构树化学成分研究

通过硅胶、ODS、SephadexLH20反复柱层析、纯化,从构树的乙醇提取物中分离得到9个化合物,利用波谱方法分离鉴定为胡萝卜苷(1),槲皮素(quercetin,2),双氢槲皮素(dihydroquercetin,3),butein4methylester(4),甘草素(liquiritigenin,5),异甘草素(isoliquiritigenin,6),异甘草黄酮醇(isolicoflavonol,7),butyrospermylacetate(8)和( )marmesin(9)。其中,化合物1～5均为首次从构树中分离得到。     

构树皮中三萜类化学成分

对构树皮的化学成分进行进一步研究,通过反复硅胶柱层析从构树皮乙醇提取物的石油醚萃取部位中分离得到六个三萜成分,利用波谱技术及理化性质鉴定其化学结构分别为3β-乙酰氧基-甘遂-7-烯-24S,25二醇(1),3β-乙酰氧基-7,23-甘遂二烯-25-醇(2),羽扇豆醇(3),α-香树脂醇乙酸酯(4),3β,25-二羟基-7,23-甘遂二烯(5)和β-香树脂醇(6)。其中化合物1为新的甘遂烷型三萜,化合物2～5为首次从该植物中分离得到。     

构树皮的化学成分研究

通过反复硅胶柱层析从构树根皮乙醇提取物石油醚部位中分离得到10个化合物,利用波谱方法分别鉴定为β-谷甾醇(1),lupeol acetate(2),6,7-二甲氧基香豆素(3),Broussonin A(4),Broussonin B(5),Broussonin F (6),(+) marmesin(7),(+)-(2...     

构树雌雄株叶片解剖结构特征的比较研究

为了研究雌雄异株植物构树（Broussonetia papyrifera（L.） Vent.）的性别差异,以其叶片为材料,采用石蜡切片法,对其主要解剖结构特征进行观察和比较。结果显示：（1）构树雌、雄株叶片解剖结构组成一致,均由表皮、叶肉组织和叶脉3部分组成。其上、下表皮均由一层细胞构成,具有较厚的角质层及丰富的表皮毛,叶肉中栅栏组织高度发达,此外,维管系统在叶中所占比例很大;（2）构树雌、雄株叶片细胞大小及厚度在各类型组织间存在一定差异,雄株叶片上表皮厚度、栅栏组织厚度、主脉维管束木质部厚度及维管束厚度均显著大于雌株叶片,且在栅海比、组织结构紧密度、组织结构疏松度和主脉维管束木质部面积占维管束的比例等方面也与雌株有极显著差异。研究结果表明构树叶片的解剖结构不仅具有旱生植物叶片的典型特征,而且还表现出明显的性别差异,这可能与构树雌、雄株的生殖分配有关。     

Comparative Studies on Differentiation of Regenerated Tissue in Broussonetia papyrifera

This paper describes the differentiation process of regenerated tissue after ordinary girdling or after removal of a section of xylem from the stem, and the disparity in differentiation of the regenerated tissues after being differently treateds in Broussonetia papyrifera. After ordinary girdling for 3–4 weeks, new bark regenerated in the xylem. During the process of rind' formation, many specks of meristematic tissue were formed in the callus, from which vascular tissue clusters were developed. In addition, the new periderm appeared almost at the same time as the new vascular cambium was seen. When a section of xylem was removed from the stem, numerous calli developed rapidly on the inner surface of the bark. Meanwhile, the vascular cambium appeared in the immature phloem. Soon after, discontinued meristematic tissue bands also occurred in the callus. These meristematic tissues then connected with each other to form a concave oblate cambial ring which developed xylem inward and phloem outward. About 2–3 weeks later, the concave oblate trunk grew lengthwisely connecting with the upper anct lower portions of the normal stem. By then, the tree continued to grow. The inner surface tissue of the bark, after the xylem was removed, differentiated about one week earlier than the tissue on the surface of the xylem after girdling.     

