Plant perception of β-aminobutyric acid is mediated by an aspartyl-tRNA synthetase Academic Article uri icon

abstract

  • Specific chemicals can prime the plant immune system for augmented defense. β-aminobutyric acid (BABA) is a priming agent that provides broad-spectrum disease protection. However, BABA also suppresses plant growth when applied in high doses, which has hampered its application as a crop defense activator. Here we describe a mutant of Arabidopsis thaliana that is impaired in BABA-induced disease immunity (ibi1) but is hypersensitive to BABA-induced growth repression. IBI1 encodes an aspartyl-tRNA synthetase. Enantiomer-specific binding of the R enantiomer of BABA to IBI1 primed the protein for noncanonical defense signaling in the cytoplasm after pathogen attack. This priming was associated with aspartic acid accumulation and tRNA-induced phosphorylation of translation initiation factor eIF2α. However, mutation of eIF2α-phosphorylating GCN2 kinase did not affect BABA-induced immunity but relieved BABA-induced growth repression. Hence, BABA-activated IBI1 controls plant immunity and growth via separate pathways. Our results open new opportunities to separate broad-spectrum disease resistance from the associated costs on plant growth.

authors

  • Luna, E
  • Van Hulten, M
  • Zhang, Y
  • Berkowitz, O
  • López, A
  • Pétriacq, P
  • Sellwood, MA
  • Chen, B
  • Burrell, M
  • Van De Meene, A
  • Pieterse, CMJ
  • Flors, V
  • Ton, J

publication date

  • 2014