Wang Anqi, Hua Juan, Wang Yangyang, Zhang Guishan, Luo Shihong
College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, P. R. China.
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China.
J Agric Food Chem. 2020 Jun 10;68(23):6308-6315. doi: 10.1021/acs.jafc.0c01352. Epub 2020 May 27.
Inoculation of crop plants with strains of beneficial bacteria can result in promotion of plant growth. In our study, we demonstrated that WRN031 as a plant-growth-promoting rhizobacteria (PGPR) improved the maize seedling growth following inoculation with WRN031. Fluorescence microscopy visualization indicated that GFP-labeled WRN031 had accumulated on the maturation zones of both primary and lateral roots of maize. Two metabolites were detected in the rhizosphere soil of maize root inoculation with WRN031 using HPLC-DAD analyses. Through guided isolation from an ethyl acetate extract of WRN031, these two nonvolatile stereoisomers 3,4-acetylbutanediol (3,4-ABD, ) and 3,4-acetylbutanediol (3,4-ABD, ) were identified and found to occur at a ratio of 1:2 (v/v) in maize rhizosphere soil. Bioactivity screening indicated that compounds and , as well as a v/v = 1:2 mixture of both and , significantly improved the root elongation of both maize and rice, with the effective enhancement concentration related to their concentration in rhizosphere soil. These results suggested that 3,4-ABD and 3,4-ABD produced by WRN031 might improve the growth of their host plants and provides evidence that nonvolatiles accumulating in the root maturation zone may regulate the relationship between roots and beneficial bacteria.
用有益细菌菌株接种农作物可促进植物生长。在我们的研究中，我们证明WRN031作为一种促植物生长的根际细菌（PGPR），在接种WRN031后能促进玉米幼苗生长。荧光显微镜观察表明，绿色荧光蛋白标记的WRN031已在玉米主根和侧根的成熟区积累。使用高效液相色谱 - 二极管阵列检测（HPLC - DAD）分析在接种WRN031的玉米根际土壤中检测到两种代谢物。通过从WRN031的乙酸乙酯提取物中进行导向分离，鉴定出这两种非挥发性立体异构体3,4 - 乙酰基丁二醇（3,4 - ABD， ）和3,4 - 乙酰基丁二醇（3,4 - ABD， ），并发现它们在玉米根际土壤中的比例为1:2（v/v）。生物活性筛选表明，化合物 和 以及 和 的v/v = 1:2混合物均显著提高了玉米和水稻的根伸长，有效增强浓度与其在根际土壤中的浓度相关。这些结果表明，WRN031产生的3,4 - ABD和3,4 - ABD可能改善其宿主植物的生长，并提供了证据表明在根成熟区积累的非挥发性物质可能调节根与有益细菌之间的关系。
