Upregulation of jasmonate biosynthesis and jasmonate-responsive genes in rice leaves in response to a bacterial pathogen mimic

Funct Integr Genomics. 2015 May;15(3):363-73. doi: 10.1007/s10142-014-0426-8. Epub 2014 Dec 12.

Abstract

Xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight of rice, secretes several cell wall degrading enzymes including cellulase (ClsA) and lipase/esterase (LipA). Prior treatment of rice leaves with purified cell wall degrading enzymes such as LipA can confer enhanced resistance against subsequent X. oryzae pv. oryzae infection. To understand LipA-induced rice defense responses, microarray analysis was performed 12 h after enzyme treatment of rice leaves. This reveals that 867 (720 upregulated and 147 downregulated) genes are differentially regulated (≥2-fold). A number of genes involved in defense, stress, signal transduction, and catabolic processes were upregulated while a number of genes involved in photosynthesis and anabolic processes were downregulated. The microarray data also suggested upregulation of jasmonic acid (JA) biosynthetic and JA-responsive genes. Estimation of various phytohormones in LipA-treated rice leaves demonstrated a significant increase in the level of JA-Ile (a known active form of JA) while the levels of other phytohormones were not changed significantly with respect to buffer-treated control. This suggests a role for JA-Ile in cell wall damage induced innate immunity. Furthermore, a comparative analysis of ClsA- and LipA-induced rice genes has identified key rice functions that might be involved in elaboration of damage-associated molecular pattern (DAMP)-induced innate immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / pharmacology*
  • Cellulase / pharmacology
  • Cyclopentanes / analysis
  • Cyclopentanes / metabolism*
  • Esterases / pharmacology
  • Gene Expression Regulation, Plant*
  • Immunity, Innate
  • Lipase / pharmacology
  • Oryza / drug effects
  • Oryza / genetics*
  • Oryza / immunology
  • Oryza / metabolism
  • Oxylipins / analysis
  • Oxylipins / metabolism*
  • Plant Leaves / chemistry
  • Plant Leaves / drug effects
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Salicylic Acid / analysis
  • Transcriptome
  • Up-Regulation

Substances

  • Bacterial Proteins
  • Cyclopentanes
  • LipA protein, Bacteria
  • Oxylipins
  • jasmonic acid
  • Esterases
  • Lipase
  • Cellulase
  • Salicylic Acid