Various Plant Diseases Caused by Xanthomonas Species

Xanthomonas is a Gram negative, aerobic, short rod shaped bacterium belonging to the family Pseudomonadaceae. This genus includes several pathovars, which are mainly plant pathogens. Extracellular proteases, and Type II secretion systems chiefly help these bacteria in colonizing the host plant. It produces a characteristic yellow pigment, xanthomonadin, which often is used as a chemotaxonomic and diagnostic marker of this genus. Xanthan gum produced by Xanthomonas is commercially important. It is an important additive in the food industry. Recently, Xanthomonas was also observed to undergo programmed cell death PCD , the morphological and biochemical features of which closely resemble eukaryotic PCD. The determination of the genus Xanthomonas and its species is relatively easy, however, the characterization of X. campestris pathovars poses problems. An unambiguous identification of the pathovars of X. campestris can be of great use in plant pathology. The X. campestris pathovars that are defined by the host or disease symptoms are difficult to identify by other phenotypic characteristics. X. campestris group is the largest of all and causes diseases in many plant species. It is, therefore, classified into pathovars differentiated by the host reaction. However, application of the newer techniques of classification has been useful. A relationship of nutritional properties, host specificity and DNA homology groups has been observed. Genetic diversity among the strains of different pathovars of X. campestris has also been studied for a number of pathovars. It is believed that the variability could be more pronounced in the regions where the host plant originated. Ribosomal RNA and DNA probes could be useful tools for the epidemiological studies and in following the genetic evolution of the strains. Dr. Dilip Kumar Sharma "Various Plant Diseases Caused by Xanthomonas Species" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-6 , October 2022, URL: https://www.ijtsrd.com/papers/ijtsrd51977.pdf Paper URL: https://www.ijtsrd.com/other-scientific-research-area/other/51977/various-plant-diseases-caused-by-xanthomonas-species/dr-dilip-kumar-sharma