【作者】 沈宗根；

【导师】 胡正海； Yitzchak Gutterman；

【作者基本信息】 西北大学 ， 植物学， 2001， 博士

【摘要】 芦荟属（Aloe）植物属百合科，在医药、日化和食品中广为应用，其药用部分为叶，主要药用成分为蒽醌类物质。我们用解剖学方法（徒手切片，石蜡切片，薄切片和超薄切片），植物化学（TLC），组织化学结合荧光观察等技术比较研究了芦荟属9种植物叶在结构上的异同、主要蒽醌类物质含量的差异，并探讨了两者间的相关性，系统研究了不同叶龄和叶的不同部位中蒽醌类物质含量的变化规律以及蒽醌类物质产生和储存的结构和它们的组织化学、形态发生及超微结构规律，并探讨了芦荟属植物叶累积蒽醌类物质的生物学意义。 研究结果表明：（1）.芦荟属植物叶的形态结构基本类似，都属于旱生肉质叶，都由表皮，叶肉和维管束构成。其表皮一层，排列紧密，外被厚的角质层，气孔下陷。叶肉分为两部分，由同化薄壁组织和储水组织组成。在同化薄壁组织中具含晶异细胞。维管束位于同化薄壁组织和储水组织之间，排列成1轮。每个维管束由维管束鞘，木质部和韧皮部组成。维管束鞘1至多层，木质部和韧皮部管状分子数量少，不发达，仅占维管束的小部分。在韧皮部中都具有数个发达的大型薄壁细胞，即芦荟素细胞常占据维管束的大部分体积，有时可达90％左右，这是该属植物叶的结构特征。储水组织发达，可占叶横切面的70-80％，由富含水分和粘液的大型薄壁细胞组成。9种芦荟属植物叶的比较解剖研究表明，在各种间叶结构的各组成部分存在明显差异。如表皮结构中，喀麦隆芦荟的表皮细胞厚度为100微米，而易变芦荟和库拉索芦荟叶的表皮细胞厚度仅25微米。其表面乳突和角质膜厚度种间差异也十分明显。气孔器常4细胞环绕，但在中华芦荟叶中首次观察到5细胞环绕的气孔器。同化薄壁组织细胞的厚度以及分化为海绵组织与栅栏组织的程度不等。多数种类叶的同化薄壁组织仅见到等径或栅栏状的薄壁细胞，木立芦荟叶则分化为栅栏状和等径两类细胞。前人报道，芦荟叶含晶异细胞中主要是长短不等的针晶，但在栗色芦荟中首次 观察到它缺乏针晶而具有长300－500微米的单晶柱。维管束以往都报道为1轮， 但在中华芦蔓叶的基部首次发现存在2轮维管束。以上叶结构上的差异为该属 植物间分类提供了新的依据。仅．TLC分析结果表明，被研究的芦苔属9种植 物叶中主含的葱醒类物质有：芦苔素或高那特芦苔素，芦苔宁和芦苔苦素。其 中，中华芦苔、库拉索芦姿（翠叶芦苔）、栗色芦苔和木立芦苔主含芦苔素；僧 帽芦苔、海莱芦苔和隐脚芦苔主含高那特芦苔素；而喀麦隆芦苔和易变芦苔则 兼含芦苔素和高那特芦苔素。对叶的各部位详细分析的结果表明，葱醒类物质 在植株上部的嫩叶中的含量要高于下部老叶；同一叶中，叶尖高于叶中部，叶 基含量最低；而叶缘含量高于叶的中央部分。叶背腹面的含量也存在差别。在 同一叶的横切面上，惫醒类物质的含量在维管束区最高，同化薄壁组织部分次 之，储水组织部分最低。门）．观察测量了不同种叶各部分的维管束密度，芦苔 素细胞在维管束中所占的比例以及同化薄壁组织在被测部分的组织中所占的比 例，结果发现：维管束密度和芦苔素细胞在维管束中所占的比值在同一横切面 上，叶缘高于叶的中央，幼叶高于老叶，叶尖高于叶基；同化薄壁组织厚度则 往往近轴面大于远轴面。通过比较这些解剖学指标在叶各部位的平均值差异和 变化趋势与葱醒类物质在叶内的含量差异的规律性变化并进行相关性分析，发 现并提出了两者间存在正相关，由此提出了选育优良的栽培芦苔品种的解剖学 指标。（）．根据葱醒类物质遇碱变色、遇重金属离子能产生特殊的结晶和沉淀 的化学特性以及葱醒类物质在紫外光下能产生的特殊荧光，我们首次对4种芦 苔叶内的葱酿类物质的产生和储存结构进行了组织化学定位。研究结果表明， 经2－5％的NaOH溶液处理新鲜材料，可以观察到在维管束韧皮部端的芦苔素细 胞呈红色或深红色反应。用5％的醋酸铅溶液处理后的材料所制的切片中，在含 芦苔素的细胞内产生结晶并沉淀。荧光显微镜观察的结果则表明，在365urn波 长的紫外光激发下，芦苔素细胞显示出芦苔素或高那特芦苔素特殊的黄色荧光， 而维管束鞘以及储水组织和同化薄壁组织分界的一圈薄壁细胞则显现兰色的荧 光，后者表明有芦苔宁或芦苔苦素等物质的存在，而在储水组织中没有发现黄 色或兰色的荧光。我们的研究结果与 Bnlll．－和 Tosi （ 982）的报道明显有别， 纠正了他们的观点。他们认为，芦苔素等葱醒类物质主要存在于同化薄壁组织 和储水组织之中，而维管束中不存在这一类物质。＊）．对木立芦苔叶中维管柬 鞘和含芦苔素细胞成熟结构的?更多还原

