Maize ZmRACK1 is involved in the plant response to fungal phytopathogens

Int J Mol Sci. 2014 May 26;15(6):9343-59. doi: 10.3390/ijms15069343.

Abstract

The receptor for activated C kinase 1 (RACK1) belongs to a protein subfamily containing a tryptophan-aspartic acid-domain (WD) repeat structure. Compelling evidence indicates that RACK1 can interact with many signal molecules and affect different signal transduction pathways. In this study, we cloned a maize RACK1 gene (ZmRACK1) by RT-PCR. The amino acid sequence of ZmRACK1 had seven WD repeats in which there were typical GH (glycine-histidine) and WD dipeptides. Comparison with OsRACK1 from rice revealed 89% identity at the amino acid level. Expression pattern analysis by RT-PCR showed that ZmRACK1 was expressed in all analyzed tissues of maize and that its transcription in leaves was induced by abscisic acid and jasmonate at a high concentration. Overexpression of ZmRACK1 in maize led to a reduction in symptoms caused by Exserohilum turcicum (Pass.) on maize leaves. The expression levels of the pathogenesis-related protein genes, PR-1 and PR-5, increased 2.5-3 times in transgenic maize, and reactive oxygen species production was more active than in the wild-type. Yeast two-hybrid assays showed that ZmRACK1 could interact with RAC1, RAR1 and SGT1. This study and previous work leads us to believe that ZmRACK1 may form a complex with regulators of plant disease resistance to coordinate maize reactions to pathogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cloning, Molecular
  • Gene Expression Regulation, Plant*
  • Plant Diseases / genetics*
  • Plant Diseases / microbiology*
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plant Leaves / microbiology
  • Plant Proteins / analysis
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Protein Interaction Maps
  • Receptors for Activated C Kinase
  • Receptors, Cell Surface / analysis
  • Receptors, Cell Surface / genetics*
  • Receptors, Cell Surface / metabolism
  • Up-Regulation
  • Zea mays / genetics*
  • Zea mays / metabolism
  • Zea mays / microbiology*

Substances

  • Plant Proteins
  • Receptors for Activated C Kinase
  • Receptors, Cell Surface