Glycoalkaloid Content Research Articles

Mismatch repair deficiency increases the transfer of antibiosis and antixenosis properties against Colorado potato beetle in somatic hybrids of Solanum tuberosum + S. chacoense.

Colorado potato beetle (CPB) has become the biggest enemy of cultivated potato worldwide. One of the most effective sources of resistance to CPB is Solanum chacoense, an accession with a high leptine glycoalkaloid content. The aim of our study was to assay the repellence and toxicity of S. chacoense, its somatic hybrids (SHs) and their backcross progenies (BC1 ) with potato for CPB adults and larvae. Transgenic S. chacoense, deficient in DNA mismatch repair (MMR), was also used to produce SHs, in order to increase homeologous recombination and hence introgression of wild-species DNA into the potato gene pool. Wild-type SH was highly resistant to CPB. Resistance to CPB of BC1 progenies showed a 1:3 inheritance pattern. MMR-deficient SHs performed better in the resistance analysis. Most MMR-deficient SHs had a similar toxicity as S. chacoense and an intensely repellent effect on CPB adults. Resistance of SHs and BC1 clones may be attributed to leptine biosynthesis, which was confirmed using a RAPD marker. This is the first report of SHs and their progenies exhibiting both antibiosis and antixenosis against CPB. Resistant SHs are an important step forward in combating this voracious pest of potato. © 2016 Society of Chemical Industry.

Localization Analysis of Natural Toxin of Solanum tuberosum L. via Mass Spectrometric Imaging

The use of mass spectrometry imaging (MSI) revealed the localization of a-solanine and a-chaconine as natural toxins for Potato ( Solanum tuberosum L. ). The content of Potato glycoalkaloids, a-solanine and a-chaconine, were quantitatively determined by high performance liquid chromatography (HPLC). Matrix assisted laser desorption/ionization-based tandem mass spectrometry (MS) could determine a-solanine and a-chaconine from raw potato extraction and section. After budbreak, a-solanine and a-chaconine were produced and localized at periderm and germ compared with that before budbreak. At germ region, these glycoalkaloids did not exist whole germ region but eccentrically localize at germ surface and central region. The amount of a-chaconine was twofold higher than a-solanine at periderm. At germ region, there was no difference between these toxins.

Characterization and Transcriptional Profile of Genes Involved in Glycoalkaloid Biosynthesis in New Varieties of Solanum tuberosum L.

Before commercial release, new potato (Solanum tuberosum) varieties must be evaluated for content of toxic compounds such as glycoalkaloids (GAs), which are potent poisons. GA biosynthesis proceeds via the cholesterol pathway to α-chaconine and α-solanine. The goal of this study was to evaluate the relationship between total glycoalkaloid (TGA) content and the expression of GAME, SGT1, and SGT3 genes in potato tubers. TGA content was measured by HPLC-MS, and reverse transcription quantitative polymerase chain reactions were performed to determine the relative expression of GAME, SGT1, and SGT3 genes. We searched for cis-elements of the transcription start site using the PlantPAN database. There was a relationship between TGA content and the relative expression of GAME, SGT1, and SGT3 genes in potato tubers. Putative promoter regions showed the presence of several cis-elements related to biotic and abiotic stresses and light. These findings provide an important step toward understanding TGA regulation and variation in potato tubers.

Next Generation Sequencing Bulk Segregant Analysis of Potato Support that Differential Flux into the Cholesterol and Stigmasterol Metabolite Pools Is Important for Steroidal Glycoalkaloid Content

Potatoes and other Solanaceae species produce biologically active secondary metabolites called steroidal glycoalkaloids (GAs) which have antimicrobial, fungicidal, antiviral and insecticidal properties. GAs are, however, also toxic to animals and humans. Compared to wild species of potato, the elite cultivars primarily used for everyday consumption have very low contents of GAs. Breeding for important agronomical traits, like e.g. pathogen resistance, often requires the use of wild species and a situation where offspring have unacceptable high contents of GAs quite frequently arises. Knowledge of metabolic pathways leading to the synthesis of GAs, as well as of the genes that are responsible for the observed differences in plant and tuber GA content is only partial. The primary purpose of this study was to identify genomic regions and candidate genes responsible for differential GA content within a diploid potato mapping population (n = 90) that shows a high variation in GA accumulation. The analysis was performed using a novel method based on next generation genome sequencing. A region on chromosome 1 was found to be associated with differential GA content. Within that region, sterol 24-C-methyltransferase (SMT1), sterol desaturase (SD) and C-4 sterol methyl oxidase (SMO) genes were found, all encoding critical enzymes in the synthesis of the GAs precursor cholesterol.

