Phytohormone Production Profiles in Trichoderma Species and Their Relationship to Wheat Plant Responses to Water Stress (original) (raw)

The production of eight phytohormones by Trichoderma species is described, as well as the 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (ACCD) activity, which diverts the ethylene biosynthetic pathway in plants. The use of the Trichoderma strains T. virens T49, T. longibrachiatum T68, T. spirale T75 and T. harzianum T115 served to demonstrate the diverse production of the phytohormones gibberellins (GA) GA1 and GA4, abscisic acid (ABA), salicylic acid (SA), auxin (indole-3-acetic acid: IAA) and the cytokinins (CK) dihydrozeatin (DHZ), isopenteniladenine (iP) and trans-zeatin (tZ) in this genus. Such production is dependent on strain and/or culture medium. These four strains showed different degrees of wheat root colonization. Fresh and dry weights, conductance, H2O2 content and antioxidant activities such as superoxide dismutase, peroxidase and catalase were analyzed, under optimal irrigation and water stress conditions, on 30-days-old wheat plants treated with four-day-old ...