A Review of the Studies and Interactions of Pseudomonas syringae Pathovars on Wheat

Wheat is affected by some pathovars of Pseudomonas syringae and by other Pseudomonas species. Of these, P. syringae pv. syringae is the major one responsible for reduction. Recent studies have been made to characterize and identify the pathogen and to determine its aggressiveness and the pattern of colonization in seed and its effects on seed yield, yield components, and source-sink relationships during postanthesis. It was found that the reduction in the aerial biomass production is the best way to evaluate the aggressiveness of this bacterium, and the spray inoculation is good tool to make evaluations at seedling stage. The characterization of bacteria fingerprintings with molecular markers such as RAPD-PCR, ERIC, and REP-PCR is available. Genomic evolution has been elucidated with next-generation genome sequencing. Also, the colonization pattern shows that, early on, microcolonies are frequently detected in the aleurone layer, later in the endospermand finally close to the crease and even in some cells of the embryo itself. In the wheat cultivars Seri M82 and Rebeca F2000 seed yield and its components are negatively affected. In general, P. syringae pv. syringae reduces the plant height, seed yield, and yield components, as well as the growth of most organs. When this bacterium attacks, the stems are the predominant sink organs and the leaf laminae and panicles are the predominant source organs.