Impact of light-exposure on the metabolite balance of transgenic potato tubers with modified glycoalkaloid biosynthesis

Metabolite profiling (liquid chromatography–mass spectrometry (LC–MS) and gas chromatography (GC–MS)) was used to assess the impact of light on the composition of transgenic potato (Solanum tuberosum L. cv. Desirée) with reduced glycoalkaloid content via the down-regulation of the SGT1 gene. Transgenic tubers exhibited an almost complete knock-out of α-solanine production and light had little impact on its accumulation. Levels of α-chaconine increased significantly in the peel of both the control and transgenic lines when exposed to light, particularly in the transgenic line. Major differences in metabolite profiles existed between outer and inner tuber tissues, and between light and dark-treated tubers. Many of the light-induced changes are explicable in terms of pathways known to be affected by stress responses. The impact of transgenesis on profiles was much less than that of tissue type or light and most differences were explicable in terms of the modification to the glycoalkaloid pathway.

The effect of herbicides on the content of glycoalkaloids in the leaves and tubers of potato

The aim of the studies was to determine the effect of the used herbicides and their mixtures on the level of glycoalkaloids (TGA) in the leaves and tubers of three edible potato cultivars. The studied factors were: I - three cultivars: Cekin, Satina and Tajfun. II - five ways of care: 1. mechanical care - the control object and four objects using herbicides Command 480 EC, Afalon Dispersion 450 SC and Stomp 400 SC. The content of glycoalkaloids both in the leaves and in the tubers of the edible potato significantly depended on the genotype. The highest content of TGA characterised the cv. Cekin - 623.5 mg/kg and 67.21 mg/kg of fresh weight (FW), respectively, while the smallest was found in cv. Satina - 339.3 mg/kg and 33.60 mg/kg of FW, respectively. Herbicides used in the experiment caused the increase of the content of glycoalkaloids compared to the tubers from the control object. However, a significantly higher concentration of TGA was stated after using the mixture of herbicides Command 480 EC + Afalon Dispersion 450 SC and Stomp 400 SC + Afalon Dispersion 450 SC.

Modifying glycoalkaloid content in transgenic potato – Metabolome impacts

Metabolite profiling has been used to assess the potential for unintended composition changes in potato (Solanum tuberosum L. cv. Desirée) tubers, which have been genetically modified (GM) to reduce glycoalkaloid content, via the independent down-regulation of three genes SGT1, SGT2 and SGT3 known to be involved in glycoalkaloid biosynthesis. Differences between the three groups of antisense lines and control lines were assessed using liquid chromatography–mass spectrometry (LC–MS) and gas chromatography (GC)–MS, and data analysed using principal component analysis and analysis of variance. Compared with the wild-type (WT) control, LC–MS revealed not only the expected changes in specific glycoalkaloid levels in the GM lines, but also significant changes in several other metabolites, some of which were explicable in terms of known pathways. Analysis of polar and non-polar metabolites by GC–MS revealed other significant (unintended) differences between SGT lines and the WT, but also between the WT control and other control lines used.

Variations in the cytotoxic glycoalkaloids solamargine and solasonine in different parts of the Solanum incanum plant during its growth and development in Oman

In addition to several important traditional medicine applications of Solanum incanum, the plant is a rich source of important cytotoxic glycoalkaloids, such as solamargine and solasonine. Because S. incanum is a potential source of compounds for steroid synthesis, it is worthwhile to study the content of these important glycoalkaloids during plant developmental stages. Therefore, an attempt has been made to quantitatively estimate solasonine and solamargine content using an optimized isolation process and a newly developed and validated HPTLC method using different parts of S. incanum plants at different developmental stages and comparing changes in the whole-plant GAs profile during the growth and development of S. incanum plants in Oman. Solamargine and solasonine produced well-separated compact bands with Rf values of 0.26 and 0.14, respectively, on silica gel HPTLC plates using chloroform:methanol:5% ammonia (7:3:0.5, v/v/v) after visualization using anisaldehyde sulphuric acid reagent. The chromatograms were scanned at 530nm wavelength and the simultaneous method was linear (r2≥0.9962) in concentrations ranging from 50 to 2000ng/spot for both of the drugs. The validated method was applied to analyse solamargine and solasonine in small, young, immature and mature leaves as well as stem and root parts up to the 40th week of plants’ growth, and showed a rich concentration of glycoalkaloids with large variations at different stages of plant development. Hence, this study highlights the importance of developmental stages of particular organs and the overall age of the plant when harvesting for these GAs from S. incanum plants.

