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Chemical priming of immunity without costs to plant growth
Author(s) -
Buswell Will,
Schwarzenbacher Roland E.,
Luna Estrella,
Sellwood Matthew,
Chen Beining,
Flors Victor,
Pétriacq Pierre,
Ton Jurriaan
Publication year - 2018
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.15062
Subject(s) - jasmonic acid , salicylic acid , biology , plant immunity , plant defense against herbivory , plant disease resistance , biochemistry , mutant , botany , arabidopsis , gene
Summary β‐Aminobutyric acid ( BABA ) induces broad‐spectrum disease resistance, but also represses plant growth, which has limited its exploitation in crop protection. BABA perception relies on binding to the aspartyl‐ tRNA synthetase (Asp RS ) IBI 1, which primes the enzyme for secondary defense activity. This study aimed to identify structural BABA analogues that induce resistance without stunting plant growth. Using site‐directed mutagenesis, we demonstrate that the ( l )‐aspartic acid‐binding domain of IBI 1 is critical for BABA perception. Based on interaction models of this domain, we screened a small library of structural BABA analogues for growth repression and induced resistance against biotrophic Hyaloperonospora arabidopsidis ( Hpa ). A range of resistance‐inducing compounds were identified, of which ( R )‐β‐homoserine ( RBH ) was the most effective. Surprisingly, RBH acted through different pathways than BABA . RBH ‐induced resistance ( RBH ‐ IR ) against Hpa functioned independently of salicylic acid, partially relied on camalexin, and was associated with augmented cell wall defense. RBH ‐ IR against necrotrophic Plectosphaerella cucumerina acted via priming of ethylene and jasmonic acid defenses. RBH ‐ IR was also effective in tomato against Botrytis cinerea . Metabolic profiling revealed that RBH , unlike BABA , does not majorly affect plant metabolism. RBH primes distinct defense pathways against biotrophic and necrotrophic pathogens without stunting plant growth, signifying strong potential for exploitation in crop protection.