百日菊管細胞形成時微細構造與酵素的變化

Abstract

本實驗以百日菊(Zinnia elegans Jacq.)葉片誘導出的癒合組織為材料，探討管細胞分化過程中，酵素與細胞微細構造變化的情形。生長在維持培養基的癒合組織移至含1mg/l BA及0.1mg/l NAA的分化培養基，誘導管細胞分化。組織內分化的管細胞比率約可達30％，木質素含量於初期及中期有較高的情形。過氧化?則分成可溶性、離子鍵結性、共價鍵結性三個部分，個別測定酵素活性變化。而2.5％戊二醛對這三部分過氧化?的抑制效果不大。次生細胞壁加厚初期於細胞壁附近可見到許多內質網、高爾基體及小囊胞，此外尚有粒線體遍佈其間。稍後粒線體則位於次生細胞壁周圍。成熟的管細胞其細胞內含物完全消失。細胞酵素定位方面，觀察到酸性磷酸?在癒合組織內分佈廣泛，主要存在細胞壁及液胞。於細胞壁上的分佈現象較分歧，有些甚至位於細胞壁外。而內質網、高爾基體、粒線體、葉綠體、細胞核等以及退化中的胞器及其細胞質內都有酸性磷酸?存在。葉片的分佈情形和癒合組織類似，尤以篩細胞附近的轉送細胞反應最強烈。以葉片組織進行過氧化?的細胞定位時，雖於次生細胞壁上亦可見類似酵素作用的反應?物，但效果並不顯著。

Calli, induced from Zinnia elegans Jacq. leaves, were ed for ultrastructural and enzymatic studies during xylo-nesis. Calli grew in differentiation medium containing mg/l benzyladenine (BA) and 0.1 mg/l α-naphthaleneacetic id (NAA) for induction of tracheary element differentiation. e proportion of tracheary elements as a percentage of total lls reached nearly 30%. During the early stages of secondary ll thickenings, cellular organells such as endoplasmic ticula, dictyosomes, Golgi vesicles and mitochondria were cated around the cell wall. In later stages mitochondria were ted accumulatedly closed to the secondary wall thickenings. the final stages cell autolysis occurred. Cytochemical study owed that acid phosphatases distributed mainly in the cell lls and vacuoles in callus tissue. Also acid phosphatases re detected in other organelles.