梨韧皮部特异表达启动子AtSUC2驱动下的GUS基因的转化和表达

 以 ‘Old Home’ 梨无菌苗叶片为外植体, 利用根癌农杆菌介导将专一在韧皮部表达启动子AtSUC2 驱动下的GUS 基因转入 ‘Old Home’中。筛选出了‘Old Home’ 梨叶片高效遗传转化的最佳条件：农杆菌和外植体在液体培养基上共培比在固体培养基上共培转化率提高5倍。 PCR分析和Southern 杂交鉴定表明GUS 基因已整合到转基因植株的基因组中,组织化学检测和Western 杂交鉴定证明了GUS 基因在转基因植株韧皮部中的表达。     

Root architecture characteristics of plant inlay in live slope grating

In the experimental garden of the Department of Soil Bioengineering and Landscape Construction, University of Applied Life Sciences in Vienna, Austria, coarse root systems of three different brush species were completely excavated and semi-automatically digitized. The species were Lonicera xylosteum, Ligustrum vulgare and Euonymus europaeus. The 3-D root ar-chitectures reveal different growth strategies between species, which are related to ecological characteristics and physical soil proper-ties. The root architecture of Lonicera xylosteum and Ligustrum vulgare, planted in the under layer of the live slope grading, where the soil is very tight and the soil water content and fertility are relatively low, is shallow. However, the root distribution of E. eu-ropaeus, planted in the middle layer, where environmental conditions are better, is deeper. Most of the root biomass of the three spe-cies is concentrated in the 0-30 cm soil layer. A quarter of the root biomass of Ligustrum vulgare is distributed in the upper layer of the plant inlay. E. europaeus has a relatively even distribution in the 30-60 cm and 60-90 cm soil layer.     

Perception and acceptance of agricultural production in and on urban buildings (ZFarming): a qualitative study from Berlin,Germany

Rooftop gardens, rooftop greenhouses and indoor farms (defined as ZFarming) have been established or planned by activists and private companies in Berlin. These projects promise to produce a range of goods that could have positive impacts on the urban setting but also carry a number of risks and uncertainties. In this early innovation phase, the relevant stakeholders’ perceptions and social acceptance of ZFarming represent important preconditions for success or failure of the further diffusion of this practice. We used the framework of acceptance to investigate the stakeholders’ attitudes and to identify the key factors that might hinder or promote the introduction of ZFarming. The results are based on an analysis of 38 qualitative interviews conducted with key stakeholders in Berlin. As the results show, major perceived benefits of ZFarming include improved consumer awareness, education, and the creation of experimental spaces. Stakeholders further perceive opportunities for resource savings, new business models, repurposing of abandoned buildings and improved aesthetics. Major perceived risks are associated with growing techniques that are considered “unnatural”, health risks (due to urban pollutants), conflicts with images of traditional agriculture, the rejection of animal production in urban areas, the risk of projects being too expensive and too complex or being implemented too early, i.e. before the mechanisms are fully understood. The analysis further reveals which contextual factors—political, legal, market-related, spatial or societal—might negatively or positively influence ZFarming acceptance.     

The origin of aluminum flocs in polluted streams

About 240,000 square kilometers of Earth's surface is disrupted by mining, which creates watersheds that are polluted by acidity, aluminum, and heavy metals. Mixing of acidic effluent from old mines and acidic soils into waters with a higher pH causes precipitation of amorphous aluminum oxyhydroxide flocs that move in streams as suspended solids and transport adsorbed contaminants. On the basis of samples from nine streams, we show that these flocs probably form from aggregation of the epsilon -Keggin polyoxocation AlO4Al12(OH)24(H2O)12(7+)(aq) (Al13), because all of the flocs contain distinct Al(O)4 centers similar to that of the Al13 nanocluster.     

Ecology-based analysis of a recent association between Spartium junceum and 16SrV phytoplasma

An outbreak of Spartium witches’ broom (SpaWB) in Sicily prompted us to identify and characterize associated phytoplasmas. Over 80 samples of Spanish broom (Spartium junceum) and around 270 individuals of the potential vector Livilla spectabilis were collected and analysed. Single and mixed infections of 16SrV and ‘Candidatus Phytoplasma spartii’ were detected in Spanish broom samples and for the first time in L. spectabilis. The 16SrV isolates were further characterized by multilocus sequence typing (MLST) to determine their phylogenetic relationship with flavescence dorée phytoplasma (FDp) and to evaluate the risk of host-jumping to grapevine. Phylogenetic analysis of most of the analysed genes using the MLST approach grouped S. junceum 16SrV-C isolates with FDp isolates infecting grapevine and Scaphoideus titanus. Notably, phylogenetic analysis of the vmpA gene clustered the S. junceum isolates with FDp genotypes transmitted by S. titanus. This study extends the knowledge of SpaWB epidemiology, focusing on the possible risk of a 16SrV host jump from Spanish broom to grapevine. Spanish broom was identified as a reservoir and potential inoculum source of phytoplasmas that cause severe disease in cultivated crops. Furthermore, the L. spectabilis psyllid may be involved in the epidemiology of this 16SrV-C phytoplasma, although in the absence of in vivo transmission trials. The study further confirms the strong ability of phytoplasmas to adapt to new hosts and vectors, thus leading to potential phytosanitary emergencies.     

