• Journal of Plant Biology
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• 제38권3호
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• pp.275-280
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• 1995

The formation of osmiophilic globules related to the granal lysis has been investigated with a shade plant ginseng (Panax ginseng C. A. Meyer) exposed to full sunlight. The changes of chloroplast were examined as a function of time over 9 days under full sunlight exposure. The ultrastructure of ginseng leaf showed swelling of the granal thylakoid during an early stage of the light exposure. The thylakoid membrane faded and small electron-opaque dots were aggregated on the edges of the granal thylakoid membrane when the exposure time was increased over 1 day. Then, the sahpe of the grana changed into round. After the exposure over 3 days, there appeared many osmiophilic globules with multi-lamellated concentric structure. The globules at this stage were partly accumulated with osmiophilic substances. The outermost membrane of these multi-lamellated osmiophilic globules was attached to the stromal thylakoid membrane connecting to the deforming grana. The osmiophilic globules were elongated after 9 days. In this stage, the multi-lamellated structure was difficult to identify due to severe accumulation of osmiophilic substances. The number of the osmiophilic globules also increased along with the full sunlight exposure time. This observation leads us to believe that the multi-lamellated osmiophilic globules came from the deformation of grana.

• Journal of Plant Biology
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• 제39권3호
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• pp.215-221
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• 1996

Sorghum leaf tissues showing the early acute response of systemic infection with maize dwarf mosaic virus (MDMV) strain A, contained unusual virus-induced cytological modifications including cell wall thickenings and protrusions, intercellular vesicles termed as "paramural bodies", modified plasmodesmata, abnormal plastids, and cylindrical inclusion bodies. Abnormal cell wall, some of which associated with paramural bodies, was frequently contained modified plasmodesmata. Various abnormal plastids were located within infected cells of leaf tissues showing the early acute response. The most important changes in chloroplast seen in the tissues are the presence of small vesicles, deformation of membranes, reduction in granal stack height, disappearance of osmiophilic globules and degeneration of stuctures. The cytological modification was not occurred in nucleus but a group of degenerated mitochondria with abnormal membranes attached to cylindrical inclusion bodies were observed. It was hard more or less to prove the relationship clearly between virus and cellular organelles in virus replication.plication.

• Journal of Plant Biology
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• 제37권3호
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• pp.285-292
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• 1994

Ultrastructural changes in Panax ginseng C. A. Meyer mesophyll chloroplasts and variation of thylakoid membrane protein in responce to the light intensity were studied in leaves of two-y-old plants exposed to two different light intensities under field coditions. The leaves were allowed to function for three months after emergence under two contrasting light conditions. The ginseng chloroplasts of 5% light were filled with highly stacked grana of condensely arrayed thylakoids, so that the stroma space was hardly observed. In contrast, chloroplasts from leaves at 100% sunlight had fewer thylakoid membranes and smaller grana stacks. The number of osmiophilic globules increased. Total Chl content and Chl b content were lower at 100% sunlight than 5% sunlight. The thylakoid membrane proteins in the leaves grown at 100% sunlight showed lower CPIa, LHCII and CP29 than those with 5% sunlight. This effect was most obvious for LHCII. Polypeptides showed major bands at 90, 64, 29-30, 22 and 14 kD, and minor bands at 59, 58, 54, 52, 49, 46, 44, 35, 23, 21 and 18-19 kD. All these bands were lower in intensity in the leaves exposed to 100% sunlight. Moreover, the bands at 58-59, 46-47 and 23 kD disappeared.

• Applied Microscopy
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• 제24권4호
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• pp.1-12
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• 1994

대마(Cannabis sativa L.)의 잎과 암꽃의 포(苞)를 투과 전자현미경으로 관찰한 결과 다음과 같은 결과를 얻었다. 어린 엽육세포에서 관찰되는 원시색소체는 타원형으로서 장축의 크기는 $1.5-2.0{\mu}m$이었으며, 스트로마 기질내에는 100nm 크기의 색소체소구가 많이 나타났다. 파종후 3주후에 채취된 시료의 엽육세포에 있어서는 그라나가 잘 발달된 엽록체가 관찰되었는데, 틸라코이드의 신장과 더불어 엽록체의 형태도 긴 장타원형을 이루고 있었다. 엽육세포가 성숙하면서 전분립의 수와 크기가 점차 증가하였고, 이에 따라서 엽록체의 형태도구형에 가까운 타원형으로 변하였다. 특히 이 시기의 그라나간틸라코이드는 매우 팽창되는 양상을 나타내었다. 엽육세포 가운데 비교적 어린 단계에 있는 세포에서는 원시색소체가 엽록체와 함께 출현하기도 하였는데, 이때의 이들 엽록체는 전분립을 전혀 지니지 않았다. 엽육조직과 암꽃의 포에서 관찰된 표피세포는 전분립을 지닌 엽록체가 세포벽을 따라 나타났으며, 핵은 세포의 기부에 규칙적으로 배열하였다. 비분비모는 세포의 중앙에 큰 액포가 발달하였으며 아주 적은 세포질이 세포벽을 따라 존재하였다. 이들 세포질내에도 옅록체가 나타났는데, 이들은 엽육세포의 엽록체에 비해 현저히 작았고, 형태도 타원형에 가까왔다. 한편, 분비모에서는 매우 특징적인 색소체가 출현하였는데, 이들은 격자구조의 막성구조(reticulate body)를 지니면서 분비작용을 왕성히 하고 있었다.