Environ Pollut
November 2024
The timing and efficiency of arsenic (As) accumulation is crucial for using the hyperaccumulator P. vittata in remediation of As-contaminated soils. In this study, through an innovative microXRF-based approach, using a new "pinna powder" sampling method, we monitored As accumulation over time in fronds of individual P.
View Article and Find Full Text PDFThis greenhouse study evaluated the effects of soil enrichment with rhizosphere bacteria on the growth and accumulation of arsenic in grown on a naturally As-rich soil. Inoculations were performed with a consortium of six bacteria resistant to 100 mM arsenate and effects were compared to those obtained on the sterilized soil. Selected bacteria from the consortium were also utilized individually: PVr_9 homologous to that produces IAA and siderophores and shows ACC deaminase activity, PVr_15 homologous to that contains the arsenate reductase gene, and PVr_5 homologous to that possesses all traits from both PVr_9 and PVr_15.
View Article and Find Full Text PDFUrban air pollution is a crucial global challenge, mainly originating from urbanization and industrial activities, which are continuously increasing. Vegetation serves as a natural air filter for air pollution, but adverse effects on plant health, photosynthesis, and metabolism can occur. Recent omics technologies have revolutionized the study of molecular plant responses to air pollution, overcoming previous limitations.
View Article and Find Full Text PDFGlobal climate change (GCC) is posing a serious threat to organisms, particularly plants, which are sessile. Drought, salinity, and the accumulation of heavy metals alter soil composition and have detrimental effects on crops and wild plants. The hormone auxin plays a pivotal role in the response to stress conditions through the fine regulation of plant growth.
View Article and Find Full Text PDFAuxin Response Factor 8 plays a key role in late stamen development: its splice variants ARF8.4 and ARF8.2 control stamen elongation and anther dehiscence.
View Article and Find Full Text PDFIn this work, arsenic (As) accumulation and distribution over time in Pteris vittata young fronds from adult plants and in whole plantlets, grown on a highly contaminated As-soil, was determined by μ-XRF. A linear increase in As content up to 60 days was found in young fronds at different times, and a progressive distribution from the apex to the base of the fronds was observed. In whole plantlets, As signal was detectable from 9 to 20 days in the apex of a few fronds and fiddleheads.
View Article and Find Full Text PDFIn Arabidopsis, stamen elongation, which ensures male fertility, is controlled by the auxin response factor ARF8, which regulates the expression of the auxin repressor IAA19. Here, we uncover a role for light in controlling stamen elongation. By an extensive genetic and molecular analysis we show that the repressor of light signaling COP1, through its targets HY5 and HYH, controls stamen elongation, and that HY5 - oppositely to ARF8 - directly represses the expression of IAA19 in stamens.
View Article and Find Full Text PDFHere, we investigated the role of auxin distribution in controlling Arabidopsis thaliana late stamen development. We analysed auxin distribution in anthers by monitoring DR5 activity: at different flower developmental stages; inhibiting auxin transport; in the rpk2-3 and ems1 mutants devoid of middle layer (ML) or tapetum, respectively; and in the auxin biosynthesis yuc6 and perception afb1-3 mutants. We ran a phenotypic, DR5::GUS and gene expression analysis of yuc6rpk2 and afb1rpk2 double mutants, and of 1-N-naphthylphthalamic acid (NPA)-treated flower buds.
View Article and Find Full Text PDFThe heterologous expression of AtPCS1 in tobacco plants exposed to arsenic plus cadmium enhances phytochelatin levels, root As/Cd accumulation and pollutants detoxification, but does not prevent root cyto-histological damages. High phytochelatin (PC) levels may be involved in accumulation and detoxification of both cadmium (Cd) and arsenic (As) in numerous plants. Although polluted environments are frequently characterized by As and Cd coexistence, how increased PC levels affect the adaptation of the entire plant and the response of its cells/tissues to a combined contamination by As and Cd needs investigation.
