XAPT and XLPT enzymes modify the glucuronic acid side chains of tissue-specific xylans in Arabidopsis and Eucalyptus
XAPT and XLPT enzymes modify the glucuronic acid side chains of tissue-specific xylans in Arabidopsis and Eucalyptus
复制标题
XAPT 和 XLPT 酶修饰拟南芥和桉树中组织特异性木聚糖的葡萄糖醛酸侧链
DOI：
10.1101/2024.01.23.575660
复制
发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Yu L
中科院分区：
文献类型：
--
作者：
Yu L
多糖结构的复杂性不仅影响细胞壁的强度和延展性，而且还阻碍了病原体和生物技术试图糖化壁。在某些物种和组织中，木聚糖上的葡萄糖醛酸侧基表现出阿拉伯吡喃糖或半乳糖装饰，其遗传和进化基础是完全未知的，阻碍了理解其功能和工程壁消化率的努力，遗传学和多糖分析被用来确定拟南芥和桉树中的相关位点，而拟南芥发现了一个共同的进化起源。GH 30-familyendo-glucuronidase活性通过电泳进行分析，它们不同的特异性通过遗传学和结构分析进行合理化。新鉴定的木聚糖阿拉伯吡喃糖基转移酶包括GT 47-A高尔基体糖基转移酶家族中一个被忽视的亚家族，以前认为主要包括木葡聚糖半乳糖基转移酶，突出了供体和受体特异性的意外适应。进一步的新功能化产生了桃金娘科特异性木聚糖半乳糖基转移酶。同时，GH 30内切葡萄糖醛酸苷酶已经收敛地适应以克服这些装饰，表明这些结构在防御中的作用。然而，葡糖醛酸木聚糖修饰基因在桉树组织中的差异表达暗示了其进一步的功能。我们的研究结果证明了生物合成和降解碳水化合物活性酶活性的快速适应性，为深入了解植物-病原体相互作用和促进植物细胞壁生物技术利用提供了依据。
Polysaccharide structural complexity not only influences cell wall strength and extensibility but also hinders pathogenic and biotechnological attempts to saccharify the wall. In certain species and tissues, glucuronic acid side groups on xylan exhibit arabinopyranose or galactose decorations whose genetic and evolutionary basis is completely unknown, impeding efforts to understand their function and engineer wall digestibility.Genetics and polysaccharide profiling were used to identify the responsible loci in Arabidopsis and Eucalyptus from proposed candidates, while phylogenies uncovered a shared evolutionary origin. GH30‐familyendo‐glucuronoxylanase activities were analysed by electrophoresis, and their differing specificities were rationalised by phylogeny and structural analysis.The newly identified xylan arabinopyranosyltransferases comprise an overlooked subfamily in the GT47‐A family of Golgi glycosyltransferases, previously assumed to comprise mainly xyloglucan galactosyltransferases, highlighting an unanticipated adaptation of both donor and acceptor specificities. Further neofunctionalisation has produced a Myrtaceae‐specific xylan galactosyltransferase. Simultaneously, GH30 endo‐glucuronoxylanases have convergently adapted to overcome these decorations, suggesting a role for these structures in defence. The differential expression of glucuronoxylan‐modifying genes across Eucalyptus tissues, however, hints at further functions.Our results demonstrate the rapid adaptability of biosynthetic and degradative carbohydrate‐active enzyme activities, providing insight into plant–pathogen interactions and facilitating plant cell wall biotechnological utilisation.