Relationships between histological and functional differentiation in C_4 plants

1.本文对高等植物叶片的免疫细胞化学观察方法进行了研究。光镜检查的一种有效方法是用抗血清处理脱蜡石蜡切片，并应用R-藻红蛋白偶联的二抗。电镜采用3%戊二醛固定2 h，LR白色树脂包埋，免疫细胞化学电镜观察。2.用免疫细胞化学电镜观察了大花马齿苋不同细胞类型的叶绿体结构和Rubisco的定位。在维管束周围典型的维管束鞘细胞的叶绿体中，Rubisco的积累和对基粒发育的抑制被证实。在靠近维管束的贮水细胞中，叶绿体也具有束鞘叶绿体的特征，但在维管束周围不具有Kranz解剖结构。3.对大花杨绿色愈伤组织和再生愈伤组织中的叶绿体结构和Rubisco定位进行了研究。在愈伤组织维管束周围的细胞中，叶绿体也有基粒。再生叶组织中维管束周围细胞叶绿体中的基粒发育受到抑制。在继代培养和再生愈伤组织中，大多数绿色组织的叶绿体中都检测到Rubisco的标记。在弱光条件下，即使在异养生长的完整植株的叶肉叶绿体中也能检测到Rubisco的标记。4.推测维管束在C_4植物叶片的结构和功能分化中起重要作用，但这种调节机制在愈伤组织和异养生长的植株中不起作用。

1.Immunocytochemical methods for observation of higher plant leaves were investigated. An effective method for light microscopy was to treat de-waxd paraffin sections with primary antiserum and apply R-phycoerythrin-conjugated secondary antibody. Observation was made under a fluorescence microscope equipped with an exciter filter unit B.For electron microscopy tissues were fixed with 3% glutaraldehyde for 2h and embedded in LR White resin.Sections were treated with primary antiserum and then with colloidal gold-conjugated secondary antibody.2.Chloroplast structure and localization of Rubisco in various cell types of Portulaca grandiflora were examined by immunocytochemical electron microscopy. Accumulation of Rubisco and suppression of granal development were confirmed in the chloroplasts of typical bundle sheath cells around peripheral vascular bundles. However, characteristics as a bundle sheath chloroplast were also detected in the chloroplasts of water storage cells adjacent to the central vascular bundle although the Kranz anatomy was not developed around the central vascular bundle.3.Chloroplast structure and localization of Rubisco were examined in green callus tissues and regenerating callus tissues of P.grandiflora. Chloroplasts possessed grana even in the cells around vascular bundles of callus. Suppression of granal development was observed in chloroplasts of cells around vascular bundles in regeneration leaf tissues. Labeling of Rubisco was detected in chloroplasts of most of the green tissues in both subculturing and regenerating calli. Labeling of Rubisco was also detected even in mesophyll chloroplasts of intact plants grown heterotrophically under low light intensity.4.It was assumed that vascular bundles play important roles in structural and functional differentiation of C_4 plant leaves but this regulatory mechanism was not function in callus tissues and plants grown heterotrophically.