Michela Schiavon

• PhD
• Professor (Associate) at University of Turin

Using renewable biomass in agriculture, particularly microalgae as a biostimulant, offers economic and environmental sustainability benefits by reducing costs, improving nutrient cycling, and enhancing water use efficiency. Microalgae contain bioactive compounds that boost crop tolerance to environmental stresses, including salinity. Saline soils,...

Background and aims Iron (Fe) plaque which normally coats rice roots has a strong affinity for phosphorus (P), with a debated effect on plant P uptake. Furthermore, plant responses to P availability shape the rhizospheric environment, possibly affecting the rates of Fe plaque formation and dissolution. The role of Fe plaque to serve as a sink or so...

Background Weeds represent a great constraint for agricultural production due to their remarkable adaptability and their ability to compete with crops. Climate change exacerbates the abiotic stresses that plants encounter. Therefore, studying plant responses to adverse conditions is extremely important. Here, the response to saline stress at differ...

Background Phosphorus (P) is an essential nutrient for plant growth, taking part in primary cellular metabolic processes as a structural component of key biomolecules. Soil processes as adsorption, precipitation, and coprecipitation can affect P bioavailability, leading to limited plant growth and excessive use of P fertilizers, with adverse impact...

Lignohumates are increasing in popularity in agriculture, but their chemistry and effects on plants vary based on the source and processing. The present study evaluated the ability of two humates (H1 and H2) to boost maize plant performance under different phosphorus (P) availability (25 and 250 µM) conditions in hydroponics, while understanding th...

Background and aims: Selenium hyperaccumulator species are of primary interest for studying the evolution of hyperaccumulation and biofortification as selenium is an essential element in human nutrition. We aimed to determine whether the distributions of selenium in Astragalus bisulcatus, Stanleya pinnata and Neptunia amplexicaulis are similar or...

Background and aims Iron (Fe) plaque which normally coats rice roots has a strong affinity for phosphorus (P), with a debated effect on plant P uptake. Furthermore, plant responses to P availability shape the rhizospheric environment, possibly affecting the rates of Fe plaque formation and dissolution. The role of Fe plaque to serve as a sink or so...

Phosphorus (P) cycling in paddy soil is closely related to iron (Fe) redox wheel; its availability to rice has thus generally been ascribed to Fe minerals reductive dissolution. However, the literature aimed to identify the best method for predicting rice available P does not uniformly point to Fe reductants. Rice plants can indeed solubilize and...

Soils high in chromium and selenium exist in some countries, like China, India and the US. In the forms of chromate and selenate, these elements can compete during uptake by plants and lead to secondary effects on the absorption of the essential nutrient sulfur. In this study, we evaluated the potential of Brassica juncea and the Se-hyperaccumulato...

Plants do not have an essential demand for selenium (Se) to support their metabolism; however, they can take up Se in either inorganic or organic forms. Selenate is the major form of Se absorbed by plants in most soils. Because of its chemical similarity with sulfate, it is taken up and translocated throughout the plant via sulfate transporters. Se...

Crop plants growing under field conditions are constantly exposed to various abiotic and biotic stress factors leading to decreased yield and quality of produce. In order to achieve sustainable development in agriculture and to increase agricultural production for feeding an increasing global population, it is necessary to use ecologically compatib...

Biofortification is the process that aims to enrich crops in micronutrients and valuable compounds. Selenium (Se) biofortification has particularly attracted increasing interest in recent times due to the growing number of individuals suffering from Se deficiency. Selenate and selenite are the Se forms most frequently administered to crops. In this...

Background and aims Phosphorus (P) is an essential nutrient for plant growth, but is also one of the least accessible in soil. Plants have evolved several strategies to cope with P deficiency and recently the role of the phytohormones strigolactones (SLs) in modulating tomato plants acclimation to P shortage has been described. How SLs regulate the...

