Iodine-Biofortified Lettuce Can Promote Mitochondrial Dependent Pathway of Apoptosis in Human Gastrointestinal Cancer Cells.

Previously, our research provided evidence that exposure of gastric and colon cancer cells to extracts from iodine-biofortified lettuce leads to a reduction of cell viability and proliferation through cell cycle arrest and upregulation of pro-apoptotic genes. The aim of the present study was to determine the potential cellular mechanisms of induction of cell death in human gastrointestinal cancer cell lines after treatment with iodine-biofortified lettuce. We demonstrated that extracts from lettuce enriched with iodine induce apoptosis in gastric AGS and colon HT-29 cancer cells and the mechanism of programmed cell death may be triggered and executed through different signaling pathways, depending on the type of cells. Western blot analysis revealed that iodine-fortified lettuce leads to cell death through the release of cytochrome c to the cytosolic fraction and activation of the primary drivers of apoptosis: caspase-3, caspase-7, and caspase-9. Furthermore, we have reported that apoptotic effects of lettuce extracts may be mediated by poly (ADP-ribose) polymerase (PARP) and activation of pro-apoptotic Bcl-2 family proteins such as Bad, Bax, and BID. We also observed mitochondrial dysfunction with the dissipation of the mitochondrial membrane potential in cells exposed to lettuce extracts. Taken together, these results indicate that the organic form of iodine such as 5-ISA and 3,5-diISA is an important factor in the activation of intrinsic mitochondrial apoptotic pathway in AGS and HT-29 cancer cells in a p53-independent manner.

Transcriptome Dynamics Underlying Planticine®-Induced Defense Responses of Tomato (Solanum lycopersicum L.) to Biotic Stresses.

The induction of natural defense mechanisms in plants is considered to be one of the most important strategies used in integrated pest management (IPM). Plant immune inducers could reduce the use of chemicals for plant protection and their harmful impacts on the environment. Planticine® is a natural plant defense biostimulant based on oligomers of α(1→4)-linked D-galacturonic acids, which are biodegradable and nontoxic. The aim of this study was to define the molecular basis of Planticine's biological activity and the efficacy of its use as a natural plant resistance inducer in greenhouse conditions. Three independent experiments with foliar application of Planticine® were carried out. The first experiment in a climatic chamber (control environment, no pest pressure) subjected the leaves to RNA-seq analysis, and the second and third experiments in greenhouse conditions focused on efficacy after a pest infestation. The result was the RNA sequencing of six transcriptome libraries of tomatoes treated with Planticine® and untreated plants; a total of 3089 genes were found to be differentially expressed genes (DEGs); among them, 1760 and 1329 were up-regulated and down-regulated, respectively. DEG analysis indicated its involvement in such metabolic pathways and processes as plant-pathogen interaction, plant hormone signal transduction, MAPK signaling pathway, photosynthesis, and regulation of transcription. We detected up-regulated gene-encoded elicitor and effector recognition receptors (ELRR and ERR), mitogen-activated protein kinase (MAPKs) genes, and transcription factors (TFs), i.e., WRKY, ERF, MYB, NAC, bZIP, pathogenesis-related proteins (PRPs), and resistance-related metabolite (RRMs) genes. In the greenhouse trials, foliar application of Planticine® proved to be effective in reducing the infestation of tomato leaves by the biotrophic pathogen powdery mildew and in reducing feeding by thrips, which are insect herbivores. Prophylactic and intervention use of Planticine® at low infestation levels allows the activation of plant defense mechanisms.

Iodine Biofortification of Dandelion Plants (Taraxacum officinale F.H. Wiggers Coll.) with the Use of Inorganic and Organic Iodine Compounds.

