Search results for "Plant"
showing 10 items of 11944 documents
Arabidopsis mutant dnd2 exhibits increased auxin and abscisic acid content and reduced stomatal conductance
2019
Arabidopsis thaliana cyclic nucleotide-gated ion channel gene 4 (AtCNGC4) loss-of-function mutant dnd2 exhibits elevated accumulation of salicylic acid (SA), dwarfed morphology, reduced hypersensitive response (HR), altered disease resistance and spontaneous lesions on plant leaves. An orthologous barley mutant, nec1, has been reported to over-accumulate indole-3-acetic acid (IAA) and to exhibit changes in stomatal regulation in response to exogenous auxin. Here we show that the Arabidopsis dnd2 over-accumulates both IAA and abscisic acid (ABA) and displays related phenotypic and physiological changes, such as, reduced stomatal size, higher stomatal density and stomatal index. dnd2 showed i…
Two ectomycorrhizal truffles, Tuber melanosporum and T. aestivum , endophytically colonise roots of non‐ectomycorrhizal plants in natural environments
2020
International audience; Serendipitous findings and studies on Tuber species suggest that some ectomycorrhizal fungi, beyond their complex interaction with ectomycorrhizal hosts, also colonise roots of nonectomycorrhizal plants in a loose way called endophytism. Here, we investigate endophytism of T. melanosporum and T. aestivum . We visualised endophytic T. melanosporum hyphae by fluorescent in situ hybridisation on nonectomycorrhizal plants. For the two Tuber species, microsatellite genotyping investigated the endophytic presence of the individuals whose mating produced nearby ascocarps. We quantified the expression of four T. aestivum genes in roots of endophyted, non‐ectomycorrhizal plan…
Rhizoctonia solani AG 11 isolated for the first time from sugar beet in Poland
2020
Abstract Two isolates of Rhizoctonia solani AG11 were isolated from sugar beet seedlings from South-west Poland. Both isolates gave C2 reactions in anastomose pairings with the tester isolates of AG11. The membership of both isolates to AG11 was confirmed by analysis of pectic isozyme profiles, and by verification that the internal transcribed spacer sequences of both isolates matched the references in the GenBank database. Both AG11 isolates formed white-beige to creamy-colored mycelium with wide concentric zonation. One of them formed light-colored sclerotia. The average daily rate of hyphal growth at 21 °C was 22.8 mm and 22.6 mm on PDA. They were mildly pathogenic to sugar beet seedling…
Assessment of the conservation status of the mat-forming lichens Cladonia subgenus Cladina in Italy
2015
Cladina species are likely to suffer the impact of human pressure, resulting in a potential, as well as currently unknown, extinction risk for some of them. In this study, we used herbarium specimen data and literature data combined with geographic information system (GIS)-based analyses to assess the threatened status of Italian Cladina species according to IUCN criteria. A total of 485 records, reported during the period 1833–2013, were evaluated. Biological traits, habitat requirements and distribution patterns were used to infer species extinction risk. Extent of occurrence and area of occupancy have been calculated at the national scale, based on a 2 km × 2 km cell grid. The potential …
Using metabarcoding to reveal and quantify plant-pollinator interactions.
2016
AbstractGiven the ongoing decline of both pollinators and plants, it is crucial to implement effective methods to describe complex pollination networks across time and space in a comprehensive and high-throughput way. Here we tested if metabarcoding may circumvent the limits of conventional methodologies in detecting and quantifying plant-pollinator interactions. Metabarcoding experiments on pollen DNA mixtures described a positive relationship between the amounts of DNA from focal species and the number of trnL and ITS1 sequences yielded. The study of pollen loads of insects captured in plant communities revealed that as compared to the observation of visits, metabarcoding revealed 2.5 tim…
Influence of parasitoid-associated viral symbionts on plant–insect interactions and biological control
2021
International audience; Insect parasitoids have evolved symbiotic interactions with several viruses and thousands of parasitoid species have established mutualistic associations with polydnaviruses (PDVs). While PDVs have often been described as virulence factors allowing development of immature parasitoids inside their herbivore hosts, there is increasing awareness that PDVs can affect plant-insect interactions. We review recent literature showing that PDVs alter not only host physiology, but also feeding patterns and composition of herbivore's oral secretions. In turn PDV-induced changes in herbivore phenotype affect plant responses to herbivory with consequences ranging from differential…
Insect repellent and chemical agronomic treatments to reduce seed numberin'Afourer'mandarin. Effect on yield and fruit diameter
2019
Abstract Obtaining citrus fruits without seeds is a recurrent objective for farmers as it is one of the most valued characteristics, especially in mandarins. ‘Afourer’ tangor is a highly valuable well-established mandarin, and a high percentage of seeded fruits are produced under cross-pollination conditions. Several agronomic techniques have been suggested to control presence of seeds, such as covering with nets and copper sulfate (CuSO4) and gibberellic acid (GA3) treatments. Natural bee repellents are also proposed to reduce the number of seeds per fruit. In this study, we aimed to compare the effect of several agronomic treatments to reduce the seed number in 'Afourer' mandarin. To this…
Secondary metabolites and eco-friendly techniques for agricultural weed/pest management
2021
In agro-ecosystems, pests (insects, weeds, and other plant’s parasites) compete with crops for edaphic resources, negatively affecting quality and crop yields [1]. Nowadays, synthetic pesticides, easy to apply and accessible to farmers, are the most common and effective methods for pest management [2]. Nevertheless, the negative impact of these chemicals on the environment, human health, and the development of herbicides/pesticides-resistance are shifting the attention to alternative pest control technologies based on natural compounds [3–6]. Therefore, new eco-friendly agronomic techniques and the use of natural or natural-like molecules might represent a valid alternative strategy for pes…
Water relations of two Sicilian grapevine cultivars in response to potassium availability and drought stress
2020
Abstract We investigated the response of two Sicilian grapevine cultivars, Catarratto and Nero d'Avola, to potassium deficiency and drought stress. Two-year-old plants grafted on 1103 Paulsen were grown in agriperlite, with or without potassium in the fertigation solution for six weeks, and subjected to moderate drought stress by suspending irrigation for one week. Potassium content of leaves, roots and xylem sap were measured with an ion-selective electrode. Changes in stomatal conductance, stem and leaf water potential and hydraulic conductance were compared between genotypes and treatments. Potassium deficiency led to significant decreases in leaf potassium content in both cultivars and …
Water Deficit Affects the Growth and Leaf Metabolite Composition of Young Loquat Plants
2020
Water scarcity in the Mediterranean area is very common and understanding responses to drought is important for loquat management and production. The objective of this study was to evaluate the effect of drought on the growth and metabolism of loquat. Ninety two-year-old plants of &lsquo