Root herbivore performance suppressed when feeding on a jasmonate‐induced pasture grass

Abstract

1. Plants defend themselves from insect herbivore attack using a range of physical and chemical defences which are in many cases regulated by phytohormones such as jasmonates. While much more is known about how jasmonates regulate defence against above‐ground herbivores (e.g. herbivores of leaves), there is increasing interest in how they influence below‐ground defences. 2. For the Poaceae, most below‐ground studies focus on highly domesticated cereals. Here it is demonstrated how exogenous application of methyl jasmonate (MeJA) to the leaf blades of a non‐domesticated pasture grass (Microlaena stipoides) caused a more than two‐fold decrease in relative growth rate (RGR) of a root‐feeding chafer (Dermolepida albohirtum). MeJA treatment did not affect root consumption rates, but substantially reduced the efficiency of conversion of ingested food to body mass. 3. Non‐targeted metabolomics identified significant changes in the metabolome of MeJA‐induced plants, with three compounds (a galactolipid, a trihydroxy fatty acid and a lysophospholipid) found to be correlated with herbivore RGR, although their roles in herbivore defence remain uncertain. 4. This study suggests that an important Australian pasture grass can become better defended against root herbivores via enhanced jasmonate activity.

Silicon supplementation and jasmonate activation synergistically increase phenolic defences against a legume herbivore

“…Three days before the feeding assay, half of the Si-supplemented plants were treated with methyl jasmonate (MeJA; 95%, Sigma Aldrich) by applying 1 mL of a solution of 100 µg mL -1 MeJA in Tween 20 ± 0.1% to the base of the stem at the surface of the soil with a pipette, as in Johnson et al (2018a). The other half were supplemented with 1 mL of Tween 20 only.…”

Silicon supplementation and jasmonate activation synergistically increase phenolic defences against a legume herbivore

“…The application of Si in the form of Na 2 SiO 3 could slightly increase soil concentrations of sodium (Na), though treatment concentrations were very low (1 mM) and plants would most likely be unaffected as uptake of Na tends to decrease as plants take up Si (Kafi & Rahimi, 2011). Three days before the feeding assay, half of the Si-supplemented plants were treated with methyl jasmonate (MeJA; 95%, Sigma Aldrich) by applying 1 mL of a solution of 100 μg mL −1 MeJA in 0.1% Tween 20 to the base of the stem at the surface of the soil with a pipette, as in Johnson, Glauser, et al (2018). The other half were supplemented with 1 mL of Tween 20 only.…”

ПЕРСПЕКТИВЫ ПРИМЕНЕНИЯ ЖАСМОНАТОВ, САЛИЦИЛАТОВ И АБСЦИЗОВОЙ КИСЛОТЫ В СЕЛЬСКОМ ХОЗЯЙСТВЕ ДЛЯ ПОВЫШЕНИЯ СТРЕССОУСТОЙЧИВОСТИ РАСТЕНИЙ (Обзор)

“…Karpets, 2021; W. Wang et al, 2018) and maintenance of the root zone microbiome (S. Lebeis et al, 2015). The range of regulatory effects of jasmonates is broad, but their functions are primarily associated with the regulation of mechanisms that determine plant tolerance to necrotrophic pathogens and insects, including root pests (C. Rohwer, J. Erwin, 2008; S. Johnson et al, 2018). Jasmonates also control plant tolerance to low temperature, salt stress, flooding, drought, ozone, heavy metals, and ultraviolet radiation (T. Savchenko Kim et al, 2021).…”

“…Регуляторные эффекты жасмонатов разнообразны, однако в первую очередь функции ЖК связывают с регуляцией механизмов, определяющих устойчивость растений к некротрофным патогенам и насекомым, включая вредителей корней (93,94). Растения, лишенные жасмонатов, очень чувствительны к действию этих биотических факторов среды.…”