RHIZOPHERIC FUNGI ISOLATED FROM BLUEBERRY AND THEIR EFFECT ON THE DEVELOPMENT OF Arabidopsis thaliana L.

Abstract

Microorganisms present in their environment influence plant growth and can be mutualists, such as mycorrhizal-forming fungi; or nonmutualists, such as endophytic fungi. In this study, fungal species from the root and rhizospheric soil of blueberry (Vaccinium corymbosum L.) cultivated in the state of Michoacán, México were isolated in order to analyze their potential as promoters of plant development. Six fungal strains were molecularly identified by the internal transcribed spacer (ITS) regions of ribosomal DNA. Its ability to modify the development of Arabidopsis thaliana (Col 0) seedlings was evaluated through two experimental configurations (compartmentalized and non-compartmentalized Petri dishes), to investigate the influence of diffusible and volatile compounds on plant phenotype. Phialocephala fortinii and Mortierella alpina promoted growth of Arabidopsis thaliana especially in compartmentalized dishes, where an increase in the main root length (≥ 2 cm) and in the number of lateral roots (≥ 34) was observed, suggesting that volatile compounds are responsible for these increases. The selected plant-development promoter species were evaluated by ARR5::GUS and DR5::GUS reporter lines to estimate the response of genes to the accumulation of cytokinins and auxins in plant tissues. Results indicate that Phialocephala fortinii and Mortierella alpina act differentially on plant growth and represent a biological resource with great potential for use as biostimulants in current agriculture.