Biocontrol of Potato Common Scab is Associated with High Pseudomonas fluorescens LBUM223 Populations and Phenazine-1-Carboxylic Acid Biosynthetic Transcript Accumulation in the Potato Geocaulosphere
Biocontrol of Potato Common Scab is Associated with High Pseudomonas fluorescens LBUM223 Populations and Phenazine-1-Carboxylic Acid Biosynthetic Transcript Accumulation in the Potato Geocaulosphere
复制标题
DOI：
10.1094/phyto-01-16-0019-r
复制
发表时间：
2016-09-01
期刊：
影响因子：
3.2
通讯作者：
Filion, Martin
中科院分区：
文献类型：
--
作者：
Arseneault, Tanya;Goyer, Claudia;Filion, Martin
假单胞菌经常被用作生防剂，因为它们展示了广泛的控制疾病的机制。马铃薯赤霉菌(Streptomyces Scabies)引起的马铃薯赤霉病是由荧光假单胞菌LBUM223通过吩嗪-L-羧酸(PCA)产生的。在本研究中，我们旨在研究LBUM223的种群动态以及参与PCA生物合成的关键基因phzC在控制和田间条件下生长的马铃薯根际和地上部的表达。对照实验的结果表明，在15周的时间里，LBUM223的土壤种群数量显著下降。然而，在第15周，与没有病原体时相比，在地质球囊圈中出现溃烂链霉菌与LBUM223的种群显著增加有关。这也导致了显著更高的phzC基因转录本数量的检测。在田间条件下，LBUM223的土壤种群在春季单次接种时遵循类似的时间下降趋势，但在每两周重新定位时保持稳定，这也导致了phzC基因转录本的较大积累。综上所述，我们的研究结果表明，LBUM223必须在高水平(107个细菌/克土壤)的马铃薯地球圈定居，才能通过增加PCA产量来实现对普通赤霉病的生物防治。
Pseudomonads are often used as biocontrol agents because they display a broad range of mechanisms to control diseases. Common scab of potato, caused by Streptomyces scabies, was previously reported to be controlled by Pseudomonas fluorescens LBUM223 through phenazine-l-carboxylic acid (PCA) production. In this study, we aimed at characterizing the population dynamics of LBUM223 and the expression of phzC, a key gene involved in the biosynthesis of PCA, in the rhizosphere and geocaulosphere of potato plants grown under controlled and field conditions. Results obtained from controlled experiments showed that soil populations of LBUM223 significantly declined over a 15-week period. However, at week 15, the presence of S. scabies in the geocaulosphere was associated with significantly higher populations of LBUM223 than when the pathogen was absent. It also led to the detection of significantly higher phzC gene transcript numbers. Under field conditions, soil populations of LBUM223 followed a similar decline in time when a single inoculation was applied in spring but remained stable when reinoculated biweekly, which also led to greater phzC gene transcripts accumulation. Taken together, our findings suggest that LBUM223 must colonize the potato geocaulosphere at high levels (107 bacteria/g of soil) in order to achieve biocontrol of common scab through increased PCA production.