The genes encoding the phosphate uptake system in Xanthomonas citri pv. glycines 12-2 were previously found to be upregulated when in soybean leaves. This study thus explored the role of the phosphate uptake system on its virulence to soybean. While phoB and pstSCAB mutants were greatly impaired in both inciting disease symptoms and growth in soybean, the virulence and growth in soybean of a phoU mutant was not reduced when compared with the wildtype strain. The expression of phoB and pstSCAB was highly induced in phosphate-deficient media. In addition, the expression of phoB, assessed with a fusion to a promoterless ice nucleation reporter gene, was greatly increased in soybean leaves, confirming that the soybean apoplast is a phosphorus-limited habitat for X. citri pv. glycines. Global gene expression profiles of phoB and phoU mutants of X. citri pv. glycines conducted under phosphate limitation conditions in vitro using RNA-seq revealed that PhoB positively regulated genes involved in signal transduction, the xcs cluster type II secretion system, cell motility, and chemotaxis, while negatively regulating cell wall and membrane biogenesis, DNA replication / recombination and repair, and several genes with unknown function. PhoU also positively regulated the same genes involved in cell motility and chemotaxis. The severity of bacterial pustule disease was decreased in soybean plants grown under high phosphate fertilization conditions, demonstrating that high phosphate availability in soybean plants can affect infection by X. citri pv. glycines by modulation of the expression of phosphate uptake systems.
BackgroundThailand is a country with large diversity in rice varieties due to its rich and diverse ecology. In this paper, 300 rice varieties from all across Thailand were sequenced to identify SNP variants allowing for the population structure to be explored.ResultsThe result of inferred population structure from admixture and clustering analysis illustrated strong evidence of substructure in each geographical region. The results of phylogenetic tree, PCA analysis, and machine learning on SNPs selected by QTL analysis also supported the inferred population structure.ConclusionThe population structure, which was inferred in this study, contains ve subpopulations such that each subpopulation has a unique ecological system, genetic pattern, as well as agronomic traits. This study can serve as a reference point of the nation-wide population structure for supporting breeders and researchers who are interested in Thai rice.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.