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.     

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。     

The relationship between soil pH and population level of Pratylenchus loosi in tea plantations of Iran

Tea root lesion nematode, Pratylenchus loosi, is one of the most important crop pests in Iran, which causes loss in quantity and quality of tea. This study was carried out to identify the relationship between soil pH and population level of P. loosi. One hundred and eighty-three soil and root samples were taken randomly from all of the tea plantations in Iran. The nematodes were extracted from root samples with Coolen and d’Herd methods and from soil samples by sieving and centrifugation. Soil pH was measured by two methods: 1:1 dilution of soil:deionised water and 1:1 dilution of soil:dilute calcium chloride 0.01?M (Cacl₂) solution. Range of mean population of P. loosi per gram of root was 0.66–884 and per 100?g of soil was 1–186 in all samples. The highest population of P. loosi was observed at pH 3.5–4.5 as if 71.33% of infested samples were observed at soil pH 3.5–4.5. The results of regression analyses showed that at pH ranges between 3.5 and 4.5, there is a correlation (P???0.05) between soil pH and mean population of nematode per gram of feeder roots. This study demonstrated that the population density and damage potential of this nematode likely increases at pH?<?4.5.     

Histopathological Changes in Tissues of Bithynia siamensis goniomphalos Incubated in Crude Extracts of Camellia Seed and Mangosteen Pericarp

The present study was performed to observe histopathological changes in tissues of Bithynia siamensis goniomphalos (Gastropoda, Bithyniidae) incubated in crude extract solutions of camellia (Camellia oleifera) seed and mangosteen (Garcinia mangostana) pericarp, and furthermore to estimate the molluscicidal effects of 2 plant substances. Substantial numbers of bithyniid snails were incubated in various concentrations of 2 plant solution for 24 hr. As the positive control, snails incubated in various concentrations of niclosamide, a chemical molluscicide, were used. The histopathological findings were observed in sectioned snail specimens of each experimental and control groups. The results showed that both camellia and mangosteen extracts had molluscicidal effects at 24 hr with 50% lethal concentration (LC₅₀) at concentrations of 0.003 and 0.002 g/ml, respectively, while niclosamide had LC₅₀ at concentrations 0.599 ppm. B. siamensis goniomphalos snail tissues (foot, gill, and digestive system) showed disruption of columnar muscle fibers of the foot, reduction of the length and number of gill cilia, numerous mucous vacuoles, and irregularly shaped of epithelial cells. Irregular apical and calciferous cells, dilatation of the digestive gland tubule, and large hemolymphatic spaces, and irregular apical surfaces, detachment of cilia, and enlargement of lysosomal vacuoles of epidermis were also shown in all groups. By the present study, it is confirmed that 2 plants, camellia and mangosteen, are keeping some substance having molluscicidal effects, and histopathological findings obtained in this study will provide some clues in further studies on their action mechanisms to use them as natural molluscicides.     

光照强度对濒危植物毛瓣金花茶光合生理特性的影响

以盆栽3年生毛瓣金花茶实生苗为材料,采用人工遮荫方法研究不同光照强度(10％、25％、50％和100％自然光强)对其光合生理特性的影响,为其迁地保护和种群恢复提供科学依据.结果显示:(1)随着光照强度的升高,毛瓣金花茶叶片最大净光合速率(Pmmax)、表观量子效率(AQY)和光饱和点(LSP)降低,光补偿点(LCP)升高,其中P…和AQY在10％和25％光强下显著高于50％和100％光强处理.(2)叶片叶绿素总量(Chl)、叶绿素a(Chla)、叶绿素b(Chl b)、类胡萝卜素(Car)含量均随光强的升高而降低,Car/Chl含量随光强的升高而升高.(3)叶绿素荧光参数FmFv、Fv/Fm、Fv/F0均随光强的升高而降低,其中Fm、Fv、Fv/Fm在100％光强下显著低于其他3个遮荫处理,3个遮荫处理间则无显著差异.(4)叶片丙二醛(MDA)和脯氨酸(Pro)含量均随光强的升高而升高,在100％光强下,MDA和Pro含量显著高于其他3个遮荫处理,50％光强下的MDA含量显著高于10％和25％光强处理.(5)在25％光强下,毛瓣金花茶未发生明显光抑制,在50％光强下,其光抑制主要是由PSⅡ的可逆失活引起的,光合机构未遭到明显破坏,在100％光强下,其PSⅡ反应中心受到严重伤害,发生了光氧化.研究表明,毛瓣金花茶虽为阴生植物,却能忍受一定程度的强光(50％光强),在种群恢复过程中,可适当间伐上层乔木,增加林下透光率,提高毛瓣金花茶种群的开花结实率,促进其自然更新,在迁地保护时可选择相对开敞的遮荫环境.