It is known that cytoskeleton-dependent trafficking of cell wall and membrane components to apical plasma membrane （PM） coupled with ion transport across pollen PM is crucial for maintaining polar pollen tube growth...It is known that cytoskeleton-dependent trafficking of cell wall and membrane components to apical plasma membrane （PM） coupled with ion transport across pollen PM is crucial for maintaining polar pollen tube growth. To elucidate whether plant hormones are involved in these processes, the effects of exogenous phytohormones, indole-3-acetic acid （IAA）, abscisic acid （ABA）, gibberellin A3 （GA3） and cytokinin （kinetin） on the growth, PM polarization, actin cytoskeleton （AC） organization and cytoplasmic pH （pile） of in vitro 4 h-growing petunia pollen tubes were investigated. IAA, ABA and GA3 displayed the growth-stimulating effects and these were accompanied by orthovanadate-sensitive hyperpolarization of the PM. Fluorescent labeling the enzyme with H＋-ATPase antibodies exhibited IAA- and ABA-induced lateral PM redistribution of it into the subapical zone of pollen tube PM. Pollen cultivation on the medium with latrunculin B, the inhibitor of actin polymerization, resulted in inhibition of pollen tube growth and simultaneously in the drop of endogenous IAA content. The IAA-growth stimulating effect was correlated with increased content of actin filaments （AF） in both apical and subapical zones of tubes, while ABA and GA3 exerted the same effect but it was accompanied by redistributing F-actin only to apical zone. In contrast, kinetin decreased the total F-actin content and inhibited pollen tube growth. It has been shown that the pHe of growing pollen tubes is sensitive to the plant hormones. In the case of male gametophyte growing for 1, 2 and 4 h, IAA induced alkalinization of the cytosol, while ABA and GA3 exerted qualitatively similar effect only after its growth for 1 h and 4 h, respectively. Kinetin, in contrast, resulted in acidification of the cytosol. All these results, taken together, indicate, for the first time, potential targets of the phytohormone action in pollen tubes.展开更多
Human fallopian tubes(FTs)play important roles in the whole reproductive process.FTs are the site for the final maturation of gametes,fertilization,transport of preimplantation embryos,and early embryonic development ...Human fallopian tubes(FTs)play important roles in the whole reproductive process.FTs are the site for the final maturation of gametes,fertilization,transport of preimplantation embryos,and early embryonic development before entering the uterus.All these functions are critical in the establishment of a successful pregnancy.When the embryo is in transit through the FT,the FT microenvironment changes through endocrine,paracrine,autocrine,and juxtacrine mechanisms which involve various hormones and bioactive substances mainly from the neighboring cells.Therefore,the interactions between the embryo and the FT may be the earliest embryo-maternal communications that are essential for the establishment of pregnancy.This review critically discusses the evidence of various hormonal and bioactive mediated control of the microenvironment in the FTs during the earliest embryo-maternal communications.Moreover,we highlight existing gaps in the knowledge and the importance of exploring more of the physiology of FTs which will hold the key to producing high-quality embryos for patients seekingin vitro fertilization(IVF)treatments.展开更多
文摘It is known that cytoskeleton-dependent trafficking of cell wall and membrane components to apical plasma membrane （PM） coupled with ion transport across pollen PM is crucial for maintaining polar pollen tube growth. To elucidate whether plant hormones are involved in these processes, the effects of exogenous phytohormones, indole-3-acetic acid （IAA）, abscisic acid （ABA）, gibberellin A3 （GA3） and cytokinin （kinetin） on the growth, PM polarization, actin cytoskeleton （AC） organization and cytoplasmic pH （pile） of in vitro 4 h-growing petunia pollen tubes were investigated. IAA, ABA and GA3 displayed the growth-stimulating effects and these were accompanied by orthovanadate-sensitive hyperpolarization of the PM. Fluorescent labeling the enzyme with H＋-ATPase antibodies exhibited IAA- and ABA-induced lateral PM redistribution of it into the subapical zone of pollen tube PM. Pollen cultivation on the medium with latrunculin B, the inhibitor of actin polymerization, resulted in inhibition of pollen tube growth and simultaneously in the drop of endogenous IAA content. The IAA-growth stimulating effect was correlated with increased content of actin filaments （AF） in both apical and subapical zones of tubes, while ABA and GA3 exerted the same effect but it was accompanied by redistributing F-actin only to apical zone. In contrast, kinetin decreased the total F-actin content and inhibited pollen tube growth. It has been shown that the pHe of growing pollen tubes is sensitive to the plant hormones. In the case of male gametophyte growing for 1, 2 and 4 h, IAA induced alkalinization of the cytosol, while ABA and GA3 exerted qualitatively similar effect only after its growth for 1 h and 4 h, respectively. Kinetin, in contrast, resulted in acidification of the cytosol. All these results, taken together, indicate, for the first time, potential targets of the phytohormone action in pollen tubes.
基金The work is partly supported by grants from the Sanming Project of Medicine in Shenzhen,China(SZSM201612083 to W.S.B.Y.)Shenzhen Key Medical Discipline(SZXK2020089)+1 种基金General Research Fund,Research Grants Council,Hong Kong(17120720 to K.F.L.)Internal research funding from the Department of Obstetrics and Gynaecology,the University of Hong Kong.
文摘Human fallopian tubes(FTs)play important roles in the whole reproductive process.FTs are the site for the final maturation of gametes,fertilization,transport of preimplantation embryos,and early embryonic development before entering the uterus.All these functions are critical in the establishment of a successful pregnancy.When the embryo is in transit through the FT,the FT microenvironment changes through endocrine,paracrine,autocrine,and juxtacrine mechanisms which involve various hormones and bioactive substances mainly from the neighboring cells.Therefore,the interactions between the embryo and the FT may be the earliest embryo-maternal communications that are essential for the establishment of pregnancy.This review critically discusses the evidence of various hormonal and bioactive mediated control of the microenvironment in the FTs during the earliest embryo-maternal communications.Moreover,we highlight existing gaps in the knowledge and the importance of exploring more of the physiology of FTs which will hold the key to producing high-quality embryos for patients seekingin vitro fertilization(IVF)treatments.