Iodine is a crucial microelement necessary for the proper functioning of human and animal organisms. Plant biofortification has been proposed as a method of improving the iodine status of the population. Recent studies in that field have revealed that iodine may also act as a beneficial element for higher plants. The aim of the work was to evaluate the efficiency of the uptake and accumulation of iodine in the plants of dandelion grown in a pot experiment. During cultivation, iodine was applied through fertigation in inorganic (KI, KIO3) and organic forms (5-iodosalicylic acid, 5-ISA; 3,5-diiodosalicylic acid, 3,5-diISA) at two concentrations (10 and 50 µM). The contents of total iodine and iodosalicylic acids, as well the plant biomass and antioxidant capacity of dandelion leaves and roots, were analyzed. The uptake of inorganic and organic forms by dandelion plants was confirmed with no negative effect on plant growth. The highest efficiency of improving iodine content in dandelion leaves and roots was noted for 50 µM KI. The applicability of iodosalicylates, especially 5-ISA, for plant biofortification purposes was confirmed, particularly as the increase in the iodine content after the application of 5-ISA was higher as compared to that with commonly used KIO3. The chemical analyses have revealed that iodosalicylates are endogenous compounds of dandelion plants.

Synthesis of Organic Iodine Compounds in Sweetcorn under the Influence of Exogenous Foliar Application of Iodine and Vanadium.

A human's diet should be diverse and rich in vitamins, macro- and microelements essential for the proper functioning of the human body. Globally, a high percentage of the human population suffers from malnutrition, deficiencies of nutrients and vitamins also known as the problem of hidden hunger. This problem it is not only common in poor countries, but also occurs in developed countries. Iodine is a nutrient crucial for the proper functioning of the human and animal body. For plants, it is referred to as a beneficial element or even a microelement. The design of the biofortification experiment was determined on the basis of the interaction of iodine and vanadium (synergistic interaction in marine algae), where vanadium-dependent iodoperoxidase catalyzes apoplastic oxidation of iodine, resulting in high efficiency of iodine uptake and accumulation in brown algae (Laminaria digitate). Three independent experiments (Exp.) were carried out with the foliar application of vanadium (V) and iodine (I) compounds. The main differences between the experiments with the adapted proper corn biofortification method were the different application stage between the individual experiments, the application intervals and the dose of the iodine-vanadium compound. In each experiment, the accumulation of iodine and vanadium in the grain was several times lower than in the leaves. The combination iodine and vanadium significantly increased the accumulation of iodine in the grain in the case of applying V with inorganic iodine compounds, and a decrease in the accumulation of I after applying V with organic iodine compound -especially in Exp. No. 3. In grain, the highest content of I-, IO3- was in combination with the application of 2-iodobenzoic acid (products of its metabolism). In most of the tested combinations, vanadium stimulated the accumulation/synthesis of exogenous/endogenous 5-iodosalicylic acid (5ISA) and 2-iodobenzoic acid (2IBeA), respectively, and decreased the content of 2,3,5-triiodobenzoic acid (2,3,5-triIBeA) in leaves and grains. The tested compounds I and V and the combinations of their application had a diversified effect on the vitamin C content in the grains. Vanadium in the lower dose of 0.1 µM significantly increased the sugar content in the grain.

The Influence of Hydroponic Potato Plant Cultivation on Selected Properties of Starch Isolated from Its Tubers.

Starch is a natural polysaccharide for which the technological quality depends on the genetic basis of the plant and the environmental conditions of the cultivation. Growing plants under cover without soil has many advantages for controlling the above-mentioned conditions. The present research focuses on determining the effect of under cover hydroponic potato cultivation on the physicochemical properties of accumulated potato starch (PS). The plants were grown in the hydroponic system, with (greenhouse, GH) and without recirculation nutrient solution (foil tunnel, FT). The reference sample was PS isolated from plants grown in a tunnel in containers filled with mineral soil (SO). The influence of the cultivation method on the elemental composition of the starch molecules was noted. The cultivation method also influenced the protein and amylose content of the PS. Considering the chromatic parameters, PS-GH and PS-FT were brighter and whiter, with a tinge of blue, than PS-SO. PS-SO was also characterized by the largest average diameters of granules, while PS-GH had the lowest crystallinity. PS-SO showed a better resistance to the combined action of elevated temperature and shear force. There was a slight variation in the gelatinization temperature values. Additionally, significant differences for enthalpy and the retrogradation ratio were observed. The cultivation method did not influence the glass transition and melting.

