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关键词： Disease   metabolome   nitrogen   pathogen   resistance   transcriptome  

摘要： Nitrogen (N) is essential for life and is a major limiting factor of plant growth. Because soils frequently lack sufficient N, large quantities of inorganic N fertilizers are added to soils for crop production. However, nitrate, urea, and ammonium are a major source of global pollution, because much of the N that is not taken up by plants enters streams, groundwater, and lakes, where it affects algal production and causes an imbalance in aquatic food webs. Many agronomical data indicate that the higher use of N fertilizers during the green revolution had an impact on the incidence of crop diseases. In contrast, examples in which a decrease in N fertilization increases disease severity are also reported, indicating that there is a complex relationship linking N uptake and metabolism and the disease infection processes. Thus, although it is clear that N availability affects disease, the underlying mechanisms remain unclear. The aim of this review is to describe current knowledge of the mechanisms that link plant N status to the plant's response to pathogen infection and to the virulence and nutritional status of phytopathogens.

关键词： GASTROINTESTINAL system -- Microbiology   INFANT nutrition   MACAQUES   RESEARCH  

摘要： The article discusses a study on breast and bottle-fed macaques, showing different effects of early diets on metabolism and driving mechanism of gut flora, a set of complex microorganisms that live in the digestive tracts, in infants.

关键词： 植物睡眠运动   睡眠理论   运动控制  

摘要： 本文从月光理论、自我保护机制理论、生物钟控制理论、生长素极性运输理论诸角度，概述了植物睡眠运动的各种理论和生物学意义。

关键词： enzymes   microorganisms   phospholipid fatty acid   restoration   soil organic matter   thin loamy ecological sites  

摘要： Following the unprecedented oil drilling presently occurring in western North Dakota, thousands of kilometers of oil roads must be reclaimed to an acceptable post-extraction condition. This study assessed the soil biological and plant communities of nine decommissioned oil roads reclaimed during three periods between 1983 and 2002 in the Little Missouri National Grasslands of western North Dakota. We hypothesized that time-since-reclamation would positively affect soil biological and plant communities and, consequently, success of reclamation at older sites. To assess this hypothesis, we measured soil enzyme activity, soil microbial community composition, plant community composition, and soil physical and chemical properties along a gradient extending from road-center to adjacent native prairie for the nine roads. Time-since-reclamation did not affect soil and plant properties measured, indicating that older reclamations are not more similar to native prairie than reclamations occurring more recently. A strong gradient between samples from road-center and native prairie was identified with univariate and ordination analyses, indicating that soil and plant communities of reclaimed oil roads do not resemble those of the surrounding prairie. Soil organic matter (SOM) was identified as the most significantly affected soil property, being 30% lower on reclaimed roads than prairie. The relationship between SOM, microbial community, and plant community suggests that incorporating additional SOM could hasten reclamation as a result of improving the physical environment for plants and providing a labile carbon and energy source for the soil microbial community which, in turn, will enhance the nutrient and physical conditions for plant growth.

关键词： Liberibacter   phloem-limited bacteria   psyllid vectors   transmission   plant diseases   symptom development  

摘要： Candidatus Liberibacter species are Gram-negative bacteria that live as phloem-limited obligate parasites in plants, and are associated with several plant diseases. These bacteria are transmitted by insects called psyllids, or jumping plant lice, which feed on plant phloem sap. Citrus huanglongbing (yellow shoot) or citrus greening disease is associated with three different species of Ca. Liberibacter - Ca. L. asiaticus, Ca. L. africanus and Ca. L. americanus - all originally found on different continents. Ca. L. asiaticus is the most severe pathogen, spread by Asian citrus psyllid Diaphorina citri and causing devastating epidemics in several countries. Ca. L. africanus occurs in Africa where it is spread by the African citrus psyllid Trioza erytreae. Ca. Liberibacter solanacearum is associated with diseases in several solanaceous plants, and transmitted by potato psyllid Bactericera cockerelli. Zebra chip disease is causing large damage in potato crops in North America. In Europe Ca. Liberibacter solanacearum is associated with diseases of the Apiaceae family of plants, carrot and celery, and transmitted by psyllids Trioza apicalis and Bactericera trigonica. When Ca. Liberibacter is suspected as the disease agent, the diagnosis is confirmed by DNA-based detection methods. Ca. Liberibacter-associated plant diseases can be controlled by using healthy plant propagation material, eradicating symptomatic plants, and by controlling the psyllid populations spreading the disease.

