A substitution mutation in OsPELOTA confers bacterial blight resistance by activating the salicylic acid pathway

J Integr Plant Biol. 2018 Feb;60(2):160-172. doi: 10.1111/jipb.12613. Epub 2018 Jan 17.

Abstract

We previously reported a spotted-leaf mutant pelota (originally termed HM47) in rice displaying arrested growth and enhanced resistance to multiple races of Xanthomonas oryzae pv. oryzae. Here, we report the map-based cloning of the causal gene OsPELOTA (originally termed splHM47 ). We identified a single base substitution from T to A at position 556 in the coding sequence of OsPELOTA, effectively mutating phenylalanine to isoleucine at position 186 in the translated protein sequence. Both functional complementation and over-expression could rescue the spotted-leaf phenotype. OsPELOTA, a paralogue to eukaryotic release factor 1 (eRF1), shows high sequence similarity to Drosophila Pelota and also localizes to the endoplasmic reticulum and plasma membrane. OsPELOTA is constitutively expressed in roots, leaves, sheaths, stems, and panicles. Elevated levels of salicylic acid and decreased level of jasmonate were detected in the pelota mutant. RNA-seq analysis confirmed that genes responding to salicylic acid were upregulated in the mutant. Our results indicate that the rice PELOTA protein is involved in bacterial leaf blight resistance by activating the salicylic acid metabolic pathway.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cell Membrane / metabolism
  • Chromosome Mapping
  • Cloning, Molecular
  • Conserved Sequence
  • Disease Resistance / genetics*
  • Endoplasmic Reticulum / metabolism
  • Gene Expression Regulation, Plant
  • Genetic Complementation Test
  • Green Fluorescent Proteins / metabolism
  • Mutation / genetics*
  • Oryza / genetics*
  • Oryza / microbiology*
  • Phenotype
  • Phylogeny
  • Plant Diseases / genetics*
  • Plant Diseases / microbiology*
  • Plant Leaves / anatomy & histology
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plant Proteins / chemistry
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Protein Transport
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Salicylic Acid / metabolism*

Substances

  • Plant Proteins
  • RNA, Messenger
  • Green Fluorescent Proteins
  • Salicylic Acid