Red Arils of Taxus baccata L.-A New Source of Valuable Fatty Acids and Nutrients.

The aim of this study, focused on the nutritional value of wild berries, was to determine the contents of macronutrients, profiles of fatty (FAs) and amino acids (AAs), and the contents of selected elements in red arils (RA) of Taxus baccata L., grown in diverse locations in Poland. Protein (1.79-3.80 g/100 g) and carbohydrate (18.43-19.30 g/100 g) contents of RAs were higher than in many cultivated berries. RAs proved to be a source of lipids (1.39-3.55 g/100 g). Ten out of 18 AAs detected in RAs, mostly branched-chain AAs, were essential AAs (EAAs). The EAAs/total AAs ratio approximating were found in animal foods. Lipids of RA contained seven PUFAs, including those from n-3 family (19.20-28.20 g/100 g FA). Polymethylene-interrupted FAs (PMI-FAs), pinolenic 18:3Δ5,9,12; sciadonic 20:3Δ5,11,14, and juniperonic 20:4Δ5,11,14,17, known as unique for seeds of gymnosperms, were found in RAs. RAs may represent a novel dietary source of valuable n-3 PUFAs and the unique PMI-FAs. The established composition of RAs suggests it to become a new source of functional foods, dietary supplements, and valuable ingredients. Because of the tendency to accumulate toxic metals, RAs may be regarded as a valuable indicator of environmental contamination. Thus, the levels of toxic trace elements (Al, Ni, Cd) have to be determined before collecting fruits from natural habitats.

Organic iodine supply affects tomato plants differently than inorganic iodine.

Iodine is a beneficial element for humans but very lowly represented in our diet. Iodine-enriched vegetables could boost the iodine content in the food chain. Despite being a beneficial element for plants, little is known about the effect of different iodine forms on plant growth. This work analyses the effect of uptake of mineral (KI) and organoiodine (5-iodosalicylic acid, 5-ISA; 3,5-diiodosalicylic acid, 3,5-di-ISA; 2-iodobenzoic acid, 2-IBeA; 4-iodobenzoic acid, 4-IBeA) compounds on tomato plants at an early stage of vegetative growth. As many organoiodine compounds are derived from salicylic (SA) and benzoic acids (BeA), treatments with I, SA and BeA in various treatments were realized and the influence of tested compounds on plant growth was analyzed. Iodine content was measured, as well as expression of key genes involved in I and SA metabolism. Organoiodine compounds accumulated mainly in roots whereas iodine accumulated in the upper parts when given as KI. The shoot system had 5, 12 and 25 times higher iodine content after KI treatment than after 4-IBeA, 5-ISA and 2-IBeA, or 3,5-diISA treatments, respectively. A toxic effect on plants was observed only for 3,5-diISA and 4-IBeA. The expression levels of a gene related to iodine metabolism (HMT, halide ion methylotransferase), a gene responsible for SA methylation in leaves (SAMT) and a gene related to SA catabolism (S3H, salicylic acid 3-hydroxylase) were modified differently depending on the iodine source. Overall, our data point out to a difference in plant uptake, transport of iodine in tomato plants based on the form of iodine compound.

The effects of peeling and cooking on the mineral content and antioxidant properties in carrots enriched with potassium iodate and/or selenite (Se(IV)) and selenite (Se(VI)).

Research covered six variants: control, unfertilized carrots and carrots fertilized with: KIO3, Na2SeO4, Na2SeO3, KIO3 and simultaneously with Na2SeO4, and fertilized with KIO3 and simultaneously Na2SeO3. Carrots enriched with iodate or selenite, or both iodate and selenite, were characterized by higher amount of these minerals. Changes to the content of micro- and macroelements, during the cooking time of the carrots, both in peeled and unpeeled carrots, did not head in the same direction (increase, decrease and no change). However, cooking an unpeeled carrot generally resulted in the increased content of polyphenol and carotenoids. On the other hand, cooking peeled carrots led to a decrease in the content of polyphenol and a general lack of change in carotenoid content in relation to the unpeeled cooked carrot. During cooking, the antioxidant activity of the carrot being assessed changed together with the direction of changes in polyphenol content but not in line with the direction of changes in carotenoids.