Earlier studies have shown that Stanleya pinnata benefits from selenium hyperaccumulation through ecological benefits and enhanced growth. However, no investigation has assayed the effects of Se hyperaccumulation on plant fitness in the field. This research aimed to analyze how variation in Se accumulation affects S. pinnata fitness, judged from ph...

Strigolactones (SLs) are plant hormones that modulate morphological, physiological and biochemical changes as part of the acclimation strategies to phosphorus (P) deficiency, but an in-depth description of their effects on tomato P-acquisition strategies under P shortage is missing. Therefore, in this study, we investigate how SLs impact on root ex...

Selenium contamination of air, aquatic environments, soils and sediments is a serious environmental concern of increasing importance. Selenium has a paradoxical feature in bringing about health benefits under the prescribed level, but only a few fold increase in its concentration causes deleterious effects to flora and fauna, humans and the environ...

Weeds account for losses in crop yields, and this event might be exacerbated by salinity. Therefore, we investigated the responses of Chenopodium album L. and soybean (Glycine max (L.) Merr.) to salt stress, as well as interferences between species. Ten-day old plants were grown for 1 week in a single- or mixed-species set-up, either with or withou...

Dietary selenium (Se)-compounds accumulated in plants are essential for human metabolism and normal physiological processes. Inorganic and organic Se species can be readily absorbed by the human body, but are metabolized differently and thus exhibit distinct mechanisms of action. They can act as antioxidants or serve as a source of Se for the synth...

Humic substances (HS) are dominant components of soil organic matter and are recognized as natural, effective growth promoters to be used in sustainable agriculture. In recent years, many efforts have been made to get insights on the relationship between HS chemical structure and their biological activity in plants using combinatory approaches. Rel...

The First Joint Meeting on Soil and Plant System Sciences (SPSS 2019), titled “Natural and Human-Induced Impacts on the Critical Zone and Food Production”, aimed at integrating different scientific backgrounds and topics flowing into the Critical Zone, where chemical, biological, physical, and geological processes work together to support life on t...

Humic substances (HS) are powerful natural plant biostimulants. However, there is still a lack of knowledge about the relationship between their structure and bioactivity in plants. We extracted HS (THE1-2) from two forest soils covered with Pinus mugo (1) or Pinus sylvestris (2). The extracts were subjected to weak acid treatment to produce size-f...

Background Selenium (Se) is an essential element for mammals and its deficiency in the diet is a global problem. Plants accumulate Se and thus represent a major source of Se to consumers. Agronomic biofortification intends to enrich crops with Se in order to secure its adequate supply by people.ScopeThe goal of this review is to report the present...

The hormones strigolactones accumulate in plant roots under phosphorus (P) shortage, inducing variations in plant phenotype. In this study, we aimed at understanding whether strigolactones control morphological and anatomical changes in tomato (Solanum lycopersicum L.) roots under varying P supply. Root traits were evaluated in wild-type seedlings...

Selenium (Se) uptake by primary producers is the most variable and important step in determining Se concentrations at higher trophic levels in aquatic food webs. We gathered data available about the Se bioaccumulation at the base of aquatic food webs and analyzed its relationship with Se concentrations in water. This important dataset was separated...

Humic substances (HS) are important soil components playing pivotal roles in guaranteeing long-term soil fertility. In this study, the chemical and biological properties of HS extracted from earthworm coprolites collected in soils subjected to different fertilization inputs (no fertilization, NF; fertilization with farmyard manure, FM; mineral inpu...

Plants that hyperaccumulate selenium (Se) contain more than 1 mg Se/g DW in their aboveground tissues. The capacity to hyperaccumulate and hypertolerate Se by these species possibly developed as a result of convergent evolution of selective transporters and biochemical pathways in distinct angiosperm clades during geological periods when Se in soil...

The main aim of this study is to identify and investigate specific humates (Hs) as potential biostimulants. Five specialty lignosulfonates (LS1-5), one commercial leonardite-humate (PH), and one commercial lignosulfonate (LH), were analyzed for their carbon, nitrogen, and sulfur contents, and the distribution of functional groups using Fourier tran...

