Papers by Antonella Furini
Analysis of genes induced by Cd and Zn in the presence of rhizosphere bacteri
Journal of Proteome Research, Jul 24, 2012
Pseudomonas putida is a saprophytic bacterium with remarkable environmental adaptability and the ... more Pseudomonas putida is a saprophytic bacterium with remarkable environmental adaptability and the capacity to tolerate high concentrations of heavy metals. The strain P. putida-Cd001 was isolated from soil contaminated with Cd, Zn and Pb. Membrane-associated and cytosolic proteomes were analyzed to identify proteins whose expression was modulated in response to 250 μM CdSO4. We identified 44 protein spots in the membrane and 21 in the cytosolic fraction differentially expressed in Cd-treated samples compared to untreated controls. Outer membrane porins from the OprD and OprI families were less abundant in bacteria exposed to Cd, whereas those from the OprF and OprL, OprH and OprB families were more abundant, reflecting the increased need to acquire energy sources, the need to maintain membrane integrity and the process of adaptation. Components of the efflux system, such as the CzcB subunit of the CBA system, were also induced by Cd. Analysis of the cytosolic proteome revealed that proteins involved in protein synthesis, degradation and folding were induced along with enzymes that combat oxidative stress, showing that the entire bacterial proteome is modulated by heavy metal exposure. This analysis provides new insights into the adaptation mechanisms used by P. putida-Cd001 to survive in Cd-polluted environments.
Journal of Experimental Botany, Feb 28, 2011
The effects of plant-microbe interactions between the hyperaccumulator Arabidopsis halleri and ei... more The effects of plant-microbe interactions between the hyperaccumulator Arabidopsis halleri and eight bacterial strains, isolated from the rhizosphere of A. halleri plants grown in a cadmium-and zinc-contaminated site, were analysed for shoot metal accumulation, shoot proteome, and the transcription of genes involved in plant metal homeostasis and hyperaccumulation. Cadmium and zinc concentrations were lower in the shoots of plants cultivated in the presence of these metals plus the selected bacterial strains compared with plants grown solely with these metals or, as previously reported, with plants grown with these metals plus the autochthonous rhizosphere-derived microorganisms. The shoot proteome of plants cultivated in the presence of these selected bacterial strains plus metals, showed an increased abundance of photosynthesis-and abiotic stress-related proteins (e.g. subunits of the photosynthetic complexes, Rubisco, superoxide dismutase, and malate dehydrogenase) counteracted by a decreased amount of plant defence-related proteins (e.g. endochitinases, vegetative storage proteins, and b-glucosidase). The transcription of several homeostasis genes was modulated by the microbial communities and by Cd and Zn content in the shoot. Altogether these results highlight the importance of plant-microbe interactions in plant protein expression and metal accumulation and emphasize the possibility of exploiting microbial consortia for increasing or decreasing shoot metal content.
International Journal of Molecular Sciences, Jul 11, 2019
Mineral nutrition of plants greatly depends on both environmental conditions, particularly of soi... more Mineral nutrition of plants greatly depends on both environmental conditions, particularly of soils, and the genetic background of the plant itself. Being sessile, plants adopted a range of strategies for sensing and responding to nutrient availability to optimize development and growth, as well as to protect their metabolisms from heavy metal toxicity. Such mechanisms, together with the soil environment, meaning the soil microorganisms and their interaction with plant roots, have been extensively studied with the goal of exploiting them to reclaim polluted lands; this approach, defined phytoremediation, will be the subject of this review. The main aspects and innovations in this field are considered, in particular with respect to the selection of efficient plant genotypes, the application of improved cultural strategies, and the symbiotic interaction with soil microorganisms, to manage heavy metal polluted soils.
