Effect of Aluminum Treatment on Proteomes of Radicles of Seeds Derived from Al-Treated Tomato Plants.
ABSTRACT: Aluminum (Al) toxicity is a major constraint to plant growth and crop yield in acid soils. Tomato cultivars are especially susceptible to excessive Al3+ accumulated in the root zone. In this study, tomato plants were grown in a hydroponic culture system supplemented with 50 µM AlK(SO?)?. Seeds harvested from Al-treated plants contained a significantly higher Al content than those grown in the control hydroponic solution. In this study, these Al-enriched tomato seeds (harvested from Al-treated tomato plants) were germinated in 50 µM AlK(SO?)? solution in a homopiperazine-1,4-bis(2-ethanesulfonic acid) buffer (pH 4.0), and the control solution which contained the buffer only. Proteomes of radicles were analyzed quantitatively by mass spectrometry employing isobaric tags for relative and absolute quantitation (iTRAQ®). The proteins identified were assigned to molecular functional groups and cellular metabolic pathways using MapMan. Among the proteins whose abundance levels changed significantly were: a number of transcription factors; proteins regulating gene silencing and programmed cell death; proteins in primary and secondary signaling pathways, including phytohormone signaling and proteins for enhancing tolerance to abiotic and biotic stress. Among the metabolic pathways, enzymes in glycolysis and fermentation and sucrolytic pathways were repressed. Secondary metabolic pathways including the mevalonate pathway and lignin biosynthesis were induced. Biological reactions in mitochondria seem to be induced due to an increase in the abundance level of mitochondrial ribosomes and enzymes in the TCA cycle, electron transport chains and ATP synthesis.
Project description:cDNA microarrays (Tom 1) were used to analyze changes in transcript accumulation in tomato (Solanum lycopersicum cv Money Maker) root cultures under Al-stress (20uM AlK(SO4)2). Out of the 1,362 genes that had significant changes in transcript accumulation (FDR<0.05), 569 were reduced and 793 were induced. The down-regulated genes included those found in the cell cycle (p34cdc2 protein kinase, cyclin, histone), putriscine synthesis, ABC transporter, germin-like protein. Al-induced genes included glutamate synthase, pectin modification, histidine synthesis, proline synthesis, metallothionein-like protein, multidrug efflux proteins (MATE), ethylene biosynthesis and detoxification proteins. Different isoforms in the multiple gene families of V-ATPase, glutathione transferases and others were either induced or repressed. A wide array of genes for regulating transcription and translation activities, and signal transduction were also affected. Overall design: Tomato (Solanum esculentum Mill cv Money Maker) seeds were surface sterilized by submerging in 50% bleach (sodium hypochloride) for 10 min followed by three washes with sterile distilled water. For seed germination, six clean seeds were placed in a 500ml flask containing 300 ml Modified Magnavaca’s solution (Magnavaca, 1982) adjusted to pH 4.5 and incubated on a shaker (150rpm) at 25C for four days. Germinating seeds were then transferred to fresh Modified Magnavaca’s solution supplemented with 20µM AlK(SO4)2. Seedlings serving as controls were placed in Magnavaca’s solution without the Al. Cultures were maintained for 12 additional days, the solution was replaced every four days. At the termination of the experiment, root tips of ~1cm in length were dissected and soaked in pre-chilled RNA extraction buffer. Each replicate of treatment/ control has 20 flasks, and root tips (2cm in length) from the 20 flasks were pooled to make one RNA extraction. Six RNA extraction replicates were preformed for Al treated and control tissues.