Two liquid protein hydrolysates obtained from chickpea (Cicer arietinum L.) (CA) and Spirulina platensis (SP) were analyzed via FT-IR and SERS spectroscopy. Their hormone-like activities and contents in indole-3-acetic acid (IAA), isopentenyladenosine (IPA), nitrogen (N), carbon (C), sulfur (S), phenols, amino acids, and reducing sugars were determ...

Biofortification can be exploited to enrich plants in selenium (Se), an essential micronutrient for humans. Selenium as selenate was supplied to two rocket species, Eruca sativa Mill. (salad rocket) and Diplotaxis tenuifolia (wild rocket), at 0–40 μM in hydroponics and its effects on the content and profile of sulphur (S)-compounds and other phytoc...

Mineral phosphorus (P) fertilization in calcareous soils is not efficient enough to ensure optimal plant growth. Therefore, a higher P input is generally needed. Polymer-coated fertilizers are a promising fertilizer category that seems to affect soil extractable P, thus permitting a reduction in fertilizer rates. We tested this hypothesis in a shor...

Appendix S1 Description of the statistical analyses of the RNA sequencing data, comparing effects of treatments, species and organs. Figure S1 Biomass production and Se and S accumulation by Stanleya pinnata and S. elata. The plants were grown from seed on agar with 0 or 20 μm sodium selenate. Figure S2 Overview of differential expression between...

Olive mill wastewaters (OMW) contain significant levels of phenolic compounds with antimicrobial/phytotoxic activity and high amounts of undecomposed organic matter that may exert negative effects on soil biology. Among OMW detoxification techniques, those focusing on oxidative degradation of phenolic compounds are relevant. The composting (bio-oxi...

A solid biostimulant (AA309) obtained through thermobaric hydrolysis applied on trimmings and shavings of bovine hides tanned with wet-blue technology was chemically characterized, and its effects in maize (Zea mays L.) were evaluated. AA309 contained 13.60% total nitrogen (N), mainly in organic forms (13.40%), and several amino acids, especially l...

Ridge and furrow systems as well as the wide-narrow row spacing are recognized as good management practices in crop production. To obtain some available information concerning the suitable agricultural practices for buckwheat cultivation in arid and semi-arid area, a two-year field study was conducted to investigate the performance of common buckwh...

Seaweed extracts can be employed as biostimulants during crop cultivation owing to their positive effects on plant performance. Therefore, in this study one extract from Laminaria (A) and five extracts from Ascophyllum nodosum (B–F) were assayed on maize (Zea mays L.) plants supplied for 2 days with 0.5 mL L⁻¹ of single products to evaluate their c...

Heat map of plant-associated parameters influenced by individual seaweed extracts. Different colors indicate different levels of induction (+, ++, +++), repression (−) or no effect (=).

Background: Selenium (Se) is a micronutrient required for many life forms, but toxic at higher concentration. Plants do not have a Se requirement, but can benefit from Se via enhanced antioxidant activity. Some plant species can accumulate Se to concentrations above 0.1% of dry weight and seem to possess mechanisms that distinguish Se from its ana...

Background: The plant Stanleya pinnata hyperaccumulates Se up to 0.5% of its dry weight in organic forms, whereas the closely related Stanleya elata does not hyperaccumulate Se. ATP sulfurylase (ATPS) can catalyze the formation of adenosine 5'-phosphoselenate (APSe) from ATP and selenate. We investigated the S. pinnata ATPS2 isoform (SpATPS2) to a...

To obtain better insight into the mechanisms of selenium hyperaccumulation in Stanleya pinnata, transcriptome-wide differences in root and shoot gene expression levels were investigated in S. pinnata and related nonaccumulator Stanleya elata grown with or without 20 μM selenate. Genes predicted to be involved in sulfate/selenate transport and assim...