关键词： Araucaria araucana   stem borer   Huequenia   Achrysonini   South America  

摘要： Araucaria trees as host plants of the longhorned beetle Huequenia livida (Coleoptera: Cerambycidae) in Argentina are reviewed. Araucaria araucana is its natural host plant in SW Argentina, but the larvae also developed in dead branches of A. angustifolia and A. bidwillii (new host plant records), when both plants were kept in the same rearing cage with the natural host plant. Pinus contorta var. murrayana, also mentioned from Argentina, may be a recently adopted secondary host. A winter and a summer generation of H. livida was documented for the first time. Huequenia livida exceeds the actual natural distribution of A. araucana following the distribution of cultivated A. araucana and Pinus trees.

关键词： Steel corrosion   Cinnamon plant extract   Polluted salt water  

摘要： The inhibition effect of cinnamon plant extract as a green corrosion inhibitor for steel in sulfide polluted salt water was studied by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM). The results showed that cinnamon plant extract in sulfide polluted salt water is a good corrosion inhibitor with inhibition efficiency reached to 80% at 250 ppm of the plant extract. The adsorption of cinnamon obeys Temkin adsorption isotherm, and acts as a mixed-type of inhibitor but dominantly as a cathodic inhibitor in sulfide polluted salt water.

关键词： hybridization   polyploidy   speciation   floral/morphological evolution  

摘要： This special commemorative issue is dedicated to the life and scientific contributions of Leslie D. Gottlieb. Dr Gottlieb\'s contributions to our understanding of plant evolution were many and varied, from which we selected some of the most influential to be included in this special issue honouring his career. Gottlieb\'s studies were largely hypothesis driven, and he invariably spelled out the rationale for the design of his research and how the results could be used to test his hypotheses. His research was of general interest and attracted widespread attention because it focused on central issues in plant evolution. Though Gottlieb used applicable state-of-the-art methods for that time period, the tremendous methodological and technical advances since his work, especially in the areas of molecular biology, genetics and now genomics, make it possible to examine in greater depth the questions that most intrigued him. The papers in this special issue, contributed by leading workers using largely cutting-edge methods, document that Leslie Gottlieb\'s work was indeed visionary and that it remains as relevant today as it was when published (figure 1).

关键词： 植物多样性   解剖学   竞赛试题   奥林匹克   生物学   生理学   种子形态学   实验  

摘要： 总分：100分时间：90min在这个测验中．有以下2个任务任务1植物多样性和解剖学（60分）A部分幼苗的形态学（14．25分）B部分种子形态学和解剖学（27．25分）C部分榕属（Flcus，无花果属）繁殖体（多个花形成的特殊果实）的解剖（5分）

关键词： Citrullus   Cucumis   hilltopping   mate-location behaviour   sphragis   Tawny Coster  

摘要： The nymphalid butterfly Acraea terpsicore has recently become established in northern Australia where it is spreading rapidly. The immature stages are briefly described, illustrated and compared with those of A. andromacha (Fabricius, 1775) from Australia, and information on its larval food plant specificity, biology and distribution is presented. The species occurs in highly modified open areas, including suburban roadsides, disturbed grassland (i.e. cleared woodland that is regularly slashed or graded) and degraded savannah woodland where it breeds primarily on Hybanthus enneaspermus (L.) F. Muell. (Violaceae), a widespread native herb that is also used as a natural larval food plant in India, and to a lesser extent on Passiflora foetida L. (Passifloraceae), an introduced vine also used as a food plant in Indo-China and Indonesia. Extensive laboratory larval feeding trials on Violaceae, Passifloraceae and Cucurbitaceae revealed limited ability of the Australian population to consume Passifloraceae and lack of ability to feed on Cucurbitaceae, indicating that A. terpsicore is unlikely to become a pest of vegetable and horticultural crops. It is hypothesised that the narrower host range in Australia is attributed to the founder effect of a limited gene pool. Within 14 months of colonisation, A. terpsicore has occupied much of the western half of the 'Top End' of the Northern Territory and spread to the eastern Kimberley of Western Australia, with an estimated extent of occurrence of 112 000 km(2) and average dispersal rate of 315 +/- 56 (SE) km/year. Because the butterfly has the ability to exploit (injure) Violaceae, and potentially outcompete A. andromacha, it may qualify as an invasive species.