Integration of semi-in vivoassays and multi-omics data reveals the effect of galloylated catechins on self-pollen tube inhibition in Camellia oleifera

Camelliaoil extracted from the seeds of Camellia oleiferaAbel. is a popular and high-quality edible oil, but its yield is limited by seed setting, which is mainly caused by self-incompatibility (SI). One of the obvious biological features of SI plants is the inhibition of self-pollen tubes; however, the underlying mechanism of this inhibition in C. oleiferais poorly understood. In this study, we constructed a semi-in vivopollen tube growth test (SIV-PGT) system that can screen for substances that inhibit self-pollen tubes without interference from the genetic background. Combined with multi-omics analysis, the results revealed the important role of galloylated catechins in self-pollen tube inhibition, and a possible molecular regulatory network mediated by UDP-glycosyltransferase(UGT) and serine carboxypeptidase-like(SCPL) was proposed. In summary, galloylation of catechins and high levels of galloylated catechins are specifically involved in pollen tube inhibition under self-pollination rather than cross-pollination, which provides a new understanding of SI in C. oleifera. These results will contribute to sexual reproduction research on C. oleiferaand provide theoretical support for improving Camelliaoil yield in production.