Identification and characterization of rice blast resistance gene Pid4 by a combination of transcriptomic profiling and genome analysis.

Map-based cloning of plant disease resistance (R) genes is time-consuming. Here, we reported the isolation of blast R gene Pid4 using comparative transcriptomic profiling and genome-wide sequence analysis. Pid4 encodes a coiled-coil nucleotide-binding site leucine-rich repeat (CC-NBS-LRR) protein and is constitutively expressed at diverse developmental stages in the rice variety Digu. The Pid4 protein is localized in both the nucleus and cytoplasm. Introduction of Pid4 into susceptible rice cultivars confers race-specific resistance to leaf and neck blast. Amino acid sequence comparison and blast resistance spectrum tests showed that Pid4 is a novel R gene, different from the previously reported R genes located in the same gene cluster. A Pid4 Indel marker was developed to facilitate the identification of Pid4 in different rice varieties. We demonstrated that a plant R gene can be quickly isolated using transcriptomic profiling coupled with genome-wide sequence analysis.