切花茎基端酚类代谢与采后茎堵塞的关系及其机理研究

切花采后极易发生茎堵塞，并直接影响其采后品质和商品价值。在本人前期研究中发现采切创伤引起的茎基端酚类代谢可能参与切花采后的生理性堵塞。但目前国际上缺乏对切花茎基端酚类代谢的研究报道，且对其影响切花采后水分输导功能的机理尚不清楚。为此，基于这一思路和前期研究基础，本项目以采后茎基端酚类代谢和茎堵塞均突出的百合、月季等主流切花为研究材料，采取理化分析、组织化学与显微结构观察、酶活性分析、基因克隆与表达分析等技术手段，并结合相关采后处理（外源酚、酚类代谢关键酶抑制剂、茎基端热水处理和不同贮运环境条件等）对切花茎基端酚类代谢的调控作用以及对切花采后茎堵塞和观赏品质的影响进行研究，系统探讨和揭示茎基端酚类代谢与切花采后茎堵塞的内在关系及其机理，并为形成和提出有效控制切花采后茎堵塞的新策略与处理技术提供科学依据。此外，研究成果对果蔬贮运与加工、植物组培等酚类代谢发生与调控研究也具有重要的借鉴意义。

Cut flowers are very prone to stem blockage during their postharvest period, which directly disrupts their ornamental quanlity and commodity value. In our preliminary study, it was found that the phenolic metabolism induced by cutting wound in the stem-ends of cut flowers is evidently involved in the physiological blockage in the tested cut flowers. But so far there are few research reports on the phenolic metabolism in the stem-ends of cut flowers, and its influencing mechnism on the water transportation in their stems need to be elucidated. Hence, according to this research thought and our related preliminary experimental results, the present project aims at exploiting and understanding the inherent relationships between phenolic metabolism and stem blockage in cut flowers and its mechanism, based on physical and chemical analyses of main phenolic compounds and metabolites, the investigations in histochemistry and microstructure (i.e. the spatial-temporal feature of phenolic compounds and their metabolites deposition in the cut ends and its effects on the morphology and structure of water-conducting tissue in cut flowers), biochemistry and molecular biology (i.e. the induction of the activities and gene expressions of PAL, PPO and POD, the key enzymes in the phenolic metabolism, and its relation to the formation of phenolic compounds and their metabolites in cut stem-ends), and postharvest physiology (i.e. the effects of various postharvest treatments and its control on phenolic metabolism and their effects on stem blockage and ornamental quality of cut flowers), using cut lily and rose flowers as the main experimental materials. The results from this project will help to reveal the features of phenolic metabolism in stem-ends of cut flowers and its regulation mechanism, and to address a new approach to inhibit phenolic metabolism and to alleviate the stem blockage, and thereby to improve the water transportation in cut flower stems.