| Title: | Potential modes of action of Pseudomonas fluorescens ZX during biocontrol of blue mold decay on postharvest citrus |
| Author(s): | Wang Z; Mei X; Du M; Chen K; Jiang M; Wang K; Zalan Z; Kan J; |
| Address: | "College of Food Science, Southwest University, Chongqing, PR China. Chinese-Hungarian Cooperative Research Centre for Food Science, Chongqing, PR China. Laboratory of Quality & Safety Risk Assessment for Agro-products on Storage and Preservation (Chongqing), Ministry of Agriculture, Chongqing, PR China. College of Life Science and Engineering, Chongqing Three Gorges University, Chongqing, PR China. Food Science Research Institute of National Agricultural Research and Innovation Center, Budapest, Hungary" |
| ISSN/ISBN: | 1097-0010 (Electronic) 0022-5142 (Linking) |
| Abstract: | "BACKGROUND: The application of chemical fungicides is currently the main method for the control of postharvest decay of fruits and vegetables. However, public concern has been growing towards the effect of fungicides on food safety, human health and environmental pollution. Thus, interest in microbial biocontrol agent development has grown, such agents being considered both safe and environmentally friendly. Pseudomonas fluorescens is widely distributed in nature, and one of the most valuable biocontrol and plant growth-promoting rhizobacteria. In this study, the efficacy and the potential associated modes of action of P. fluorescens ZX against Penicillium italicum on oranges (Citrus sinensis Osbeck) were investigated. RESULTS: The application of P. fluorescens ZX significantly reduced blue mold lesion size and incidence in comparison to the control, where P. fluorescens ZX was effective when applied preventatively but not curatively. In dual cultures, treatment with cell-free autoclaved cultures or culture filtrate had a limited capacity to suppress P. italicum, while P. italicum was inhibited by bacterial fluid and bacterial suspension with living cells in vitro. The P. fluorescens ZX isolate displayed protease, but not chitinase, glucanase or cellulose, activity, and produced siderophores and volatile organic compounds with antifungal abilities. Competition tests showed P. fluorescens ZX could use fructose, sucrose, aspartic acid, threonine, serine, glycine, valine, lysine and proline better than P. italicum. Furthermore, an effective biofilm that peaked after a 24-hour incubation at 30 degrees C was formed by the P. fluorescens ZX isolate. Light microscopy and scanning electron microscopy observations indicate the P. fluorescens ZX isolate could not undergo direct parasitism or hyperparasitism. CONCLUSIONS: Competition for nutrients and niches, biofilm formation, inhibition of spore germination and mycelial growth, and production of inhibitory metabolites may play important roles in P. fluorescens ZX antagonism of P. italicum. (c) 2019 Society of Chemical Industry" |
| Keywords: | *Antibiosis Biofilms Citrus/*microbiology Fruit/microbiology Mycelium/growth & development/metabolism Penicillium/growth & development/metabolism Plant Diseases/microbiology/prevention & control Pseudomonas fluorescens/*physiology Citrus sinensis Osbeck P; |
| Notes: | "MedlineWang, Zhirong Mei, Xiaofei Du, Muying Chen, Kewei Jiang, Mengyao Wang, Kaituo Zalan, Zsolt Kan, Jianquan eng China is 2016YFE0130600; in Hungary is TET_16_C/Chinese-Hungarian Intergovernmental Scientific and Technological Industrial R+D program/ cx2018095/Venture & Innovation Support Program for Chongqing Overseas Returnees/ England 2019/10/23 J Sci Food Agric. 2020 Jan 30; 100(2):744-754. doi: 10.1002/jsfa.10079. Epub 2019 Nov 25" |
