Primary Photodynamic Reactions Occurring During the Breakdown of Photosynthetic Pigments

Ethane was used as an indicator of lipid peroxidation in order to characterize the membrane damage induced by electrical pulses during the processes of electrofusion and electropermeabilization. The increase of ethane in fused protoplasts ofVicia faba L. was found to be correlated with the intensity of field strength and pulse number, which also affected the yield of hybrids. The degree of membrane damage is postulated to depend on the accumulation of lipid free-radicals, which can be increased by light, by longer storage time of protoplasts and by higher field strength and pulse number. As a result, the conditions for electropermeabilization lead to greater membrane damage compared with those for electrofusion. The measurement of ethane production may prove to be useful for characterization of the membrane integrity, viability and regeneration ability of protoplasts.

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Metabolism of Labeled Exogenous Glucose in Fiber Flax Tissues

Chikov

Avvakumova

Bakirova

et al. 2005

Biol Bull Russ Acad Sci

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Labeled glucose solution was introduced into cut fiber flax plants (45-50 cm high) under a pressure of 0.1 bar for 30 min, 1, and 2 h using a special device. The highest quantities of labeled carbon were revealed in the woody tissue. Sucrose made up a considerable proportion in low molecular weight products of [2-14 C]-glucose transformation (23.5%). Metabolism of labeled glucose in the leaves exposed to sunlight yielded a set of metabolites similar to products of 14 CO 2 photoassimilation. In the shade, the pattern of 14 C distribution in labeled compounds of the alcohol/water soluble fraction was similar to that in the light in mature leaves; while in juvenile leaves, 14 C content decreased in sucrose and increased in organic and amino acids. In the shade, the incorporation of 14 C into starch and hot water soluble polysaccharides increased at the expense of the acetone fraction (lipids and pigments), water/salt soluble proteins, and cellulose. Low light conditions increased the radioactivity ratio of sparingly soluble (KOH and Triton X-100 soluble) proteins to albumins and globulins. We propose that the synthesis of components of the photosynthetic apparatus in juvenile leaves is directly powered by photosynthesis and the photosynthesis of sucrose and the polymers compete for photosynthetic ATP. Appearance of sucrose in the xylem is due to its release from the phloem to the stem apoplast and the radial transfer to the xylem, where it is transported to the upper part of the shoot with the transpiration stream.

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Primary Photodynamic Reactions Occurring During the Breakdown of Photosynthetic Pigments

Cited by 12 publications

References 13 publications

Naturally Occurring Perylenequinones

Naturally Occurring Perylenequinones

Differential effects of electrofusion and electropermeabilization parameters on the membrane integrity of plant protoplasts

Metabolism of Labeled Exogenous Glucose in Fiber Flax Tissues

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