植物细胞壁衍生的寡糖,即,损伤相关分子模式(DAMPs),可以在病原体攻击后或在正常的植物发育过程中产生,被细胞壁受体感知,并且可以改变免疫力和细胞壁组成。因此,我们假设低聚木糖(XOS)可以作为激发子并触发免疫反应。为了测试这个,我们用木二糖(XB)处理拟南芥并研究了不同的参数。XB处理显著触发了活性氧(ROS)的产生,激活的MAPK蛋白磷酸化,并诱导call体沉积。XB(DAMP)和flg22a微生物相关分子模式(MAMP)的组合进一步增强了ROS反应和PTI标记基因的基因表达。RNA测序分析显示,与24小时XB处理的叶片相比,30分钟后更多的基因受到差异调节,与ROS反应相关。XB处理30分钟和3小时后,观察到木糖苷酶活性和可溶性木糖水平增加,这可能削弱了DAMP反应。然而,在30分钟和24小时观察到总细胞壁糖的增加和糖醛酸水平的降低。阿拉伯糖,鼠李糖,和木糖水平在30分钟内增加,与模拟处理的叶子相比,葡萄糖在24小时内增加。茉莉酸的水平,脱落酸,生长素,XB治疗后细胞分裂素也受到影响。总的来说,我们的数据显示,最短的XOS可以充当DAMP,触发PTI反应并改变细胞壁组成和激素水平。
Plant cell wall-derived oligosaccharides, i.e., damage-associated molecular patterns (DAMPs), could be generated after pathogen attack or during normal plant development, perceived by cell wall receptors, and can alter immunity and cell wall composition. Therefore, we hypothesised that xylo-oligosaccharides (XOS) could act as an elicitor and trigger immune responses. To test this, we treated Arabidopsis with xylobiose (XB) and investigated different parameters. XB-treatment significantly triggered the generation of reactive oxygen species (ROS), activated MAPK protein phosphorylation, and induced callose deposition. The combination of XB (DAMP) and flg22 a microbe-associated molecular pattern (MAMP) further enhanced ROS response and gene expression of PTI marker genes. RNA sequencing analysis revealed that more genes were differentially regulated after 30 min compared to 24 h XB-treated leaves, which correlated with ROS response. Increased
xylosidase activity and soluble xylose level after 30 min and 3 h of XB-treatment were observed which might have weakened the DAMP response. However, an increase in total cell wall sugar and a decrease in uronic acid level was observed at both 30 min and 24 h. Additionally, arabinose, rhamnose, and xylose levels were increased in 30 min, and glucose was increased in 24 h compared to mock-treated leaves. The level of jasmonic acid, abscisic acid, auxin, and cytokinin were also affected after XB treatment. Overall, our data revealed that the shortest XOS can act as a DAMP, which triggers the PTI response and alters cell wall composition and hormone level.