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

Camellia oil extracted from the seeds of Camellia oleifera Abel.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.oleifera is poorly understood.In this study,we constructed a semi-in vivo pollen 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.oleifera and provide theoretical support for improving Camellia oil yield in production.

Factors involved in the success of Castanea henryi stem cuttings in different cutting mediums and cutting selection periods

Chinquapin(Castanea henryi) is a dual-purpose tree species in China valued for as a source of timber and starch.We investigated the effect of four cutting mediums(pure vermiculite;peat:river sand at 3:1 v/v;peat:krasnozem at 1:1 v/v;and pure krasnozem) and three stem cutting periods(March,May,and July) on rooting performance of C.henryi cuttings.Different cutting periods and cutting mediums greatly influenced the rooting rate of C.henryi,ranging from 3.35 to 77.31%.Principal component analysis indicated that the best combination of cutting period and cutting medium was semi-hardwood cuttings(May cuttings)+krasnozem.Histological evidence indicated that adventitious root initials were present by week 5-6,and that the site of root primordia initiation was observed in the vascular cambium.Stem anatomical structures observed at different periods indicated that a xylem/radius ratio of29.90-37.42% and a fractured phloem fiber ring are indicative of rooting success.The relational model between rooting index and medium properties indicated that nutrient content and porosity significantly influenced callus production.However,pH strongly affected C.henryi root formation,with the Pearson correlation coefficients for May and July cuttings of-0.856 and-0.947,respectively.Our protocol is helpful to achieve mass clone propagation of improved C.henryi genotypes,thus overcoming a common hurdle in chinquapin breeding programs.