An xa5 Resistance Gene-Breaking Indian Strain of the Rice Bacterial Blight Pathogen Xanthomonas oryzae pv. oryzae Is Nearly Identical to a Thai Strain

• Published in: Frontiers in microbiology 2020-10, Vol.11, p.579504-579504
• Main Authors: Carpenter, Sara C. D., Mishra, Prashant, Ghoshal, Chandrika, Dash, Prasanta K., Wang, Li, Midha, Samriti, Laha, Gouri S., Lore, Jagjeet S., Kositratana, Wichai, Singh, Nagendra K., Singh, Kuldeep, Patil, Prabhu B., Oliva, Ricardo, Patarapuwadol, Sujin, Bogdanove, Adam J., Rai, Rhitu
• Format: Article
• Language: English
• Subjects: bacterial blight of rice; Microbiology; single molecule real-time sequencing; susceptibility genes; SWEET genes; transcription activator-like effectors
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2020.579504

The rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae ( Xoo ) constrains production in major rice growing countries of Asia. Xoo injects transcription activator-like effectors (TALEs) that bind to and activate host “susceptibility” ( S ) genes that are important for disease. The bacterial blight resistance gene xa 5, which reduces TALE activity generally, has been widely deployed. However, strains defeating xa 5 have been reported in India and recently also in Thailand. We completely sequenced and compared the genomes of one such strain from each country and examined the encoded TALEs. The two genomes are nearly identical, including the TALE genes, and belong to a previously identified, highly clonal lineage. Each strain harbors a TALE known to activate the major S gene SWEET11 strongly enough to be effective even when diminished by xa 5. The findings suggest international migration of the xa5 -compatible pathotype and highlight the utility of whole genome sequencing and TALE analysis for understanding and responding to breakdown of resistance.