Project description:The tomato (Solanum lycopersicum) ripening process from mature green (MG) to turning and then to red stages is accompanied by the occurrences of physiological and biochemical reactions, which ultimately result in the formation of the flavor, color and texture of ripe fruits. The two trivalent metal ions Al3+ and La3+ are known to induce different levels of phytotoxicity in suppressing root growth. This paper aims to understand the impacts of these two metal ions on tomato fruit proteomes. Tomato 'Micro-Tom' plants were grown in a hydroponic culture system supplemented with 50 ?M aluminum sulfate (Al? (SO4)?.18H?O) for Al3+ or La?(SO?)? for La3+. Quantitative proteomics analysis, using isobaric tags for relative and absolute quantitation, were performed for fruits at MG, turning and red stages. Results show that in MG tomatoes, proteins involved in protein biosynthesis, photosynthesis and primary carbohydrate metabolisms were at a significantly lower level in Al-treated compared to La-treated plants. For the turning and red tomatoes, only a few proteins of significant differences between the two metal treatments were identified. Results from this study indicate that compared to La3+, Al3+ had a greater influence on the basic biological activities in green tomatoes, but such an impact became indistinguishable as tomatoes matured into the late ripening stages.
Project description:Glyoxalase I (Gly I) is the first enzyme in the glutathionine-dependent glyoxalase pathway for detoxification of methylglyoxal (MG) under stress conditions. Transgenic tomato 'Money Maker' plants overexpressing tomato SlGlyI gene (tomato unigene accession SGN-U582631/Solyc09g082120.3.1) were generated and homozygous lines were obtained after four generations of self-pollination. In this study, SlGlyI-overepxressing line (GlyI), wild type (WT, negative control) and plants transformed with empty vector (ECtr, positive control), were subjected to Al-treatment by growing in Magnavaca's nutrient solution (pH 4.5) supplemented with 20?µM Al3+ ion activity. After 30 days of treatments, the fresh and dry weight of shoots and roots of plants from Al-treated conditions decreased significantly compared to the non-treated conditions for all the three lines. When compared across the three lines, root fresh and dry weight of GlyI was significant higher than WT and ECtr, whereas there was no difference in shoot tissues. The basal 5?mm root-tips of GlyI plants expressed a significantly higher level of glyoxalase activity under both non-Al-treated and Al-treated conditions compared to the two control lines. Under Al-treated condition, there was a significant increase in MG content in ECtr and WT lines, but not in GlyI line. Quantitative proteomics analysis using tandem mass tags mass spectrometry identified 4080 quantifiable proteins and 201 Al-induced differentially expressed proteins (DEPs) in root-tip tissues from GlyI, and 4273 proteins and 230 DEPs from ECtr. The Al-down-regulated DEPs were classified into molecular pathways of gene transcription, RNA splicing and protein biosynthesis in both GlyI and ECtr lines. The Al-induced DEPs in GlyI associated with tolerance to Al3+ and MG toxicity are involved in callose degradation, cell wall components (xylan acetylation and pectin degradation), oxidative stress (antioxidants) and turnover of Al-damaged epidermal cells, repair of damaged DNA, epigenetics, gene transcription, and protein translation. A protein-protein association network was constructed to aid the selection of proteins in the same pathway but differentially regulated in GlyI or ECtr lines. Proteomics data are available via ProteomeXchange with identifiers PXD009456 under project title '25Dec2017_Suping_XSexp2_ITAG3.2' for SlGlyI-overexpressing tomato plants and PXD009848 under project title '25Dec2017_Suping_XSexp3_ITAG3.2' for positive control ECtr line transformed with empty vector.
Project description:A balanced nutrient supply is essential for the healthy growth of plants in hydroponic systems. However, the commonly used electrical conductivity (EC)-based nutrient control for plant cultivation can provide amounts of nutrients that are excessive or inadequate for proper plant growth. In this study, we investigated the kinetics of major and minor nutrient uptake in a nutrient solution during the growth of tomato (Solanum lycopersicum var. cerasiforme Alef.) in a closed hydroponic system. The concentrations of major and minor ions in the nutrient solution were determined by various analytical methods including inductively coupled plasma-optical emission spectroscopy (ICP-OES), ion chromatography (IC), ion specific electrodes, and/or colorimetric methods. The concentrations of the individual nutrient ions were compared with changes in the EC. The EC of the nutrient solution varied according to the different growth stages of tomato plants. Variation in the concentrations of NO3-, SO42-, Mg2+, Ca2+, and K+ was similar to the EC variation. However, in the cases of PO43-, Na+, Cl-, dissolved Fe and Mn, Cu2+, and Zn2+, variation did not correspond with that of EC. These ions were generally depleted (to 0 mg L-1) during tomato growth, suggesting that these specific ions should be monitored individually and their supply increased. Nutrient uptake rates of major ions increased gradually at different growth stages until harvest (from < 3 mg L-1 d-1 to > 15 mg L-1 d-1). Saturation indices determined by MINEQL+ simulation and a mineral precipitation experiment demonstrated the potential for amorphous calcium phosphate precipitation, which may facilitate the abiotic adsorptive removal of dissolved Fe, dissolved Mn, Cu2+, and Zn2+.
