scholarly journals Far-Red Light-Induced Changes in Intracellular Potentials of Spinach Mesophyll Cells

1983 ◽  
Vol 73 (3) ◽  
pp. 671-676 ◽  
Author(s):  
Michel Montavon ◽  
Benjamin A. Horwitz ◽  
Hubert Greppin
Keyword(s):  
Red Light ◽  
Mesophyll Cells ◽  
Intracellular Potentials ◽  
Induced Changes

Kinetic of Lipoquinone and Pigment Synthesis during Red Light-Induced Thylakoid Formation in Etiolated Barley Seedlings

1975 ◽  
Vol 30 (5-6) ◽  
pp. 337-341 ◽  
Author(s):  
K. H. Grumbach ◽  
H. K. Lichtenthaler
Keyword(s):  
Blue Light ◽  
Vitamin K ◽  
Red Light ◽  
Pigment Synthesis ◽  
The Individual ◽  
Induced Changes ◽  
Β Carotene

Abstract Red light induces in etioplasts of dark-grown barley seedlings (H ordeum vulgare L.) parallel to the formation of chlorophyll an increased synthesis of carotenoids, lipophilic benzoquinones and of vitamin K1. 1. Among the carotenoids red light initiates an enhanced synthesis of β-carotene, lutein, violaxanthine and neoxanthine whereas the pools of zeaxanthine and antheraxanthine are decreased. 2. The formation of plastoquinone-9, vitamin K1 and a-tocoquinone is more enhanced than that of a-tocopherol. 3. The red light-induced changes of carotenoid and lipoquinone metabolism are similar in a qualitative sense to those obtained under continuous far-red, white or blue light. 4. In contrast to blue light, red light induces in the first hours of illumination a lower rate of chlorophyll and vitamin K1 formation. There are also differences in the ratios of the individual pigments and lipoquinones throughout the greening period.

scholarly journals Water stress-induced changes in morphology and anatomy of flag leaf of spring wheat

2014 ◽  
Vol 63 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Barbara Zagdańska ◽  
Janusz Kozdój
Keyword(s):  
Water Stress ◽  
Leaf Anatomy ◽  
Flag Leaf ◽  
Decisive Role ◽  
Mesophyll Cells ◽  
Flag Leaves ◽  
Leaf Area And Thickness ◽  
Total Cell Volume ◽  
Simultaneous Decrease ◽  
Induced Changes

Flag leaves of wheat (drought hardened and non-hardened) were examined by light microscopy to determine whether the differences in leaf anatomy could be related to the known differences in dehydration tolerance. Plants exposure to water stress during tissue differentiation of flag leaves resulted in an irreversible reduction of leaf area and thickness, increased frequencies of stomata and higher number of bulliform cells with simultaneous decrease in number of intermediate veins and an increase in the share of the cell walls in total cell volume. The smaller leaf thickness was due to a diminished number of mesophyll layers and a decreased size of mesophyll cells. Such altered leaf anatomy indicated development of leaf xerophily. It was found that the irreversible changes in anatomy of wheat flag leaves play a decisive role in acquiring drought tolerance during wheat acclimation to drought.

Die Synthese von Lipochinonen und isoprenoiden Pigmenten bei der Ergrünung von Etioplasten im Blaulicht / Synthesis of Lipoquinones and Isoprenoid Pigments during Greening of Etioplasts in Blue Light

1974 ◽  
Vol 29 (3-4) ◽  
pp. 142-146 ◽  
Author(s):  
Hans Kleudgen ◽  
Hartmut Lichtenthaler
Keyword(s):  
Blue Light ◽  
Red Light ◽  
Lipid Synthesis ◽  
Reduced Form ◽  
Synthesis Rate ◽  
Absorption Bands ◽  
Lipid Formation ◽  
Phytochrome System ◽  
Induced Changes ◽  
Β Carotene

Abstract Blue light induces in etioplasts of Hordeum seedlings parallel to the formation of chlorophyll an increased synthesis of carotenoids, plastidic benzoquinones and vitamin K1. 1. Blue light induces an enhanced synthesis of β-carotene, lutein, violaxanthin, and neoxanthin, while the levels of antheraxanthin and zeaxanthin are decreased. 2. In contrast to the etiolated tissue a much higher portion of total plastoquinone-9 (oxidized and reduced form) is formed in blue light than total α-tocopherol (+ α-tocoquinone), and a higher portion of the oxidized quinone forms plastoquinone-9 and α-tocoquinone. 3. The blue-light-induced changes of the isoprenoid lipid synthesis described here are similar to those obtained in continuous far-red light. It is, therefore, suggested that blue light is effective via the blue absorption bands of the phytochrome system. 4. Blue-light-induced greening of etioplasts results in a much higher synthesis rate of chlorophyll a and other isoprenoid thylakoid lipids as compared to red light. This enhancement of thylakoid lipid formation appears to be a special blue light effect.

