Sucrose uptake and metabolism in Trichoderma virens. Control of the association with plant roots is mediated by sucrose metabolism

VARGAS WA, CRUTCHER FK, KENERLEY CM (WAV, CORRESPONDING AUTHOR)

NEW PHYTOLOGIST

WILEY-BLACKWELL PUBLISHING, INC

Año: 2011 vol. 189 p. 777 - 798

0028-646X

?Sucrose exuded by plants into the rhizosphere is a crucial component for the symbiotic association between the beneficial fungus Trichoderma and plant roots. In this article we sought to identify and characterize the molecular basis of sucrose uptake into the fungal cells. ?Several bioinformatics tools enabled us to identify a plant-like sucrose transporter in the genome of T. virens Gv29-8 (TvSut). Gene expression profiles in the fungal cells were analyzed by Northern blotting and qRT-PCR. Biochemical and physiological studies were conducted on Gv29-8 and fungal strains impaired in the expression of TvSut. ?TvSut exhibits biochemical properties similar to those described for sucrose symporters from plants. The null expression of tvsu caused a detrimental effect on fungal growth when sucrose was the sole source of carbon in the medium, and also affected the expression of genes involved in the symbiotic association. ?Similar to plants, T. virens contains a highly specific sucrose/H+ symporter that is induced at early stages of root colonization. Our results suggest an active sucrose transference from the plant to the fungal cells during the beneficial associations. In addition, our expression experiments suggest the existence of a sucrose-dependent network in the fungal cells that regulates the symbiotic association.