The De-Etiolated 1 Homolog of Arabidopsis Modulates the ABA Signaling Pathway and ABA Biosynthesis in Rice

Plant Physiol. 2016 Jun;171(2):1259-76. doi: 10.1104/pp.16.00059. Epub 2016 May 2.

Abstract

DEETIOLATED1 (DET1) plays a critical role in developmental and environmental responses in many plants. To date, the functions of OsDET1 in rice (Oryza sativa) have been largely unknown. OsDET1 is an ortholog of Arabidopsis (Arabidopsis thaliana) DET1 Here, we found that OsDET1 is essential for maintaining normal rice development. The repression of OsDET1 had detrimental effects on plant development, and leaded to contradictory phenotypes related to abscisic acid (ABA) in OsDET1 interference (RNAi) plants. We found that OsDET1 is involved in modulating ABA signaling in rice. OsDET1 RNAi plants exhibited an ABA hypersensitivity phenotype. Using yeast two-hybrid (Y2H) and bimolecular fluorescence complementation assays, we determined that OsDET1 interacts physically with DAMAGED-SPECIFIC DNA-BINDING PROTEIN1 (OsDDB1) and CONSTITUTIVE PHOTOMORPHOGENIC10 (COP10); DET1- and DDB1-ASSOCIATED1 binds to the ABA receptors OsPYL5 and OsDDB1. We found that the degradation of OsPYL5 was delayed in OsDET1 RNAi plants. These findings suggest that OsDET1 deficiency disturbs the COP10-DET1-DDB1 complex, which is responsible for ABA receptor (OsPYL) degradation, eventually leading to ABA sensitivity in rice. Additionally, OsDET1 also modulated ABA biosynthesis, as ABA biosynthesis was inhibited in OsDET1 RNAi plants and promoted in OsDET1-overexpressing transgenic plants. In conclusion, our data suggest that OsDET1 plays an important role in maintaining normal development in rice and mediates the cross talk between ABA biosynthesis and ABA signaling pathways in rice.

MeSH terms

  • Abscisic Acid / biosynthesis*
  • Abscisic Acid / pharmacology
  • Arabidopsis Proteins / chemistry*
  • Darkness
  • Etiolation* / genetics
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant / drug effects
  • Genetic Pleiotropy / drug effects
  • Germination / drug effects
  • Germination / genetics
  • Green Fluorescent Proteins / metabolism
  • Intracellular Signaling Peptides and Proteins
  • Multiprotein Complexes / metabolism
  • Nuclear Proteins / chemistry*
  • Oryza / drug effects
  • Oryza / genetics
  • Oryza / metabolism*
  • Plant Leaves / drug effects
  • Plant Leaves / genetics
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plants, Genetically Modified
  • Protein Binding / drug effects
  • Proteolysis / drug effects
  • RNA Interference / drug effects
  • Seedlings / drug effects
  • Seedlings / genetics
  • Seedlings / growth & development
  • Sequence Homology, Amino Acid*
  • Signal Transduction* / drug effects
  • Signal Transduction* / genetics
  • Stress, Physiological / drug effects
  • Stress, Physiological / genetics
  • Transcriptome / genetics

Substances

  • Arabidopsis Proteins
  • DET1 protein, Arabidopsis
  • Intracellular Signaling Peptides and Proteins
  • Multiprotein Complexes
  • Nuclear Proteins
  • Plant Proteins
  • Green Fluorescent Proteins
  • Abscisic Acid