Department of Microbiology, Techno India University, West Bengal EM-4 Sector-V, Saltlake City, Kolkata, West Bengal, 700091, India.
Department of Microbiology, Techno India University, West Bengal EM-4 Sector-V, Saltlake City, Kolkata, West Bengal, 700091, India.
Microb Pathog. 2020 Dec;149:104559. doi: 10.1016/j.micpath.2020.104559. Epub 2020 Oct 10.
Xanthomonas oryzae pv. oryzae (Xoo) induces bacterial leaf blight (BLB), is known to be the most devastating disease of rice. The present investigation for the first time explains the antibacterial, anti-biofilm, and antivirulence potential of the simplest allelochemical catechol. Bacterial viability and growth are significantly reducing in catechol treatment. Further study also reveals that catechol also inhibits primary attachment and preformed biofilm of Xoo even at half MIC concentration. The half MIC concentration of catechol also induce a significant decrease in virulence factors like swimming, swarming, exopolysaccharide, and xanthomonadin production. Next, we investigate the possible antibacterial mode of action of catechol against Xoo. Results show that, the catechol caused oxidative stress and targets cell membrane for its antibacterial activity. Whereas, in silico study reveals that, catechol binds with the catalytic domain of XanA protein and this may be consider as a reason for antibiofilm activity of catechol. Moreover, in virulence assay on rice plants, we observe significant decrement in lesion length in catechol and Xoo co-treated rice leaves as compared with only Xoo treated leaves. All the results clearly show, allelochemical catechol to be a potential compound for the antibacterial, anti-biofilm, and antivirulence agent against Xoo and consequently mitigating the BLB disease advancement in rice.
稻黄单胞菌（Xoo）引发细菌性叶斑病（BLB），是水稻最具破坏性的疾病之一。本研究首次解释了最简单的化感物质儿茶酚的抗菌、抗生物膜和抗病毒活力的潜力。儿茶酚处理可显著降低细菌活力和生长。进一步的研究还表明，儿茶酚即使在半 MIC 浓度下，也能抑制 Xoo 的初始附着和预形成生物膜。儿茶酚的半 MIC 浓度也能显著降低游动、群集、胞外多糖和黄单孢菌素产生等毒力因子的产生。接下来，我们研究了儿茶酚对 Xoo 的可能抗菌作用模式。结果表明，儿茶酚引起氧化应激，并针对细胞膜发挥其抗菌活性。而在计算机模拟研究中，儿茶酚与 XanA 蛋白的催化结构域结合，这可能是儿茶酚具有抗生物膜活性的原因。此外，在对水稻植物的毒力测定中，我们观察到儿茶酚和 Xoo 共处理的水稻叶片中的病斑长度与仅用 Xoo 处理的叶片相比明显减少。所有结果均清楚地表明，化感物质儿茶酚是一种具有抗菌、抗生物膜和抗病毒活力的潜在化合物，可对抗 Xoo，从而减缓水稻 BLB 病的发展。
