Botany Department, Queen's University, Belfast, Northern Ireland.
Planta. 1967 Mar;74(1):72-85. doi: 10.1007/BF00385172.
The mature cotyledon of Pisum arvense L. comprises several distinct tissue regions; these are the epidermis, hypodermis, storage parenchyma and procambium. The storage parenchyma includes two zones: an outer abaxial zone and an inner adaxial zone. The cells of both zones contain abundant starch grains and protein bodies. Scattered through the storage tissue but increasing in frequency towards the periphery are certain cells which differ to a slight extent from the majority of the parenchyma cells. They have a more opaque, granular cytoplasm and a higher level of cytoplasmic RNA. the cotyledon has a complex, reticulate vascular system. Differentiation of the conducting elements from the procambium appears to begin about 12 hours and to be completed 48 hours after the commencement of imbibition. Differentiation of phloem preceeds that of xylem. The relationship between the timing of vascular differentiation and various physiological events in the cotyledon is discussed.Mobilization of the reserves in the storage parenchyma is initiated at the periphery of the cotyledon and proceeds inwards. There appears to be a correlation between the breakdown of the reserves and changes in DNA and RNA content of the cells.
野豌豆成熟子叶包含几个不同的组织区域；这些是表皮、下皮、贮藏组织和原形成层。贮藏组织包括两个区：外背区和内腹区。两个区的细胞都含有丰富的淀粉粒和蛋白体。散布在贮藏组织中的某些细胞与大多数薄壁细胞略有不同，但频率会向边缘增加。它们的细胞质较不透明，呈颗粒状，细胞质 RNA 水平较高。子叶具有复杂的网状脉系统。从原形成层分化出的导水组织似乎在吸水开始后约 12 小时开始，并在 48 小时后完成。韧皮部的分化先于木质部。讨论了子叶中脉分化与各种生理事件的时间关系。贮藏组织中储备物质的动员始于子叶的边缘并向内进行。储备物质的分解与细胞中 DNA 和 RNA 含量的变化之间似乎存在相关性。