scholarly journals Role of Proton Motive Force in Photoinduction of Cytoplasmic Streaming in Vallisneria Mesophyll Cells

Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 376
Author(s):  
Akiko Harada ◽  
Yoshiji Okazaki ◽  
Toshinori Kinoshita ◽  
Reiko Nagai ◽  
Shingo Takagi
Keyword(s):  
Cytoplasmic Streaming ◽  
Red Light ◽  
Proton Motive Force ◽  
Motive Force ◽  
Activation Mechanism ◽  
Dependent Manner ◽  
Mesophyll Cells ◽  
P Type ◽  
Exchange Activity

In mesophyll cells of the aquatic monocot Vallisneria, red light induces rotational cytoplasmic streaming, which is regulated by the cytoplasmic concentration of Ca2+. Our previous investigations revealed that red light induces Ca2+ efflux across the plasma membrane (PM), and that both the red light-induced cytoplasmic streaming and the Ca2+ efflux are sensitive to vanadate, an inhibitor of P-type ATPases. In this study, pharmacological experiments suggested the involvement of PM H+-ATPase, one of the P-type ATPases, in the photoinduction of cytoplasmic streaming. We hypothesized that red light would activate PM H+-ATPase to generate a large H+ motive force (PMF) in a photosynthesis-dependent manner. We demonstrated that indeed, photosynthesis increased the PMF and induced phosphorylation of the penultimate residue, threonine, of PM H+-ATPase, which is a major activation mechanism of H+-ATPase. The results suggested that a large PMF generated by PM H+-ATPase energizes the Ca2+ efflux across the PM. As expected, we detected a putative Ca2+/H+ exchange activity in PM vesicles isolated from Vallisneria leaves.

Regulation of cytoplasmic streaming in Vallisneria mesophyll cells

1983 ◽  
Vol 62 (1) ◽  
pp. 385-405
Author(s):  
S. Takagi ◽  
R. Nagai
Keyword(s):  
Cytoplasmic Streaming ◽  
Calcium Concentration ◽  
External Medium ◽  
Red Light ◽  
Middle Lamella ◽  
Pond Water ◽  
Free Calcium ◽  
Mesophyll Cells ◽  
Free Calcium Concentration ◽  
In Cells

Induction and cessation of the rotational cytoplasmic streaming in Vallisneria mesophyll cells could be controlled by external stimuli. In cells that had been kept in darkness the cytoplasm remained quiescent. However, when the cells were treated in the dark with EGTA solution (10 mM or 20 mM buffered with 10 mM-Tris-maleate at pH 7.0), rotational cytoplasmic streaming was induced. When the cells were transferred again to artificial pond water in the dark, the induced streaming was inhibited; that is, only 50% of the observed cells exhibited active streaming after 2 h. When the cells were irradiated continuously with far-red light (lambda max = 750 nm, 0.4 W/m2) in the same external medium, the induced streaming was inhibited almost completely within 2 h. The relative quantum effectiveness of monochromatic light (450–800 nm) in producing cessation of streaming was also investigated. Irradiation with light of 450, 550 and 600 nm was almost as effective as darkness. Light of 500 and 650 nm was less effective than dark exposure. Only irradiation at 750 nm stopped streaming in almost all cells. But when calcium was excluded from the external medium, the effect of far-red light decreased to almost the dark control level. Light of 800 nm also inhibited the streaming but the effect was much less than that of far-red light. Microfilaments in bundles with the long axis parallel to the streaming direction were localized in the vicinity of the cell membrane. Their configuration, localization and distribution were the same in the present experimental system irrespective of whether the cytoplasm was streaming or quiescent. Intracellular calcium was examined by electron microscopic cytochemistry and X-ray microanalysis. In cells with streaming induced by EGTA, only a small amount of calcium-containing precipitates formed in the cytoplasm in the presence of antimony. A few precipitates were found in the chloroplasts, the middle lamella of the cell wall and at the border between the cytoplasm and the cell wall. On the other hand, in cells treated with EGTA and subsequently irradiated with far-red light in artificial pond water, many precipitates were observe in the cytoplasm, chloroplasts, mitochondria and endoplasmic reticulum. The middle lamella was also heavily stained. On the basis of these observations, it was concluded that rotational cytoplasmic streaming in Vallisneria cells can be induced when the free calcium concentration in the cytoplasm decreases and that the induced streaming is arrested when the free calcium concentration in the cytoplasm increases. Far-red light accelerates the increase of calcium in the cytoplasm.

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