Application of Plant-Growth-Promoting Fungi Trichoderma longibrachiatum T6 Enhances Tolerance of Wheat to Salt Stress through Improvement of Antioxidative Defense System and Gene Expression

Abstract

Soil salinity is a serious problem worldwide that reduces agricultural productivity. Trichoderma longibrachiatum T6 (T6) has been shown to promote wheat growth and induce plant resistance to parasitic nematodes, but whether the plant-growth-promoting fungi T6 can enhance plant tolerance to salt stress is unknown. Here, we determined the effect of plant-growth-promoting fungi T6 on wheat seedlings’ growth and development under salt stress, and investigated the role of T6 in inducing the resistance to NaCl stress at physiological, biochemical, and molecular levels. Wheat seedlings were inoculated with the strain of T6 and then compared with non-inoculated controls. Shoot height, root length, and shoot and root weights were measured on 15 days old wheat seedlings grown either under 150 mM NaCl or in a controlled setting without any NaCl. A number of colonies were re-isolated from the roots of wheat seedlings under salt stress. The relative water content in the leaves and roots, chlorophyll content, and root activity were significantly increased, and the accumulation of proline content in leaves was markedly accelerated with the plant growth parameters, but the content of leaf malondialdehyde under saline condition was significantly decreased. The antioxidant enzymes-superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in wheat seedlings were increased by 29, 39, and 19%, respectively, with the application of the strain of T6 under salt stress; the relative expression of SOD, POD, and CAT genes in these wheat seedlings were significantly up-regulated. Our results indicated that the strain of T6 ameliorated the adverse effects significantly, protecting the seedlings from salt stress during their growth period. The possible mechanisms by which T6 suppresses the negative effect of NaCl stress on wheat seedling growth may be due to the improvement of the antioxidative defense system and gene expression in the stressed wheat plants.

Effect of Trichoderma viride pre‐inoculation in pine species with different levels of susceptibility to Fusarium circinatum: physiological and hormonal responses

“…However, an increase in the speed of symptom appearance and internal stem necrosis was found in P. radiata inoculated with T. viride prior to challenge with F. circinatum , and several parameters were influenced either by amplifying its response (lower water potential and A , higher C i ) or by revealing novel responses not reported in plants inoculated exclusively with F. circinatum (decrease in RWC, increase in EL and SA concentration). Moreover, although P. radiata RWC increased upon T. viride inoculation, as verified in wheat in the presence of Trichoderma longibrachiatum (Zhang et al , ), when both fungi co‐occurred a reverse response was found.…”

“…Based on the literature, either a beneficial or neutral effect of Trichoderma on Pinus response against F. circinatum would be expected (reviewed by Mart ın-Garc ıa et al, 2019). However, an increase in the speed of symptom appearance and internal stem necrosis was found in P. radiata inoculated with T. viride prior to challenge with F. circinatum, and several parameters were influenced either by amplifying its response (lower water potential and A, higher C i ) or by revealing novel (Zhang et al, 2016), when both fungi co-occurred a reverse response was found. Although Shemakhanova (1962) reported that T. viride may reduce mycorrhiza formation and seedling growth in woody plants, the time elapsed between T. viride and F. circinatum inoculations in the present study (2 weeks) seems too short to shift the plant natural microbiome and suppress immunity.…”

“…Trichoderma is one of the most studied BCAs in plants, being part of several commercial formulations. This may be explained by its antimicrobial activity arising from mechanisms such as antibiosis, mycoparasitism and/or competition (Zeilinger et al , ); ability to induce systemic resistance and plant defence (Hermosa et al , ); positive effects on seed germination and plant growth (Zhang et al , ); and versatility and cosmopolitan distribution (Hermosa et al , ). However, although the beneficial role of Trichoderma on plant growth and productivity is universally accepted, some negative effects have also been reported (Menzies, ; Marín‐Guirao et al , ).…”

Phosphorus-solubilizing Trichoderma spp. from Amazon soils improve soybean plant growth

“…Triple superphosphate, a readily available source in the soil, presented the most promising result because the analysis was performed twenty days after the planting of the crop, a result that was already expected. Some authors have demonstrated the increase on chlorophyll level due the presence of Trichoderma on different cultures as cucumber, wheat, soybean and lettuce plants [59][60][61][62] .…”

Expression of Sucrose Transporters from Vitis vinifera Confer High Yield and Enhances Drought Resistance in Arabidopsis

“…Then, ddH 2 O was added to the samples until the extract solutions reached a final volume of 100 mL for grape berries and 10 mL for A. thaliana leaves. Measurements were performed as previously described with some modifications [54,55]. A 0.5 mL aliquot of extract solution was mixed with 5 mL of 4% anthrone solution (dissolved in 88% concentrated sulfuric acid) and incubated in a 90 • C water bath for 15 min.…”