Purification and characterization of a mannose-binding lectin from the rhizomes of Aspidistra elatior Blume with antiproliferative activity

A lectin with a novel N-terminal amino acid sequence was purified from the rhizomes of Aspidistra elatior Blume by ammonium sulphate precipitation, ion exchange chromatography on diethylaminoethyl-Sepharose and carboxymethyl-Sepharose and gel filtration chromatography on Sephacryl S-100. The A. elatior Blume lectin （AEL） is a heterotetramer with a molecular mass of 56 kDa and composed of two homodimers consisting of two different polypeptides of 13.5 kDa and 14.5 kDa held together by noncovalent interactions. Hapten inhibition assay indicated that hemagglutinating activity of AEL towards rabbit erythrocytes could be inhibited by D-mannose, mannan, thyroglobulin and ovomucoid. The lectin was stable up to 70 ℃ , and showed maximum activity in a narrow pH range of 7.0-8.0. Chemical modification and spectrum analysis indicated that tryptophan, arginine, cysteine and carboxyl group residues were essential for its hemagglutinating activity. However, they might not be present in the active center, except some carboxyl group residues. AEL also showed significant in vitro antiproliferative activity towards Bre-04 （66%）, Lu-04 （60%） and HepG2 （56%） of human cancer cell lines.     

中国大陆天麻属(兰科)一新记录种——乌来天麻

该文报道了在广西七冲国家级自然保护区发现的中国大陆兰科(Orchidaceae)天麻属(Gastrodia R. Brown)一新记录种——乌来天麻(G. uraiensis T. C. Hsu & C. M. Kuo)。乌来天麻形态较近似于春天麻(G. fontinalis T. P. Lin),但乌来天麻的花序、花被筒较短,唇盘中部具4条纵向脊,脊向舌状先端延伸、合并成更高的2条,易与春天麻相区别。同时,还描述了新记录种的形态特征,提供了彩色图版,并讨论了此次新发现的生物地理学意义。     

地黄属的一个新异名

在比较研究标本室标本、野外考察、杂交实验和DNA片段序列分析的基础上,确认高地黄(Rehmannia elataN.E.Brown)与裂叶地黄(R.piasezkii Maxim.)为同种植物,并把前者作为后者的异名处理。     

Purification and characterization of a novel anti-fungal protein from Gastrodia elata

An anti-fungal protein GAFP-1 (Gastrodia anti-fungal protein, also called gastrodianin) was purified from Gastrodia elata B1. f. flavida S. Chow (Orchidaceae), a parasitic plant on the fungus Armillaria mellea. It can inhibit the hyphal growth of some phytopathogenic fungi such as Valsa ambiens, Rhizoctonia solani, Gibberella zeae, Ganoderma lucidum and Botrytis cinerea in vitro. GAFP-1 is a monomer with a molecular mass of 10 kDa and a pI of 8.45. The optimum pH for its inhibitory activity is 5.0 ∼ 6.0. GAFP-1 is insensitive to high temperatures. It can preserve 75% inhibitory activity after 30 min at 60°C. Amino acid composition analysis revealed that GAFP-1 is rich in Asp (22.1%), Gly (10.0 %) and Leu (9.4 %), and does not contain any Pro. The amino acid sequence of the N-terminal was determined and found to share high homology with those of other lectins from orchids such as Listera ovata and Epipactis helleborine. GAFP-1 could not agglutinate trypsin-treated rabbit erythrocytes. It could bind to chitin, immobilized mannose and N-acetylglucosamine in 50mM sodium acetate buffer (pH 5.0) with 2 M ammonium sulfate. These data suggest that GAFP-1 could be a lectin-like protein with strong inhibitory activity against certain fungal pathogens.     