Seed germination response to temperature for a range of international populations of Conyza canadensis

Conyza canadensis is a surface‐germinating ruderal facultative winter annual with recruitment that is highly susceptible to changes in microsite conditions. A key adaptive characteristic for a facultative winter annual species, like C. canadensis, is germination response to temperature. The objective of this study was to determine the germination response to temperature for C. canadensis seed sourced from regions around the world with differing climates and, by doing so, gain insight into the role that seed germination biology plays in the adaptiveness and weediness of facultative winter annual weeds. Seed was sourced from populations in Málaga, Spain, Hertfordshire, UK, Shiraz, Iran and southern Ontario, Canada, and grown out in a common garden under controlled conditions to produce seed for this study. These seeds were then subjected to temperatures from 6.5 to 20°C at 1.5°C increments using a thermogradient plate. Cumulative daily germination counts for 30 days were recorded. Results indicated that temperature and source location had a significant effect on germination response. Estimated base germination temperature ranges were significantly different among the populations [Ontario (8–9.5°C), Iran (9.5–11°C), Spain (12.5–14°C), UK (11–12.5°C)], as were accumulated growing degree days (GDDs; d°C) required to reach 50% germination. For three of the four populations, estimated base germination temperature range values were below those previously reported in the literature. These differences are most likely rapid evolutionary adaptations to local climate and highlight the potential C. canadensis has to be problematic as a native and invasive species.     

GH3::GUS reflects cell-specific developmental patterns and stress-induced changes in wood anatomy in the poplar stem

GH3 genes related to the auxin-inducible Glycine max (L.) Merr. GmGH3 gene encode enzymes that conjugate amino acids to auxin. To investigate the role of GH3 enzymes in stress responses and normal wood development, Populus x canescens (Ait.) was transformed with the promoter-reporter construct GH3::GUS containing a GH3 promoter and the 5' UTR from soybean. beta-Glucuronidase (GUS) activity was present in the vascular tissues of leaves and in developing lateral roots and was inducible in silent tissues by external auxin application. A decrease in GUS activity from the stem apex to the bottom corresponded to decreases in auxin concentrations in these tissues. High auxin concentration and high GH3::GUS activity were present in the pith tissue, which may provide storage for auxin compounds. GH3 reporter was active in ray cells, paratracheal parenchyma cells, maturing vessels and in cells surrounding maturing phloem fibers but not in the cambium and immature phloem, despite high auxin concentrations in the latter tissues. However, the GH3 promoter in these tissues became active when the plants were exposed to abiotic stresses, like bending or salinity, causing changes in wood anatomy. We suggest that adjustment of the internal auxin balance in wood in response to environmental cues involves GH3 auxin conjugate synthases.     

Effect of NaCl on growth and ion relations in two salt-tolerant strains of Paxillus involutus

The effect of NaCl on growth, biomass and ion relations of two salt-tolerant isolates of Paxillus involutus, MAJ and NAU were investigated. The two Paxillus strains were exposed to the following concentrations of NaCl： 0, 100, 200 and 500 mmol·L^-1. Growth of MAJ and NAU was enhanced by 100 mmol·L^-1 NaCl but severely inhibited at the concentration of 500 mmol·L^-1. NAU exhibited a greater capacity to exclude Na^＋ and Cl^- under all salinity levels, whereas the salt-includer MAJ had a higher capacity in nutrient uptake under salt stress. The ratios Na^＋/K^＋, Na^＋/Ca^2＋ and Na^＋/Mg^2＋ in NaCl-treated MAJ and NAU did not increase at levels of 100 and 200 mmol·L^-1 NaCl but markedly increased at 500 mmol·L^-1. This suggests that the two strains, especially MAJ, enhanced nutrient uptake corresponding to the increased Na^＋ influx at moderate salinity. We conclude that both MAJ and NAU are able to tolerate 500 mmol·L^-1 NaCl but there are species-specific differences in retaining ionic homeostasis in the two Paxillus strains. NAU is a salt-excluder, MAJ is a salt-includer but retains a high capacity in nutrient selectivity under saline conditions. Their definite mechanisms to enhance salt tolerance of mycorrhizal hosts need further study.     

Intracompartmental muscle pressure, temperature and pH in the horse undergeneral anesthesia

Intracompartmental muscle pressure, temperature and pH were measured in a group of 23 anesthetized horses in an attempt to elucidate the etiology of post-anesthetic lameness (PAL). The intramuscular pressure remained reasonably constant throughout anesthesia in most horses, while muscle temperature and pH fell. Five of the horses became lame after anesthesia. Two of these lame horses exhibited atypical trends in the physiological variables measured. The etiology of PAL is discussed in the lightof the results.