Whole Genome Sequencing and Tn<i>5</i>-Insertion Mutagenesis of <i>Pseudomonas taiwanensis</i> CMS to Probe Its Antagonistic Activity Against Rice Bacterial Blight Disease

• Main Authors: Wen-Jen Chen, Tzu-Yen Kuo, Chun-Yi Chen, Feng-Chia Hsieh, Yu-Liang Yang, Je-Ruei Liu, Ming-Che Shih
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: International Journal of Molecular Sciences
• Subjects: <i>Pseudomonas taiwanensis</i>; <i>Xanthomonas oryzae </i>pv<i>.oryzae </i>(<i>Xoo</i>); Rice bacterial blight; biocontrol agent
• Online Access: https://www.mdpi.com/1422-0067/21/22/8639
• ISSN: 1661-6596; 1422-0067

The Gram-negative bacterium <i>Pseudomonas taiwanensis </i>is a novel bacterium that uses shrimp shell waste as its sole sources of carbon and nitrogen. It is a versatile bacterium with potential for use in biological control, with activities including toxicity toward insects, fungi, and the rice pathogen <i>Xanthomonas oryzae </i>pv<i>.oryzae </i>(<i>Xoo</i>). In this study, the complete 5.08-Mb genome sequence of <i>P. taiwanensis</i> CMS was determined by a combination of NGS/Sanger sequencing and optical mapping. Comparison of optical maps of seven<i> Pseudomonas</i> species showed that <i>P. taiwanensis </i>is most closely related to <i>P. putida </i>KT 2400. We screened a total of 11,646 individual Tn<i>5</i>-transponson tagged strains to identify genes that are involved in the production and regulation of the iron-chelator pyoverdine in<i> P. taiwanensis</i>, which is a key anti-<i>Xoo </i>factor. Our results indicated that the two-component system (TCS) EnvZ/OmpR plays a positive regulatory role in the production of pyoverdine, whereas the sigma factor RpoS functions as a repressor. The knowledge of the molecular basis of the regulation of pyoverdine by <i>P. taiwanensis </i>provided herein will be useful for its development for use in biological control, including as an anti-<i>Xoo</i> agent.