Identification of fungus-responsive cis-acting element in the promoter of Brassica juncea chitinase gene, BjCHI1

Plant Sci. 2014 Feb;215-216:190-8. doi: 10.1016/j.plantsci.2013.11.008. Epub 2013 Nov 16.

Abstract

Chitinases are a group of pathogenesis-related proteins. The Brassica juncea chitinase gene BjCHI1 is highly inducible by pathogenic fungal infection, suggesting that the promoter of BjCHI1 might contain specific cis-acting element responsive to fungal attack. To identify the fungus-responsive element in BjCHI1 promoter (BjC-P), a series of binary plant transformation vectors were constructed by fusing the BjC-P or its deletion-derivatives to β-glucuronidase (GUS) reporter gene. Expression of the GUS reporter gene was systematically assayed by a transient gene expression system in Nicotiana benthamiana leaves treated with fungal elicitor Hexa-N-Acetyl-Chitohexaose, as well as in transgenic Arabidopsis plants inoculated with fungus Botrytis cinerea. The histochemical and quantitative GUS assays showed that the W-box-like element (GTAGTGACTCAT) in the region (-668 to -657) was necessary for the fungus-response, although there were another five W-box-like elements in BjC-P. In addition, gain-of-function analysis demonstrated that the fragment (-409 to -337) coupled to the W-box-like element was needed for full magnitude of the fungal induction. These results revealed the existence of a novel regulation mechanism of W-box-like element involved in plant pathogenic resistance, and will benefit the potential application of BjC-P in engineering crops.

Keywords: Fungal elicitor; Inducible promoter; Transient expression; W-box-like; cis-Acting element.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / microbiology
  • Botrytis
  • Chitinases / genetics*
  • Chitinases / metabolism
  • Disease Resistance / genetics*
  • Gene Expression Regulation, Plant*
  • Genes, Plant*
  • Genes, Reporter
  • Glucuronidase / genetics
  • Mustard Plant / genetics*
  • Mustard Plant / metabolism
  • Mustard Plant / microbiology
  • Oligosaccharides / pharmacology
  • Plant Diseases / genetics
  • Plant Diseases / microbiology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • Promoter Regions, Genetic*
  • Regulatory Sequences, Nucleic Acid*
  • Tobacco / drug effects
  • Tobacco / genetics

Substances

  • Oligosaccharides
  • Plant Proteins
  • N-acetylchitohexaose
  • Chitinases
  • Glucuronidase