Wang Ning, Wang Luyao, Zhu Kai, Hou Sensen, Chen Lin, Mi Dandan, Gui Ying, Qi Yijun, Jiang Chunhao, Guo Jian-Hua
Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Nanjing, China.
Front Microbiol. 2019 Jan 31;10:98. doi: 10.3389/fmicb.2019.00098. eCollection 2019.
The biological control process mediated by microbes relies on multiple interactions among plants, pathogens and biocontrol agents (BCAs). One such efficient BCA is AR156, a bacterial strain that controls a broad spectrum of plant diseases and potentially works as a microbe elicitor of plant immune reactions. It remains unclear, however, whether the interaction between plants and AR156 may facilitate composition changes of plant root exudates and whether these changes directly affect the growth of both plant pathogens and AR156 itself. Here, we addressed these questions by analyzing the influences of root exudate changes mediated by AR156 during biocontrol against tomato bacterial wilt caused by Indeed, some upregulated metabolites in tomato root exudates induced by AR156 (REB), such as lactic acid and hexanoic acid, induced the growth and motile ability of AR156 cells. Exogenously applying hexanoic acid and lactic acid to tomato plants showed positive biocontrol efficacy (46.6 and 39.36%) against tomato bacterial wilt, compared with 51.02% by AR156 itself. Furthermore, fructose, lactic acid, sucrose and threonine at specific concentrations stimulated the biofilm formation of AR156 in Luria-Bertan- Glycerol- Magnesium medium (LBGM), and we also detected more colonized cells of AR156 on the tomato root surface after adding these four compounds to the system. These observations suggest that the ability of AR156 to induce some specific components in plant root exudates was probably involved in further biocontrol processes.
由微生物介导的生物防治过程依赖于植物、病原体和生物防治剂（BCA）之间的多重相互作用。一种这样高效的生物防治剂是AR156，它是一种能控制多种植物病害的细菌菌株，并且可能作为植物免疫反应的微生物激发子发挥作用。然而，尚不清楚植物与AR156之间的相互作用是否会促进植物根系分泌物的成分变化，以及这些变化是否会直接影响植物病原体和AR156自身的生长。在这里，我们通过分析AR156介导的根系分泌物变化在防治由[具体病原体名称缺失]引起的番茄青枯病的生物防治过程中的影响来解决这些问题。事实上，AR156诱导的番茄根系分泌物（REB）中的一些上调代谢产物，如乳酸和己酸，诱导了AR156细胞的生长和运动能力。与AR156自身的防治效果51.02%相比，向番茄植株外源施用己酸和乳酸对番茄青枯病显示出积极的生物防治效果（分别为46.6%和39.36%）。此外，特定浓度的果糖、乳酸、蔗糖和苏氨酸刺激了AR156在Luria-Bertan-甘油-镁培养基（LBGM）中的生物膜形成，并且在向系统中添加这四种化合物后，我们还检测到番茄根表面有更多定殖的AR156细胞。这些观察结果表明，AR156诱导植物根系分泌物中某些特定成分的能力可能参与了进一步的生物防治过程。
