单囊壳属一新种——乌蔹莓单囊壳

本文报道了单囊壳属Sphaerotheca的一新种:乌蔹莓单囊壳Sphaerotheca cayratiae Z.Q.Yuan et A.Q.Wang sp.nov.。新种寄生于葡萄科Vitaceae植物角花乌蔹莓Cayratia corniculata(Benth.)Gagnep上,为单囊壳属的寄主科世界新记录。文中对该新种的形态特征作了拉丁文和中文描述,并讨论了新种与本属内相似种的区别。模式标本存于新疆八一农学院植保系真菌标本室。     

Developmental changes in the diurnal water budget of the grape berry exposed to water deficits

The diurnal water budget of developing grape (Vitis vinifera L.) berries was evaluated before and after the onset of fruit ripening (veraison). The diameter of individual berries of potted ‘Zinfandel’ and ‘Cabernet Sauvignon’ grapevines was measured continuously with electronic displacement transducers over 24 h periods under controlled environmental conditions, and leaf water status was determined by the pressure chamber technique. For well-watered vines, daytime contraction was much less during ripening (after veraison) than before ripening. Daytime contraction was reduced by restricting berry or shoot transpiration, with the larger effect being shoot transpiration pre-veraison and berry transpiration post-veraison. The contributions of the pedicel xylem and phloem as well as berry transpiration to the net diurnal water budget of the fruit were estimated by eliminating phloem or phloem and xylem pathways. Berry transpiration was significant and comprised the bulk of water outflow for the berry both before and after veraison. A nearly exclusive role for the xylem in water transport into the berry was evident during pre-veraison development, but the phloem was clearly dominant in the post-veraison water budget. Daytime contraction was very sensitive to plant water status before veraison but was remarkably insensitive to changes in plant water status after veraison. This transition is attributed to an increased phloem inflow and a partial discontinuity in berry xylem during ripening.     

Coordinate induction by UV light of stilbene synthase,phenylalanine ammonia-lyase and cinnamate 4-hydroxylase in leaves of vitaceae

A stilbene synthase catalyzing the formation of resveratrol from 4-hydroxycinnamoyl-CoA and malonyl-CoA was found in the leaves of several Vitaceae. This stilbene synthase and two other enzymes functioning on the route from phenylalanine to stilbenes were induced concurrently upon irradiation of the leaves with UV light. With leaves of Cissus antarctica, an increase of stilbene synthase activity, more than hundred-fold, was observed with a maximum appearing 15 h after the induction with UV light.Abbreviations EDTA Na₂-ethylenediaminotetraacetate - Hepes 4-(2-Hydroxyethyl)-1-piperazineethanesulfonic acid - Mes morpholinoethanesulfonic acid     

Diurnal change of tartrate dissimilation during the ripening of grapes

l(+)-tartrate-[U-¹⁴C] or sucrose-[U-¹⁴C] was fed into grape berries and ¹⁴CO₂ evolution was determined. ¹⁴CO₂ evolution front l(+)-tartrate-[U-¹⁴C] was slightly higher in mature than immature berries, and that from sucrose-[U-¹⁴C] was higher in immature than mature ones. ¹⁴CO₂ evolution from l(+)-tartrate-[U-¹⁴C] was irregular throughout the day until 2 or 3 weeks after flowering. This stage shifted to regular ¹⁴CO₂ evolution until 6 or 7 weeks after flowering, and the mode of ¹⁴CO₂ evolution showed diurnal variation; higher in the day than at night. Then the stage without variation of ¹⁴CO₂ evolution followed 10 weeks after flowering. These observations indicate that tartrate is not biochemically inert in grape berries, while the amount of ¹⁴CO₂ evolution from sucrose-[U-¹⁴C] was higher at night than in the day through the whole ripening process, except in the early stage.     

Identification of Vitis vinifera (-)-alpha-terpineol synthase by in silico screening of full-length cDNA ESTs and functional characterization of recombinant terpene synthase

The flavour and aroma of certain Vitis vinifera grape varieties is dominated by volatile terpenes and small volatile aldehydes. Monoterpenes contribute to the final grape and wine aroma and flavour in form of free volatiles and as glycoside conjugates of monoterpene alcohols. Typical monoterpenol components of the cultivar Gewürztraminer and other aroma-rich grape varieties are linalool, geraniol, nerol, citronellol, and alpha-terpineol. In a functional genomics effort to identify genes for the formation of monoterpene alcohols in V. vinifera, a database of full-length cDNA sequences was screened in silico and yielded two clones for putative monoterpene synthases. The gene products were functionally characterized by expression in Escherichia coli, in vitro enzyme assay and gas chromatography-mass spectrometry (GC-MS) product identification as multi-product (-)-alpha-terpineol synthases.     

