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The Bacillus subtilis germinant receptor GerA triggers premature germination in response to morphological defects during sporulation
Author(s) -
RamírezGuadiana Fernando H.,
Meeske Alexander J.,
Wang Xindan,
Rodrigues Christopher D. A.,
Rudner David Z.
Publication year - 2017
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13728
Subject(s) - bacillus subtilis , biology , spore , mutant , spore germination , germination , budding , receptor , phenotype , microbiology and biotechnology , wild type , population , genetics , gene , botany , bacteria , sociology , demography
Summary During sporulation in Bacillus subtilis , germinant receptors assemble in the inner membrane of the developing spore. In response to specific nutrients, these receptors trigger germination and outgrowth. In a transposon‐sequencing screen, we serendipitously discovered that loss of function mutations in the gerA receptor partially suppress the phenotypes of > 25 sporulation mutants. Most of these mutants have modest defects in the assembly of the spore protective layers that are exacerbated in the presence of a functional GerA receptor. Several lines of evidence indicate that these mutants inappropriately trigger the activation of GerA during sporulation resulting in premature germination. These findings led us to discover that up to 8% of wild‐type sporulating cells trigger premature germination during differentiation in a GerA‐dependent manner. This phenomenon was observed in domesticated and undomesticated wild‐type strains sporulating in liquid and on solid media. Our data indicate that the GerA receptor is poised on a knife's edge during spore development. We propose that this sensitized state ensures a rapid response to nutrient availability and also elicits premature germination of spores with improperly assembled protective layers resulting in the elimination of even mildly defective individuals from the population.