科研之友
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摘要
beta-Pinene, an oxygenated monoterpene, is one of the major monoterpenes emitted into the atmosphere from forest areas and trees. Besides, it is a principal component of essential oils of a number of aromatic plants, which are involved in a variety of ecological interactions, including allelopathy, in the natural environment. However, studies pertaining to phytotoxicity and biochemical effect(s) of beta-pinene are largely lacking. We investigated the effect of beta-pinene (0.02, 0.04, 0.08, 0.20, 0.40 and 0.80 mg/ml) in a dose- and time-dependent manner on early seedling growth, dry weight accumulation, photosynthetic pigments and changes in macromolecule (protein and carbohydrate) content and activities of enzymes-proteases, alpha- and beta-amylases, polyphenol oxidases and peroxidases- in rice (Oryza sativa) after 3rd, 5th and 7th day of exposure. beta-pinene (a parts per thousand yen0.04 mg/ml) significantly reduced the root (by 13-87%) and coleoptile (by 5-80%) length of rice. Exposure to beta-pinene reduced total chlorophyll content in rice coleoptiles suggesting a negative impact on photosynthesis. The content of macromolecules (proteins and carbohydrates) enhanced significantly in response to beta-pinene, whereas the activities of hydrolyzing enzymes-proteases, alpha-amylases, and beta-amylases-declined (by 30-85, 26-84, 27-74%, respectively) in beta-pinene-exposed seedlings. In contrast, the activities of peroxidases (POX) and polyphenol oxidases (PPO) enhanced significantly (by 16-152 and 53-290%, respectively) in rice roots in response to beta-pinene in a dose- and time-dependent manner. Increased activities of POX and PPO indicate their involvement in providing protection and/or conferring resistance against beta-pinene-induced stress. The study concludes that beta-pinene inhibits the early growth of rice by altering the plant biochemical status and enhancing activities of POXs and PPOs involved in general plant defense.
- 出版日期2011-11
