本文用磷酸铅沉淀技术对金鱼草(Antirrhinum majus L.)开花前2天和开花当天胚珠中 ATP 酶的超微细胞化学进行了研究。卵器没有酶活反应;中央细胞的质膜、细胞质和核质中均有酶活反应。胚囊壁与其外方角质层之间有一间隙层,其中含有一些...本文用磷酸铅沉淀技术对金鱼草(Antirrhinum majus L.)开花前2天和开花当天胚珠中 ATP 酶的超微细胞化学进行了研究。卵器没有酶活反应;中央细胞的质膜、细胞质和核质中均有酶活反应。胚囊壁与其外方角质层之间有一间隙层,其中含有一些絮状和小囊泡状物质,该层呈现强烈的酶活反应。合点端承珠盘组织的细胞核、质膜及其特殊的厚壁内有大量的酶,并通过合点端角质层的不连续区段与上述间隙层中的酶连成一片。一般珠被薄壁细胞仅质膜和胞间连丝上有酶活反应,但珠被绒毡层细胞核质中相当显著。根据 ATP 酶在胚珠中的分布特点,着重讨论了珠被绒毡层和承珠盘的功能,并推测胚囊壁外间隙层可能构成一个为胚囊提供养料的质外体运输系统。展开更多
The micropyle of Gossypium hirsutum consists of an exostome and an endostome.On semithin serial transections, the exostome was visualized as a branched narrow gap except its outer and inner openings, whereas the endos...The micropyle of Gossypium hirsutum consists of an exostome and an endostome.On semithin serial transections, the exostome was visualized as a branched narrow gap except its outer and inner openings, whereas the endostome only a narrow linear gap. Ultrastructurally, the micropyle gap was formed by the integumental epidermal cells coated with a cuticle.The cells lining the micropyle gap were characterized by a large nucleus and abundant organelles as mitochondria, plastids, rough endoplasmic reticulum, vesicle secreting dictyosomes and small vacuoles.One or two pollen tubes were seen growing through the exostome and endostome gaps.Thus, the micropyle in cotton was basically a closed type as has been found in sunflower, but similar asymmetrical structural features were not observed.展开更多
文摘本文用磷酸铅沉淀技术对金鱼草(Antirrhinum majus L.)开花前2天和开花当天胚珠中 ATP 酶的超微细胞化学进行了研究。卵器没有酶活反应;中央细胞的质膜、细胞质和核质中均有酶活反应。胚囊壁与其外方角质层之间有一间隙层,其中含有一些絮状和小囊泡状物质,该层呈现强烈的酶活反应。合点端承珠盘组织的细胞核、质膜及其特殊的厚壁内有大量的酶,并通过合点端角质层的不连续区段与上述间隙层中的酶连成一片。一般珠被薄壁细胞仅质膜和胞间连丝上有酶活反应,但珠被绒毡层细胞核质中相当显著。根据 ATP 酶在胚珠中的分布特点,着重讨论了珠被绒毡层和承珠盘的功能,并推测胚囊壁外间隙层可能构成一个为胚囊提供养料的质外体运输系统。
文摘The micropyle of Gossypium hirsutum consists of an exostome and an endostome.On semithin serial transections, the exostome was visualized as a branched narrow gap except its outer and inner openings, whereas the endostome only a narrow linear gap. Ultrastructurally, the micropyle gap was formed by the integumental epidermal cells coated with a cuticle.The cells lining the micropyle gap were characterized by a large nucleus and abundant organelles as mitochondria, plastids, rough endoplasmic reticulum, vesicle secreting dictyosomes and small vacuoles.One or two pollen tubes were seen growing through the exostome and endostome gaps.Thus, the micropyle in cotton was basically a closed type as has been found in sunflower, but similar asymmetrical structural features were not observed.
