Exogenous methyl jasmonate regulates cytokinin content by modulating cytokinin oxidase activity in wheat seedlings under salinity

J Plant Physiol. 2016 Feb 1:191:101-10. doi: 10.1016/j.jplph.2015.11.013. Epub 2015 Dec 9.

Abstract

The treatment of 4-days-old wheat seedlings with methyl jasmonate (MeJA) in concentration optimal for their growth (0.1 μM) resulted in a rapid transient almost two-fold increase in the level of cytokinins (CKs). MeJA-induced accumulation of CKs was due to inhibition of both cytokinin oxidase (CKX) (cytokinin oxidase/dehydrogenase, EC 1.5.99.12) gene expression and activity of this enzyme. Pretreatment of wheat seedlings with MeJA decreased the growth-retarding effect of sodium chloride salinity and accelerated growth recovery after withdrawal of NaCl from the incubation medium. We speculate that this protective effect of the hormone might be due to MeJA's ability to prevent the salinity-induced decline in CK concentration that was caused by inhibition of gene expression and activity of CKX in wheat seedlings. The data might indicate an important role for endogenous cytokinins in the implementation of growth-promoting and protective effects of exogenous MeJA application on wheat plants.

Keywords: Cytokinin; Cytokinin oxidase; Methyl jasmonate; Salinity; Triticum aestivum L..

MeSH terms

  • Acetates / pharmacology*
  • Biomass
  • Cyclopentanes / pharmacology*
  • Cytokinins / metabolism*
  • Electrolytes / metabolism
  • Gene Expression Regulation, Plant / drug effects
  • Mitotic Index
  • Oxidoreductases / genetics
  • Oxidoreductases / metabolism*
  • Oxylipins / pharmacology*
  • Plant Growth Regulators / metabolism
  • Salinity*
  • Seedlings / drug effects
  • Seedlings / enzymology*
  • Triticum / drug effects
  • Triticum / enzymology*
  • Triticum / genetics

Substances

  • Acetates
  • Cyclopentanes
  • Cytokinins
  • Electrolytes
  • Oxylipins
  • Plant Growth Regulators
  • methyl jasmonate
  • Oxidoreductases
  • cytokinin oxidase