Changes of potentially anti-nutritive components in Hungarian potatoes from organic and conventional farming

Anti-nutritive components in multi resistant potato cultivars were investigated in relation to conventional and organic farming for three years. Glycoalkaloids, nitrate, nitrite, asparagine, and glutamine contents of tubers were examined. Farming technology was found not to have an effect on the level of glycoalkaloids, which was influenced mostly by the genotype and season. Nitrogen fertilisation caused significant increase in nitrate, asparagine, and glutamine contents as compared to organic farming. Nitrite content was found to be more independent of farming technologies than nitrate. Tubers of cultivar Rioja had the lowest nitrate content irrespective of season or technology. In conclusion, the absolute amount and changes of different anti-nutritive components of potato tubers were influenced differently by the technology, genotype, and season in a complex manner. Organic farming had no effect on the glycoalkaloid content, but the nitrate levels had a tendency to be lower compared to conventional farming. This can be seen as a positive effect of organic farming.

Effect of cultivar, flesh colour, location and year of cultivation on the glycoalkaloid content in potato tubers

In the three-year field trials (2009–2011) at two locations with different altitudes a total of 14 potato cultivars with different colour of flesh (yellow, white, red and purple) were grown. The content of total glycoalkaloids (TGA) was determined by HPLC. TGA content ranged from 18.8 to 102.4 mg/kg fresh matter and none of the cultivars reached the value of risk to human health. Conclusive and decisive influence on the content of the TGA was recorded in genotype. Individual cultivars reached 0.47 to 1.45 of the TGA content in the control cv. Agria. In terms of the colour of the flesh the highest TGA content was found in group of red-fleshed cultivars (1.53 × higher than the average of cultivars with yellow or white flesh); while red-fleshed cv. Rote Emma reached the absolutely lowest TGA content of 14 cultivars, which confirms the decisive role of genotype. On warm, dry habitats in the lowlands a higher TGA content was observed when compared with the amount raised in a typical potato field.

Glycoalkaloids Content influenced by Tuber Parts and Storage Period in Major Potato Cultivars of Korea

Yul-Ho Kim1*, Guem Hee Kim1, Hye Rim Ji1, Yu-Young Lee2, Hyang-Mi Park2, Oh-Keun Kwon3, Su Jeong Kim1, Whang-Bae Sohn1, Yong-Ik Jin1, Su-Young Hong1, Jeong-Hwan Nam1, Kibum Kweon1, Jong-Taek Suh1, and Jin-Cheol Jeong1. Korean J. Breed. Sci. 2014;46:209-17. https://doi.org/10.9787/KJBS.2014.46.3.209

Effect of Genotype and Storage on Glycoalkaloid and Acrylamide Content and Sensory Attributes of Potato Chips

Potato chips are the most popular snack foods consumed in Western countries. Potato chips contain beneficial bioactive compounds such as resistant starch, polyphenols etc. along with naturally occurring glycoalkaloids (GA) and processing induced acrylamide (AL). Information on the effect of genotype and storage on both GA and AL are limited. In this study the effect of cultivar and storage on both GA and AL content in potato chips was evaluated using four potato cultivars. In addition, reducing sugars and sensory attributes were measured in response to storage time and cultivar. Potato chips made from fresh and stored tubers were analyzed for total GA and AL using High Performance Liquid Chromatography and Ultra Performance Liquid Chromatography, respectively. Raw potatoes were analyzed for reducing sugars using a spectrophotometer. Sensory attributes of potato chips were assessed using 114 untrained panelists. The effect of storage on GA and AL content is cultivar dependent. Purple-fleshed cultivars were more susceptible to storage induced increase in AL content. Storage of potatoes at low temperature (4 °C) resulted in a significant increase in GA, AL and reducing sugar content after 90 days. Positive correlations were observed for the overall acceptability, texture, taste, ranking and GA/AL content, emphasizing the positive role of GA/AL on sensory qualities. These results indicate that an increase in GA and AL content with storage is dependent on cultivar. Thus, it is critical to select cultivars and optimize the storage conditions to lower GA/AL content in the potato chips, while retaining the sensory attributes and health-benefiting compounds.

