Development of hypersensitive response by Xanthomonas campestris pv. Sesami on Lycopersicon esculentum L., and Solanum tuberosum L., leaves

Xanthomonas campestris pv. Sesame (Xcs), causes bacterial blight disease which can significantly reduce the production of sesame. Previously collected isolate of Xcs differed in their ability to induce the hypersensitive response (HR) on tomato and potato. Tomato was most sensitive to HR induction by Xcs. Isolate Xcs caused a HR on tested plants. The minimal concentration of Xcs needed to induce HR was approximately 1x10(-9) CFU (Colony Forming Unit) mL-1. It was found that different temperatures and light treatments did not affect HR development, except that the HR did not develop in plants maintained continuously at 0 degree C. When plants were placed under natural light the tissues showed strong chlorosis within 2 days after infiltration. High relative humidity affected the development of HR, in the absence or relative low humidity HR did not develop.