Iodine enriched kale (Brassica oleracea var. sabellica L.)-The influence of heat treatments on its iodine content, basic composition and antioxidative properties.

Iodine deficiency in the diet globally continues to be a cause of many diseases and disabilities. Kale is a vegetable that has health-promoting potential because of many nutrients and bioactive compounds (ascorbic acid, carotenoids, glucosinolates and phenolic compounds). Brassica vegetables, including kale, have been strongly recommended as dietary adjuvants for improving health. The nutrient and health-promoting compounds in kale are significantly affected by thermal treatments. Changes in phytochemicals upon such activities may result from two contrary phenomena: breakdown of nutrients and bioactive compounds and a matrix softening effect, which increases the extractability of phytochemicals, which may be especially significant in the case of iodine-fortified kale. This study investigated changes of basic composition, iodine, vitamin C, total carotenoids and polyphenols contents as well as antioxidant activity caused by steaming, blanching and boiling processes in the levels of two cultivars of kale (green and red) non-biofortified and biofortified via the application to nutrient solutions in hydroponic of two iodoquinolines [8-hydroxy-7-iodo-5-quinolinesulfonic acid (8-OH-7-I-5QSA) and 5-chloro-7-iodo-8-quinoline (5-Cl-7-I-8-Q)] and KIO3. Thermal processes generally significantly reduced the content of the components in question and the antioxidant activity of kale, regardless of cultivar and enrichment. It was observed that the red cultivar of kale had a greater ability to accumulate and reduce iodine losses during the culinary processes. 8-hydroxy-7-iodo-5-quinolinesulfonic acid showed a protective effect against the treatments used, compared to other enrichments, thus contributing to the preservation of high iodine content.

Study on chromium-binding capacity of Callitriche cophocarpa in an aquatic environment.

The aim of the present study was to investigate the binding strength of chromium (Cr) ions to aquatic macrophyte Callitriche cophocarpa. Shoots of the plants were incubated in a natural water solution containing Cr(III) or Cr(VI) at a concentration ranging from 0.5 to 4 mM under laboratory conditions. We found that C. cophocarpa has an extremely high capacity to bind Cr. The average level of accumulation reached 28,385 or 7,315 mg kg(-1) dry weight for plants incubated with Cr(III) or Cr(VI), respectively. Shoots incubated in a 0.5 mM concentration of Cr(III) for 5 days removed almost 100 % of the metal from solution. The major pool of the bound Cr(III) ions follows the strongest mechanism of metal-binding to an organic matter. In contrast, we found that only 25 % of Cr(VI) ions are bound into the metallo-organic compounds and 57 % of Cr(VI) exists in an easily remobilizable form. Activity of a photosynthetic electron transport (as F V/F M) was evaluated with respect to the Cr-binding mechanism. Our results contribute to the development of knowledge on processes controlling bioremediation of heavy-metallic compounds in aquatic systems.

Evaluation of the chemical composition and nutritional value of lettuce (Lactuca sativa L.) biofortified in hydroponics with iodine in the form of iodoquinolines.