Stanleya pinnata not only hyperaccumulates selenium (Se) to 0.5% of its dry weight, but also exhibits higher tissue Se‐to‐sulfur (S) ratios than other species and its surroundings. To investigate the mechanisms underlying this Se enrichment, we compared S. pinnata with the nonhyperaccumulators S. elata and Brassica juncea for selenate uptake in lon...

An alfalfa-based protein hydrolysate (EM) has been tested in tomato (Solanum lycopersicon L.) plants at two different concentrations (0.1 and 1 mL L⁻¹) to get insight on its efficacy as biostimulant in this species and to unravel possible metabolic targets and molecular mechanisms that may shed light on its mode of action. EM was efficient in promo...

The element selenium (Se) is required for the growth and healthy metabolism of a variety of microalgae. These organisms represent important vectors of Se in water ecosystems. Excessive Se accumulation in cells may impact algal growth, as well as the aquatic populations that feed on them. On the other hand, micro- and macroalgae that contain Se can...

Selenium (Se) is a trace element indispensable for humans, animals and some microorganisms. For plants its essentiality has not yet been established, despite its responsibility for a number of beneficial effects in several plant species. Plants take up Se mainly as selenate and selenite, using root high-affinity membrane transporters that normally...

Selenium (Se) is an essential trace element for many organisms including humans, while in plants it can trigger a variety of beneficial effects. Plants absorb Se mainly in the form of selenate using high affinity root sulfate transporters. Consequently, availability of sulfur (S) has a major impact on Se accumulation due to competition effects of t...

Selenium (Se) is an intriguing element because it is metabolically required by a variety of organisms, but it may induce toxicity at high doses. Algae primarily absorb selenium in the form of selenate or selenite using mechanisms similar to those reported in plants. However, while Se is needed by several species of microalgae, the essentiality of t...

The importance of selenium (Se) for medicine, industry and the environment is increasingly apparent. Se is essential for many species, including humans, but toxic at elevated concentrations. Plant Se accumulation and volatilization may be applied in crop biofortification and phytoremediation. Topics covered here include beneficial and toxic effects...

The use of energy crops in the treatment of wastewaters is of increasing interest, particularly in view of the widespread scarcity of water in many countries and the possibility of obtaining renewable fuels of vegetable origin. The aim of this study was to evaluate the feasibility of landfill leachate phytotreatment using sunflowers, particularly a...

Two selenium (Se) fertilization methods were tested for their effects on levels of anticarcinogenic selenocompounds in radish (Raphanus sativus), as well as other nutraceuticals. First, radish was grown on soil and foliar selenate applied 7 days before harvest at 0, 5, 10, and 20 mg Se per plant. Selenium levels were up to 1200 mg Se/kg DW in leave...

The capacity of Ulva australis Areschoug to tolerate and accumulate selenium (Se) supplied in the form of selenate or selenite was investigated. The macroalga was provided for 3 and 7 days with concentrations of selenate (Na2SeO4) or selenite (Na2SeO3) ranging from 0 to 400 μM. U. australis exhibited the highest ability to accumulate selenium when...

In recent years, the use of biostimulants in sustainable agriculture has been growing. Biostimulants can be obtained from different organic materials and include humic substances (HS), complex organic materials, beneficial chemical elements, peptides and amino acids, inorganic salts, seaweed extracts, chitin and chitosan derivatives, antitranspiran...

The element selenium (Se) is both essential and toxic for most life forms, with a narrow margin between deficiency and toxicity. Phytotechnologies using plants and their associated microbes can address both of these problems. To prevent Se toxicity due to excess environmental Se, plants may be used to phytoremediate Se from soil or water. To allevi...

Background: World demand for agricultural products is increasing. New insights are required in order to achieve sufficient and sustainable yields to meet global food request. Chemical fertilizers have been studied for almost 200 years, and it is unlikely that they could be improved. However, to produce food for a growing world population, various m...

Selenium (Se) at very low doses has crucial functions in humans and animals. Since plants represent the main dietary source of this element, Se-containing crops may be used as a means to deliver Se to consumers (biofortification). Several strategies have been exploited to increase plant Se content. Selenium assimilation in plants affects both sulfu...

