K+ efflux as an ionic response to Phytophthora capsici in seedlings of Capsicum annuum

Abstract

Mexico is one of the main producers of green chili in the world, and one of the most important diseases affecting this crop is chili pepper wilt caused by Phytophthora capsici. This oomycete is a plant pathogen that causes extensive damage to solanaceous vegetable crops. An understanding of the biochemical events that occur in the early interaction phase would be essential for describing the initial mechanism of pathogen-host interactions. The ion fluxes that mediate the initial host-pathogen interaction are critical for activating the immune response of plants, so it is important to study the response of plants to their attack at the physiological and ionic levels. Seedlings of Capsicum annuum L. cultivars were inoculated with P. capsici zoospores and the severity of damage and K+ transport using the Microelectrode Ion Flux Estimation technique (MIFE™) were monitored. The susceptibility of C. annuum L. Jalapeño genotype to P. capsici was confirmed and a lower K+ efflux in the sensitive Jalapeño cultivar than in the tolerant cultivar CM33 was demonstrated as an early response to P. capsici zoospores.

Keywords

• Ionic fluxes
• Oomycete infection
• Plant pathogen interactions