Changes of Peroxidase and Estease Isozymes During Periodicity of Cambial Activity in Broussonetia papyrifera (L.) Vent.

Methods of sampling and sections preparaction were the same as reported previously. Except that sampling was made at monthly intervals between May 20 and July 30, then at 7–14 day-intervals between July 30 and October 14, and then at monthly intervals between October 14 and March 25 in the next year. The stored starch in various tissues was stained with PAS reaction. During active period of cambium in Broussonetia papyrifera after July 30, the cell layers of immature xylem and phloem decreased progressively, and the formation of mature xylem and phloem increased rapidly. The formation of late wood started early in August, formation of xylem ceased after September 5, followed by ceasation of phloem formation about 1.5 months later. Increasing and decreasing of stored starch were closely related to the periodicity of cambial activity during the year. Starch grains decreased progressively after cambial activity was resumed in early spring until they disappeared in all the stem tissues. Then, starch accumulated progressively again after cambial activity slowed down, particularly after the ceasation of xylem formation. However, after the formation of phloem had ceased, the stored starch once again disappeared progressively until the end of December, and accumulated again. Such changes might be related to the transition of cambium activity involving two periods of dormancy.     

构树种子化学成分研究

对构树种子的脂肪油、氨基酸、矿质元素进行分析,结果表明:种子含脂肪油40.18%,主要成分为:亚油酸(85.42%)、油酸(4.29%)、棕榈酸(7.35%)、亚麻酸(0.98%)等。此外,还含有17种氨基酸和24种矿质元素。     

构树可培养内生真菌的多样性初探

构树Broussonetia papyrifera为桑科重要的资源植物。为调查逆境构树内生真菌的多样性,我们对铅锌矿区构树根、茎、叶和果实各部位进行内生真菌分离鉴定,从中分离得到187株内生真菌,根据形态学与分子生物学方法鉴定为20属,其中链格孢属Alternaria（50.27%）、镰孢属Fusarium（11.76%）为优势属。不同培养基的内生真菌分离率结果表明,马铃薯葡萄糖琼脂培养基（PDA）分离出的菌株数最多,占总数的73.96%;构树不同部位的菌株分离数目显示,叶中分离出的菌株较多,占38.02%。在属的分类水平上,根、茎、叶、果实不同部位的真菌数量也存在明显差异。Shannon-Wiener多样性指数和Simpson多样性指数分析结果提示不同样地的构树内生真菌的多样性也存在差异。Chao1指数和ACE指数也提示构树内生真菌丰富度与样地和组织有关。     

楮叶中香豆素和黄酮类化学成分研究

本文对楮树(Broussonetia papyrifera(L.)Vent.)叶中的香豆素和黄酮类成分进行研究,利用柱层析、重结晶、色谱技术等分离手段,分离得到了10个化合物,经理化性质和波谱数据分析鉴定为伞形花内酯(1)、七叶内酯(2)、芹菜素(3)、木犀草素(4)、山柰酚(5)、牡荆素(6)、芹菜素-7-O-β-D-葡萄糖醛酸(7)、芫花素(8)、槲皮素(9)、二氢槲皮素(10).化合物1～7均为首次从该植物中分离得到.     

Anatomy of the Lithocyst in the Epidermis of Leaf in Broussonetia papyrifera

This paper deals with the structure, development and composition of the lithocysts and their cystoliths in the epidermis of leaf in Broussonetia papyrifera (L.) Vent. Both epidermal layers had the hair-like lithocysts. The lithocyst seen in the adaxial epidermis had a central hair-like lithocyst with 1–3 rosette-forming small round lithocysts at its base which was absent in the comparatively fine hairy litbocyst on the abaxial epidermis. All these lithocysts had cystoliths. The hair4ike lithocysts in adaxial epidermis developed more quickly, and showed obvious“gliding growth”. One or two stalks were seen clearly in the early stage of the cystolith development. Later, the stalks were covered gradually by the cystolith deposition. The majority of cystoliths were mainly composed of polysaccharides, also mixed with a little suberin and calcium carbonate. But, large variation in material composition was found in different cystoliths and different developmental stages of individual cystolith. Exceptionally, there were large amorphous and shaped crystals of calcium carbonate in the cystoliths of the hair-like lithocysts. The ultrastructure of cystolith components exhibited no orderly arrangement and there was no stratification as seen under optical micoscope.     

