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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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Unexpected Role of Humic Acids in Wax Biosynthesis of Higher Plantsтезисы доклада
- Авторы: Kulikova N., Tsvetkova E., Badun G., Perminova I., Chernysheva M.
- Сборник: Abstracts of Second International Conference of CIS IHSS on Humic Innovative Technologies «Natural and engineered nanoparticles in clean water and soil technologies»
- Том: 2
- Тезисы
- Год издания: 2012
- Место издания: Moscow, Russia
- Первая страница: 28
- Последняя страница: 28
- Аннотация: The beneficial effects of humic acids (HA) have been numerously reported. According to a modern view on biological activity of HA they can affect plant growth by different ways such as increasing respiration, enhancing mineral nutrition, and/or stimulating hormonal activities Although a large dataset of evidence indicates that HA can directly affect plant development in several metabolic pathways, relatively little attention has been paid to uptake of HA by plants. However, realization of the above mentioned mechanisms requires HA entering plants and translocation from their roots to shoots. Therefore, uptake of HA by plants is a keystone in understanding nature of HA activity. Recently it was demonstrated that endodermis possessing hydrophobic character due to cell wall suberinization was seemingly the main control point for HA transport in plants [1]. The objective of this work was to study distribution of HA in plants lipid fraction using tritium labeled humics. Tritium-labeled coal humic acids ([3H]HA) were prepared as described in [2]. Seedlings of wheat Triticum aestivum L. were used for the experiments. Eight-day old plants were transferred into the vials containing 15 mL of HA at concentration 50 mg⋅L–1 with specific radioactivity ∼0.7 mCi L–1. After 24 h plants were taken out from the solutions and wheat shoots were subjected to lipid extraction and separation by thin layer chromatography (TLC) procedure followed by autoradiography of the chromatograms. Then the band where the highest radioactivity was observed was subjected to GC-MS analyses. Compounds of the [3H]HA band of plant lipid extract determined using CG-MS analyses were found to be mainly hydrocarbons including normal and branched alkanes (about 73% of total amount of compounds) and normal alkenes (about 19% of total amount of compounds). In case with lipid fraction of humics, alkanes (normal and branched) and normal alkenes totally accounted for about 54% of determined compounds. It could be therefore hypothesized that compounds from HA (or at least part of them) must not be metabolized by plants before assimilation but assimilated in crudo. Alkanes can be usually found in plants in waxes which are associated with cuticle and suberized tissues, and the determined composition of HA in lipid fraction might therefore reflect their role as part of the waxes associated with suberized tissues. In most plants there are two principal wax biosynthetic pathways: an acyl reduction pathway, which gives rise to primary alcohols and wax esters, and a decarbonylation pathway, leading to the formation of aldehydes, alkanes, secondary alcohols and ketones. It is the decarbonylation pathway providing principally wax biosynthesis, and the principal step of the decarbonylation pathway is the hydroxylation of alkanes to secondary alcohols. Therefore, HA-derived hydrocarbons could be hypothesized to be involved in the wax biosynthesis as precursors for secondary alcohols. References. 1. Kulikova NA, Abroskin DP, Beer AS, Badun GA, Chernysheva MG, Korobkov VI, Perminova IV (2012) Endodermis is the major control point for radial transport of humic substances into vascular system of plant. In: Functions of natural organic matter in changing environment. Xu J., We J., He Y. (Eds.). Springer, Zhejiang Univ. Press, ISBN 978-7-308- 10271-1, pp. 491-492. 2. Badun GA, Chernysheva MG, Tyasto ZA, Kulikova NA, Kudryavtsev AV, Perminova IV (2010) A new technique for tritium labeling of humic substances. Radiochim Acta 98: 161-166.
- Добавил в систему: Бадун Геннадий Александрович