Selenium (Se) hyperaccumulation, the capacity of some species to concentrate Se to levels upwards of 0.1% of dry weight, is an intriguing phenomenon that is only partially understood. Questions that remain to be answered are: do hyperaccumulators have one or more Se-specific transporters? How are these regulated by Se and sulfur (S)? In this study,...

Selenium (Se) is a fundamental microelement for several organisms, including humans. Higher plants represent the main dietary source of Se and their enrichment in Se may influence sulfur (S) accumulation and consequently, the synthesis of health promoting S-containing compounds. In this study, the effect of selenate foliar fertilization on the prod...

The excessive use of chemical fertilizers has affected soil and water quality causing the reduction of organic matter content in soils and the increase of nitrates in waters. Organic products known as “biostimulants” could be used in agricultural practices to promote plant growth and mineral nutrient uptake. Previous studies showed that application...

Arsenic (As) is recognized as a toxic pollutant in soils of many countries. Since phosphorus (P) and sulphur (S) can influence arsenic mobility and bioavailability, as well as the plant tolerance to As, phytoremediation techniques employed to clean-up As-contaminated areas should consider the interaction between As and these two nutrients. In this...

The extensive use of copper-bearing fungicides in vineyards is responsible for the accumulation of copper (Cu) in soils. Grass species able to accumulate Cu could be cultivated in the vineyard inter-rows for copper phytoextraction. In this study, the capacity of Festuca rubra cv Merlin and Sinapis alba to tolerate and accumulate copper (Cu) was fir...

While selenium (Se) is a known anticarcinogen, little is known regarding how Se affects other nutritional qualities in crops. Tomato (Solanum lycopersicon) was supplied with 0-50 μM selenate and analyzed for elemental composition and antioxidant compounds. When supplied at low doses (5 and 10 μM) via the roots, Se stimulated the synthesis of phenol...

Arsenic is recognised as a toxic metalloid and a strong pollutant in soils of many countries. Thus, the reclamation of contaminated areas is fundamental in order to protect both human health and agricultural production. This study is focused on the assisted phytoextraction, a technology for reclaiming polluted soils that takes advantage of the capa...

Relative effect of EM and TRIA on root and leaf fresh weight of salt-treated Z. mays plants grown calculated within each NaCl concentration group.

A differential display cDNA-AFLP derived technique was used to identify gene transcripts regulated by chromium (Cr) in relation to sulfur (S) nutrition in Brassica juncea. Twelve-day old plants were grown with 200μM sulfate (+S), without sulfate (-S), with 200μM sulfate plus 200μM chromate (+S+Cr), or without sulfate plus 200μM chromate (-S+Cr). Fo...

The impact of selenium (Se) on Ulva sp., a green macroalga naturally growing in the Venice Lagoon, was investigated. The alga was provided for 10 days with concentrations of selenate (Na(2)SeO(4)) ranging from 0 to 100 μM. Se accumulation in the algal biomass was linearly related to the selenate dose and this relationship was not affected by the hi...

In the last years Brassica juncea plants have been studied and utilized for heavy metal phytoremediation. In the present study plants of Brassica juncea were exposed for 24 h to 200 μM molybdate, and the interaction between molybdate and sulfate was evaluated. The presence of Mo in the medium affected the biomass of the plants. In particular, the e...

Background & Aims The effects of an alfalfa plant (Medicago sativa L.) hydrolysate-based biostimulant (EM) containing triacontanol (TRIA) and indole-3-acetic acid (IAA) were tested in salt-stressed maize plants. Methods Plants were grown for 2 weeks in the absence of NaCl or in the presence (25, 75 and 150 mM). On the 12th day, plants were supplie...

The interaction of selenate and molybdate with the transport and assimilation of sulfate, and the effect of S on Se and Mo accumulation were investigated in Brassica juncea. Plants were supplied with different combinations of S and Se, or S and Mo for 24 h, and selenate and molybdate were given to plants at concentrations (200 μM) equal to that of...

