Expressão de genes relacionados à defesa em plantas de Solanum tuberosum tratadas com acido salicílico e extrato bacteriano

Abstract

Potato is currently the third most consumed food crop after rice and wheat, and it is a valuable resource for alleviating poverty in undeveloped countries. However, potato crop fields are attacked by numerous pests and pathogens, which represent a threat to the global potato production. Unlike animals, plants do not possess an adaptive immune system. Therefore, each individual plant cell needs to be able to perceive the pathogen, release signals to neighbor cells, and produce a defense response. Plant cells recognize the pathogen through Pattern Recognition Receptors (PRRs), triggering a signaling cascade that results in the activation of defense-related genes, which characterize the occurrence of Systemic Acquired Resistance (SAR). Among the factors involved in the regulation of defense-related genes, salicylic acid is widely known as an elicitor of plant defense against biotrophic pathogens.Besides this hormone, it has been demonstrated that a bacterial extract of Xanthomonas axonopodis pv. citri (referred to as XTH) is capable of inducing resistance against pectolytic bacteria via poorly understood mechanisms. Considering the different signaling pathways involved in plant defense, we intended to investigate the occurrence of systemic resistance in Solanum tuberosum plants treated with XTH or salicylic acid, by analyzing the expression of PR-1b, PR-2, ChtA, PAL, Pin2, JAZ1/TIFY10A, and ERF1 genes. Our results suggest that XTH is capable of inducing systemic resistance in potato plants via concomitant activation of the salicylic acid, jasmonic acid, and ethylene signaling pathways.