The effect of amino acids and amides on the regulation of nitrate uptake by wheat seedlings     

Claudio O. Rodgers  Atilio J. Barneix 《Journal of plant nutrition》2013,36(2):337-348

Wheat plants grown hydroponically increased their nitrate uptake rate more than two‐fold after three days of N starvation. Exogenously supplied amino acids and amides had no effect on the nitrate uptake rate of plants well nourished in N. After three days of N starvation, however, some of the amino acids and amides supplied to plants inhibited up to 50% of the nitrate uptake rate. The most effective inhibitor was aspartic acid. Asparagine, glutamine or phenylalanine did not show any inhibitory effect. The percentage of inhibition was not increased by increasing the amino acid concentration, nor did the addition of mixed amino acids and amides increase the inhibition exerted by one amino acid alone. During the three days of N starvation, there was a decrease in the concentration of endogenous amino acids in the roots, but not all amino acids decreased their concentration at the same rate.

It is suggested that the endogenous levels of some amino acids may repress the nitrate uptake system in plants well supplied with N. During the development of the N deficiency, the concentration of these amino acid decreases, de‐repressing the nitrate uptake system.  相似文献   

Neural networks in climate spatialization and their application in the agricultural zoning of climate risk for sunflower in different sowing dates     

Lucas Eduardo de Oliveira Aparecido  José Reinaldo da Silva Cabral de Moraes  Glauco de Souza Rolim  Lucieta Guerreiro Martorano  Kamila Cunha de Meneses  Taynara Tuany Borges Valeriano 《Archives of Agronomy and Soil Science》2013,59(11):1477-1492

ABSTRACT

Sunflower is a species that is sensitive to local climate conditions. However, studies that use artificial neural networks (ANNs) to evaluate this influence and create tools such as agricultural zoning of climate risk (ZARC) have not been conducted for this species. Due to the importance of sunflower as a human food source and for biodiesel production, and also the necessity of conducting research to evaluate the suitability of this oleaginous species under different climatic conditions. Thus, we seek to construct a ZARC for sunflower in Brazil simulating sowing on different dates and using meteorological elements spatialized by ANNs. Climate data were used: air temperature (T), rainfall (P), relative air humidity (UR), solar radiation (MJ_m^?2_d^?1) and wind velocity (U²). Climatic regions considered suitable for the cultivation of sunflower had average annual values for T between 20 and 28°C, P between 500 and 1.500 mm per cycle, and soil water deficit (DEF) below 140 mm per cycle. A neural network is an efficient tool that can be used in spatialization of climate variables quickly and accurately. Sunflower sowing in the spring and summer are the ones that provide the largest suitable areas in southeastern Brazil, with 58.13 and 64.36% of suitable areas, respectively.  相似文献   

Abundance of White-fronted Parrots and diet of an urban parrot assemblage(Aves:Psittaciformes)in a green Neotropical city     

Cristel álvarez-Castillo  Ian MacGregor-Fors  Stefan L.Arriaga-Weiss  Claudio Mota-Vargas  Diego Santiago-Alarcon 《中国鸟类》2022,(1):36-42

Urban ecosystems are evolutionarily recent novel environments acting as biodiversity filters.Psittacidae birds are considered successful urban adapters mainly d...  相似文献   

Agriculturally intensified landscapes are associated with reduced body condition of lady beetles     

Tiede  Julia  Iuliano  Benjamin  Gratton  Claudio 《Landscape Ecology》2022,37(7):1921-1936

Landscape Ecology - Agricultural intensification is contributing to a global species decline. Underlying mechanisms include toxic effects of pesticides on non-target organisms and reductions in...  相似文献   

Genetic diversity via REML-BLUP of ex situ conserved macauba [Acrocomia aculeata (Jacq.) Lodd. ex Mart.] ecotypes     

de Sá  Silvia Ferreira  dos Santos  Luísa C. Aragão  da Conceição  Léo D. H. C. Schwartzhaupt  Braga  Marcelo Fideles  Laviola  Bruno Galvêas  Cardoso  Alexandre Nunes  Sayd  Ricardo Meneses  Junqueira  Nilton T. Vilela 《Genetic Resources and Crop Evolution》2021,68(8):3193-3204

Genetic Resources and Crop Evolution - Macauba [Acrocomia aculeata (Jacq.) Lodd. ex Mart.], a palm tree native to Brazil, has a high potential as an alternative source for vegetal oil production....  相似文献   

Increase in Iron and Zinc Concentrations in Rice Grains Via the Introduction of Barley Genes Involved in Phytosiderophore Synthesis   总被引：1，自引：1，他引：0  

Hiroshi Masuda  Motofumi Suzuki  Kendi Claudio Morikawa  Takanori Kobayashi  Hiromi Nakanishi  Michiko Takahashi  Masahiko Saigusa  Satoshi Mori  Naoko K. Nishizawa 《Rice》2008,1(1):100-108