微波法提取楮实子多糖的工艺研究

采用单因素试验和正交试验,对微波法提取楮实子多糖的工艺进行研究,得到了最佳工艺条件:料液比1∶15,微波处理时间12 min,微波功率450 w,浸泡时间180min.在此条件下,楮实子多糖的提取率为8.79％.     

构树幼苗对接种丛枝菌根真菌的生长响应

利用石灰岩适生植物构树进行菌根真菌摩西球囊霉(GM)、地表球囊霉(GV)和透光球囊霉(GD)的单独接种(SI)、混合接种(CI)和不接种(N)处理试验,测定了构树幼苗生长3个月后的形态及生长指标.结果表明:接种VA真菌促进了宿主构树的生长,单株地上部分、地下部分生物量和全株生物量等生长指标均较对照组显著提高,4种处理下构树幼苗生物量较对照提高了2.49～8.19倍,其中CI处理生物量最大,而单株叶片数目与对照组没有显著差异.不同接种处理的构树幼苗生长响应不同.在SI处理中,GD对构树幼苗生长效应最大,而CI处理较SI处理对构树幼苗的促进效应更加明显.CI处理中地径、苗高和总叶面积分别是对照组的1.5、2.2和6.0倍.各处理中根冠比最大的为CI(0.446).说明宿主植物与菌种存在一定的选择性.     

Change in the Concentration and Tissue localization of Endogenous IAA During the Regeneration of Vascular Tissues After Xylem Removal in Broussonetia papyrifera

Change in the concentration of endogenous IAA was monitored with enzyme-linked immunesorbent assay (ELISA), and IAA localization in the tissues was demonstrated by means of immunogold-silver microscopy, with authors' modification, during the regeneration after removal of xylem in Broussonetia popyrifera (L.) Vent. The stimulation exerted from xylem removal produced a rapid increase of about 70% of the endogenous IAA concentration. However, the concentration decreased during differentiation of the vascular tissues. Although removal of the tree crown inhibited the regeneration of vascular tissues, the change tendency in the concentration of endogenous IAA during the regeneration remained the same as if the tree crown was intact. This suggested that rapid increase of endogenous IAA induced by wounding could be a result from a release of the combined form into free IAA. Tissue-localization showed that there were more silver-grains labelled in the rays, callus and the regenerated differentiating vascular tissue cells than in other tissues. It could suggest that the high concentration of endogenous IAA triggered the dedifferentiation of the vascular tissues after removal of xylem, and the less concentrated IAA flow could promote the initiation and activity of the regenerated cambium.     

不同培养条件对光叶楮试管苗玻璃化的影响

以MS为基本培养基,研究生长调节剂、蔗糖、琼脂、光照强度和温度等因素对光叶楮试管苗玻璃化的影响。结果表明,最佳的生长调节剂配比是1.0 mg/L 6-BA、0.3 mg/L NAA,蔗糖浓度3.5%,琼脂浓度0.35%,光照强度2 000 lx,培养温度25℃。该优化培养条件能有效防止玻璃化苗的发生,获得较高的增殖系数和较健壮的苗木,且能降低生产成本。     