Project description:In order to decipher the molecular alterations caused by the growing medium, we harvested the roots of plants grown in hydroponics and on soil for 6 weeks under 10-hour short days. The temperature was 20Â°C (day and night), the relative humidity was 70 %, and the light was provided by cool-white fluorescent tubes at 100 Î¼E.mâ??2.sâ??1 during the first 10 days, 60 Î¼E.mâ??2.sâ??1 later. The soil was composed of a mixture of peat compost and sand (3:1 v/v), which was watered daily with tap water. Plants were transferred to 1-liter containers (six plants/container) 18 days after sowing. Plants grown in hydroponics were sown on agar-containing (6.7 g.lâ??1; Kalys, France) seed-holders placed on 2-liter black containers and accessories (http://www.araponics.com). The hydroponic solution, changed every two weeks, was prepared as described in Tocquin et al. (2003). During the first three weeks of growth, the number of plants per 2-liter tank was 35 and 18 afterwards. Harvesting was performed 8 hours after the beginning of the light period (16h30), and the roots from 35 to 45 individuals were pooled. Three independent biological replicates were performed for plants grown on both media.
Project description:The effects of salt-induced stress in drug-type Cannabis sativa L. (C. sativa), a crop with increasing global importance, are almost entirely unknown. In an indoor controlled factorial experiment involving a type-II chemovar (i.e., one which produces ?9-tetrahydrocannabinolic acid ~THCA and cannabidiolic acid ~ CBDA), the effects of increasing NaCl concentrations (1-40 mM) was tested in hydroponic and aquaponic solutions during the flowering stage. Growth parameters (height, canopy volume), plant physiology (chlorophyll content, leaf-gas exchange, chlorophyll fluorescence, and water use efficiency), and solution physicochemical properties (pH, EC, and nutrients) was measured throughout the experiment. Upon maturation of inflorescences, plants were harvested and yield (dry inflorescence biomass) and inflorescence potency (mass-based concentration of cannabinoids) was determined. It was found that cannabinoids decreased linearly with increasing NaCl concentration: -0.026 and -0.037% THCA·mM NaCl-1 for aquaponic and hydroponic solutions, respectively. The growth and physiological responses to NaCl in hydroponic-but not the aquaponic solution-became negatively affected at 40 mM. The mechanisms of aquaponic solution which allow this potential enhanced NaCl tolerance is worthy of future investigation. Commercial cultivation involving the use of hydroponic solution should carefully monitor NaCl concentrations, so that they do not exceed the phytotoxic concentration of 40 mM found here; and are aware that NaCl in excess of 5 mM may decrease yield and potency. Additional research investigating cultivar- and rootzone-specific responses to salt-induced stress is needed.