Increasing the iron (Fe) and zinc (Zn) concentrations of staple foods, such as rice, could solve Fe and Zn deficiencies, which are two of the most serious nutritional problems affecting humans. Mugineic acid family phytosiderophores (MAs) play a very important role in the uptake of Fe from the soil and Fe transport within the plant in graminaceous plants. To explore the possibility of MAs increasing the Fe concentration in grains, we cultivated three transgenic rice lines possessing barley genome fragments containing genes for MAs synthesis (i.e., HvNAS1, HvNAS1, and HvNAAT-A and HvNAAT-B or IDS3) in a paddy field with Andosol soils. Polished rice seeds with IDS3 inserts had up to 1.40 and 1.35 times higher Fe and Zn concentrations, respectively, compared to non-transgenic rice seeds. Enhanced MAs production due to the introduced barley genes is suggested to be effective for increasing Fe and Zn concentrations in rice grains.  相似文献   

Map- vs. homology-based cloning for the recessive gene ol-2 conferring resistance to tomato powdery mildew     

Stefano Pavan  Zheng Zheng  Mariya Borisova  Petra van den Berg  Concetta Lotti  Claudio De Giovanni  Pim Lindhout  Hans de Jong  Luigi Ricciardi  Richard G. F. Visser  Yuling Bai 《Euphytica》2008,162(1):91-98

The recessive gene ol-2 confers papilla-associated and race-non-specific resistance to tomato powdery mildew caused by Oidium neolycopersici. In order to facilitate marker assisted selection (MAS) in practical breeding programmes, we identified two simple sequence repeat (SSR) markers and one cleaved amplified polymorphic sequence (CAPS) marker which are linked to the resistance locus and co-dominantly inherited. Aiming to provide a base for ol-2 positional cloning, we used a large segregating F₂ population to merge these markers with all the ol-2 linked amplified fragment length polymorphism (AFLP^®) markers previously identified in an integrated genetic map. By screening a tomato bacterial artificial chromosome (BAC) library, we detected two BAC clones containing two expressed sequence tags (ESTs) homologous to the gene mlo, responsible for powdery mildew resistance in barley, as well as an ol-2-linked marker. Chromosomal mapping by Fluorescence in situ Hybridization (FISH) revealed major signals of the two BAC DNAs in the pericentromeric heterochromatin of the short arm of chromosome 4, in the same region where the ol-2 gene was previously mapped. The genetic and cytogenetic co-localisation between ol-2 and tomato mlo-homologue(s), in addition to the similarity of ol-2 and mlo resistances for both genetic and phytopathological characteristics, suggests that ol-2 is likely a mlo-homologue. Thus, a homology-based cloning approach could be more suitable than positional cloning for ol-2 isolation.  相似文献   

A natural fungicide for the control of <Emphasis Type="Italic">Erysiphe betae</Emphasis> and <Emphasis Type="Italic">Erysiphe cichoracearum</Emphasis>     

Domenico Rongai  Claudio Cerato  Luca Lazzeri 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(4):613-619

This study examines the effects of a vegetable fungicide on sugar beet powdery mildew (Erysiphe betae) and cucumber powdery mildew (Erysiphe cichoracearum). The formulations consisting of a dispersion of Brassicaceae meal in vegetable or mineral oils on infected leaves of sugar beet, reared in the greenhouse, and of musk melons cultivated under plastic tunnels, were tested in comparison to each oil taken separately. Both formulations containing Brassicaceae meals, caused 94% of conidia to be distorted while for the untreated group only 2% were distorted. Furthermore, the leaf area infected by E. betae was 56% for untreated plants and 2.7 and 9.9% respectively, for plants treated with meal containing mineral and vegetable oil. Vegetable oil considered separately or with Brassicaceae meals showed no phytotoxicity, while the formulations based on mineral oil showed a significantly lower fresh and dry weight on tomato plants. The low level or absence of phytotoxicity of plants treated with vegetable oil formulations suggests that to improve the efficacy of powdery mildew control, they could be used mixed with sulphur. The efficiency of the vegetable formulations in the powdery mildew control observed during these trials encourages further investigation on other parasitic fungi and foliar pathogens.  相似文献   

Detection of a broad range of class I and II Newcastle disease viruses using a multiplex real-time reverse transcription polymerase chain reaction assay.     

L Mia Kim  David L Suarez  Claudio L Afonso 《Journal of veterinary diagnostic investigation》2008,20(4):414-425

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Open‐label clinical trial of rectally administered levetiracetam as supplemental treatment in dogs with cluster seizures     

Giulia Cagnotti  Rosangela Odore  Iride Bertone  Cristiano Corona  Elena Dappiano  Giulia Gardini  Barbara Iulini  Claudio Bellino  Antonio D'Angelo 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2019,33(4):1714-1718

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