Intensive land use may affect soil properties (e.g., decreased soil organic matter [SOM] content) and, consequently, reduce crop yields considerably. One way of counteracting the loss of SOM and stimulating plant productivity could be the use of organic residues from agro-industrial processes as bioactive products. The present study was focused on...

A high molecular weight humic fraction (>3,500 Da) was characterized chemically by DRIFT and 1H NMR spectroscopy, and was applied to Zea mays L. plants to evaluate its effect on phenylpropanoid metabolism. The activity and gene expression of phenylalanine (tyrosine) ammonia-lyase (PAL/TAL), and the concentrations of phenolics and their amino acid p...

The current study evaluates the potential amelioration of the water quality of the Po River by monitoring the accu-mulation of four heavy metals, Cu, Zn, Ni and Cr, in Phragmites australis plants growing within an experimental con-structed wetland (CW) sited in Castelnovo Bariano. The plant growth rate displayed during the time of study was typical...

Aluminum (Al), cobalt (Co), sodium (Na), selenium (Se), and silicon (Si) are considered beneficial elements for plants: they are not required by all plants but can promote plant growth and may be essential for particular taxa. These beneficial elements have been reported to enhance resistance to biotic stresses such as pathogens and herbivory, and...

The effects through which an alfalfa protein hydrolysate (EM) possessing gibberellin- and auxin-like activity may promote plant nitrogen (N) nutrition have been investigated in Zea mays L. Treatment with 0.01 or 0.1 mg L(-1) EM for 48 h resulted in enhanced plant growth and leaf sugar accumulation. Concomitantly, the level of nitrates decreased, wh...

The overexpression of either gamma-glutamylcysteine synthetase (gamma-ECS) or glutathione synthetase (GS) in Brassica juncea transgenics was shown previously to result in higher accumulation of glutathione (GSH) and phytochelatins (PCs), as well as enhanced Cd tolerance and accumulation. The present study was aimed at analyzing the effects of gamma...

The effects of chromate on sulfate uptake and assimilation were investigated in the accumulator Brassica juncea (L.) Czern. Seven-day-old plants were grown for 2 d under the following combination of sulfate and chromate concentration: (i) no sulfate and no chromate (-S), (ii) no sulfate and 0.2 mmol L(-1) chromate (-S +Cr), (iii) 1 mmol L(-1) sulfa...

Plants can withstand the potentially toxic effects exerted by a number of heavy metals through exclusion, which consists in restricted metal transport into plant tissues, or accumulation of metals, accompanied by the development of concomitant internal tolerance mechanisms. Plant tolerance and accumulation to heavy metals are known to be related to...

In this research a differential display based on the detection of cDNA-AFLP markers was used to identify candidate genes potentially involved in the regulation of the response to chromium in four different willow species (Salix alba, Salix eleagnos, Salix fragilis and Salix matsudana) chosen on the basis of their suitability in phytoremediation tec...

In this study the chromate accumulation and tolerance were investigated in ZEA MAYS L. in relation to sulfur availability since sulfate may interact with chromate for transport into the cells. Chromate inhibited sulfate uptake when supplied to plants for a short-term period, whereas phosphate uptake remained unchanged. Sulfate absorption was also r...

Among the Arabidopsis thaliana accessions Columbia (Col), Landsberg erecta (Ler), and Wassilewskija (Ws), Ler and Ws showed higher copper (Cu) tolerance than Col, while accumulating more Cu. Thus, Cu tolerance did not appear to be related to metal exclusion. Rather, the higher Cu tolerance of Ler and Ws may reflect less Cu-induced nutrient deficien...

To investigate selenium tolerance mechanisms in Arabidopsis thaliana, genetic and physiologic studies were performed in the three Arabidopsis accessions Landsberg erecta (Ler), Columbia (Col) and Wassilewskija (Ws). Accession Ler was significantly less tolerant to selenate than Ws and Col, whereas Ws was less tolerant to selenite than the others. A...