The rapid development of omics sequencing technology has facilitated the identification of thousands of long non-coding (lnc)RNAs in plant species, but the role of lncRNAs in plant–pathogen interactions remains largely unexplored. We used comparative transcriptome analysis ofPhytophthora infestans-resistant and -susceptible tomatoes to identify differentially expressed genes (DEGs) and lncRNAs (DELs), and examine lncRNA-mRNA networks. A total of 1037 DEGs and 688 DELs were identified betweenP. infestans-resistant and -susceptible tomatoes. The co-localization networks, including 128 DEGs and 127 DELs, were performed. We found thatlncRNA16397acted as an antisense transcript ofSlGRX22to regulate its expression, and also inducedSlGRX21expression whenlncRNA16397was overexpressed. In addition, disease symptoms and reactive oxygen species (ROS) accumulation in tomatoes overexpressinglncRNA16397andSpGRXwere fewer and lower than those in wild-type afterP. infestansinfection. This result suggests that tomatolncRNA16397inducesSlGRXexpression to reduce ROS accumulation and alleviate cell membrane injury, resulting in enhanced resistance toP. infestans. Our results provide insight into lncRNAs involved in the response of tomato toP. infestansinfection, demonstrate that the lncRNA16397-GRXs network is an important component of theP. infestansnetwork in tomato, and provide candidates for breeding to enhance biotic stress-resistance in tomato.Significance Statement
There are thousands of lncRNAs in plants, but their role in plant-pathogen interactions remains largely unexplored. Here, by using comparative transcriptome analysis of Phytophthora infestans-resistant and susceptible tomato, we show that lncRNA16397 can induce gene expression to reduce ROS accumulation and alleviate cell membrane injury, thus enhancing resistance to P. infestans. We also pinpoint other candidate genes that can be used to breed for enhanced biotic stress-resistance.