Comparative study of Trichoderma gene expression in interactions with tomato plants using high-density oligonucleotide microarrays

dTrichothecenes are fungal sesquiterpenoid compounds, the majority of which have phytotoxic activity. They contaminate food and feed stocks, resulting in potential harm to animals and human beings. Trichoderma brevicompactum and T. arundinaceum produce trichodermin and harzianum A (HA), respectively, two trichothecenes that show different bioactive properties. Both compounds have remarkable antibiotic and cytotoxic activities, but in addition, trichodermin is highly phytotoxic, while HA lacks this activity when analyzed in vivo. Analysis of Fusarium trichothecene intermediates led to the conclusion that most of them, with the exception of the hydrocarbon precursor trichodiene (TD), have a detectable phytotoxic activity which is not directly related to the structural complexity of the intermediate. In the present work, the HA intermediate 12,13-epoxytrichothec-9-ene (EPT) was produced by expression of the T. arundinaceum tri4 gene in a transgenic T. harzianum strain that already produces TD after transformation with the T. arundinaceum tri5 gene. Purified EPT did not show antifungal or phytotoxic activity, while purified HA showed both antifungal and phytotoxic activities. However, the use of the transgenic T. harzianum tri4 strain induced a downregulation of defense-related genes in tomato plants and also downregulated plant genes involved in fungal root colonization. The production of EPT by the transgenic tri4 strain raised levels of erg1 expression and reduced squalene accumulation while not affecting levels of ergosterol. Together, these results indicate the complex interactions among trichothecene intermediates, fungal antagonists, and host plants.A number of Trichoderma species are known for the ability to act as important biocontrol agents against phytopathogenic fungi (1, 2). Trichoderma species are able to act as biofertilizers, to induce plant defense responses, and to increase tolerance to abiotic stresses (3, 4). Trichoderma arundinaceum and T. brevicompactum also produce trichothecenes, sesquiterpenoid compounds which are harmful to plants and to the animals which consume contaminated food or feed stocks. Several studies on the structure-activity relationships of Fusarium trichothecene toxins in alga, plant, and animal models (5-7) indicate that certain Fusarium trichothecenes and intermediates have different toxic effects. Using an Arabidopsis leaf assay, Desjardins and coworkers found that toxicity varied Ͼ200-fold between different trichothecene compounds, while trichodiene (TD), a hydrocarbon precursor, was not phytotoxic (6).Biosynthesis of trichothecenes starts with the cyclization of farnesyl diphosphate (FPP), catalyzed by the terpene cyclase trichodiene synthase encoded by tri5 (8), to produce TD. In Trichoderma, TD is then oxygenated at C-2, C-11, and C-13 by a P450 monooxygenase encoded by tri4 (9, 10) to give the intermediate isotrichodiol, which is nonenzymatically converted to 12,13-epoxytrichothec-9-ene (EPT). The oxygenation of these three carbons is a characteristic that Trichoderma...

Section: Methodsmentioning

confidence: 99%

Effects of Trichothecene Production on the Plant Defense Response and Fungal Physiology: Overexpression of the Trichoderma arundinaceum tri4 Gene in T. harzianum

Cardoza

McCormick

Malmierca

et al. 2015

“…T. parareesei-tomato hydroponic cultures were carried out as previously described (15). Briefly, T6 was cultured in minimal medium (MM) (30) containing 2% glucose at 28°C with stirring for 48 h. The mycelium was then collected, washed, and used to inoculate Phytatray II boxes (Sigma-Aldrich, Madrid, Spain) containing 2-week-old tomato plants in Murashige-Skoog (MS) medium (Duchefa Biochemie BV, Haarlem, The Netherlands) supplemented with 1% (wt/vol) sucrose, pH 5.7.…”

Section: Methodsmentioning

confidence: 99%

“…In addition, Trichoderma strains are also able to stimulate defense responses in plants, inducing resistance to biotic and abiotic stresses, and to promote plant growth (5)(6)(7). Several studies have reported the responses of plants to the presence of a rootcolonizing Trichoderma biocontrol strain (8)(9)(10)(11)(12), and investigations describing the Trichoderma transcriptomic changes elicited by plants using macroarray (13,14) and microarray (15,16) analyses have been performed with biocontrol species.…”

mentioning

confidence: 99%

Identifying Beneficial Qualities of Trichoderma parareesei for Plants

Rubio

Quijada

Pérez

et al. 2014

Self Cite

104

Trichoderma parareesei and Trichoderma reesei (teleomorph Hypocrea jecorina) produce cellulases and xylanases of industrial interest. Here, the anamorphic strain T6 (formerly T. reesei) has been identified as T. parareesei, showing biocontrol potential against fungal and oomycete phytopathogens and enhanced hyphal growth in the presence of tomato exudates or plant cell wall polymers in in vitro assays. A Trichoderma microarray was used to examine the transcriptomic changes in T6 at 20 h of interaction with tomato plants. Out of a total 34,138 Trichoderma probe sets deposited on the microarray, 250 showed a significant change of at least 2-fold in expression in the presence of tomato plants, with most of them being downregulated. T. parareesei T6 exerted beneficial effects on tomato plants in terms of seedling lateral root development, and in adult plants it improved defense against Botrytis cinerea and growth promotion under salt stress. Time course expression patterns (0 to 6 days) observed for defense-related genes suggest that T6 was able to prime defense responses in the tomato plants against biotic and abiotic stresses. Such responses undulated, with a maximum upregulation of the jasmonic acid (JA)/ethylene (ET)-related LOX1 and EIN2 genes and the salt tolerance SOS1 gene at 24 h and that of the salicylic acid (SA)-related PR-1 gene at 48 h after T6 inoculation. Our study demonstrates that the T. parareesei T6-tomato interaction is beneficial to both partners.

“…Tomato-Trichoderma hydroponic cultures were carried out as previously described (45). First, sterile tomato seeds were placed inside Phytatray II boxes (Sigma, St. Louis, MO) (30 seeds per box) on a sterile gauze sheet over a sterile stainless steel screen, which held them 1 cm above 100 ml of Murashige and Skoog (MS) medium (Duchefa, Netherlands), and maintained at 25°C in a plant growth chamber with controlled light and humidity, as described above, for 2 weeks.…”

Section: Methodsmentioning

confidence: 99%

Involvement of Trichoderma Trichothecenes in the Biocontrol Activity and Induction of Plant Defense-Related Genes

Malmierca

Cardoza

Alexander

et al. 2012

150

130

cTrichoderma species produce trichothecenes, most notably trichodermin and harzianum A (HA), by a biosynthetic pathway in which several of the involved proteins have significant differences in functionality compared to their Fusarium orthologues. In addition, the genes encoding these proteins show a genomic organization differing from that of the Fusarium tri clusters. Here we describe the isolation of Trichoderma arundinaceum IBT 40837 transformants which have a disrupted or silenced tri4 gene, a gene encoding a cytochrome P450 monooxygenase that oxygenates trichodiene to give rise to isotrichodiol, and the effect of tri4 gene disruption and silencing on the expression of other tri genes. Our results indicate that the tri4 gene disruption resulted in a reduced antifungal activity against Botrytis cinerea and Rhizoctonia solani and also in a reduced ability to induce the expression of tomato plant defense-related genes belonging to the salicylic acid (SA) and jasmonate (JA) pathways against B. cinerea, in comparison to the wild-type strain, indicating that HA plays an important function in the sensitization of Trichoderma-pretreated plants against this fungal pathogen. Additionally, the effect of the interaction of T. arundinaceum with B. cinerea or R. solani and with tomato seedlings on the expressions of the tri genes was studied.