Investigating the Impact Trichoderma virens on Maize Phytohormones During Drought, Salt, and Cold Stress

Abiotic stresses are becoming increasingly frequent and severe due to climate change, leading to significant reductions in crop yields. Though sessile, plants are not defenseless. They can invite plant-growth promoting microbes to colonize their rhizosphere and help reprogram their chemical defense systems. Through these partnerships, plants can more rapidly and robustly recover from environmental stressors compared to those grown in isolation. In this study, the role of the beneficial microbe Trichoderma virens in phytohormone production was explored in maize, a globally important staple crop, under drought, salt, and cold stress, with or without microbial inoculation. Using a liquid chromatography mass spectrometer (LC MS), key signaling molecules such as abscisic acid (ABA), indole-3-acetic acid (IAA), salicylic acid (SA), and jasmonic acid (JA), as well as metabolic precursors such as cinnamic acid (CA), p Coumaric acid, 12-oxo-phytodienoic acid (12-OPDA) and other oxylipins like 13(S)-Hydroperoxy-9(Z),11(E)-octadecadienoic acid (13 HPOD), 13(S)-Hydroperoxy-9(Z),11(E),15(Z)-octadecatrienoic acid (13 HPOT), and 13-oxo-tridecadienoic acid (13 OTD) were characterized for any pattern with any of the stressors. T. virens may not have had a pronounced effect on signaling molecule production during cold stress, but during drought and salt stress moderately elevated levels of ABA, CA, p-Coumaric acid, and SA, along with strong jasmonates responses, particularly JA and 12 OH JA Phe made up the profile of this microbe’s signaling molecule response to abiotic stress in maize.