CAJ | 학술논문

对果胶酶在烟草(Nicotiana tabacum L.)花粉母细胞减数分裂前期Ⅰ的活性进行了电镜细胞化学定位,以研究其在次生胞间连丝和胞质通道形成中的作用.结果表明:在细线期,酶反应产物主要存在于光面内质网及其衍生小泡内;偶线期,当次生胞间连丝和胞质通道开始形成时,反应产物明显增强.同时果胶酶活性也出现在细胞壁上,尤其是出现在简单或者复杂分枝状的胞间连丝和胞质通道内部或沿着它们附近细胞壁的中胶层分布.胞吐小泡中的酶活性表明果胶酶和纤维素酶一样,也是通过内质网及其衍生小泡由胞吐作用分泌到细胞壁的,并在那里通过特异性降解果胶质而和纤维素酶协同作用导致次生胞间连丝和胞质通道的形成.
대과효매재연초(Nicotiana tabacum L.)화분모세포감수분렬전기Ⅰ적활성진행료전경세포화학정위,이연구기재차생포간련사화포질통도형성중적작용.결과표명:재세선기,매반응산물주요존재우광면내질망급기연생소포내;우선기,당차생포간련사화포질통도개시형성시,반응산물명현증강.동시과효매활성야출현재세포벽상,우기시출현재간단혹자복잡분지상적포간련사화포질통도내부혹연착타문부근세포벽적중효층분포.포토소포중적매활성표명과효매화섬유소매일양,야시통과내질망급기연생소포유포토작용분비도세포벽적,병재나리통과특이성강해과효질이화섬유소매협동작용도치차생포간련사화포질통도적형성.
Pectinase activity was localized at the ultrastructural level in pollen mother cells of tobacco (Nicotiana tabacum L.) during meiotic prophase Ⅰ to elucidate its role in the biogenesis of secondary plasmodesma (sPD) and cytoplasmic channel (CC). At the leptotene stage the enzyme was mainly present in the cisternae of smooth endoplasmic reticulum (SER) and their derived vesicles, but absent in the Golgi body and Golgi vesicles. Later at the zygotene stage, when sPDs and CCs were actively formed, strong pectinase activity was observed not only in the SER cisternae and their derived vesicles but also in the cell wall, especially in the vicinity of or within both simple and branched plasmodesmata, notably along the middle lamellae, which also characterized the sites of CCs being formed. The presence of exocytotic vesicles containing reaction products suggests that pectinase shares the same excretive pathway as that used by cellulase for its delivery into the wall, i.e. in active form via smooth endoplasmic reticulum (ER) and its derived vesicles by exocytosis. In combination with cellulase, peotinase also promotes the secondary formation of plasmodesmata and CCs by specifically digesting the pectin in middle lamella.