植物花粉漫谈

花粉是植物的雄性生殖细胞。它的形态各异,壁的纹饰在不同的种类有不同的图案,分类学家可以此作为植物分类的重要依据。花粉内所含的成份很复杂。经测定,花粉中所含水份为7％～12％,蛋白质和游离氨基酸24.9％,类脂物4.6％,糖39.02％,木质素16.2％,灰分2.98％,未知物12.3％。花粉含氨基酸近20种,所含糖类主要是人体易吸收的葡萄糖和果糖等,花粉中含有维生素如硫胺素(B_1)、核黄素(B_2)、泛酸、维生素PP、叶酸等,此外,还有芸香苷等。花粉中还含有15种微量元素,多种酶、辅酶、有机酸、黄酮类、激素等。因此,花粉的用途非常广泛。     

植物花粉

花粉的形态及壁上的纹饰是植物分类的重要依据。近年来的研究发现,花粉内含有丰富的营养,如利用得好,将会给人类带来很大的益处。花粉内含有多种成份,目前人们已经发现的有蛋白质、游离氨基酸、类脂、糖、木质素、灰分、水等。还有一些目前尚不清楚的物质。花粉内含有的氨基酸近20种。糖类主要有葡萄糖和果糖。维生素有硫胺素、核黄素、叶酸等。己发现在百合花粉中,葫萝卜素和类葫萝卜素比红葫萝卜中的含量高20倍。花粉中还含有人体所     

不同温湿条件下贮藏的3种禾本科植物花粉的一些生理变化

测定了水稻、玉米和狼尾草花粉在低温(4℃),低湿(RH45％),低温(4℃)高湿(RH90％),高温(35℃),低湿(RH45％)和高温(35℃),高湿(RH90％)4种贮藏条件下的蛋白酶活性,蛋白质含量,游离氨基酸含量的变化,结果表明：在低温高湿条件下,蛋白质降解和游离氨基酸含量上升慢;在高温条件下蛋白质降解快,游离氨基酸含量迅速上升。3种植物花粉中,水稻花粉蛋白酶活性强,在贮藏过程中蛋白质降解速率和游离氨基酸含量上升快：狼尾草花粉蛋白酶活性低,在贮藏过程中蛋白质降解速率和游离氨基酸含量上升慢;玉米花粉的蛋白酶活性、蛋白质降解速率和游离氨基酸含量上升速率居两者之间。     

油松、白皮松和青木千花粉营养成分的研究

通过对我国有巨大生产量和应用潜力的油松、白皮松和青木千花粉的18种氨基酸、蛋白质、维生素A、维生素E、维生素C、磷脂、葡萄糖氧化酶等重要营养成分含量的测定,发现这三种花粉的以上成分含量都很高.其中青木千花粉的维生素A含量达70641.6IU/100g,氨基酸总量达24.443mg/100mg.从营养的角度来看,青木千花粉是较优秀的花粉.     

油松、白皮松和青木千花粉营养成分的研究

通过对我国有巨大生产量和应用潜力的油松、白皮松和青杄花粉的18种氨基酸、蛋白质、维生素A、维生素E、维生素C、磷脂、葡萄糖氧化酶等重要营养成分含量的测定,发现这三种花粉的以上成分含量都很高。其中青杄花粉的维生素A含量达70 641.6 IU/100 g,氨基酸总量达24.443 mg/100 mg。从营养的角度来看,青杄花粉是较优秀的花粉。     

花粉中的游离脯氨酸及其生理功能

五十年代中期,Bathurst、Fukasa-wa、Virtanen、Belartz等先后报道了花粉内含有丰富的游离脯氨酸,在一些草本植物中其含量可高达花粉干重的1.6％,占游离总氨基酸的50％以上。花粉是一个高度退化的雄配子体,通常它仅由一个营养细胞和一个生殖细胞构成,但是,它却含有如此高的游离脯氨酸,这使人们推测,花粉中的     

利用氨基酸分析快速测定甘蓝自交不亲和性

利用氨基酸分析方法,对甘蓝（ＢｒａｓｉｃａｏｌｅｒａｃｅａＬ．ｖａｒ．ｃａｐｉｔａｔａ）自交不亲和系与亲和系的柱头和花粉蛋白质进行了研究。结果表明,自交不亲和系与亲和系的柱头和花粉氨基酸组分有显著差别。柱头中苏氨酸和酪氨酸含量以及花粉中甘氨酸和丙氨酸含量可以作为评价自交不亲和性的指标。鉴定标准：自交不亲和系柱头中苏氨酸含量高于０．２２３％,酪氨酸含量高于０．３８５％;花粉中甘氨酸含量高于１．５９３％,丙氨酸含量高于１．４６４％。亲和系柱头中苏氨酸含量低于０．１８５％,酪氨酸含量低于０．１６４％;花粉中甘氨酸含量低于１４７０％,丙氨酸含量低于１００６％     

油松、白皮松和青杄花粉营养成分的研究

通过对我国有巨大生产量和应用潜力的油松、白皮松和青木千花粉的 1 8种氨基酸、蛋白质、维生素A、维生素E、维生素C、磷脂、葡萄糖氧化酶等重要营养成分含量的测定 ,发现这三种花粉的以上成分含量都很高。其中青木千花粉的维生素A含量达 70 641 .6IU/ 1 0 0g ,氨基酸总量达 2 4 .443mg/ 1 0 0mg。从营养的角度来看 ,青木千花粉是较优秀的花粉。     

代谢抑制剂去氧葡萄糖对水稻花药培养的促进作用

不同浓度去氧葡萄糖(2-deoxyglucose 2-DG)补加在5％蔗糖并含2mg/1 2,4-D的N_6培养基中,使产愈花药数从46.7％提高到56.2％,愈伤组织产量从237.4％提高到335.6％,效果均达差异显著标准。细胞学观察发现,愈伤组织产量提高的主要原因是药剂有效地防止了多细胞花粉退化并促进多细胞花粉破壁长成多细胞团。     

蜜源油菜花粉有效成份的研究

油菜(Brassica campestrisLinn.var.oleifera DC.)花粉含有七种可溶性糖和一个中性多糖;十七种游离氨基酸和十八种水解氨基酸;十一种维生素;四种黄酮类化合物;九种脂肪酸;五种有机酸和廿二种矿质元素。因此,油菜花粉是一种营养与有效成份极其丰富的营养品。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various