VA真菌对构树(Broussonetia papyrifera)幼苗物质代谢的影响

石灰岩地区因其干旱瘠薄的生境特征,植被难以恢复,然而仍有一些适生植物如构树生长良好,原因可能与根际微生物有关。就石灰岩适生植物构树（Broussorretia papyrifera）进行菌根真菌摩西球囊霉（Glomus mosseea）、地表球囊霉（Glomus versiforme）、透光球囊霉（Glomus diaphanum）的单独接种、混合接种和不接种处理,幼苗生长3个月后测定其生理指标,以期从代谢水平上了解植物对VA真菌的生理响应。结果表明：构树幼苗叶片可溶性糖、蛋白质,脯氨酸和叶绿素均较非接种处理有不同程度的显著提高,丙二醛含量则较对照降低。各代谢物质存在一定相关性。在物质代谢水平上,构树幼苗对不同VA真菌处理有不同的生理响应。宿主植物和VA真菌之间存在一定的相互选择。接种VA真菌提高了石灰岩适生植物构树的抗逆性。     

Evaluation of polyphenols from Broussonetia papyrifera as coronavirus protease inhibitors

The current study was designed to assess the inhibitory activity of Broussonetia papyrifera-derived polyphenols against 3-chymotrypsin-like and papain-like coronavirus cysteine proteases. The isolated compounds were broussochalcone B (1), broussochalcone A (2), 4-hydroxyisolonchocarpin (3), papyriflavonol A (4), 3′-(3-methylbut-2-enyl)-3′,4,7-trihydroxyflavane (5), kazinol A (6), kazinol B (7), broussoflavan A (8), kazinol F (9), and kazinol J (10). All polyphenols were more potent against papain-like protease (PL^pro) than against 3-chymotripsin-like protease (3CL^pro); therefore, we investigated their structural features that were responsible for this selectivity. Compound 4 was the most potent inhibitor of PL^pro with an IC₅₀ value of 3.7?μM. The active compounds displayed kinetic behaviors, and the binding constants of their interaction with PL^pro were determined from surface plasmon resonance analysis. Our results suggest B. papyrifera constituents as promising candidates for development into potential anti-coronaviral agents.     

The Resumption of Cambial Activity and the Change of Peroxidase Isozymes in Broussonetia papyrifera

Five Broussonetia papyrifera (L.) Vent. trees were selected in a natural stand located on the campus of Peking University, Beijing, China. The trees were ca. 5-6 years old, 3-4 m tall,and had diameters of about 3 cm measured 1.2 m above ground level. They were samplied at monthly intervals between January 28 and March 25, then at ten-day intervals between March 25 and May 20,1991. On each occasion, one 3-year-old shoot was cut from the tree. Two blocks (about 1 cm ×1 cm) contained peridern,phloem,cambium and wood with more than one annual ring were cut from every shoot,fixed in FAA,and then were prepared for anatomical studies. And on each occasion,7 layers of tissues (from periderm to mature xylem)were scraped off from the shoots and 100 mg of separate tissues were randomly extracted in 0.1 ml of 20% sucrose. The extracts were used for isoelectric-focusing in polyacrylamide gel slabs (85 mm × 60 mm × 1 mm). Benziding and odianisidine was used as substrate. After electrophoresis the gel slabs were placed in the substrate buffer until the isozyme bands were visible. Owing to the ring-porous structure of the wood of Broussonetia papyrifera, the cambial activity was comparable with that in the most ring-porous dicots. The cambium activity started about ten days before bud sprouting. On April 4,the dormant cambial zone consisted of ca. 4 cell layers. The trees did not sprout until April 16,but ca. 2 cell layers of immature xylem and phloem were formed concomitantly. Ten days later, 8-9 cell layers of xylem and ca. 5 cell layers of phloem were formed. The formation of immature phloem cells continued to increase slowly between April 4 and May 20, whereas that of immature xylem cells increased rapidly between April 4 and April 26,and then decreased between April 26 and May 20. It was suggested that differentiation of immature xylem into mature xylem lasted ca. 10 days,whereas that of immature phloem into mature one lasted ca. 20 days. There were totally 6 peroxidase isozyme bands in dormant cambial region and functional phloem. Variation of zymogram in cambial region occurred before cambial activity activated which is followed by more or less minor changes of bands in all other tissues. These indicated that several significant changes were related to the level of endogenous IAA and differentiation of vascular tissues.     