Plant Signaling & Behavior, Jun 1, 2010
Journal of Integrative Plant Biology, Oct 1, 2008
Environmental pollution is one of the major problems for human health. Toxic heavy metals are nor... more Environmental pollution is one of the major problems for human health. Toxic heavy metals are normally present as soil constituents or can also be spread out in the environment by human activity and agricultural techniques. Soil contamination by heavy metals as cadmium, highlights two main aspects: on one side they interfere with the life cycle of plants and therefore reduce crop yields, and on the other hand, once adsorbed and accumulated into the plant tissues, they enter the food chain poisoning animals and humans. Considering this point of view, understanding the mechanism by which plants handle heavy metal exposure, in particular cadmium stress, is a primary goal of plant-biotechnology research or plant breeders whose aim is to create plants that are able to recover high amounts of heavy metals, which can be used for phytoremediation, or identify crop varieties that do not accumulate toxic metal in grains or fruits. In this review we focus on the main symptoms of cadmium toxicity both on root apparatus and shoots. We elucidate the mechanisms that plants activate to prevent absorption or to detoxify toxic metal ions, such as synthesis of phytochelatins, metallothioneins and enzymes involved in stress response. Finally we consider new plant-biotechnology applications that can be applied for phytoremediation.
Phytoremediation: OECD Environmental and Molecular Biological Aspects, 2004
identification of transcripts induced by cadmiu
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Plant MYB transcription factors play key roles in an extremely wide variety of processes, from ce... more Plant MYB transcription factors play key roles in an extremely wide variety of processes, from cellular growth and plant development to secondary metabolism and the response to stresses. A differential screening analysis performed to determine genes modulated by cadmium treatment in Brassica juncea resulted in the identification of a gene orthologous to an Arabidopsis thaliana MYB transcription factor, that was induced after two hours of cadmium exposure. The corresponding A. thaliana MYB transcription factor, MYB59, has previously been reported as involved in the regulation of cell cycle and root growth. The MYB59 locus produces three splicing isoforms, that are also up-regulated in response to cadmium treatment, as well as modulated by other abiotic stresses. myb59 knock-out mutant shows a mild phenotype of altered growth in comparison to wild-type, associated with reduced dimensions of leaf cells. In addition, myb59 mutant is more tolerant to cadmium during seed germination compared to wild-type. The transcriptomic comparison on leaves of wild-type and myb59 plants highlights the modulation of several genes involved in calcium homeostasis and signaling: in particular, 15% of all up-regulated genes in myb59 consisted of transcripts encoding calmodulin-like proteins (CMLs), with calcium-binding properties and involved in calcium signaling. The analysis of stomatal opening indicates that myb59 responds differently than wild-type to exogenous calcium supplementation; moreover, the moderate, even though appreciable, alteration in the patterns of calcium fluxes in guard cells supports the hypothesis that MYB59 transcription factor is involved in the regulation of calcium signaling rather than transport and homeostasis. These results suggest that MYB59 participates in the control of both cell growth and response to abiotic stress by regulating the processes of calcium signaling
transcription analysis of genes induced by cadmium in Brassica junce
Metallomics, 2013
Heavy metals are often present naturally in soils, but many human activities (e.g. mining, agricu... more Heavy metals are often present naturally in soils, but many human activities (e.g. mining, agriculture, sewage processing, the metal industry and automobiles) increase their prevalence in the environment resulting in concentrations that are toxic to animals and plants. Excess heavy metals affect plant physiology by inducing stress symptoms, but many plants have adapted to avoid the damaging effects of metal toxicity, using strategies such as metal chelation, transport and compartmentalization. Understanding the molecular basis of heavy metal tolerance in plants will facilitate the development of new strategies to create metal-tolerant crops, biofortified foods and plants suitable for the phytoremediation of contaminated sites.