Iodine deficiency in the diet creates the need to search for innovative, more sustainable and more effective strategies for enriching food with this microelement. The adopted research hypothesis assumed that the use of organic forms of iodine for supplementation of lettuce (Lactuca sativa L.), compared to mineral iodine, has a more favorable effect not only on the concentration of iodine, but also on the yield and the content of other chemical components determining its nutritional and health-promoting value. Lettuce was planted in a nutrient film technique (NFT) hydroponic study in a greenhouse. The following application of iodine compounds (all in 5 µM molar mass equivalents) were tested in the studies: control (without of iodine application); potassium iodate (positive iodine control), 8-hydroxy-7-iodo-5-quinolinesulfonic acid, 5-chloro-7-iodo-8-quinolinol, 5,7-diiodo-8-quinolinol and 4-hydroxy-8-iodo-3-quinolinecarboxylic acid. In this work, it was shown for the first time that iodoquinolines can be 1) a source of iodine for plants; 2) they have a biostimulating effect on their yielding and 3) they increase the resistance of crops to stress (due to a significant increase in the level of polyphenolic compounds). Lettuce with the addition of 8-hydroxy-7-iodo-5-quinolinesulfonic acid was characterized by the highest content of iodine, which was 221.7 times higher than in control plants. The weight gain of the whole plant was particularly visible in the case of lettuce enriched with 5-chloro-7-iodo-8-quinolinol and amounted to 26.48% compared to the control. Lettuce biofortified with iodine in the form of iodoquinolines can successfully become part of a sustainable diet based on plant products, which has a low impact on the environment and contributes to the long-term good health of an individual or community. Reducing iodine deficiency through the use of organoiodine compounds can help achieve the sustainability goal of eliminating hidden hunger, improving nutritional status and promoting sustainable agriculture.

Curly Kale (Brassica oleracea var. Sabellica L.) Biofortified with 5,7-Diiodo-8-quinolinol: The Influence of Heat Treatment on Iodine Level, Macronutrient Composition and Antioxidant Content.

Many disorders are a result of an inadequate supply of macronutrients and micronutrients in the diet. One such element is iodine. This study used curly kale (Brassica oleracea var. Sabellica L.) biofortified with the 5,7-diiodo-8-quinolinol iodine compound. The effect of the heat treatment on the chemical composition of the curly kale was studied. In addition, iodine bioavailability was evaluated in in vivo studies. Our investigation showed that iodine loss depends on the type of heat treatment as well as on the variety of kale. Curly kale biofortified with iodoquinoline had significantly higher iodine levels after thermal processing (steaming, blanching, boiling) than the vegetable biofortified with KIO3. Generally, steaming was the best thermal processing method, as it contributed to the lowest iodine loss in curly kale. The red variety of kale, 'Redbor F1', showed a better iodine stability during the heat treatment than the green variety, 'Oldenbor F1'. The thermal treatment also significantly affected the dry matter content and the basic chemical composition of the tested varieties of the 5,7-diI-8-Q biofortified kale. The steaming process caused a significant increase in total carbohydrates, fiber, protein and crude fat content ('Oldenbor F1', 'Redbor F1'), and antioxidant activity ('Oldenbor F1'). On the other hand, boiling caused a significant decrease, while steaming caused a significant increase, in protein and dry matter content ('Oldenbor F1', 'Redbor F1'). The blanching process caused the smallest significant decrease in ash compared to the other thermal processes used ('Oldenbor F1'). A feeding experiment using Wistar rats showed that iodine from the 5,7-diI-8-Q biofortified kale has a higher bioavailability than that from the AIN-93G diet. A number of promising results have been obtained, which could form the basis for further research.

Transcriptomic and metabolic studies on the role of inorganic and organic iodine compounds in lettuce plants.

Iodine (I) is considered a beneficial element or even micronutrient for plants. The aim of this study was to determine the molecular and physiological processes of uptake, transport, and metabolism of I applied to lettuce plants. KIO3, KIO3 + salicylic acid, 5-iodosalicylic acid and 3,5-diiodosalicylic acid were applied. RNA-sequencing was executed using 18 cDNA libraries constructed separately for leaves and roots from KIO3, SA and control plants. De novo transcriptome assembly generated 1937.76 million sequence reads resulting in 27,163 transcripts with N50 of 1638 bp. 329 differentially expressed genes (DEGs) in roots were detected after application of KIO3, out of which 252 genes were up-regulated, and 77 were down-regulated. In leaves, 9 genes revealed differential expression pattern. DEGs analysis indicated its involvement in such metabolic pathways and processes as: chloride transmembrane transport, phenylpropanoid metabolism, positive regulation of defense response and leaf abscission, and also ubiquinone and other terpenoid-quinone biosynthesis, protein processing in endoplasmic reticulum, circadian rhythm including flowering induction as well as a putative PDTHA (i.e. Plant Derived Thyroid Hormone Analogs) metabolic pathway. qRT-PCR of selected genes suggested their participation in the transport and metabolism of iodine compounds, biosynthesis of primary and secondary metabolites, PDTHA pathway and flowering induction.

