Institute of Biotechnology, Federal University of Uberlandia, Av. Amazonas, Bloco 2E, Campus Umuarama, 38400-902 Uberlandia MG, Brazil.
Department of Plant Sciences, College of Agriculture and Environmental Sciences, University of California, Davis, 1 Shields Ave, Davis, CA 95616, USA.
Int J Mol Sci. 2020 Sep 15;21(18):6769. doi: 10.3390/ijms21186769.
colonizes the xylem of various cultivated and native plants worldwide. Citrus production in Brazil has been seriously affected, and major commercial varieties remain susceptible to Citrus Variegated Chlorosis (CVC). Collective cellular behaviors such as biofilm formation influence virulence and insect transmission of . The reference strain 9a5c produces a robust biofilm compared to Fb7 that remains mostly planktonic, and both were isolated from symptomatic citrus trees. This work deepens our understanding of these distinct behaviors at the molecular level, by comparing the cellular and secreted proteomes of these two CVC strains. Out of 1017 identified proteins, 128 showed differential abundance between the two strains. Different protein families were represented such as proteases, hemolysin-like proteins, and lipase/esterases, among others. Here we show that the lipase/esterase LesA is among the most abundant secreted proteins of CVC strains as well, and demonstrate its functionality by complementary activity assays. More severe symptoms were observed in inoculated with strain Fb7 compared to 9a5c. Our results support that systemic symptom development can be accelerated by strains that invest less in biofilm formation and more in plant colonization. This has potential application in modulating the bacterial-plant interaction and reducing disease severity.
在全球范围内定殖于各种栽培和本地植物的木质部。巴西的柑橘生产受到严重影响，主要商业品种仍然容易感染柑橘杂色褪绿病（CVC）。生物膜形成等集体细胞行为会影响 的毒力和昆虫传播。参考菌株 9a5c 与主要浮游的 Fb7 相比，产生了强大的生物膜，两者均从有症状的柑橘树上分离得到。通过比较这两种 CVC 菌株的细胞和分泌蛋白质组，这项工作在分子水平上加深了我们对这些不同行为的理解。在鉴定出的 1017 种蛋白质中，有 128 种在两种菌株之间表现出丰度差异。不同的蛋白质家族被代表，如蛋白酶、溶血素样蛋白和脂肪酶/酯酶等。在这里，我们表明脂酶/酯酶 LesA 也是 CVC 菌株中最丰富的分泌蛋白之一，并通过互补活性测定证明了其功能。与接种 9a5c 相比，接种 Fb7 的植株表现出更严重的症状。我们的结果支持这样一种观点，即系统症状的发展可以通过那些较少投资于生物膜形成而更多投资于植物定植的菌株来加速。这在调节细菌-植物相互作用和减轻疾病严重程度方面具有潜在的应用价值。
