PubMed · 2026-03-19
Scientists discovered that a plant hormone called jasmonate controls whether cucumber flowers open properly and whether pollen is viable. They also mapped out the chain of molecular switches that carry this hormone's signal into the cell machinery that builds healthy stamens.
Cucumber plants unable to produce jasmonate (the Csopr3 mutant) had flowers that failed to open and pollen that ruptured and became nonviable.
Applying a synthetic form of jasmonate (MeJA) to deficient mutants fully rescued normal flower opening, anther dehiscence, and pollen germination ability.
A regulatory cascade was identified: the protein CsMYC2 activates two WRKY transcription factors (CsWRKY45 and CsWRKY57), which in turn suppress CsXTH33, a cell-wall remodeling gene that otherwise impairs stamen fertility.
