摘要
The developmental process of oil cells in the shoot of Litsea pungens Hemsl. has been studied with transmission electron microscopy. According to the development of the three layers of cell wall, the developmental process could be divided into 4 stages. In stage 1, the cell wall consisted only of a primary (the outmost) cellulose layer, which might further be divided into two substages, the oil cell initial, and the vacuolizing oil cell. During this stage, there were some small electron translucent vesicles and dark osmiophilic droplets of variant sizes in the different-shaped plastids. It was observed that some dark and gray osmiophilic materials coalesced to vacuoles in the cytoplasm. In stage 2, a lamellated suberin layer accumulated inside the primary cellulose layer. In stage 3, a thicker and looser inner cellulose wall layer was formed gradually inside the suberin layer. Some dark osmiophilic droplets have been observed in this loose inner cellulose wall layer. The plasmodesmata were blocked up and became a special structure. Then, the big vacuole, which is the oil sac, was full of osmiophilic oil. In stage 4, the oil cell became matured and the cytoplasm disintegrated. The oil sac enveloped from plasmalemma was attached to the cupule, which was formed by the protuberance of the inner cellulose wall layer into the lumen. After the maturity of oil cell, the ground cytoplasm began to disintegrate and became electron opaque or exhibited in a disordered state, and the osmiophilic oil appeared light gray.
利用超薄切片法和透射电镜研究了木姜子 (LitseapungensHemsl.)油细胞的发育过程。油细胞 3层细胞壁的发育可分为 4个阶段。阶段 1:油细胞仅有初生纤维素壁层 ,又可分为原始细胞和细胞液泡化两个时期。此阶段质体具透明小泡和黑色嗜锇滴 ,细胞质中也存在嗜锇物质 ,并与液泡融合。阶段 2 :木栓质化壁层的形成 ,片层状木栓质不断叠加在初生纤维素壁内侧 ,其细胞结构与前期相似。阶段 3:内纤维素壁层的形成 ,较厚而松散的内纤维素壁层叠加在木栓质化壁层的内侧 ,在内纤维素壁层中可见黑色嗜锇物质 ,胞间连丝成为被阻塞的特化结构 ,此时大液泡被嗜锇油脂充满 ,成为油囊。阶段 4:油细胞成熟及细胞质解体 ,杯形构造由内纤维素壁层向细胞腔内突起形成 ,油囊由液泡膜包被连接到杯形构造上 ,油呈浅灰色嗜锇状态 ,其细胞质和细胞器解体 。
基金
SupportedbytheShaanxiNaturalScienceFoundation (98SM0 5 )