高羊肚菌菌丝球液体培养的研究

本文探讨了高羊肚菌菌丝球在不同液体培养基中的生长情况。结果表明,在黄豆芽玉米玢培养基中菌丝球最多,大小均匀,菌丝生长量最大,在麦麦夫蛋白胨培养基上菌丝的糖含量最高。     

应用放射性自显影技术研究标记紫萁小菇侵染天麻种胚的过程

用~3H—葡萄糖对紫萁小菇进行氚标记,然后用标记的紫萁小菇伴播天麻种子,发现标记紫萁小菇在侵入天麻胚柄状细胞后,菌丝即被溶解、消化,未被侵染的大型细胞中有标记化合物的踪迹。随着胚的发育,在胚顶端分生细胞中也有大量标记物的显影银粒云集,表明同化的标记化合物由细胞壁进入并通过胞间连丝进行运输,直观证明了紫萁小菇为天麻种子萌发提供了营养。     

天麻内生真菌菌群组成的初步研究

从采自贵州、陕西、四川和云南的天麻组织中共分离获得62株内生真菌。经形态学与分子生物学相结合鉴定,62株内生真菌分属于3个亚门、5纲、7目、9科、13属。研究结果还表明采自不同地点的天麻以及天麻不同部位的内生真菌的类群与分布存在明显差异。     

天麻抗真菌蛋白基因(gafp)转化彩色棉的研究

天麻抗真菌蛋白(gastrodia antifungal protein简称GAFP)是从我国传统中药天麻(Gastrodia elata B1．)中分离到的一种具有广谱抗真菌活性的蛋白质,它对许多植物真菌病包括棉花枯萎病、黄萎病等的致病菌离体具有很强的抑制作用,因此,在植物抗真菌病基因工程上有很重要的应用价值。本研究通过花粉管通道法,将GAFP的基因．gafp转入3个新疆彩色棉品种中,通过田间抗病筛选和分子检测,得到了高抗黄萎病的转基因植株,两株Southem杂交阳性植株LB-5-8和ZB-1—49对黄萎病表现整株免疫。RT-PCR的结果显示,LB-5-8和ZB-1—49中均有gafp的正确转录;离体的抑菌实验也表明,它们的蛋白粗提物对棉花黄萎病致病菌离体有明显的抑制,表明了gafp在转基因植株中的正确表达,翻译的产物具有活性。经过进一步选育和扩繁,发现转基因彩色棉后代具有稳定的、较强的抗黄萎病能力,本研究为通过植物抗病基因工程的方法防治棉花黄萎病提供了一条新的途径。     

转天麻抗真菌蛋白GAFP基因烟草的获得及离体抑菌活性检测

通过根癌农杆菌(Agrobacteriumtumefaciens)介导,采用叶盘法将天麻(GastrodiaelataBl.)抗真菌蛋白基因GAFP转入烟草(NicotianatabacumL.),PCR和Southern blotting分析证明已将GAFP基因整合进烟草植株。体外抑菌实验表明GAFP转基因的烟草植株对真菌瑞氏木霉(Trichodermareesei)表现出一定的抑菌活性。     

天麻种子／原球茎和营养繁殖茎被菌根真菌定殖后的细胞分化

天麻（Gastrodia elata Bl.)种子可与紫萁小菇（Mycena osmundicola Lange),兰小菇（M.orchidicola Fan et Guo)等一类小菇属真菌共生萌发形成原球茎。侵入种皮的菌丝集结在柄状细胞外周的胚柄残迹中,首先侵入胚的柄状细胞,然后自柄状细胞侵入其他原胚细胞。原胚细胞发生功能分化,形成菌丝结细胞和消化细胞,初被菌丝定殖的原胚细胞具有消化菌丝的功能,随后,部分原胚细胞逐渐被菌丝充满,充育成菌丝结细胞。菌丝由菌丝结细胞进一步侵入消化细胞后最终被消化。由原球茎分化形成的营养繁殖茎（以下简称营繁茎）进一步被蜜环菌（Armilariella mellea(Vahl.Fr.)Karst.)定植,蜜环菌与紫箕小菇的菌丝同时存在于营繁茎中,但两菌相遇时都停止蔓延,互不交错侵染。