A quorum of mechano-sensing fungal consortia

Bacteria use a chemical language of Quorum sensing (QS) to assemble biofilms, coordinate infections and survive in harsh environmental conditions. We discovered a new type of QS in yeast that does not involve chemical signal but instead relies on mechanical contact detection between cells that is controlled by FLO11 adhesin and SLN1 histidine kinase. This quorum mechano-sensing (QMS) controls downstream gene expression in cell density-dependent manner to resolve growth conflicts in mixed fungal consortia based on asymmetries in FLO11 activity. FLO11 mediates SLN1 inhibition, providing an adaptive limiter for the cell-density dependent regulation of gene expression in the population of cells. Genetic deletion of FLO11 removes inhibition of SLN1, yielding spontaneous activation of gene expression. Our study reveals an alternative QS mechanism that links FLO11 and SLN1 to intracellular regulation of gene expression, challenging classical view of chemically-driven QS systems and providing new strategies for controlling cellular collectives. One-Sentence Summary Quorum macho sensing (QMS) mediates growth conflict resolution in mixed fungal consortia