View Article and Find Full Text PDFThe heavy metal cadmium (Cd) is a widespread environmental contaminant with harmful effects on living cells. In plants, phytochelatin (PC)-dependent Cd detoxification requires that PC-Cd complexes are transported into vacuoles. Here, it is shown that Arabidopsis thaliana seedlings defective in the ABCC transporter AtABCC3 (abcc3) have an increased sensitivity to different Cd concentrations, and that seedlings overexpressing AtABCC3 (AtABCC3ox) have an increased Cd tolerance.
View Article and Find Full Text PDFArabidopsis abcb1 abcb19 double mutants defective in the auxin transporters ABCB1/PGP1 and ABCB19/PGP19 are altered in stamen elongation, anther dehiscence and pollen maturation. To assess the contribution of these transporters to stamen development we performed phenotypic, histological analyses, and in situ hybridizations on abcb1 and abcb19 single mutant flowers. We found that pollen maturation and anther dehiscence are precocious in the abcb1 but not in the abcb19 mutant.
View Article and Find Full Text PDFIt has been suggested that, in Arabidopsis, auxin controls the timing of anther dehiscence, possibly by preventing premature endothecium lignification. We show here that auxin content in anthers peaks before the beginning of dehiscence and decreases when endothecium lignification occurs. We show that, in the auxin-perception mutants afb1-3 and tir1 afb2 afb3, endothecium lignification and anther dehiscence occur earlier than wild-type, and the gene encoding the transcription factor MYB26, which is required for endothecium lignification, is over-expressed specifically at early stages; in agreement, MYB26 expression is reduced in naphthalene acetic acid-treated anthers, and afb1 myb26 double mutants show no endothecial lignification, suggesting that auxin acts through MYB26.
View Article and Find Full Text PDFWe previously described the expression of a tumour-targeting antibody (mAb H10) in Nicotiana benthamiana by vacuum-agro-infiltration and the remarkable yields of highly pure protein achieved. The objective of the present work was to investigate different strategies for transient overexpression of the mAb H10 in which glycan configuration was modulated and assess how these strategies affect the accumulation yield and stability of the antibody. To this aim, three procedures have been assayed: (1) Site-directed mutagenesis to abolish the glycosylation site; (2) endoplasmic reticulum retention (C-terminal SEKDEL fusion) to ensure predominantly high-mannose type glycans; and (3) expression in a N.
View Article and Find Full Text PDFPrevious studies demonstrated that expression of the Arabidopsis phytochelatin (PC) biosynthetic gene AtPCS1 in Nicotiana tabacum plants increases the Cd tolerance in the presence of exogenous glutathione (GSH). In this paper, the Cd tolerance of Arabidopsis plants over-expressing AtPCS1 (AtPCSox lines) has been analysed and the differences between Arabidopsis and tobacco are shown. Based on the analysis of seedling fresh weight, primary root length, and alterations in root anatomy, evidence is provided that, at relatively low Cd concentrations, the Cd tolerance of AtPCSox lines is lower than the wild type, while AtPCS1 over-expressing tobacco is more tolerant to Cd than the wild type.
View Article and Find Full Text PDFIt was previously demonstrated that the tumour-targeting antibody mAb H10 can be transiently expressed and purified at high levels in Nicotiana benthamiana by using a vacuum-agroinfiltration system boosted by the use of a virus silencing suppressor protein. Scope of this work was to analyse different steps of protein extraction from agroinfiltrated leaves to optimise the purification process of the secretory mAb H10 providing new insights in the field of large-scale plant production. Two different extraction procedures (mechanical shearing/homogenisation and recovery of intercellular fluids -IFs-) were evaluated and compared in terms of purified antibody yields, antibody degradation and total phenolic compounds content.
View Article and Find Full Text PDFThe aims of this work were to obtain a human antibody against the tumour-associated antigen tenascin-C (TNC) and to compare the yield and quality of plant-produced antibody in either stable transgenics or using a transient expression system. To this end, the characterization of a full-sized human immunoglobulin G (IgG) [monoclonal antibody H10 (mAb H10)], derived from a selected single-chain variable fragment (scFv) and produced in plants, is presented. The human mAb gene was engineered for plant expression, and Nicotiana tabacum transgenic lines expressing both heavy (HC) and light (LC) chain were obtained and evaluated for antibody expression levels, in vivo assembly and functionality.
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