Indeterminate Domain Proteins Regulate Rice Defense to Sheath Blight Disease

Abstract

Background: Loose Plant Architecture 1 (LPA1), an indeterminate domain (IDD) protein, exhibits almost no expression in the leaves, but the overexpression of LPA1 significantly increases the resistance of rice to sheath blight disease (ShB) via the activation of PIN-FORMED 1a (PIN1a). Results: In this study, we determined that Rhizoctonia solani infection significantly induced LPA1 expression in the leaves, and lpa1 was more susceptible to R. solani compared with the wild-type and revertant plants. In addition, infection with R. solani altered the expression of IDD3, IDD5, IDD10, and IDD13, and yeast two-hybrid, split-GFP, and coimmunoprecipitation assays showed that LPA1 interacts with IDD3 and IDD13. IDD13 RNAi plants were more susceptible, while IDD13 overexpressors were less susceptible to ShB compared with the wild-type. In parallel, idd3 exhibited no significant differences, while IDD3 overexpressors were more susceptible compared to the wild-type response to ShB. Additional chromatin-immunoprecipitation and electrophoretic mobility shift assay experiments indicated that IDD13 and IDD3 bound to the PIN1a promoter, and the transient assay indicated that IDD13 and IDD3 positively and negatively regulate PIN1a expression, respectively. Moreover, IDD13, IDD3, and LPA1 form a transcription factor complex that regulates PIN1a. A genetic study showed that the LPA1 repressor lines were similar to lpa1/IDD13 RNAi and were more susceptible than the lpa1 and IDD13 RNAi plants in response to ShB. The overexpression of IDD13 increased resistance to ShB in the lpa1 background.Conclusions: Taken together, our analyses established that IDD3, IDD13, and LPA1 form a transcription factor complex to regulate the defense of rice against ShB possibly via the regulation of PIN1a.

Strategies to Manage Rice Sheath Blight: Lessons from Interactions between Rice and Rhizoctonia solani

“…The G-protein γ subunit DEP1 (dense and erect panicle 1) interacts with LPA1 and suppresses DNA binding ability of LPA1 and thereby inhibiting expression of PIN1a. Consistently, mutation of G-protein γ subunit DEP1 can promote rice resistance to RSB (Liu et al 2020;Sun et al 2019;Sun et al 2020a). Furthermore, auxin application enhances rice resistance to sheath blight (Qiao et al 2020;Sun et al 2019).…”

“…The siR109944 -overexpressing rice plants have a significantly enhanced susceptibility to R. solani , while FBL55-overexpression causes the transgenic plants to be more resistant to RSB (Qiao et al 2020 ). Additionally, multiple indeterminate domain (IDD) proteins including LPA1 (Loose Plant Architecture 1), IDD3 and IDD13 form a transcription factor complex and regulate expression of the auxin efflux carrier gene PIN-FORMED 1a ( PIN1a ) in rice through binding to its promoter (Sun et al 2019 ; Sun et al 2020a ). Interestingly, LPA1 and IDD13 positively regulate PIN1a expression and RSB resistance, while IDD3 is a negative regulator in PIN1a expression and RSB resistance (Sun et al 2019 ; Sun et al 2020a ).…”

“…Additionally, multiple indeterminate domain (IDD) proteins including LPA1 (Loose Plant Architecture 1), IDD3 and IDD13 form a transcription factor complex and regulate expression of the auxin efflux carrier gene PIN-FORMED 1a ( PIN1a ) in rice through binding to its promoter (Sun et al 2019 ; Sun et al 2020a ). Interestingly, LPA1 and IDD13 positively regulate PIN1a expression and RSB resistance, while IDD3 is a negative regulator in PIN1a expression and RSB resistance (Sun et al 2019 ; Sun et al 2020a ). The G-protein γ subunit DEP1 (dense and erect panicle 1) interacts with LPA1 and suppresses DNA binding ability of LPA1 and thereby inhibiting expression of PIN1a .…”

“… Maize Ubiquitin 1 promoter, A. tumefaciens -mediated transformation Overexpression of LPA1 and IDD13 enhances rice defenses against sheath blight via the activation of PIN1a in rice. Sun et al ( 2019 ) Sun et al ( 2020a , 2020b ) DEP1 DEP1, a G-protein γ subunit, is a novel interactor of LPA1 and controls dense and erect panicle of rice. The knock-out mutant dep1 (PFG_3A-02648) was generated with T-DNA insertion.…”

Loose Plant Architecture 1-Interacting Kinesin-like Protein KLP Promotes Rice Resistance to Sheath Blight Disease

“…Overexpression of Loose Plant Architecture 1 (LPA1), containing an indeterminate domain (IDD), promoted the defense of rice against ShB via activation of PIN1a (Sun et al 2019). Furthermore, IDD13, IDD3, and the G-protein γ subunit DEP1 interact with LPA1 to differentially regulate the resistance of rice to ShB (Miao Liu et al 2020;Sun et al 2020). However, the mechanism by which LPA1 regulates resistance against ShB remains to be investigated.…”