Differentiation of bundle sheath, mesophyll, and distinctive cells in the C4 grass Arundinella hirta (Poaceae)
Differentiation of bundle sheath, mesophyll, and distinctive cells in the C4 grass Arundinella hirta (Poaceae)
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DOI：
10.1002/j.1537-2197.1996.tb13933.x
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发表时间：
1996-11
影响因子：
3
通讯作者：
N. Dengler;P. Donnelly;R. Dengler
中科院分区：
文献类型：
--
作者：
N. Dengler;P. Donnelly;R. Dengler
C4草Arundinella hirta的特征在于不寻常的叶片解剖学：静脉间隔很宽，并且独特的细胞--剑鞘样细胞形成与维管组织无关的纵向股。虽然独特细胞（DCs）的功能与束鞘细胞（BSCs）相似，但它们在发育上有两个不同之处：它们来自基本分生组织而不是原形成层，并且它们在1-2个质体年代后形成。本研究描述了叶片发育过程中BSCs、DCs和相关叶肉细胞（MC）分化的超微结构特征。BSC和DC与相邻MC的不同之处在于经历了更早的细胞增大、更大的叶绿体增大速率、在分化后期叶绿体类囊体的减少、更广泛的淀粉形成、更大的壁增厚和木栓质片层的沉积。维管束鞘层的早熟划分反映在早期BSC扩大和液泡生长。起源于基本分生组织的树突状细胞与叶绿体大小、壁厚和胞间连丝密度的后期发育变化相关。尽管在事件发生的时间上存在这些差异，特别是在早期阶段，但BSC和DC的特化结构特征的发展基本上是相似的。因此，接近血管组织似乎是不必要的协调和调节BSC和MC特定的发展事件。
The C4 grass Arundinella hirta is characterized by unusual leaf blade anatomy: veins are widely spaced and files of bundle-sheath-like cells, the distinctive cells, form longitudinal strands that are not associated with vascular tissue. While distinctive cells (DCs) appear to function like bundle sheath cells (BSCs), they differ developmentally in two ways: they are derived from ground meristem rather than procambium and they are formed 1-2 plastochrons later. This study describes ultrastructural features of differentiating of BSCs, DCs, and associated mesophyll cells (MCs) during leaf development. BSCs and DCs differ from adjacent MCs by undergoing earlier cell enlargement, greater rates of chloroplast enlargement, reduction of chloroplast thylakoids at late stages of differentiation, more extensive starch formation, greater wall thickening, and deposition of a suberin lamella. The precocious delimitation of the bundle sheath layer is reflected in earlier BSC enlargement and vacuole growth. Derivation of DCs from ground meristem is correlated with late developmental changes in chloroplast size, wall thickness, and plasmodesmatal density. Despite these differences in timing of events, particularly at early stages, the development of the specialized structural features of BSCs and DCs is essentially similar. Thus, proximity to vascular tissue appears to be nonessential for the coordination and regulation of BSC- and MC-specific developmental events.