Periodicity of Cambial Activity and Changes of Starch Content in Broussonetia papyrifera

Methods of sampling and sections preparaction were the same as reported previously. Except that sampling was made at monthly intervals between May 20 and July 30, then at 7–14 day-intervals between July 30 and October 14, and then at monthly intervals between October 14 and March 25 in the next year. The stored starch in various tissues was stained with PAS reaction. During active period of cambium in Broussonetia papyrifera after July 30, the cell layers of immature xylem and phloem decreased progressively, and the formation of mature xylem and phloem increased rapidly. The formation of late wood started early in August, formation of xylem ceased after September 5, followed by ceasation of phloem formation about 1.5 months later. Increasing and decreasing of stored starch were closely related to the periodicity of cambial activity during the year. Starch grains decreased progressively after cambial activity was resumed in early spring until they disappeared in all the stem tissues. Then, starch accumulated progressively again after cambial activity slowed down, particularly after the ceasation of xylem formation. However, after the formation of phloem had ceased, the stored starch once again disappeared progressively until the end of December, and accumulated again. Such changes might be related to the transition of cambium activity involving two periods of dormancy.     

构树(Broussonetia papyrifera)幼苗氮、磷吸收对接种AM真菌的响应

对石灰岩适生植物构树(Broussonetia papyrifera)进行菌根真菌摩西球囊霉(Glomus mosseea)、地表球囊霉(G.versiforme)、透光球囊霉(G.diaphanum)的单独接种、混合接种和不接种处理,幼苗生长3个月后测定其根茎叶N、P含量和土壤酶活性,结果表明:接种AM真菌后构树幼苗生物量显著增加,植株根茎叶N含量较对照组显著提高,其含量为根<茎<叶。各处理中除了透光球囊霉处理的茎含量与对照差异不显著外,其余各处理含量均呈显著或极显著差异。AM真菌对构树苗P的促进效应主要体现在根、茎的利用上,而叶片P含量除混合接种外则有所降低,但M (接种处理)与M-(非接种处理)间无显著差异。构树苗根茎叶等量干物质P含量依次为叶>根>茎。进一步研究表明,接种AM真菌显著提高了土壤酶活性,这种显著性主要体现在蛋白酶和碱性磷酸酶上,植株N含量与土壤蛋白酶和碱性磷酸酶活性有显著相关性,而P含量只是根部吸收与多酚氧化酶活性显著相关。结果表明,接种AM真菌促进了宿主植物构树生物量的积累,提高了根际土壤酶活性,增加了植株对N、P的吸收。     

光叶楮扦插生根的吲哚乙酸氧化酶、多酚氧化酶、过氧化物酶活性变化研究

对光叶楮扦插生根过程中吲哚乙酸氧化酶（IAAO）、多酚氧化酶（PPO）、过氧化物酶（POD）3种酶进行了动态跟踪分析。结果表明：IAAO活性在扦插初期逐渐上升,第10d上升到高峰,之后下降再上升,第30d达到新高峰,然后迅速下降;前25d POD活性变化规律与IAAO相似,但30d以后活性一直上升;PPO活性在扦插前期缓慢上升,第20d上升到了最高点,此后变化不大。还研究了IAAO、PPO、POD与不定根的发生和发展关系,认为光叶楮扦插生根可分为愈伤组织形成期、根诱导期和根的伸长期3个阶段,愈伤组织形成期3种酶活性都呈上升趋势,根诱导期IAAO和POD的活性达到高峰;而根伸长期IAAO和POD活性下降,PPO活性上升。