Molecular Effects of Iodine-Biofortified Lettuce in Human Gastrointestinal Cancer Cells.

Considering the growing number of cancer cases around the world, natural products from the diet that exhibit potential antitumor properties are of interest. Our previous research demonstrated that fortification with iodine compounds is an effective way to improve the antioxidant potential of lettuce. The purpose of the present study was to evaluate the effect of iodine-biofortified lettuce on antitumor properties in human gastrointestinal cancer cell lines, gastric AGS and colon HT-29. Our results showed that extracts from iodine-biofortified lettuce reduce the viability and proliferation of gastric and colon cancer cells. The extracts mediated cell cycle arrest which was accompanied by inactivation of anti-apoptotic Bcl-2 and activation of caspases, as assessed by flow cytometry. However, extracts from lettuce fortified with organic forms of iodine acted more effectively than extracts from control and KIO3-enriched plants. Using quantitative PCR, we detected the increase in pro-apoptotic genes BAD, BAX and BID in AGS cells whereas up-regulation of cell cycle progression inhibitor CDKN2A and downregulation of pro-proliferative MDM2 in HT-29 cells. Interestingly, lettuce extracts led to down-regulation of pro-survival AKT1 and protooncogenic MDM2, which was consistent for extracts of lettuce fortified with organic form of iodine, 5-ISA, in both cell lines. MDM2 downregulation in HT-29 colon cancer cells was associated with RB1 upregulation upon 5-ISA-fortified lettuce extracts, which provides a link to the epigenetic regulation of tumor suppressor genes by RB/MDM2 pathway. Indeed, SEMA3A tumor suppressor gene was hypomethylated and upregulated in HT-29 cells treated with 5-ISA-fortified lettuce. Control lettuce exerted similar effects on RB/MDM2 pathway and SEMA3A epigenetic activation in HT-29 cells. Our findings suggest that lettuce as well as lettuce fortified with organic form of iodine, 5-ISA, may exert epigenetic anti-cancer effects that can be cancer type-specific.

Effectiveness of enriching lettuce with iodine using 5-iodosalicylic and 3,5-diiodosalicylic acids and the chemical composition of plants depending on the type of soil in a pot experiment.

Iodine is a beneficial element for humans, animals and plants. This study was a comparison of the effectiveness of iodosalicylate uptake by lettuce. The experiment included two sub-blocks: organic soil and mineral soil with the addition of the same fertigation of plants (8 times every 7 days) with 10 µM solutions (100 mL/per one plant/one application) of potassium iodate (KIO3), salicylic acid (SA) alone or together with KIO3, 5-iodosalicylic acid (5-ISA) or 3,5-diiodosalicylic acid (3,5-diISA). None of the tested iodine compounds negatively affected the yield of lettuce. When growing plants on mineral soil, plants accumulated more iodine in the leaves than plants grown on peat substrate. The use of 5-ISA allowed for achieving better efficiency of plant biofortification in iodine than the application of KIO3 and 3,5-diISA. The type of soil significantly modified the chemical composition of lettuce.

Effectiveness of Foliar Biofortification of Carrot With Iodine and Selenium in a Field Condition.

