LncRNA39026 Enhances Tomato Resistance to by Decoying miR168a and Inducing Gene Expression.

Our previous study has indicated that a long noncoding RNA (lncRNA), lncRNA39026, can be responsive to infection. However, the function and regulation mechanism of lncRNA39026 during tomato resistance to are unknown. In this study, an lncRNA39026 sequence was cloned from tomato Zaofen No. 2, and this sequence contained an endogenous target mimicry for miR168a, which might suppress the expression of miR168a. LncRNA39026 was strongly downregulated at 3 h in the tomato plants infected with , and its expression level displayed a negative correlation with the expression level of miR168a and a positive correlation with the expression levels of genes (target gene of miR168a) upon infection. Tomato plants in which lncRNA39026 was overexpressed displayed enhanced resistance to , decreased level of miR168a, and increased level of , whereas the resistance was impaired, level of miR168a was increased, and level of was decreased after lncRNA39026 silencing. In addition, lncRNA39026 could also induce the expression of pathogenesis-related (PR) genes, as shown by increased and decreased expression levels of PR genes in tomato plants with overexpressed and silenced lncRNA39026, respectively. The result demonstrated that lncRNA39026 might function to decoy miR168a and affect the expression of PR genes in tomato plants, increasing resistance to disease.