Pyrophosphate-dependent phosphofructokinase from pollen: properties and possible roles in sugar metabolism

To evaluate the role of pyrophosphate-dependent phosphofructokinase (PFP. EC 2.7.1.90) in the sugar metabolism of pollen. its occurrence and properties were studied in pollen grains of several plants including camellia ( Camellia japonica L.). In all pollen samples, PFP was strongly activated by fructose-2,6-bisphosphate (F2,6BP), and the activity of F2,6BP-activated PFP was higher than that of phosphofructokinase (PFK. EC 2.7.1.11). PFP partially purified from camellia pollen required Mg²⁺ for activity with an optimum at 1 m M . and was almost unaflected by a variety of metabolites at 1 m M . Its molecular mass was around 220 kDa, and apparent K_m values for F6P, PP_i. F1, 6BP and P_i were 294, 4, 20 and 580 u M , respectively. The levels of F2.6BP. PP_i and F6P in camellia pollen were sufficent to support the forward reaction by PFP, and PFP, was 20- to 40-fold more active than PFK during pollen growth. These results suggest that pollen PFP plays a role in glycolysis but not gluconeogenesis. and the possible relevance of this to pollen tube growth is discussed.     

Isolation of a psychrotolerant Debaryomyces hansenii strain from fermented tea plant (Camellia sinensis) leaves

Abstract

A psychrotolerant, halotolerant and alkalophilic yeast was isolated from fermented leaves of Camellia sinensis Kuntze, the tea plant. The yeast strain, named Tea-Y1, was both phenotypically and genotypically identified as belonging to the species Debaryomyces hansenii. This assignment was confirmed by scanning and transmission electron microscopy. The analysis of growth curves demonstrated the ability this yeast strain to grow in a temperature range between 4°C and 28°C, with an optimum of 23°C. The ecology of this yeast in the C. sinensis phyllosphere, as well as its possible role in tea fermentation and storage, with particular reference to iced tea, are discussed.     

A New Acylated Anthocyanin from the Red Flowers of Camellia hongkongensis and Characterization of Anthocyanins in the Section Camellia Species

Twelve anthocyanins (1-12) were isolated from the red flowers of Camellia hongkongensis Seem. by chromatography using open columns. Their structures were elucidated on the basis of spectroscopic analyses, that is, proton-nuclear magnetic resonance, carbon 13-nuclear magnetic resonance, heteronuclear multiple quantum correlation, heteronuclear multiple bond correlation, high resolution electrospray ionization mass and ultraviolet visible spectroscopies. Out of these anthocyanins, a novel acylated anthocyanin, cyanidin 3-O-(6-O-(Z)-p-coumaroyl)-β-galactopyranoside (6), two known acylated anthocyanins, cyanidin 3-O-(6-O-(E)-p-coumaroyl)-β-galactopyranoside (7) and cyanidin 3-O-(6-O-(E)-caffeoyl)-β-galactopyranoside (8), and three known delphinidin glycosides (10-12) were for the first time isolated from the genus Camellia. Furthermore, pigment components in C. japonica L., C. chekiangoleosa Hu and C. semiserrata Chi were studied.The results indicated that the distribution of anthocyanins was differed among these species. Delphinidin glycoside was only detected in the flowers of C. hongkongensis, which is a special and important species in the section Camellia. Based on the characterization of anthocyanins in the section Camellia species, there is a close relationship among these species,and C. hongkongensis might be an important parent for creating new cultivars with bluish flower color.     

云南澜沧景迈古茶园生态系统植物多样性评价

云南澜沧县境内的景迈古茶园是云南省现存面积最大的古茶园.本文应用植物学样地调查和农业生物多样性调查评价(HH-ABA)方法,在景迈古茶园内设置了78个20 m×20 m的样方,对植物多样性进行调查,并就古茶园的管理及资源利用等问题进行了问卷调查和农户访谈.研究结果表明,景迈芒景地区植物地理成分的热带性明显.在景迈古茶园中发现的珍稀濒危保护植物达15种,其中濒危种5个,易危种7个,稀有种3个,含国家三级保护植物11种.从古茶园、天然林、新式茶园3类生态系统的物种多样性分析来看,古茶园与天然林较为接近而比新式茶园高得多,因而在该区生物多样性的维护上起着非常重要的作用.古茶园的物种数按照生活型排序为草本＞乔木＞灌木＞藤本＞附生.与天然林相比,古茶园内乔木和灌木种类的比例减少,草本和附生(寄生)植物的比例大大增加,这与古茶园内乔木郁闭度及茶树的存在密切相关.农业生物多样性分析显示,不同村寨的物种丰富度和物种利用率均存在差异.6个村寨的农业物种丰富度指数的平均值为0.059,高于同纬度地区旱谷地和橡胶林,可见人们在古茶园管理中有意识地保留了可利用的物种.由于不同农户采取的管理措施不同,影响了古茶园内的植物多样性和古茶树的更新,因而使各农户的茶叶经济效益存在差别.古茶园生态系统是自然资源保护与利用相结合的典型例子,建议应当传承并发展当地人民对古茶园的管理经验,由政府、科研机构和农户共同参与,通过示范和培训加强学习指导,对古茶园进行保护和合理的开发利用.     

