Strategies for enhancement of bioactive flavonol glycosides in plants

增强植物中生物活性黄酮醇苷的策略

• 批准号: RGPIN-2015-03950
• 负责人: Bozzo, Gale
• 金额: $ 1.75万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=646113
• 关键词: Strategies; enhancement; bioactive; flavonol; glycosides

Flavonols (e.g. quercetin) are well known phytochemicals. Their incorporation in the human diet may prevent accumulation of damaging radicals associated with chronic diseases including Alzheimer's. Approximately 5% of Canadians over the age of 65 are diagnosed with some form of dementia. Flavonols offer a preventative measure to offset the $33 billion spent annually to treat these disorders in Canada. In the human diet, flavonols are not as available as their glycosides, forms which tend to predominate across vegetative (e.g. onion, kale, broccoli) and fruit (e.g. apple, grape, pepper, tomato) tissues. In plants, flavonols exists as conjugates of one or more sugars, including monoglycosides, diglycosides and bisglycosides (e.g. quercetin 3-O-ß-glucoside-7-O-a-rhamnoside). The physiological roles of these compounds in plants are not yet clear, but evidence suggests they are linked to growth, environmental stress, and plant-insect interactions. Plant accumulation of flavonol bisglycosides occurs in response to environmental perturbations, including UV-B light, chilling, nutrient deficiencies, and is dependent upon transcriptional regulation of the biosynthetic pathway. Flavonol preservation in plants, including foodstuffs, is not solely dependent upon biosynthetic processes as losses on the order of 1-35% per day are typical, including during postharvest handling. Enhanced levels of flavonol bisglycosides may be achieved by minimizing their degradation in planta, processes that are little understood. ***Over the past 6 years, my laboratory has established the biochemical evidence for the loss of flavonol bisglycosides and their related molecules from plants. Our current research focuses on characterizing this catabolism in Arabidopsis thaliana, a model plant for flavonol biochemistry due to the availability of genetic mutants. A highlight of our research includes the identification of an enzymatic component, specifically a ß-glucosidase, as a possible first step in the loss of these bioactive compounds. We are interested in elucidation of the complete flavonol bisglycoside catabolism pathway in plants. Our laboratory uses cutting edge analytical chemistry platforms together with physiology, classical biochemistry and biotechnology to identify the genes/enzymes associated with the turnover of these important small molecules. In addition to providing unique training opportunities for students in biochemistry, molecular biology and analytical chemistry, this research aims to enhance knowledge of plant flavonol catabolism. Moreover, this novel research provides potential tools for genetic engineering and molecular breeding strategies targeting flavonol biofortification in economically important crop plants.***********

黄酮醇（例如槲皮素）是众所周知的物理。它们在人类饮食中的掺入可能会阻止与包括阿尔茨海默氏症在内的慢性疾病相关的破坏辐射。 65岁以上的加拿大人中约有5％被诊断出患有某种形式的痴呆症。黄酮醇提供了一种预防措施，以抵消每年在加拿大治疗这些疾病的330亿美元。在人类饮食中，黄酮醇不像其糖苷那样可用，它们倾向于跨蔬菜（例如洋葱，羽衣甘蓝，西兰花）和水果（例如苹果，葡萄，胡椒，番茄）组织占主导地位。在植物中，黄酮醇作为一种或多种糖的缀合物存在，包括单糖苷，二糖苷和双糖苷（例如槲皮素3-O-β-葡萄糖苷-7-O-A-A-Rhamnoside）。这些化合物在植物中的物理作用尚不清楚，但证据表明它们与生长，环境压力和植物侵入相互作用有关。植物双糖苷的植物积累是响应环境扰动而发生的，包括UV-B光，寒冷，营养缺乏，并依赖于生物合成途径的转录调节。包括食品在内的植物中的黄酮醇保存不仅依赖于生物合成过程，因为每天1-35％的损失是典型的，包括后票后处理。可以通过最大程度地减少其在植物学中的降解，而几乎没有理解的过程来最大程度地减少它们的降解，从而达到了黄酮醇的水平增强。 ***在过去的6年中，我的实验室已经建立了生化证据，证明了双糖苷及其与植物相关的分子的丧失。我们目前的研究重点是表征拟南芥这种分解代谢，该拟南芥是由于遗传突变体的可用性而用于黄酮醇生物化学的一种模型植物。我们研究的亮点包括鉴定酶促成分，特别是β-葡萄糖苷酶，这是这些生物活性化合物丧失的第一步。我们有兴趣阐明植物中完整的双糖苷分解代谢途径。我们的实验室使用尖端分析化学平台，以及生理学，经典生物化学和生物技术，以识别与这些重要小分子的营业额相关的基因/酶。除了为学生的生物化学，分子生物学和分析化学提供独特的培训机会外，该研究旨在增强植物黄酮分解代谢的知识。此外，这项新颖的研究为靶向黄酮醇生物实现的基因工程和分子育种策略提供了潜在的工具。****************