Indeterminate Domain Proteins Regulate Rice Defense to Sheath Blight Disease

Area of Science:

• Plant Pathology
• Molecular Biology
• Genetics

Background:

• Loose Plant Architecture 1 (LPA1) is an indeterminate domain (IDD) protein.
• LPA1 overexpression enhances rice resistance to sheath blight disease (ShB) by activating PIN-FORMED 1a (PIN1a).

Purpose of the Study:

• Investigate the role of LPA1 and other IDD proteins in rice defense against Rhizoctonia solani.
• Elucidate the molecular mechanism underlying LPA1-mediated ShB resistance.

Main Methods:

• Gene expression analysis (RT-qPCR).
• Yeast two-hybrid, split-GFP, and co-immunoprecipitation assays for protein interactions.
• Chromatin-immunoprecipitation and electrophoretic mobility shift assays for DNA binding.
• RNA interference (RNAi) and overexpression studies.
• Sheath blight disease assays.

Main Results:

• Rhizoctonia solani infection induced LPA1 expression in rice leaves.
• lpa1 mutants showed increased susceptibility to R. solani.
• LPA1 interacts with IDD3 and IDD13.
• IDD13 positively regulates ShB resistance, while IDD3 has a dual role.
• IDD13 and IDD3 bind to the PIN1a promoter, regulating its expression.
• LPA1, IDD3, and IDD13 form a complex regulating PIN1a.

Conclusions:

• A transcription factor complex involving IDD3, IDD13, and LPA1 regulates rice defense against ShB.
• This regulation is potentially mediated through the control of PIN1a expression.