Plant Journal, 1995
CDeT6-19 is an ABA-regulated gene which has been isolated from Craterostigma plantagineum. The CD... more CDeT6-19 is an ABA-regulated gene which has been isolated from Craterostigma plantagineum. The CDeT6-19 gene promoter has been fused to the beta-glucuronidase reporter gene (GUS) and used to stably transform Arabidopsis thaliana and Nicotiana tabacum. This construct has been shown to be expressed in stomatal guard cells and often in the adjacent epidermal cells of both species in response to both exogenous ABA and drought stress. These results indicate that the stomatal guard cell is competent to relay an ABA signal to the nucleus. In contrast GUS expression directed by the promoter from a predominantly seed-specific, ABA-regulated gene, Em, or the promoter from the ABA-regulated CDeT27-45 gene is not detectable in the epidermal or guard cells of tobacco or Arabidopsis in response to ABA. The fact that not all ABA-regulated gene promoters are active in stomatal guard cells suggests that effective transduction of the signal is dependent upon particular regions within the gene promoter or that guard cells lack all or part of the specific transduction apparatus required to couple the ABA signal to these promoters. This suggests that there are multiple ABA stimulus response coupling pathways. The identification of a regulatory sequence from an ABA-induced gene which is expressed in stomatal guard cells creates the possibility of examining the role of Ca2+ and other second messengers in ABA-induced gene expression.
New Phytologist, Jul 15, 2008
• Craterostigma plantagineum can lose up to 96% of its water content but fully recover within hou... more • Craterostigma plantagineum can lose up to 96% of its water content but fully recover within hours after rehydration. The callus tissue of the plant becomes desiccation tolerant upon pre-incubation with abscisic acid (ABA). In callus and vegetative organs, ABA addition and water depletion induce a set of dehydrationresponsive genes. • Previously, activation tagging led to the isolation of Craterostigma desiccation tolerant (CDT-1), a dehydration-related ABA-inducible gene which renders callus desiccation tolerant without ABA pre-treatment. This gene belongs to a family of retroelements, members of which are inducible by dehydration. • Craterostigma plantagineum transformation with mutated versions of CDT-1 indicated that protein is not required for the induction of callus desiccation tolerance. Northern analysis and protoplast transfection indicated that CDT-1 directs the synthesis of a double-stranded 21-bp short interfering RNA (siRNA), which opens the metabolic pathway for desiccation tolerance. • Via transposition, these retroelements have progressively increased the capacity of the species to synthesize siRNA and thus recover after dehydration. This may be a case of evolution towards the acquisition of a new trait, stimulated by the environment acting directly on intra-genomic DNA replication.
Shoot regeneration from leaf explants has been achieved in Nipponanthemum nipponicum (syn. Chrysa... more Shoot regeneration from leaf explants has been achieved in Nipponanthemum nipponicum (syn. Chrysanthemum nipponicum), a diploid-related species to cultivated hexaploid chrysanthemums. Effects of 6-benzylaminopurine (BA) and indolacetic acid (IAA), each at three levels of concentration, were tested on three progenies derived from self-fertilisation of a cultivated clone. Optimal BA concentration for regeneration was 2.2 \u3bcM, while no significant differences were detected between the IAA concentrations tested. Significant differences between the progenies were observed. Several genotypes were then tested for their shoot-forming ability. Seven out of 23 did not produce shoots, six produced shoots in more than 50% of the explants. The mean number of shoots per regenerating explant was up to thre
analysis of plant mechanisms to survive dehydratio
A small group of vascular angiosperm plants termed resurrection plants have evolved unique mechan... more A small group of vascular angiosperm plants termed resurrection plants have evolved unique mechanisms of desiccation tolerance. These mechanisms can be usefull to understand and improve water stress tolerance in economically valuable crop
Current Issues in Plant Molecular and Cellular Biology, 1995
Drought tolerance in the resurrection plant Craterostigma plantagineum is restricted to fully dev... more Drought tolerance in the resurrection plant Craterostigma plantagineum is restricted to fully developed plants. In callus this phenomenon can be induced by treatment with abscisic acid. We have used a recently established protocol for Craterostigma transformation by Agrobacterium tumefaciens (Furini et al., 1994) for the stable integration of a T-DNA carrying a transcriptional enhancer element. By this method a gene was tagged whose induced expression resulted in the formation of a desiccation-tolerant callus in the absence of exogenously applied abscisic acid. Craterostigma genes normally induced by desiccation are constitutively induced in the transgenic callus. The tagged gene was cloned from a genomic library and used for the isolation of the corresponding cDNA clone.
