Cell wall-degrading isoenzyme profiles of Trichoderma biocontrol strains show correlation with rDNA taxonomic species.
Trichoderma is known for being the most frequently used biocontrol agent in agriculture. A fundamental part of the Trichoderma antifungal system relies on a series of genes coding for a variety of extracellular lytic enzymes. Characterization of the polymorphism between five putative isoenzymatic activities [beta-1,3-glucanase (EC 3.2.1.39, EC 3.2.1.58), beta-1,6-glucanase (EC 3.2.1.75), cellulase (EC 3.2.1.4; EC 3.2.1.21, EC 3.2.1.91), chitinase (EC 3.2.1.30, EC 3.2.1.52), protease (EC 3.4.11; EC 3.4.13-19; EC 3.4.21-24, EC 3.4.99)] was carried out using 18 strains from three sections of Trichoderma. Of these, seven strains were from T. sect. Pachybasium, nine from T. sect. Trichoderma and two from T. sect. Longibrachiatum. Thirty-seven different alleles in total were identified: 13 for beta-1,3-glucanase, four for beta-1,6-glucanase, three for cellulase, eight for chitinase and nine for protease activity. A dendrogram (constructed by the unweighted pair group method with arithmetic averages) based on isoenzymatic data separated the 18 strains into three main enzymatic groups: T. harzianum, T. atroviride/T. viride/T. koningii and T. asperellum/T. hamatum/T. longibrachiatum. Isoenzymatic groupings obtained from biocontrol strains are discussed in relation to their phylogenetic location, based on their sequence of internal transcribed spacer 1 in ribosomal DNA and their antifungal activities.
Departamento de Microbiología y Genética, Centro Hispano Luso de Investigaciones Agrarias, Universidad de Salamanca, 37007 Salamanca, Spain.
Luis
L
Sanz
Manuel
M
Montero
Isabel
I
Grondona
Juan Antonio
JA
Vizcaíno
Antonio
A
Llobell
Rosa
R
Hermosa
Enrique
E
Monte
D000935:Antifungal Agents / Q000494:pharmacology*; D002473:Cell Wall / Q000378:metabolism*; D044602:Cellulases / Q000494:pharmacology; D002688:Chitinases / Q000494:pharmacology; D004275:DNA, Ribosomal / Q000145:classification / Q000235:genetics / Q000378:metabolism; D043326:Glucan 1,3-beta-Glucosidase / Q000494:pharmacology; D007527:Isoenzymes; D010447:Peptide Hydrolases / Q000494:pharmacology; D010572:Pest Control, Biological; D010802:Phylogeny; D011110:Polymorphism, Genetic; D014242:Trichoderma / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics
D000935:Antifungal Agents; D004275:DNA, Ribosomal; D007527:Isoenzymes; D044602:Cellulases; D002688:Chitinases; D043326:Glucan 1,3-beta-Glucosidase; D010447:Peptide Hydrolases