【Abstract】 Comparative and the Correlative Studies on the Structureand the Content of Anthraquinoncs in AIoe LeavesBy f Shen ZonggenSupervisor: Pro f Hu Zheng-haiInstitute of Botany, NorthWst University Xi’an 710069, PR.ChinaSuPervisor f Pro f YtZchak GuttermanBen-Gurion University of the Negev, Unit for Ecophysiology and Introductionof Desert Plans, Wyler DepartInent of Drylands AgricultUre, Jacob BlauSteinInstit’Ute for Desert Research, Sede Boker Campus, 84990, IsraelAbstractThe AlOe comPtises a large genus of over 300 species, to which additionsare regUlar being made. The genus is native to Affica, from the CaPe and thedeserts of South Affica to the tropical pats of Affica, and to the southemparts of AIabian Peninsula. Because of the widespread use of Aloe speciessince ancient times as both drugs (their phannaceutical activity anthraquinonesand their derivative) and cosmetics, Aloe plants have spread in cultivationthroughout the world. However, little information is available as to therelationships betWeen chemicals and the leaf smictures within the grouPs.In this study, we systematically investigated the structural differences, thedifferent content of mainly anthraquinones in leaves of different ages and leafparts and the correlation betWeen the smicture and the content of fOurmetabolites, barbaloin, homonataloin, Aloenin and and isomers of Aloeresin, inl0 Aloe species. We used the multiple aPProaches - anatomical, phytochemistryfluorescent, ligh and scanning electron microscopes and histochemistrymethods. The morphogenesis, histochemial location and ultfa-struCture of thestructures for production and accumulation of these metabolites were alsocarried out.The anatomical results revealed that the smicthel feamres of AlOe leavesare similar Aloe leaves usually consist of epidermis, chlorenchyma andvascular bundles. The 1eaf surface is covered by a layer of ePidermal cells thatare covered by a thick cllticle. Many sunken stomata are uniformly distributedin the ePidermis. Mesophyll can be divided into chlorenchyma and aquiferous4tissues. IdioblastS are usually distributed axnong chlorenchymatous cells.Vascular bundles, which are composed of one layer ofparenchymatus cells as asheath, phloem and Xylem tissues, are located betWeen the chlorenchyma andaquiferous tissues. There are several well-developed large parenchymatouscells, i.e. aloin cells, at the phloem pole of each bundle. The aloin cells occupythe most of the area of the cross section of a bundle. Aquiferous tissue iscomPosed of many large cells, which is full of mucilage and water, and willoccuPy 70-80% of a leaf cross-section.The results from comPndive studies indicated that there are somedifferences in leaf structutes among the different species of AlOe plants. Thethickness of epidermis in A. cameronii is about l00 pm, but in A. mutabilis andA. vera L. var chinensis it is only about 25 pm. The different pattems of thecuticle were also Observed. In general, four guard cells surround the each stoma,however, five cells toes were firstly rePorted. In addition, the thicbess ofchlorenchyma and the degree of differentiation of the chlorenchyma are alsodifferent among l0 plans tested. Most of the plants did not differentiate intopalisade and spongy tissues. In A. arborescens, the chlorenchyma can bedivided into tWo parts, palisade and isodiametfic cells. It was rePorted that thecrystals in idioblasts are mainly needle-shaPed that vary in length. However,we first observed there are no needle crystals in A. arborescens bllt 300-500pm long single column crystals in A. cmptDPada. Instead of one ring ofvascular bundles, we fOund that there are tWo rings of bundles in the basal partsof A. vera L. var chlbensltr leaves. The above smictUral differences are the newdata fOr classification of Aloe.TLC analysis demonstrated that four secondmp metabolites are mainlycontained in 9 AlOe plants, they are barbaloin, hom更多还原