Partial silencing of a hydroxy-methylglutaryl-CoA reductase-encoding gene in Trichoderma harzianum CECT 2413 results in a lower level of resistance to lovastatin and lower antifungal activity.
In the present article, we describe the cloning and characterization of the Trichoderma harzianum hmgR gene encoding a hydroxymethylglutaryl CoA reductase (HMGR), a key enzyme in the biosynthesis of terpene compounds. In T. harzianum, partial silencing of the hmgR gene gave rise to transformants with a higher level of sensitivity to lovastatin, a competitive inhibitor of the HMGR enzyme. In addition, these hmgR-silenced transformants produced lower levels of ergosterol than the wild-type strain in a minimal medium containing lovastatin. The silenced transformants showed a decrease in hmgR gene expression (up to a 8.4-fold, after 72h of incubation), together with an increase in the expression of erg7 (up to a 15.8-fold, after 72h of incubation), a gene involved in the biosynthesis of triterpenes. Finally, hmgR-silenced transformants showed a reduction in their antifungal activity against the plant-pathogen fungi Rhizoctonia solani and Fusarium oxysporum.
Cardoza
Rosa Elena
RE
Spanish-Portuguese Centre of Agricultural Research, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental Lab 208, Plaza Doctores de la Reina s/n, 37007 Salamanca, Spain.
Hermosa
María Rosa
MR
Vizcaíno
Juan Antonio
JA
González
Fran
F
Llobell
Antonio
A
Monte
Enrique
E
Gutiérrez
Santiago
S
D000898:Antibiosis; D003001:Cloning, Molecular; D025141:Drug Resistance, Fungal; D004875:Ergosterol / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics*; D005670:Fusarium / Q000502:physiology; D020868:Gene Silencing; D005800:Genes, Fungal; D006903:Hydroxymethylglutaryl CoA Reductases / Q000235:genetics*; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D008148:Lovastatin / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D012232:Rhizoctonia / Q000502:physiology; D013729:Terpenes / Q000378:metabolism; D014242:Trichoderma / Q000187:drug effects* / Q000502:physiology*
D005656:Fungal Proteins; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D013729:Terpenes; D008148:Lovastatin; D006903:Hydroxymethylglutaryl CoA Reductases; D004875:Ergosterol