An Overview About Ultrastructure of Kranz Anatomy in Cyperaceae (Poales)

Abstract An overview about ultrastructure of Kranz anatomy in Cyperaceae (Poales) - The ultrastructure of the Kranz tissues in Cyperaceae species with the four types of Kranz anatomy (chlorocyperoid, eleocharoid, fimbristyloid and rhynchosporoid) was studied and compared with species already described in the literature, with the goal verifying the occurrence of patterns for the Kranz types. In addition, chloroplasts and mitochondria were quantified for the first time for all Kranz types. The chloroplast’s structure is similar in the mesophyll cells (PCA) in the four Kranz types, but differs in some features in the bundle sheath cells (PCR). In the chlorocyperoid and rhynchosporoid types the bundle sheath cells (PCR) present centrifugal or scattered chloroplasts with convoluted or parallel thylakoids. In the eleocharoid types, the chloroplasts are scattered with parallel thylakoids. The fimbristyloid type presents centrifugal chloroplasts with convoluted and parallel thylakoids. To eleocharoid and fimbristyloid types and to Cyperus and Pycreus (chlorocyperoid) was observed pattern in the chloroplasts position. In most of the studied species the number of mitochondria in the bundle sheath cells (PCR) is significantly higher than in the mesophyll cells (PCA) and this result diverges from the results found in previous studies.

摘要 莎草科（Cyperaceae，禾本目Poales）克兰兹解剖结构（Kranz anatomy）超微结构研究概述——本研究针对具备四种克兰兹解剖类型（氯莎草型chlorocyperoid、荸荠型eleocharoid、飘拂草型fimbristyloid及刺子莞型rhynchosporoid）的莎草科物种，对其克兰兹组织的超微结构展开分析，并与文献已报道的物种进行比对，旨在验证各类克兰兹类型的结构模式。此外，本研究首次对所有四类克兰兹类型的叶绿体与线粒体进行定量统计。四类克兰兹类型的叶肉细胞（PCA）中，叶绿体结构整体相似，但维管束鞘细胞（PCR）的叶绿体结构存在部分特征差异。在氯莎草型与刺子莞型中，维管束鞘细胞（PCR）的叶绿体呈离心分布或散在分布，且具有卷曲或平行的类囊体结构。荸荠型的叶绿体呈散在分布，类囊体为平行排列。飘拂草型的叶绿体呈离心分布，类囊体兼具卷曲与平行两种形态。针对荸荠型、飘拂草型，以及氯莎草型类群的莎草属（Cyperus）和扁莎属（Pycreus），其叶绿体的分布位置存在统一模式。在多数供试物种中，维管束鞘细胞（PCR）内的线粒体数量显著高于叶肉细胞（PCA），该结果与既往研究结论存在分歧。