艾纳香腺毛结构、发育及其与左旋龙脑积累关系研究

The only source plant of the Traditional Chinese Medicine aipian (l-borneol) is Blumea balsamifera. However, lacking of good varieties, the concentration of essential oil and l-borneol in plants were instability, resulting low product efficiency. We found the glandular hair is the secretary structure on the plant, and may be the crucial factor affecting the l-borneol accumulation in the plant. .In some plant species, glandular hairs development relates closely with quality and quantity of oils. Does it work similarly in B. balsamifera? This question is yet to answer and the present project is to study the internal relation between plant morphology transformations, microstructural or ultra-micro structural changes and the accumulation of l-borneol in B. balsamifera glandular hair. .We will operate the whole research under a stable environment. First, we will employ electron microscopic enzyme histochemical method to show the changes of the enzyme activity during glandular hairs formation. Second, we are to study the structural developmental processes of the glandular hair, and for these there are wide ranges of approaches such as frozen sectioning, paraffin sectioning and tissue clearing available. Third, we are to analyze the relation between the distributions of glandular hairs and the accumulation of l-borneol with counting and gas chromatography. .As a result, this project may illustrate the synthesizing site, transporting mode and storing position of essential oils in the glandular hairs. .In summary, this project will expound the accumulation pattern of l-borneol. Also it will provide an optimal harvest conditions suggestion and a set of evaluation index of quality control. By performing present project, we may increase the production efficiency of aipian, and thus promote relative industries.

艾纳香是中药艾片（左旋龙脑）的唯一来源植物，但艾片生产效率低，经济效益差。对艾纳香最佳采收条件认识不清，原料的左旋龙脑含量低且不稳定，是限制艾片生产效率的瓶颈。左旋龙脑存在于艾纳香精油中，申请人发现腺毛是其精油的重要分泌结构，与左旋龙脑的积累密切相关，推断腺毛是影响艾片生产效率的关键。本项目设定稳定的环境因素，以腺毛为研究对象，以腺毛的发育为线索，拟采用薄切片、冰冻切片、整体透明等技术从超微、显微和宏观水平研究精油合成、转运、积累和分泌的过程，再采用电镜酶细胞化学、组织化学定位、GC/MS等化学手段研究其中精油分布、含量和成分变化，特别是左旋龙脑含量的变化。本项目的实施有望阐明左旋龙脑在艾纳香中积累的规律，提出艾纳香的最佳采收条件建议和品质控制的综合评价指标，从而达到提高艾片产率，促进产业发展的目的。

艾纳香（Blumea balsamifera （L.）DC.）是中药艾片（左旋龙脑）唯一来源植物，但左旋龙脑在艾纳香叶中含量低，导致艾片生产效率低，经济效益差。对艾纳香最佳采收条件认识不清，原料左旋龙脑含量低且不稳定，是限制艾片生产效率的瓶颈。左旋龙脑存在于艾纳香精油中，申请人发现腺毛是其精油重要分泌结构，与左旋龙脑积累密切相关，推断腺毛是影响艾片生产效率的关键。基于此，本项目以艾纳香克隆苗的腺毛为研究对象，采用超微、显微和宏观观察结合化学分析技术，研究精油合成、转运、积累和分泌的过程，研究其中精油含量和成分变化，特别是左旋龙脑含量的变化。结果显示：在超微结构水平，艾纳香精油合成场所在艾纳香腺毛和叶肉组织中叶绿体中，早在未分化的幼嫩叶中已有萜类合成，并观察到附近有高尔基体分布；在显微结构水平，艾纳香叶表皮毛最早发生于第一片真叶远轴面，腺毛发生晚于非腺毛。在叶肉、叶腺毛中均观察到精油积累。不同发育阶段腺毛中精油积累由少增多并存在头部破裂释放的过程；在宏观组织水平，腺毛密度最高的幼叶精油和左旋龙脑含量均最高，此后随叶片生长发育，腺毛密度下降，精油和左旋龙脑含量均下降。比较不同月份艾纳香中精油和左旋龙脑含量结果显示大体而言下半年精油和左旋龙脑积累显著高于上半年，但植株生物量在7月至10月仍快速上升，由于左旋龙脑产量是总生物量×左旋龙脑含量（干物质浓度），综合考虑植株生物量、挥发油和左旋龙脑含量，11月采收可望获得较高左旋龙脑产量。本研究结果提示腺毛和叶肉中叶绿体均参与了艾纳香精油的合成，都是艾纳香精油的合成场所，高尔基体可能参与了艾纳香萜类物质的转运；叶片的腺毛和叶肉组织同时发挥了储藏精油的功能；随着叶片发育，腺毛衰老并释放部分精油，但所有发育阶段叶片均含精油和左旋龙脑，含量显著高于主茎、花和根。因此建议采收的最佳部位为所有发育阶段的叶片和嫩枝，不采收花、老茎与根；最佳采收株龄为3年，较好采收时段为下半年，最佳采收月份为11月。最佳采收条件显微特征为功能叶横切面经苏丹Ⅲ染色可见大量橙色油滴，且表面显微观察可见大量腺毛的植株。对应的化学指标为精油含量高且左旋龙脑干物质浓度高的植株。