Disease Resistance and Susceptibility Genes to Bacterial Blight of Rice

Rice (Oryza sativa L.) is a valuable resource for understanding the complex processes controlling yield and value-added traits. Bacterial blight (BB) is a vascular disease of rice, caused by strains of Xanthomonas oryzae pv. oryzae (Xoo) and provides insight, both practical and basic, into the concepts of susceptibility and resistance. Basic knowledge has been empirically and, more recently, intentionally exploited for broad and durable resistance to the disease. Bacterial blight involves representatives of most classes of resistance genes (R genes) and pathways for basal plant immunity. The study of BB also revealed novelties not observed in other models, possibly due to the long history of rice cultivation and the constant disease pressure. Conspicuous are the recessive R genes that target the notorious type III Transcription Activator-like effectors (TALes) of Xoo. Results indicate that pathogen and host are currently in a battle over a small patch of ground involving TALes function. At the same time, analyses of rice disease physiology are adding to a growing body of knowledge for plant disease processes and to how these processes are intertwined with disease susceptibility. The basic processes of BB present rich targets for the rapid advances in genome editing.