Effect of Genotype and Environment on the Glycoalkaloid Content of Rare, Heritage, and Commercial Potato Varieties

Potatoes accumulate toxic steroidal compounds that could be harmful for humans if consumed in high quantities and must be controlled. In this study, we were interested in assessing the levels and variation of glycoalkaloid content in 60 varieties of potato planted in 2 trial sites over 2 y. Total glycoalkaloid levels ranged from 4 to 957 mg/kg of dry weight in the flesh and from 150 to 8133 mg/kg in the skin, with the latter accumulating generally more α-chaconine than α-solanine. Contents in the flesh were below the safe limit for all varieties, but were generally above in the skin. Maximum values in each site and year of cultivation were found for varieties "Beauty of Hebron," "May Queen," and "Arran Pilot" in the skin and "Beauty of Hebron," "International Kidney," and "Congo" in the flesh. Year of cultivation had a significant effect on total glycoalkaloid content (P < 0.0001), with interactions between variety and site of cultivation and variety and year of cultivation also significant (P < 0.0001), implying that environmental effects seem to act differentially and could induce high levels in genetically predisposed varieties. This paper reports the levels of toxic glycoalkaloids in 60 varieties of potato. Dietary intake and safety of consumers is discussed and varieties used by the potato processing industry are assessed in terms of safety and potential use of waste peel as raw material.

The influence of French fries processing on the glycoalkaloid content in coloured-fleshed potatoes

French fries made from coloured-fleshed potatoes may be interesting alternative to the traditional snacks for consumers. However, potatoes contain glycoalkaloids (TGA), so potato tubers and obtained fried snacks should be subjected to comprehensive examination. The aim of this study was to determine the effect of different stages of French fries processing on the content of TGA (α-solanine and α-chaconine) in the red- and blue-fleshed potatoes, in semi-products and ready-to-eat products. It was stated that during the processing of French fries prepared from coloured-flesh potato varieties significantly decreased the content of TGA (α-solanine and α-chaconine) in the samples obtained at different stages of the process compared to the raw material. Potatoes with blue-fleshed of Vitelotte variety and red-fleshed of Highland Burgundy Red variety can be used to French fries processing due to their low content of TGA (in unpeeled and peeled potatoes). However, Blue Congo variety with blue-fleshed should not be applied to French fries processing, because of high TGA content in raw material and first of all in peeled potatoes flesh. The peeling process of coloured-fleshed potatoes decreased in TGA content on average by about 50 %, cutting process on average by about 53 %, whereas blanching on average by about 58 % compared with the raw material. The highest decrease in TGA content was caused by frying process. The mean values were about 97.5 % in ready-to-eat French fries. In French fries after I and II steps of frying, the ratio α-solanine to α-chaconine was lower (1.0:2.0) than in unpeeled potatoes (1.0:2.3).

Toxic compound levels in potatoes are dependent on cultivation methods

The quality of potato tubers and their chemical composition are influenced by genetics as well as the soil fertility, weather conditions, the soil profile, and the chemical treatments that are applied. This field study on potato cultivation methods was conducted near Wroclaw (Lower Silesia), Poland. The variables used in the study included the potato cultivar [Asterix, Pirol (medium-to-early maturing varieties) and Syrena (medium-to-late maturing variety)] and the potato cultivation technology (organic, integrated and conventional). The experiment was conducted from 2005 through 2007.The purpose of this study was to compare the effects of ecological (organic), integrated and conventional cultivation methods on the nitrate and glycoalkaloid content of potato tubers. The cultivation method was determined to have a significant effect on the toxic compound concentrations in the potato tubers. The lowest glycoalkaloid and nitrate (NO3−) concentrations occurred in the potato tubers from the ecological plots. Mi...

Recovery of native protein from potato root water by expanded bed adsorption with amberlite XAD7HP

Potato root water (PRW) contains ∼1.5% protein. In this study, expanded bed adsorption (EBA) chromatography with Amberlite XAD7HP resin adsorbent was used to isolate native protein from crude PRW. The optimal pH and ionic strength for potato protein binding onto Amberlite XAD7HP were 5.0 and 20 mmol/L. The EBA-refined proteins were dried by vacuum freeze drying and spray drying at varying outlet temperatures. Results indicated that low temperature spray drying was the most cost effective method with respect to retaining protease inhibitor activities. The dried protein concentrates appeared bright yellow or dark reddish brown, with a total glycoalkaloid content of ∼170 μg/g. The protease inhibitor activity was ∼400 mg/g and 11 ∼ 12 mg/g for trypsin inhibition and chymotrypsin inhibition, respectively. The results presented here suggest that EBA using Amberlite XAD7HP as the adsorbent is a feasible strategy for the direct adsorption of native protein from crude PRW.

