Laboratory of Plant Cell Wall Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, Haryana, 121001, India.
Plant Mol Biol. 2023 Dec;113(6):383-400. doi: 10.1007/s11103-023-01391-z. Epub 2023 Nov 22.
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.
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正常植物发育过程中产生，被细胞壁受体感知，并可以改变免疫和细胞壁组成。因此，我们假设木寡糖（XOS）可以作为一种诱导剂并触发免疫反应。为了验证这一点，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，激活了 MAPK 蛋白磷酸化，并诱导了胼胝质沉积。XB（DAMP）和 flg22（一种微生物相关分子模式（MAMP））的组合进一步增强了 ROS 反应和 PTI 标记基因的表达。RNA 测序分析显示，与 24 小时 XB 处理叶片相比，30 分钟后有更多的基因差异表达，这与 ROS 反应相关。在 30 分钟和 3 小时的 XB 处理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 小时时观察到总细胞壁糖增加和羧酸水平降低。此外，阿拉伯糖、鼠李糖和木糖水平在 30 分钟时增加，葡萄糖水平在 24 小时时与对照处理叶片相比增加。XB 处理后，茉莉酸、脱落酸、生长素和细胞分裂素的水平也受到影响。总的来说，我们的数据表明，最短的 XOS 可以作为一种 DAMPs，触发 PTI 反应，并改变细胞壁组成和激素水平。
