Indeterminate domain 3 negatively regulates plant erectness and the resistance of rice to sheath blight by controlling gene expressions.

Plant architecture and disease resistance are the key factors that control the production of yield. However, the mechanism behind these factors is largely unknown. In this study, we identified that () was obviously induced by inoculation of AG1-IA. Plants that overexpressed were more susceptible, while mutants showed a similar response to sheath blight disease compared with wild-type plants. Interestingly, plants developed a wider tiller angle and exhibited altered shoot gravitropism, while knock-out mutants showed no visible morphological differences compared with the wild-type plants. is ubiquitously expressed in different tissues and stages, and the transcript was induced by exogenously applied auxin. Expression of the and genes was altered in compared with wild-type plants. Furthermore, plants are sensitive to auxin and the polar auxin transporter inhibitor N-1-naphthylphalamic acid (NPA). Further yeast-one hybrid, chromatin immunoprecipitation (ChIP) and transient assays revealed that IDD3 directly represses via promoter binding. Inoculation with indicated that plants are more susceptible to sheath blight disease (ShB) compared with the wild-type. Taken together, our analyses suggest that controls plant architecture and the resistance of rice to ShB via the regulation of auxin transporter genes.