Iodine (I) and selenium (Se) are essential to human and animal development. There is a worldwide deficit of I and Se in the diet of humans, as well as in animals. It is advisable to enrich plants with these elements to ensure adequate uptake in animals and humans. The aim of this study was to determine the efficacy of the application of I and Se in the cultivation of carrot crops, to better understand the metabolic pathways and processes of I applied through foliar spray. Carrots were fertilized with 4-fold foliar applications of I and Se, which were applied as the liquid fertilizers "I + Se", "Solo iodine" and "Solo selenium", all containing an organic stabilizer, in two field trials. Foliar nutrient applications of I and Se were translocated by the plant for storage in the roots. The level of enriched I and Se in the roots was considered safe for the consumer. The Recommended Daily Allowance values for I and Se in the roots of 100 g of fresh carrots are 4.16% and 4.37%, respectively. Furthermore, I and Se accumulated in the roots to a level that was physiologically tolerated by carrot. Biofortification through foliar feeding did not impact negatively on the yield or quality of the carrot crop. Iodides applied via foliar application were the dominant form of I in the plant tissues and were included in the metabolic process of the synthesis of iodosalicylates, iodobenzoates, iodotyrosine (I-Tyr), and plant-derived thyroid hormone analogs. No synergistic or antagonistic interaction between I and Se, with respect to the effectiveness of biofortification in roots, was observed in any treatments. The molar ratio of I:Se in the roots after foliar application of both elements was approximately 1.6:1 and was similar to the control (1.35:1).

Anti- and pro-oxidant potential of lettuce (Lactuca sativa L.) biofortified with iodine by KIO3, 5-iodo- and 3,5-diiodosalicylic acid in human gastrointestinal cancer cell lines.

Vegetables are particularly rich sources of micronutrients and phytochemicals such as polyphenols and vitamins. These plant-derived bioactive compounds provide antitumor and antioxidant properties due to their capacity to interact with reactive oxygen species (ROS). The objective of this study was to determine the effect of iodine biofortification (potassium iodate/KIO3/, 5-iodosalicylic acid/5-ISA/, and 3,5-diiodosalicylic acid/3,5-diISA/) on the antioxidant activity of lettuce (Lactuca sativa L. capitata) cv. 'Melodion'. In this work, HPLC analysis was used to identify polyphenolic compounds while the antioxidant activity of iodine-enriched vegetables was determined by using DPPH, ABTS and FRAP methods. The content of the water-soluble vitamins was analyzed by using the LC-MS/MS technique. The impact of extracts from iodine-biofortified lettuce on production of reactive oxygen species (ROS) in gastrointestinal cancer cells was also evaluated. The results from this research indicate that application of iodine compounds improves the antioxidant potential of lettuce by increasing the concentration of some vitamins, antioxidant enzymes and polyphenolic compounds in the enriched plants. Moreover, the study has shown that iodine-biofortified lettuce induces production of ROS in cancer cells, resulting in an anticancer effect by the induction of programmed cancer cell death.

New Aspects of Uptake and Metabolism of Non-organic and Organic Iodine Compounds-The Role of Vanadium and Plant-Derived Thyroid Hormone Analogs in Lettuce.

The process of uptake and translocation of non-organic iodine (I) ions, I- and IO3 -, has been relatively well-described in literature. The situation is different for low-molecular-weight organic aromatic I compounds, as data on their uptake or metabolic pathway is only fragmentary. The aim of this study was to determine the process of uptake, transport, and metabolism of I applied to lettuce plants by fertigation as KIO3, KIO3 + salicylic acid (KIO3+SA), and iodosalicylates, 5-iodosalicylic acid (5-ISA) and 3,5-diiodosalicylic acid (3,5-diISA), depending on whether additional fertilization with vanadium (V) was used. Each I compound was applied at a dose of 10 µM, SA at a dose of 10 µM, and V at a dose of 0.1 µM. Three independent 2-year-long experiments were carried out with lettuce; two with pot systems using a peat substrate and mineral soil and one with hydroponic lettuce. The effectiveness of I uptake and translocation from the roots to leaves was as follows: 5-ISA > 3,5-diISA > KIO3. Iodosalicylates, 5-ISA and 3,5-diISA, were naturally synthesized in plants, similarly to other organic iodine metabolites, i.e., iodotyrosine, as well as plant-derived thyroid hormone analogs (PDTHA), triiodothyronine (T3) and thyroxine (T4). T3 and T4 were synthesized in roots with the participation of endogenous and exogenous 5-ISA and 3,5-diISA and then transported to leaves. The level of plant enrichment in I was safe for consumers. Several genes were shown to perform physiological functions, i.e., per64-like, samdmt, msams5, and cipk6.

