School of Life Sciences and Institute for Microorganisms, Kyungpook National University, Daegu 702-701, Korea.
Plant Pathol J. 2013 Jun;29(2):174-81. doi: 10.5423/PPJ.SI.09.2012.0143.
The plant growth-promoting rhizobacterium Ochrobactrum lupini KUDC1013 elicited induced systemic resistance (ISR) in tobacco against soft rot disease caused by Pectobacterium carotovorum subsp. carotovorum. We investigated of its factors involved in ISR elicitation. To characterize the ISR determinants, KUDC1013 cell suspension, heat-treated cells, supernatant from a culture medium, crude bacterial lipopolysaccharide (LPS) and flagella were tested for their ISR activities. Both LPS and flagella from KUDC1013 were effective in ISR elicitation. Crude cell free supernatant elicited ISR and factors with the highest ISR activity were retained in the n-butanol fraction. Analysis of the ISR-active fraction revealed the metabolites, phenylacetic acid (PAA), 1-hexadecene and linoleic acid (LA), as elicitors of ISR. Treatment of tobacco with these compounds significantly decreased the soft rot disease symptoms. This is the first report on the ISR determinants by plant growth-promoting rhizobacteria (PGPR) KUDC1013 and identifying PAA, 1-hexadecene and LA as ISR-related compounds. This study shows that KUDC1013 has a great potential as biological control agent because of its multiple factors involved in induction of systemic resistance against phytopathogens.
促生根瘤菌 Ochrobactrum lupini KUDC1013 诱导烟草对果胶杆菌软腐病的系统抗性（ISR）。我们研究了其参与 ISR 诱导的因子。为了表征 ISR 决定因素，KUDC1013 细胞悬浮液、热处理细胞、培养基上清液、粗细菌脂多糖（LPS）和鞭毛被测试其 ISR 活性。来自 KUDC1013 的 LPS 和鞭毛都能有效诱导 ISR。无细胞上清液诱导 ISR，具有最高 ISR 活性的因子保留在正丁醇部分。对 ISR 活性部分的分析表明，苯乙酸（PAA）、1-十六烯和亚油酸（LA）等代谢物是 ISR 的诱导剂。用这些化合物处理烟草可显著减轻软腐病症状。这是首次报道植物促生根瘤菌（PGPR）KUDC1013 的 ISR 决定因素，并确定 PAA、1-十六烯和 LA 为与 ISR 相关的化合物。这项研究表明，由于 KUDC1013 参与诱导对植物病原体的系统抗性的多种因素，因此它具有作为生物防治剂的巨大潜力。
