Salicylate activity. 1. Protection of plants from paraquat injury

J Agric Food Chem. 2005 Dec 14;53(25):9764-8. doi: 10.1021/jf0513819.

Abstract

Paraquat (1,1'-dimethyl-4,4'-bipyridinium; methylviologen) is a widely used, nonselective contact herbicide that rapidly stimulates free radical generation. It has been found that the addition of sodium salicylate (sodium 2-hydroxybenzoate; NaSA) to paraquat spray solutions significantly decreased herbicidal activity. This protection was observed in tobacco (Nicotiana tabacum) regardless of whether NaSA was foliar-applied along with or prior to paraquat application or NaSA was soil-applied prior to paraquat application. Because salicylic acid (SA) is an inducer of systemic acquired resistance (SAR) to plant disease, paraquat protection by three SAR inducers (acibenzolar-S-methyl, harpin, and probenazole) and selected salicylate derivatives was assessed. Twenty-two of 24 compounds tested decreased herbicidal activity when foliar-applied with paraquat. Protection from paraquat was greatest with 5-chlorosalicylate, and no protection was observed with benzoic acid. NaSA decreased paraquat activity on npr1-2, an Arabidopsis mutant that is compromised in NaSA-induced SAR, and on ein2-1, an ethylene-insensitive Arabidopsis mutant. Thus, salicylate protection from paraquat is independent of disease resistance and ethylene perception. This suggests the existence of an NaSA-mediated pathway capable of protecting plants from reactive oxygen stress.

MeSH terms

  • Arabidopsis / drug effects
  • Ethylenes
  • Nicotiana / drug effects
  • Oxidative Stress / drug effects
  • Paraquat / pharmacology*
  • Plants / drug effects*
  • Sodium Salicylate / administration & dosage*
  • Solutions

Substances

  • Ethylenes
  • Solutions
  • ethylene
  • Paraquat
  • Sodium Salicylate