Seed treatment using methyl jasmonate induces resistance to rice water weevil but reduces plant growth in rice

PLoS One. 2019 Sep 23;14(9):e0222800. doi: 10.1371/journal.pone.0222800. eCollection 2019.

Abstract

The jasmonic acid cascade plays a pivotal role in induced plant resistance to herbivores. There have been a number of investigations into the potential uses of derivatives of this hormone for pest management. Understanding the phenotypic plasticity of plant defense traits interactions in agricultural systems may facilitate the development of novel and improved management practices, which is desirable as management of insects in most agricultural systems is currently heavily reliant on insecticides. The rice water weevil (RWW), Lissorhoptrus oryzophilus Kuschel, is a pest of rice, Oryza sativa, in the southern U.S. and globally. The effects of the jasmonic acid derivative, methyl jasmonate (MJ), on induced defenses to RWW in rice, and the potential costs of MJ-induced resistance to plant growth and fitness, were tested in a series of field and greenhouse trials. It was hypothesized that seed treatments with MJ would reduce densities of larval RWW. A second hypothesis was that MJ seed treatments would alter emergence, biomass accumulation, and yield of rice. The final hypothesis was that induction of plant resistance to the RWW would diminish as the time from seed treatment increased. In order to investigate these hypotheses, RWW densities were determined in greenhouse and field trials. Plant growth was measured in the field by assessing plant emergence, root and shoot biomass, time of heading, and yield (grain mass). Results indicated that MJ seed treatments induced resistance to RWW, although this effect decayed over time. Additionally, there were costs to plant growth and fitness; emergence and heading were delayed and biomass was reduced. Importantly, however, yields on a per-plant were not significantly reduced by MJ treatment. Overall, these results are promising and show the potential for the use of jasmonate elicitors as part of a pest management program in rice.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acetates / pharmacology*
  • Animals
  • Cyclopentanes / pharmacology*
  • Disease Resistance / drug effects
  • Insect Control / methods
  • Larva / drug effects
  • Larva / physiology
  • Oryza / drug effects*
  • Oryza / growth & development
  • Oryza / parasitology
  • Oxylipins / pharmacology*
  • Plant Development / drug effects
  • Plant Diseases / parasitology
  • Plant Growth Regulators / pharmacology
  • Seeds / drug effects*
  • Seeds / growth & development
  • Seeds / parasitology
  • Weevils / drug effects*
  • Weevils / physiology

Substances

  • Acetates
  • Cyclopentanes
  • Oxylipins
  • Plant Growth Regulators
  • methyl jasmonate

Grants and funding

MJS was supported by a grant from the Louisiana Rice Research Board and by the USDA National Institute of Food and Agriculture, Hatch project accession number 0218143. ECK was supported by a scholarship from the Louisiana Agricultural Consultants Association in 2017 and the Ray and Dorothy Young Endowed Assistantship in Agricultural Pest Management in 2018. Funders had no role in the design, data collection, analysis, decision to publish, or preparation of the manuscript.