Occurrence of Abnormal Chloroplasts in Tobacco Leaves Infected Systemically with the Ordinary Strain of Cucumber Mosaic Virus

Ehara, Yoshio; Misawa, Tadao

doi:10.1111/j.1439-0434.1975.tb03564.x

Cited by 16 publications

(7 citation statements)

References 25 publications

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“…These low-temperature-induced damages appear on very young leaves, whereas there is no discernible effect of low temperature on tobacco leaves that are fully developed prior to exposure to low temperatures (Kodama et al, 1994):The observed results with tobacco plants are consistent with observations for the fud5 and fud6 mutants (Hugly and Somerville, 1992). In tobacco plants, most plastids are in the proplastid phase or in early developmental phase of chloroplasts in the young, 2-cm-long leaves and they enter into the later stage of differentiation or maturation in leaves with a length ranging from 6 to 8 cm (Ehara and Misawa, 1975). Because the TA lcontent in young leaves was remarkably low (Fig.…”

Section: Fatty Acid Desaturation As a Factor In Chilling Tolerancesupporting

confidence: 74%

Fatty Acid Desaturation during Chilling Acclimation Is One of the Factors Involved in Conferring Low-Temperature Tolerance to Young Tobacco Leaves

et al. 1995

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The FAD7 gene, a gene for a chloroplast w-3 fatty acid desaturase, is responsible for the trienoic fatty acid (TA) formation in leaf tissues. The TA content of the leaf tissue of the 25°C-grown transgenic tobacco (Nicotiana tabacum cv SR1) plants, in which the FAD7 gene from Arabidopsis thaliana was overexpressed, increased uniformly by about 10%. Fatty acid unsaturation in all major leaf polar lipid species increased in the 25OC-grown FAD7 transformants but was approximately the same between the control plants and the FAD7 transformants when grown at 15°C. Therefore, the overexpression of the exogenous FAD7 gene leads to the same consequence in the tobacco plants as the low-temperature-induced TA production that may be catalyzed by an endogenous, temperatureregulated chloroplast w-3 fatty acid desaturase. In the 25°C-grown control plants, the chilling treatment caused symptoms of leaf chlorosis and suppression of leaf growth. The 25°C-grown FAD7 transgenic plants conferred alleviation of these chilling-induced symptoms. A reduction of the chilling injury similar to that of the FAD7 transformants was also observed in the 15°C-preincubated control plants. These results indicate that the increased TA production during chilling acclimation is one of the prerequisites for the normal leaf development at low, nonfreezing temperatures.

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Section: Fatty Acid Desaturation As a Factor In Chilling Tolerancesupporting

confidence: 74%

Fatty Acid Desaturation during Chilling Acclimation Is One of the Factors Involved in Conferring Low-Temperature Tolerance to Young Tobacco Leaves

et al. 1995

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“…Formation of the vesicles may differ among plant species or structure. Concentric circles of thylakoid membrane appeared with thylakoid plexus (Fig 2d), as previously observed in mutants of maize (Zea mays L.) (Bachmann et al, 1967), in tobacco (Nicotiana tabacum L.) leaves infected by virus (Ehara and Misawa 1975), in tangerine tomato (Rosso, 1967), and in Capsicum fruit (Spurr and Harris, 1968). How the concentric circles are formed is not known, but they may result from stacking and rolling of stroma thylakoid after grana disintegrate and change to thylakoid plexus.…”

Section: Resultssupporting

confidence: 86%

Scanning Electron Microscopic Study of Modified Chloroplasts in Senescing Broccoli Florets

Terai¹,

Watada²,

Murphy³

et al. 2000

HortSci

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Structural changes in chloroplasts of broccoli (Brassica oleracea L., Italica group) florets during senescence were examined using light microscopy, scanning electron microscopy (SEM) with freeze-fracture technique, and transmission electron microscopy (TEM) to better understand the process of chloroplast degradation, particularly at the advanced stage of senescence. Light microscopy revealed that chloroplasts, which initially were intact and green, became obscure in shape, and their color faded during senescence. Small, colored particles appeared in cells as the florets approached the final stage of senescence and became full- to dark-yellow in color. Scanning electron microscopy showed that stroma thylakoids in the chloroplast initially were parallel to each other and grana thylakoids were tightly stacked. As senescence advanced, the grana thylakoids degenerated and formed globules. The globules became larger by aggregation as senescence progressed, and the large globules, called “thylakoid plexus,” formed numerous vesicles. The vesicles ultimately were expelled into the cytosol, and the light microscope revealed many colored particles in the senescent cells. These results indicate that the degradation of chloroplasts in broccoli florets progresses systematically, with the final product being colored particles, which are visible in yellow broccoli sepal cells.

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“…Unexpectedly, the elevated 18:1 content receded to a level similar to WT in fully expanded leaves of the transgenic plants and this was not induced by rebound of FAD2 transcript. In tobacco plants, most chloroplasts are in proplastid phase or in early developmental phase in the unexpanded leaves, and they enter into the later stage of differentiation or maturation in the larger leaves (Ehara and Misawa, 1975). Based on these observations, we assumed that the development of chloroplasts might be involved in the decrease of 18:1 accumulation in the FAD2-silenced tobacco throughout leaf expansion.…”

Section: Discussionmentioning

confidence: 96%

Oleate accumulation, induced by silencing of microsomal omega-6 desaturase, declines with leaf expansion in transgenic tobacco

Yang

2007

Journal of Plant Physiology

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Occurrence of Abnormal Chloroplasts in Tobacco Leaves Infected Systemically with the Ordinary Strain of Cucumber Mosaic Virus

Cited by 16 publications

References 25 publications

Fatty Acid Desaturation during Chilling Acclimation Is One of the Factors Involved in Conferring Low-Temperature Tolerance to Young Tobacco Leaves

Fatty Acid Desaturation during Chilling Acclimation Is One of the Factors Involved in Conferring Low-Temperature Tolerance to Young Tobacco Leaves

Scanning Electron Microscopic Study of Modified Chloroplasts in Senescing Broccoli Florets

Oleate accumulation, induced by silencing of microsomal omega-6 desaturase, declines with leaf expansion in transgenic tobacco

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