Genetic transformation of korean chrysanthemum (Dendranthema zawadskii x D. x grandiflorum) has b... more Genetic transformation of korean chrysanthemum (Dendranthema zawadskii x D. x grandiflorum) has been successfully achieved by co-cultivation with Agrobacterium tumefaciens strain EHA101 carrying the plasmid pIGP3 containing the maize transposable element Ac and the nptII gene as selectable marker. Selection with 100 mg l-1 kanamycin led to a transformation frequency of 7.8% with respect to co-cultivated explants. The nptII gene was detected by PCR analysis in transgenic regenerants and in the 4 progenies achieved. Southern blot analysis confirmed the presence of Ac in both the primary transformants and in their progeny. The restriction analysis of DNA with the methylation sensitive enzyme PvuII showed that the transposon was in a non-methylated status at the PvuII sites. We hypothesize that the Ac element is inserted in an active form and Ac might be successfully employed as gene tagging system in korean chrysanthemum and related diploid species
Physical Stresses in Plants, 1996
The resurrection plant Craterostigma plantagineum is being used as an experimental model system t... more The resurrection plant Craterostigma plantagineum is being used as an experimental model system to dissect pathways leading to desiccation tolerance. This plant can recover from severe desiccation within 24 h of contact with water. During drying or ABA treatment novel gene products accumulate rapidly in leaves and other tissues. It is proposed that these gene products contribute to the protection of cellular structures during dehydration. It has been a major goal to isolate genes and determine parameters which regulate the expression of the responsive genes. One approach was to characterize promoters. Three promoters from different lea type genes and three promoters from genes encoding inducible enzymes of the carbohydrate metabolism have been analyzed for their responsiveness to drought and ABA in transient assays and in transgenic plants. The promoter activities in transgenic plants suggest differences in the mode of the regulatory pathways and point to at least two transduction pathways. Evidence has been accumulated that the activation of at least one promoter in vegetative tissues depends on a gene product related to the Arabidopsis abi3-gene. In gel shift mobility assays it was shown that nuclear proteins from ABA treated callus and leaves specifically bind sequence elements in the promoter region. Other environmental factors such as light interact with desiccation stress and modulate the expression level of the proteins involving post-transcriptional and post-translational mechanisms. To dissect events in this signal transduction chain, two other experimental approaches have been initiated. A T-DNA based tagging experiment was carried out in order to obtain positive mutations over- expressing gene products downstream of the ABA signal. One such mutant has been obtained and has been molecularly characterized. A subtractive and differential screening is being used to isolate cDNA clones which encode transcripts expressed during the very early events of dehydration.
Plant Molecular Biology, 1994
Plant responses to water loss are very complex and depend on the severity of the water loss as we... more Plant responses to water loss are very complex and depend on the severity of the water loss as well as on the developmental stage and the physiological condition of the affected plants. To study responses to protoplastic dehydration at the molecular level we initiated research with the objective to identify gene products which may contribute to water stress tolerance. The unique ability of resurrection plants to withstand severe water loss greater than 90% make them a suitable system to study water stress tolerance: upon rewatering these plants recover quickly from the stress (Gaff 1971, Bartels et al. 1990). We have chosen Craterostigma plantagineum as a representative of the resurrection plants for our studies. An attractive feature of this resurrection plant is that we can analyse desiccation tolerance in undifferentiated callus tissue, too. Callus withstands rapid dehydration if it is treated with the plant hormone abscisic acid (ABA) prior to the drying treatment (Bartels et al. 1990). This makes two experimental systems available from the same plant for the isolation of molecular components relevant to desiccation. Initially we isolated a large number of cDNA clones which are induced upon dehydration and/or ABA treatment (Bartels et al. 1990, Piatkowski et al. 1990, Bartels et al. 1992). The purpose of this chapter is to summarize some characteristic structural and regulatory features of the expressed genes.
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Papers by Antonella Furini