The changes in cell wall architecture during lignification of bamboo, Phyllostachys aurea Carr.
The changes in cell wall architecture during lignification of bamboo, Phyllostachys aurea Carr.
复制标题
DOI：
10.1007/s004680000084
复制
发表时间：
2001-03-01
影响因子：
2.3
通讯作者：
Itoh, T
中科院分区：
文献类型：
--
作者：
Suzuki, K;Itoh, T
采用速冻深蚀刻（RFDE）电镜对竹材生长不同发育阶段细胞壁结构进行了研究。未木质化初生壁（ULP）的特征是纤维中纤维素微原纤维之间的间距狭窄，而薄壁细胞中纤维素微原纤维之间的间距较小。未木质化的次生壁（ULS）主要由密集的纤维素微原纤维组成，具有狭窄的间距或“狭缝状”孔隙。然而，这种孔隙在木质化的纤维次生壁（LS）中很难观察到。纤维脱木质素次级壁（DLS）的细胞壁结构表现出与ULS相似的多孔性。木质化后，纤维中ULS中间薄片和次级壁的气孔显著减少或立即消失。然而，脱木质素后毛孔重新出现。这些发现表明木质素在LS成熟过程中立即在孔隙中沉积。RFDE电镜图像显示，竹子的初级和次级纤维壁孔径明显小于桉树和松树，这表明竹子纤维壁中纤维素微原纤维的排列比这两种树种都要密集。作者推测，竹纤维中纤维素微原纤维之间的狭窄间距可能是竹中木质素沉积少于其他树种的原因之一。这是关于竹材中未木质化和木质化墙体的三维建筑的第一篇报道。
The cell wall architecture of bamboo at various developmental stages of culm growth was investigated by rapid-freezing and deep-etching (RFDE) electron microscopy. The unlignified primary wall (ULP) was characterized by the narrow spacing between the cellulose microfibrils in fibres, but not in parenchyma cells. The unlignified secondary wall (ULS) largely consisted of dense cellulose microfibrils with narrow spacing or "slit-like" pores. However, such pores are difficult to observe in the lignified secondary wall (LS) of fibres. The cell wall architecture of the delignified secondary wall (DLS) in fibres showed porosity similar to that of ULS. Pores in the middle lamella and secondary walls of ULS in fibres were reduced considerably or disappeared immediately after lignification. However, the pores reappeared following delignification. These findings suggest that deposition of lignin in ULS immediately proceeds in the pores during maturation to LS. Based on RFDE electron microscopic images, the pore sizes of primary and secondary fibre walls were significantly smaller in bamboo than in either Eucalyptus or Pinus, suggesting a denser arrangement of cellulose microfibrils in bamboo fibre walls than in either tree species. The author hypothesizes that the narrow spacing between cellulose microfibrils in bamboo fibres may be one of the reasons for the deposition of less lignin in bamboo than in tree species. This is the first report on the three-dimensional architecture of unlignified and lignified walls in bamboo.