不同群落中川鄂连蕊茶的生殖分配与个体大小之间关系的探讨

 研究了缙云山川鄂连蕊茶（Camellia rosthorniana）在3个群落类型中的生殖分配、生殖分配与个体大小之间的关系和座果率。结果表明：1）在地径1.0～3.5 cm范围内,种群间生殖分配差异显著,即毛竹林＞针阔混交林＞常绿阔叶林;在地径1.0～5.0 cm范围内,针阔混交林和常绿阔叶林之间差异不显著;在地径1.0～6.0 cm范围内,毛竹林显著高于针阔混交林和常绿阔叶林,而针阔混交林和常绿阔叶林之间差异不显著;因此种群间生殖分配比较时,应考虑种群间的大小分布。运用生殖分配的有关学说对川鄂连蕊茶生殖分配格局进行了解释,生境稳定性学说和生活史理论假说相结合可以解释川鄂连蕊茶生殖分配格局。2）川鄂连蕊茶个体生殖分配与个体大小之间存在抛物线关系。3）种群密度对川鄂连蕊茶座果率没有影响。     

茶树鲜花饮料澄清技术研究

茶树鲜花与茶叶具有相似的营养成分,榨汁后经调配可开发成适口性好、风味独特的鲜花饮料。对茶树鲜花饮料的壳聚糖絮凝、酶法澄清、超滤澄清效果进行了比较,结果表明,采用10万分子截留量的超滤膜处理获得能够较好的澄清效果,且对茶多酚造成的操作损失较小。     

四个DNA片段在山茶属分子系统学研究中的应用

选取山茶属14个组中的10组21种植物对目前常用于属内种间的4个DNA片段（ITS、waxy、trnL-F、rpL16）进行序列测定。结果表明：（1）来自叶绿体基因组的2个片段（trnL-F、rpL16）其PCR扩增和测序都很容易,但两者的进化速率都非常慢,序列矩阵只有很少信息位点（trnL-F含9个,rpL16为20个）,不能提供必要的系统发育信息。（2）来自核基因组的ITS片段其PCR产物比较容易获得,但其序列的测定存在较多问题。（3）waxy是来自核基因组的另一个片段,其PCR扩增因受模板DNA的数量和质量的影响很大而有一定难度,但其进化速率较快,序列矩阵具有较多信息位点（92个）,并且在山茶属是单拷贝,这对于解决山茶属这类具有许多近缘物种的类群的系统关系有重要价值。基于tsnL-F、rpL16和waxy三组数据所建分子系统树支持山茶属为一单系,但属下系统由于取样等原因有待进一步研究。     

Bioactivity of Piper guineense Schum. & Thonn seed and Moringa oleifera Lam. leaf powder against Trogoderma granarium Everts (Coleoptera: Dermestidae)

Laboratory studies were carried out to investigate bioactivity of Piper guineense seeds and Moringa oleifera leaf powders applied singly or in a mixture against larvae and adult Trogoderma granarium Everts in airtight containers. Three levels (0.0 g, 0.5 g, and 1.0 g/20 g groundnut seeds) of the plant powders were used and pirimiphos-methyl was applied at 0.01 g/20 g seeds (recommended dose). Another control consisting of untreated seeds with aerated lids was included in the bioassay. Both larvae and adults were not killed in control with aerated lids throughout the experimental period and larvae were also tolerant to airtight storage conditions. Adults were more susceptible to plant powders than larvae and adult mortality recorded in P. guineense at 1.0 g, 0.5 g and M. oleifera at 1.0 g/20 g seeds were not significantly different from the mortality observed with the recommended dose of Pirimiphos methyl at five days after treatment (DAT). Larval mortality observed in a mixture of both plants (1:1; w/w) caused significantly higher mortality (77.5%) than other treatments at 5 DAT. All treatments (P. guineense and M. oleifera applied singly or in a mixture) were repellant to larvae T. granarium with 60% repellency recorded in the mixture of plants, 50% repellency in P. guineense and 30% repellency in M. oleifera slurry. The water absorption capacity of treated seeds was not affected by treatment with plant powders and ranged from 31.98% to 37.59%.