Project description:Trichoderma harzianum strain SQR-T037 is a biocontrol agent that has been shown to enhance the uptake of nutrients (macro- and microelements) by plants in fields. The objective of this study was to investigate the contribution of SQR-T037 to P and microelement (Fe, Mn, Cu and Zn) nutrition in tomato plants grown in soil and in hydroponic conditions. Inoculation with SQR-T037 significantly improved the biomass and nutrient uptake of tomato seedlings grown in a nutrient-limiting soil. So we investigated the capability of SQR-T037 to solubilise sparingly soluble minerals in vitro via four known mechanisms: acidification by organic acids, chelation by siderophores, redox by ferric reductase and hydrolysis by phytase. SQR-T037 was able to solubilise phytate, Fe2O3, CuO, and metallic Zn but not Ca3(PO4)2 or MnO2. Organic acids, including lactic acid, citric acid, tartaric acid and succinic acid, were detected by HPLC and LC/MS in two Trichoderma cultures. Additionally, we inoculated tomato seedlings with SQR-T037 using a hydroponic system with specific nutrient deficiencies (i.e., nutrient solutions deficient in P, Fe, Cu or Zn and supplemented with their corresponding solid minerals) to better study the effects of Trichoderma inoculation on plant growth and nutrition. Inoculated seedlings grown in Cu-deficient hydroponic conditions exhibited increases in dry plant biomass (92%) and Cu uptake (42%) relative to control plants. However, we did not observe a significant effect on seedling biomass in plants grown in the Fe- and Zn-deficient hydroponic conditions; by contrast, the biomass decreased by 82% in the P-deficient hydroponic condition. Thus, we demonstrated that Trichoderma SQR-T037 competed for P (phytate) and Zn with tomato seedlings by suppressing root development, releasing phytase and/or chelating minerals. The results of this study suggest that the induction of increased or suppressed plant growth occurs through the direct effect of T. harzianum on root development, in combination with indirect mechanisms, such as mineral solubilisation (including solubilisation via acidification, redox, chelation and hydrolysis).
Project description:The goal of this experiment is to identify the changes in protein expression induced by Al treatment with a view towards developing a molecular level understanding of Al tolerance in an important crop species. In this particular experiment the focus was on protein expression in tomato embryo. Tomato (Solanum lycopersicum ‘Micro-Tom’) plants were treated in Magnavaca’s solution (pH 4.5) supplemented with 50 µM AlK(SO4)2·12H2O providing 7.5 µM Al3+ activity over a four-month period beginning at the emergence of the first flower buds and ending when a few leaves started to turn yellow. Proteins from root, leaf, embryo and seed-coat tissues were identified using a 8-plex iTRAQ labeling strategy followed by a two-dimensional (high- and low-pH) chromatographic separation, and final generation of MS/MS spectra of tryptic peptides on an LTQ-Orbitrap Elite-mass spectrometer
Project description:Hydroponic systems and intensive irrigation are used widely in horticulture and thus have the potential for rapid spread of water-transmissible plant pathogens. Numerous plant viruses have been reported to occur in aqueous environments, although information on their survival and transmission is minimal, due mainly to the lack of effective detection methods and to the complexity of the required transmission experiments. We have assessed the role of water as a source of plant infection using three mechanically transmissible plant pathogens that constitute a serious threat to tomato and potato production: pepino mosaic virus (PepMV), potato virus Y (PVY), and potato spindle tuber viroid (PSTVd). PepMV remains infectious in water at 20 ± 4°C for up to 3 weeks, PVY (NTN strain) for up to 1 week, and PSTVd for up to 7 weeks. Experiments using a hydroponic system show that PepMV (Ch2 genotype) and PVY (NTN strain) can be released from plant roots into the nutrient solution and can infect healthy plants through their roots, ultimately spreading to the green parts, where they can be detected after a few months. In addition, tubers developed on plants grown in substrate watered with PSTVd-infested water were confirmed to be the source of viroid infection. Our data indicate that although well-known pathways of virus spread are more rapid than water-mediated infection, like insect or mechanical transmission through leaves, water is a route that provides a significant bridge for rapid virus/viroid spread. Consequently, water should be taken into account in future epidemiology and risk assessment studies.
Project description:The goal of this experiment is to identify the changes in protein expression induced by Al treatment with a view towards developing a molecular level understanding of Al tolerance in an important crop species. In this particular experiment the focus was on protein expression in tomato seed coat. Tomato (Solanum lycopersicum ‘Micro-Tom’) plants were treated in Magnavaca’s solution (pH 4.5) supplemented with 50 µM AlK(SO4)2·12H2O providing 7.5 µM Al3+ activity over a four-month period beginning at the emergence of the first flower buds and ending when a few leaves started to turn yellow. Proteins from root, leaf, embryo and seed-coat tissues were identified using a 8-plex iTRAQ labeling strategy followed by a two-dimensional (high- and low-pH) chromatographic separation, and final generation of MS/MS spectra of tryptic peptides on an LTQ-Orbitrap Elite-mass spectrometer