Study on the New Mechanism of Cucumber Pistil Fertility Regulation
Published:31 Jan.2023 Source:BAP
Pollen tube guidance within female tissues of flowering plants can be divided into preovular guidance, ovular guidance and a connecting stage called pollen tube emergence. As yet, no female factor has been identified to positively regulate this transition process.
Recently, a research paper entitled "Pollen tube emergence is mediated by ovary-expressed ALCATRAZ in cucumber" was published in Nature Communications, which revealed that the bHLH transcription factor ALCATRAZ (ALC) in cucumber positively mediated the "penetration" process of cucumber pollen tube in the pistil, and positively regulated the pistil fertility by promoting the expression of two rapid alkalizing factors, small peptide CsRALF4/19, in the ovary transmission channel.
In this study, it was found that an ovary-expressed bHLH transcription factor Cucumis sativus ALCATRAZ (CsALC) functions in pollen tube emergence in cucumber. CsALC knockout mutants showed diminished pollen tube emergence, extremely reduced entry into ovules, and a 95% reduction in female fertility. Further examination showed two rapid alkalinization factors CsRALF4 and CsRALF19 were less expressed in Csalc ovaries compared to WT.
In brief, CsALC regulates female fertility and promotes CsRALF4/19 expression in the ovary during pollen tube guidance in cucumber.