Biofortification of Six Varieties of Lettuce (Lactuca sativa L.) With Iodine and Selenium in Combination With the Application of Salicylic Acid.

The agrotechnical methods of biofortification of plants, i.e., enriching them in iodine (I) and selenium (Se) could be effective methods to enrich food products in these elements. The advantage of agrotechnical methods of biofortification is the incorporation of elements in organic compounds in plants; therefore, they have better health-promoting properties than pure technical salts. Two-year studies were conducted in a greenhouse with hydroponic cultivation of three botanical varieties of lettuce in an NFT (nutrient film technique) system: two cultivars butterhead lettuces (abb. BUTL) 'Cud Voorburgu' and 'Zimujaca,' two cultivars iceberg lettuces (abb. ICEL) 'Maugli' and 'Królowa lata' (all this four cultivars are classified as Lactuca sativa L. var. capitata) as well two cultivars Lactuca sativa L. var. crispa L. cultivars (abb. REDL) 'Lollo rossa' and 'Redin' having little red leaves. The study included the application of I (as KIO3), Se (as Na2SeO3), and SA into the nutrient solution. The tested treatments were as follows: (1) control, (2) I+Se, (3) I+Se+0.1 mg SA dm-3, (4) I+Se+1.0 mg SA dm-3, and (5) I+Se+10.0 mg SA dm-3. KIO3 was used at a dose of 5 mg I dm-3, while Na2SeO3 was 0.5 mg Se dm-3. Regardless of the kind of the applied compound, the highest biomass of heads was produced by the REDL 'Redin' variety. Furthermore, this variety, as the only one in six varieties tested, reacted with the decrease in yield to the application of I+Se and I+Se+three concentrations of SA. In the heads of all cultivars, the level of I accumulation was 10-30 times higher than of Se. The level of I accumulation formed the following order: REDL 'Lollo rossa' > REDL 'Redin' = BUTL 'Cud Voorburgu' > BUTL 'Zimujaca' > ICEL 'Maugli' > ICEL 'Królowa lata'. The order of Se content in leaves was as follows: REDL 'Redin' = BUTL 'Cud Voorburgu' > REDL 'Lollo rossa' > ICEL 'Maugli' > BUTL 'Zimujaca' > ICEL 'Królowa lata'. The obtained results indicate that the introduction of SA to the nutrient solutions in hydroponic systems may allow an improve the effectiveness of - biofortification.

Iodine biofortification through expression of HMT, SAMT and S3H genes in Solanum lycopersicum L.

The uptake process and physiological reaction of plants to aromatic iodine compounds have not yet been documented. The aim of this research was to compare uptake by tomato plants of KI and KIO3, as well as of organic iodine compounds - 5-ISA (5-iodosalicylic acid), 3,5-diISA (3,5-diiodosalicylic acid), 2-IBeA (2-iodobenzoic acid), 4-IBeA (4-iodobenzoic acid) and 2,3,5-triIBeA (2,3,5-triiodobenzoic acid). Only 2,3,5-triIBeA had a negative influence on plant development. All organic iodine compounds were taken up by roots and transported to leaves and fruits. Among all the compounds applied, the most efficiently transferred iodine was 2-IBeA - to fruits, and 4-IBeA - to leaves. The order of iodine accumulation in fruit cell compartments was as follows: organelles > cell walls > soluble portions of cells; for leaf and root cells, it was: organelles > cell walls or soluble portions, depending on the compound applied. The compounds studied influence iodine metabolism through expression of the HMT gene which encodes halide ion methyltransferase in leaves and roots. Also, their influence on modification of the activity of the SAMT and S3H genes that encode salicylic acid carboxyl methyltransferase and salicylic acid 3-hydroxylase was established. It was discovered that exogenously applied 5-ISA, 3,5-diISA, 2-IBeA and 4-IBeA are genuinely (endogenously) synthesised in tomato plants; to date, this has not been described for the tomato, nor for any other species of higher plant.