cell wall assembly. Arabinogalactan-proteins (AGPs) are glycoproteins that interact with other cell wall polymers to influence plant growth and developmental processes. Glucuronic acid, which is transferred to the AGP glycan by β-glucuronosyltransferases (GLCATs), is the only acidic sugar in AGPs with the ability to bind calcium. We carried out a comprehensive genome-wide analysis of a putative GLCAT gene family involved in AGP biosynthesis by examining its sequence diversity, genetic architecture, phylogenetic and motif characteristics, selection pressure and gene expression in plants. We report the identification of 161 putative GLCAT genes distributed across 14 plant genomes and a widely conserved GLCAT catalytic domain. We discovered a phylogenetic clade shared between bryophytes and higher land plants of monocot grass and dicot lineages and identified positively selected sites that do not result in functional divergence of GLCATs. RNA-seq and microarray data analyses of the putative GLCAT genes revealed gene expression signatures that likely influence the assembly of plant cell wall polymers which is critical to the overall growth and development of edible and bioenergy crops.
利用植物生物质生产生物乙醇需要了解植物细胞壁组装所涉及的分子机制。阿拉伯半乳聚糖蛋白（AGPs）是一类糖蛋白，它们与其他细胞壁聚合物相互作用，以影响植物的生长和发育过程。葡萄糖醛酸是通过β-葡萄糖醛酸基转移酶（GLCATs）转移到AGP聚糖上的，它是AGPs中唯一具有结合钙能力的酸性糖。我们通过研究其序列多样性、遗传结构、系统发育和基序特征、选择压力以及在植物中的基因表达，对参与AGP生物合成的一个假定GLCAT基因家族进行了全面的全基因组分析。我们报告了在14个植物基因组中鉴定出161个假定的GLCAT基因以及一个广泛保守的GLCAT催化结构域。我们发现苔藓植物与单子叶禾本科和双子叶谱系的高等陆地植物之间共享一个系统发育分支，并鉴定出不会导致GLCATs功能分化的正选择位点。对假定的GLCAT基因进行RNA测序和微阵列数据分析，揭示了可能影响植物细胞壁聚合物组装的基因表达特征，这对食用和生物能源作物的整体生长和发育至关重要。
