Effects of the phosphate-solubilizing fungus Talaromyces flavus on the development and efficiency of the Gigaspora rosea-Triticum aestivum symbiosis

Abstract

This study analyzed the interaction between thephosphate-solubilizing fungus (PSF) Talaromyces flavus andthe arbuscular mycorrhizal fungus (AMF) Gigaspora roseain vitro, and whether the in vivo application of T. flavuswas able to stimulate the efficiency of the symbiosis betweenG. rosea and wheat (Triticum aestivum). In vitro, the solublechemical substances released by T. flavus promoted the development of pre-infective mycelium from germinating AMFspores, increasing the length of each branch and the numberof branches. In vivo, the inoculation of T. flavus increasedplant wet and dry weight of mycorrhizal plants, regardless ofthe P conditions. AMF root colonization was inhibited underhigh P conditions but was promoted by T. flavus inoculation.The inoculation of T. flavus also improved the symbioticefficiency of mycorrhizal plants, measured as APA, and increased the total plant phosphate content and shoot:root phosphate ratio in mycorrhizal plants. To our knowledge, this is thefirst report where exudates produced by a PSF as T. flavuspromote pre-infective development, root colonization andsymbiotic efficiency of G. rosea in wheat. Finally, the roleof T. flavus in rhizosphere interactions is discussed.