Root pressure and specific conductivity in temperate lianas: exotic Celastrus orbiculatus (Celastraceae) vs. native Vitis riparia (Vitaceae)

The exotic temperate liana (woody vine) Celastrus orbiculatus has become a weed in Michigan, occurring in many of the same habitats as the native liana Vitis riparia. However, C. orbiculatus frequently develops into extensive monospecific infestations, while V. riparia does not. Freezing-induced embolism may be responsible for limiting liana distribution. Root pressure has been observed in numerous tropical lianas and temperate species of Vitis and has been implicated as vital to the recovery of xylem function in wide vessels following winter freezes. For both of these co-occurring lianas we investigated root pressure and water conductance as possible explanatory factors for their differential spread. According to our hypothesis, C. orbiculatus should have produced greater or more frequent root pressures than V. riparia. However, the reverse proved true, indicating that root pressure is not a prerequisite for weedy proliferation of C. orbiculatus. Additionally, the seasonal patterns of specific conductivity of stem xylem indicate that each species responds differently to environmental constraints. Vitis riparia establishes conductivity early in the growing season, before the leaves emerge, using root pressure to reverse embolism, but loses conductivity with the first freeze in early autumn. Celastrus orbiculatus is slow to establish conductivity, depending on new wood production, but leafs out sooner than V. riparia and maintains green leaves after the first freeze. Vulnerability curves of xylem to cavitation caused by water stress for the two species indicate that they respond similarly to dehydration. These results indicate that root pressures are not responsible for the invasive success of C. orbiculatus and suggest that other factors must be key to its prolific invasion.     

Synergism and redundancy in a plant volatile blend attracting grapevine moth females

A flight tunnel study was done to decipher the behavioral effect of grape odor in grapevine moth Lobesia botrana. A blend of 10 volatile compounds, which all elicit a strong antennal response, attracts mated grapevine moth females from a distance, by upwind orientation flight. These 10 grape volatiles are in part behaviorally redundant, since attraction to a 3-component blend of beta-caryophyllene, (E)-beta-farnesene and (E)-4,8-dimethyl-1,3,7-nonatriene was not significantly different from the 10-component blend. Blending these three compounds had a strong synergistic effect on female attraction, and omission of any one compound from this 3-component blend almost abolished attraction. It was nonetheless possible to substitute the three compounds with the other grape volatiles which are perceived by the female antenna, to partly restore attraction. Several blends, of varying composition, elicited significant attraction. The observed behavioral plasticity in response to grape volatile blends probably reflects the variation of the natural plant signal, since females oviposit on different grape varieties, in different phenological stages.     

Inflorescence development in the Vitis–Ampelocissus clade of Vitaceae: the unusual lamellate inflorescence of Pterisanthes

Pterisanthes (Vitaceae) is a genus of c. 20 species of scandent climbers endemic to Southeast Asia with unusual lamellate inflorescences. Molecular phylogenetic analysis supports its relationship in the well‐supported Vitis–Ampelocissus–Nothocissus–Pterisanthes clade (i.e. the Ampelocissus–Vitis clade). Shoot tips and floral buds were collected from wild and greenhouse‐grown P. eriopoda at different developmental stages and were examined using epi‐illumination, light and scanning electron microscopy. Inflorescence and floral ontogeny was studied to discover how the lamellate inflorescence evolved and to make morphological comparisons to infer relationships with closely related members of Vitaceae. The second‐order branches in P. eriopoda are racemose and develop helically around the inflorescence axis in a similar fashion to Vitis and Ampelocissus. Inflorescence branching is restricted to the second order in P. eriopoda, whereas in Vitis and most Ampelocissus species subsequent branching orders culminate in the typical vitaceous determinate dichasium. In P. eriopoda subsequent lateral growth of the second‐order branches combined with the inhibition of peduncle or pedicel formation and loss of dichasial branching results in the unique lamellae in Pterisanthes, on which the floral primordia arise directly in a helical pattern. Floral development in P. eriopoda is the same as in other genera of Vitaceae examined to date with initiation of floral whorls centripetally, the calyx ring developing first and calyx lobes fused to cover the petals and stamen primordia. Given the recent phylogenetic results that placed Pterisanthes firmly within Ampelocissus, the most likely scenario is that the Pterisanthes inflorescence is derived from the thyrse of an Ampelocissus‐like ancestor and that the thyrse is a morphological synapomorphy of the Ampelocissus–Vitis clade. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 725–741.     

白粉藤的木脂素和三萜成分

从白粉藤（Cissus repens Lank）地上部分分离得到5个木脂素和8个三萜,其中一个木脂素是新化合物,它的结构通过波谱分析和碱水解的方法鉴定为：（＋）-异落叶松树脂醇-9′-（2-对-香豆酰）-O-β-D-吡喃木糖苷（1）。其余化合物分别是：（＋）-异落叶松树脂醇-9′-O-β-D-吡喃木糖苷（2）,（＋）-Lyoniside（3）,（—）-开环异落叶松树脂醇-9-O-β-D-吡喃木糖苷（4）,（7′R,8′S）-4′-hydroxy-3′,5-dimethoxy-7,8′-dihydrobenzofuran-1-propanolneolignan-9′-O-β-D-xylopyranoside（5）,木栓酮（6）,表木栓醇（7）,蒲公英赛醇乙酸酯（8）,熊果酸（9）,2α-羟基乌索酸（10）,积雪草酸（11）,Niga-ichigoside F1（12）,羽扇豆醇（13）。这些化合物都是首次从该植物中分离得到。