Proteins Related to the Biocontrol of Pythium Damping-off in Maize with Trichoderma harzianum Rifai

Abstract

Induced resistance has been evidenced as one of mechanisms of Trichoderma to control plant diseases, however, no study showed the change of host proteomics in Trichoderma-induced resistance of maize against damping-off caused by Pythium ultimum Trow. The mechanism of Trichoderma harzianum Rifai for controlling maize seedling disease caused by Pythium ultimum Trow was investigated firstly by proteome technique and the result suggested that T. harzianum strain T22 was not only able to promote seedling growth but also protein accumulation. One-dimensional electrophoresis assay showed that more bands appeared on the gel with T22 or T22 combined with P. ultimum (T22 + P. ultimum) treatment than with other treatments. Enzyme assay showed that two chitinases of the root sample were more activated in the treatments with T22 than in the other treatments without T22. Proteins in the seedling roots from the various treatments were separated through protein extraction and 2-D electrophoresis technique. In the seedlings produced from the T22-treated seeds, there were 104 up-regulated proteins and 164 down-regulated proteins relative to the control, and 97 and 150, respectively, after treatment with T22 + P. ultimum; however, with P. ultimum alone the values were much lower than with the other two treatments. The correlation coefficient values were 0.72, 0.51 and 0.49 for the comparison of protein spot distribution on gel among control with T22, P. ultimum and T22 + P. ultimum, respectively. So it seemed that P. ultimum infection was more effective than T22 in interfering with the host proteome profile. Furthermore, analysis with MALDI-TOF-MAS showed that some important proteins associated with defensive reactions were identified in T22 or T22 + P. ultimum treatments, including endochitinase, pathogenesis-related protein PRMS (pathogenesisrelated maize seed), GTP-binding protein, isoflavone reductase and other proteins related to respiration. All those proteins are probably part of the network of resistance or development-related proteins. Interestingly, P. ultimum treatment resulted in elimination of pathogenesis-related protein PRMS on gel, and therefore damping-off could be in part attributed to inhibition of the expression of this protein by P. ultimum infection. Some unknown proteins are also related to the defensive reaction of the host.

Induced Systemic Resistance and Plant Responses to Fungal Biocontrol Agents

“…This local silencing of plant defense response probably enables symbiotic interactions, as has been observed for other symbiotic systems. Downregulation of the PR protein, PRMS, in roots by Trichoderma inoculation is in agreement with local silencing of defense to allow fungal growth into the roots (22). P. indica also seems to be able to silence root defense mechanisms and probably for the same reason.…”

Trichoderma harzianum- mediated reprogramming of oxidative stress response in root apoplast of sunflower enhances defence against Rhizoctonia solani

“…An example of BCAs are Trichoderma spp., which have been shown to induce local and systemic defence responses in cucumber (Segarra et al 2007;Viterbo et al 2005;Viterbo et al 2007;Yedidia et al 1999Yedidia et al , 2003 and other economically important agricultural crops, such as cotton, tobacco, lettuce, maize, chickpea and bell pepper (Ahmed et al 2000;Chen et al 2005;De Meyer et al 1998;Howell et al 2000;Singh et al 2007;Wilson et al 2008). Induced disease resistance is the phenomenon by which a plant mobilises its own defence mechanism to restrict disease development (Harman et al 2004).…”

The Molecular Basis of Shoot Responses of Maize Seedlings to Trichoderma harzianum T22 Inoculation of the Root: A Proteomic Approach

“…A mitogenactivated protein kinase, necessary for the process, was also potentiated similarly (Shoresh et al, 2006). Recent proteomic studies also demonstrate the involvement of defense-related proteins in plants inter-acting with Trichoderma (Chen et al, 2005;Marra et al, 2006;Djonovic et al, 2007).…”