Trichoderma harzianum

About: Trichoderma harzianum is a research topic. Over the lifetime, 4731 publications have been published within this topic receiving 96796 citations.

Trichoderma harzianumのキチン分解酵素:純化したキトビオシダーゼとエンドキチナーゼ

Abstract: Trichoderma harzianum strain P1 produces a variety of chitinolytic enzymes including N-acetyl-β-D-glucosaminidases, chitin 1,4-β-chitobiosidases, and an endochitinase. Chitabiosidases and an endochitinase were purified from dialyzed, concentrated culture filtrates using gel filtration, chromatofocusing, and isoelectric focusing. Three protein bands were evident in the purified chitobiosidase preparation, representing different levels of N-glycosylation of the same protein. The pI of all purified proteins was ∼3.9 []

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

Abstract: Trichoderma spp. are effective biocontrol agents for several soil-borne plant pathogens, and some are also known for their abilities to enhance systemic resistance to plant diseases and overall plant growth. Root colonization with Trichoderma harzianum Rifai strain 22 (T22) induces large changes in the proteome of shoots of maize (Zea mays) seedlings, even though T22 is present only on roots. We chose a proteomic approach to analyze those changes and identify pathways and genes that are involved in these processes. We used two-dimensional gel electrophoresis to identify proteins that are differentially expressed in response to colonization of maize plants with T22. Up- or down-regulated spots were subjected to tryptic digestion followed by identification using matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry and nanospray ion-trap tandem mass spectrometry. We identified 91 out of 114 up-regulated and 30 out of 50 down-regulated proteins in the shoots. Classification of these revealed that a large portion of the up-regulated proteins are involved in carbohydrate metabolism and some were photosynthesis or stress related. Increased photosynthesis should have resulted in increased starch accumulation in seedlings and did indeed occur. In addition, numerous proteins induced in response to Trichoderma were those involved in stress and defense responses. Other processes that were up-regulated were amino acid metabolism, cell wall metabolism, and genetic information processing. Conversely, while the proteins involved in the pathways noted above were generally up-regulated, proteins involved in other processes such as secondary metabolism and protein biosynthesis were generally not affected. Up-regulation of carbohydrate metabolism and resistance responses may correspond to the enhanced growth response and induced resistance, respectively, conferred by the Trichoderma inoculation.

Molecular Characterization and Identification of Biocontrol Isolates of Trichoderma spp.

Abstract: The most common biological control agents (BCAs) of the genus Trichoderma have been reported to be strains of Trichoderma virens, T. harzianum, and T. viride. Since Trichoderma BCAs use different mechanisms of biocontrol, it is very important to explore the synergistic effects expressed by different genotypes for their practical use in agriculture. Characterization of 16 biocontrol strains, previously identified as "Trichoderma harzianum" Rifai and one biocontrol strain recognized as T. viride, was carried out using several molecular techniques. A certain degree of polymorphism was detected in hybridizations using a probe of mitochondrial DNA. Sequencing of internal transcribed spacers 1 and 2 (ITS1 and ITS2) revealed three different ITS lengths and four different sequence types. Phylogenetic analysis based on ITS1 sequences, including type strains of different species, clustered the 17 biocontrol strains into four groups: T. harzianum-T. inhamatum complex, T. longibrachiatum, T. asperellum, and T. atroviride-T. koningii complex. ITS2 sequences were also useful for locating the biocontrol strains in T. atroviride within the complex T. atroviride-T. koningii. None of the biocontrol strains studied corresponded to biotypes Th2 or Th4 of T. harzianum, which cause mushroom green mold. Correlation between different genotypes and potential biocontrol activity was studied under dual culturing of 17 BCAs in the presence of the phytopathogenic fungi Phoma betae, Rosellinia necatrix, Botrytis cinerea, and Fusarium oxysporum f. sp. dianthi in three different media.

Interactions Between Trichoderma harzianum Strain T22 and Maize Inbred Line Mo17 and Effects of These Interactions on Diseases Caused by Pythium ultimum and Colletotrichum graminicola

Abstract: Seed treatment with Trichoderma harzianum strain T22, which results in colonization of plant roots but little or no colonization of shoots or leaves, had substantial effects on growth of and disease expression in maize inbred line Mo17. Shoots and roots of 10-day-old seedlings grown in a sandy loam field soil were larger (roots were nearly twice as long) in the presence of T22 than in its absence. Both main and secondary roots were increased in size and area and the root hair area was greater with T22. However, root hair area per unit of root length was greater in control plants. Increased growth probably was due to direct stimulation of plant growth in addition to effects from biological control of deleterious microflora. Seedlings of Mo17 grown in autoclaved or mefenoxamtreated sandy loam field soil were larger than those produced in untreated soil. However, seedlings grown in the presence of T22, either in treated or untreated soil, were larger than those produced in its absence. Infestation o...