Calcium Nutrition of a Blight-susceptible Cotton and Its Effects on Interactions with Xanthomonas Campestris Pv. Mal V Ace Arum

Abstract

Leaves of susceptible cotton WbM (4.0) were inoculated with Xanthomonas campestris pv. malvacearum. Plants were grown in either 0.1 mM or 10 mM calcium nutrient solution. Macroscopically, inoculated leaves of cotton receiving low levels of calcium became water-soaked while leaves of plants receiving high levels of calcium were dry and chlorotic. Bacterial growth curves showed insignificant differences between treatments except at day five . Changes at the light microscope level were studied at three and five days post-inoculation. Bacteria were aggregated near host cells of cotton receiving the higher level of calcium, but not in the other treatment. Ultrastructural studies were conducted up to five days and demonstrated what appeared to be increased levels of damage in plants receiving the higher level of calcium compared to plants receiving a low levelof calcium.