Correction: Trichoderma-Plant Root Colonization: Escaping Early Plant Defense Responses and Activation of the Antioxidant Machinery for Saline Stress Tolerance

Abstract

Trichoderma spp. are versatile opportunistic plant symbionts which can colonize the apoplast of plant roots. Microarrays analysis of Arabidopsis thaliana roots inoculated with Trichoderma asperelloides T203, coupled with qPCR analysis of 137 stress responsive genes and transcription factors, revealed wide gene transcript reprogramming, proceeded by a transient repression of the plant immune responses supposedly to allow root colonization. Enhancement in the expression of WRKY18 and WRKY40, which stimulate JA-signaling via suppression of JAZ repressors and negatively regulate the expression of the defense genes FMO1, PAD3 and CYP71A13, was detected in Arabidopsis roots upon Trichoderma colonization. Reduced root colonization was observed in the wrky18/wrky40 double mutant line, while partial phenotypic complementation was achieved by over-expressing WRKY40 in the wrky18 wrky40 background. On the other hand increased colonization rate was found in roots of the FMO1 knockout mutant. Trichoderma spp. stimulate plant growth and resistance to a wide range of adverse environmental conditions. Arabidopsis and cucumber (Cucumis sativus L.) plants treated with Trichoderma prior to salt stress imposition show significantly improved seed germination. In addition, Trichoderma treatment affects the expression of several genes related to osmo-protection and general oxidative stress in roots of both plants. The MDAR gene coding for monodehydroascorbate reductase is significantly up-regulated and, accordingly, the pool of reduced ascorbic acid was found to be increased in Trichoderma treated plants. 1-Aminocyclopropane-1-carboxylate (ACC)-deaminase silenced Trichoderma mutants were less effective in providing tolerance to salt stress, suggesting that Trichoderma, similarly to ACC deaminase producing bacteria, can ameliorate plant growth under conditions of abiotic stress, by lowering ameliorating increases in ethylene levels as well as promoting an elevated antioxidative capacity.

Dissection of Trichoderma longibrachiatum-induced defense in onion (Allium cepa L.) against Fusarium oxysporum f. sp. cepa by target metabolite profiling

“…However, a significant variability in their PGPF traits was observed. T1 exhibited a significantly stronger P solubilization ( Supplementary Table S1) and much higher IAA induction (Supplementary Table S1), as compared with T2, suggesting that T1 might likely act through auxin-dependent mechanism as plant growth stimulator as reported for several PGPFs isolated earlier [9,32,33]. In agreement with this finding, T1-treatment enhanced germination of onion seeds, seedling weight and height when compared with T2-treatment and SDW-treated control (Fig.…”

“…3 and Supplementary Table S2) revealed a substantial accumulation in these metabolites in the T1-and T1+FOC-primed onion plants compared with control, which provides a building stone to the functional role of the Trichoderma-primed onion against ROS accumulation generated by abiotic or biotic stress. Our finding was in harmony with the work of Brotman et al, [32], which reported the activation of antioxidant systems in Trichoderma-Arabidopsis.…”

“…Little is known about the host mechanism that connects the Trichoderma root colonization to the metabolite dynamics, leading to activation of the plant developmental and stress responses. It's assumed that Trichoderma induces the activation of a signaling cascade that provokes a variety of responses, including accumulation of antimicrobial reactive oxygen species (ROS) and induction of defense-related secondary metabolites [32].…”

Detecting the Hormonal Pathways in Oilseed Rape behind Induced Systemic Resistance by Trichoderma harzianum TH12 to Sclerotinia sclerotiorum

“…Other studies have shown that different T . harzianum strains can induce systemic resistance against necrotrophic pathogens in different crops [15, 53–55]. …”

“…is soil-borne, versatile opportunistic plant symbiont that induces growth and resistance to a wide variety of phytopathogens [13, 15]. It has been reported that some Trichoderma spp., can stimulate ISR in crops via signaling molecules, such as jasmonic acid (JA), ethylene (ET), and salicylic acid (SA), to plant diseases caused by biotrophic or necrotrophic pathogens, such as S .…”