The influence of dehydrated potatoes processing on the glycoalkaloids content in coloured-fleshed potato

The aim of this study was to determine the effect of different temperatures of blanching and pre-drying used in the laboratory production of dried potato dice on the content of glycoalkaloids in red and blue fleshed potato varieties.Studied potatoes of coloured fleshed varieties were characterised by a low glycoalkaloids content at 5.47mg100g−1. The production of dehydrated potato dice influenced on the decrease in glycoalkaloids content in potato products. The majority of these compounds were removed during the peeling (70%) and blanching process (29%). Potato dice blanched at the highest temperature (85°C) and pre-dried at 120°C was characterised by the lowest quantity of glycoalkaloids content, whereas the highest content of these compounds was found in dice blanched potato at the lowest temperature (65°C) and pre-dried at 120°C. The blanching process much influenced on the decrease in glycoalkaloids content than pre-drying process.

Variation of nitrogenous components in potato (Solanum tuberosum L.) tubers produced under organic and conventional crop management

The information related to protein and other nitrogenous components in organically produced potato tubers can be interesting for consumers with specific diets. Such information is still limited. Here we report results on the effects of organic and conventional production systems on accumulation of nitrogenous substances including total tuber protein and the nutritiously most important tuber protein, patatin, observed in five cultivars on two localities during three consecutive years. Organically produced potato tubers contained significantly lower content of total nitrogen, crude protein, nitrates and glycoalkaloids (α-solanine and α-chaconine). Protein content, patatin relative abundance in total tuber protein and patatin content in organically produced potato tubers were slightly lower than in conventional ones but the differences were not statistically significant. The cultivar and interactions between cultivars and other production factors affected considerably contents of crude protein, protein, glycoalkaloids and patatin relative abundance. The effect of cultivar on these nitrogenous characteristics was stronger for potatoes produced under conventional farming indicating the sensitive reaction of organically produced potatoes on less favourable agro-ecological production conditions. The results indicate that cultivar-specific genetic factors play the predominant role in the reciprocal interaction with other cultivation factors affecting the nitrogenous qualitative parameters of organically produced potato tubers. This should be considered to include primarily the cultivar in quality standards of organic farming. The late maturing cultivar Bionta exhibited high instability in tubers yield, total protein and patatin protein characteristics when produced under organic farming system, while the early maturing cultivar Karin reacted on the conditions of organic farming by an increase of the patatin content.

Glycoalkaloid contents in potato leaves and tubers as influenced by insecticide application

The field experiment was carried out during 2004&amp;ndash;2006. The aim of the study was to determine the influence of insecticides (Actara 25 WG &amp;ndash; 0.08 kg/ha, Regent 200 SC &amp;ndash; 0.1 L/ha, Calypso 480 SC &amp;ndash; three rates: 0.05; 0.075;0.1 L/ha), used for controlling Colorado potato beetle, on total glycoalkaloid (TGA) content in potato leaves and tubers of three cultivars (Mors, Wiking, Żagiel). The insecticides significantly increased (Calypso 480 SC) or decreased (Actara 80 WG, Regent 200 SC) the TGA content in potato leaves, and increased TGA in tubers as compared with tubers harvested from the control. Leaves and tubers of cultivar Mors had the highest TGA contents, whereas Żagiel leaves and Wiking tubers had the lowest levels.

Anti-inflammatory properties of potato glycoalkaloids in stimulated Jurkat and Raw 264.7 mouse macrophages

AimsThe potato glycoalkaloids, α-chaconine, α-solanine and solanidine, along with potato peel extracts were investigated for potential anti-inflammatory effects in vitro. Their potential to reduce two biomarkers of inflammation, cytokine and nitric oxide (NO) productions, were assessed in the stimulated Jurkat and macrophage models, respectively. Main methodsCytokine and nitric oxide productions were stimulated in Jurkat and Raw 264.7 macrophages with Concanavalin A (Con A; 25μg/ml) and lipopolysaccaride (LPS; 1μg/ml), respectively. Selective concentrations of glycoalkaloids and potato peel extracts were added simultaneously with Con A or LPS for 24h to investigate their potential to reduce inflammatory activity. Key findingsα-Chaconine and solanidine significantly reduced interleukin-2 (IL-2) and interleukin-8 (IL-8) productions in Con A-induced Jurkat cells. The potato peel extracts did not influence cytokine production. In LPS-stimulated Raw macrophages, α-solanine, solanidine and two potato peel extracts significantly reduced induced NO production. SignificanceOur findings suggest that sub-cytotoxic concentrations of potato glycoalkaloids and potato peel extracts possess anti-inflammatory effects in vitro and with further investigation may be useful in the prevention of anti-inflammatory diseases.