Total Glycoalkaloid Research Articles

Assessment of the Content of Glycoalkaloids in Potato Snacks Made from Colored Potatoes, Resulting from the Action of Organic Acids and Thermal Processing.

Glycoalkaloids (TGAs, total glycoalkaloids), toxic secondary metabolites, are found in potatoes (110-335 mg·kg-1 DW), mainly in the peel. Colorful, unpeeled potatoes are an innovative raw material for the production of snacks which are poorly tested in terms of their glycoalkaloid content. Third-generation snacks and French fries made from red-fleshed Mulberry Beauty (MB) and purple-fleshed Double Fun (DF) potatoes were produced with the use of 1% solutions of ascorbic, citric, lactic, malic, and tartaric acids to stabilize the structure of anthocyanins in the raw material and maintain their color in obtained products. The influence of the type of acid and thermal processes, like frying, microwaving, and baking, on the content of glycoalkaloids in ready-made products was examined. Only 0.45-1.26 mg·100 g-1 of TGA was found in pellet snacks and 1.32-1.71 mg·100 g-1 in French fries. Soaking blanched potatoes in organic acid solution reduced the α-chaconine content by 91-97% in snacks and by 57-93% in French fries in relation to the raw material to the greatest extent after the use of malic acid and the DF variety. The effect of lactic and citric acid was also beneficial, especially in the production of baked French fries from MB potatoes.

Bioactivities and chemical profiling comparison and metabolomic variations of polyphenolics and steroidal glycoalkaloids in different parts of Solanum nigrum L.

Solanum nigrum L. is a traditional medicinal herb and edible plant. Many studies provide evidence that S. nigrum L. is a nutritious vegetable. Polyphenols and steroidal glycoalkaloids are the main components. This study aimed to systemically evaluate the phytochemical profile, quantification, and bioactivities of polyphenolics and glycoalkaloids in different parts of S. nigrum L. Total polyphenols (TPC) and total glycoalkaloids (TGK) were determined using the Folin-Ciocalteu and acid dye colorimetric methods, respectively. A total of 55 polyphenolic constituents (including 22 phenolic acids and 33 flavonoids) and 24 steroidal glycoalkaloids were identified from different parts using ultrahigh-performance liquid chromatography Q-exactive high-resolution mass spectrometry (UHPLC-QE-HRMS), of which 40 polyphenols (including 15 phenolic acids and 25 flavonoids) and one steroidal glycoalkaloid were characterised for the first time in S. nigrum L. Moreover, typical polyphenols and glycoalkaloids were determined using HPLC-UV and HPLC-evaporative light-scattering detector (ELSD), respectively. In addition, the TPC and TGK and their typical constituents were compared in different anatomical parts. Finally, the antioxidant capacities of polyphenolic extracts from different parts of S. nigrum L. were evaluated by ·OH, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric-reducing antioxidant power (FRAP) assay in vitro. In addition, the antitumour effects of TGK from different parts of S. nigrum L. on the proliferation of PC-3 cells were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Polyphenolic and glycoalkaloid extracts from different parts of S. nigrum L. showed different antioxidant and cytotoxic capacities in vitro. This is the first study to systematically differentiate between polyphenolic and glycoalkaloid profiles from different parts of S. nigrum L.

Effects of light intensity on Solanum mauritianum (Solanaceae) morphological and chemical traits and the performance of its biological control agent Gargaphia decoris (Hemiptera: Tingidae)

The lace bug Gargaphia decoris Drake (Hemiptera: Tingidae) has been released in New Zealand for the biological control of woolly nightshade Solanum mauritianum Scopoli (Solanaceae). It has been observed that at release sites, G. decoris more commonly infests plants growing in shaded locations, compared to plants growing under full sunlight conditions. To explore the mechanisms for this preferential selection, we tested the effects of low shade (LS) and high shade (HS) on the physical and chemical traits of S. mauritianum and the performance of G. decoris under glasshouse conditions. New leaves of older plants under LS conditions were smaller, thicker, had longer trichomes, lower water content and lower specific leaf area compared to HS leaves. Leaves of LS plants increased their C:N ratio but total glycoalkaloid concentration decreased as the plants grew older. High shade plants were taller, with higher shoot-to-root ratios, and new leaves of older plants had higher photosynthetic efficiency compared to LS plants. Gargaphia decoris showed no discrimination between HS and LS leaves for oviposition or feeding. We observed no differences on first- and second-generation G. decoris performance traits, such as fecundity (e.g., eggs/female), fertility (% egg hatch) and adult survival. However, as the plants grew older, second generation G. decoris females failed to oviposit on LS plants and displayed smaller bodies compared to the females that developed feeding on HS plants. We concluded that light intensity did affect physical and chemical traits of S. mauritianum plants and these effects influenced G. decoris performance. Although, the key factor behind the differential performance of G. decoris under contrasting light conditions remains unclear, we believe that plant glycoalkaloid concentrations contribute to G. decoris host plant selection.

Organoleptic characteristics and the total glycoalkaloids content of edible potato tubers depending on a cultivation technology and storage

Organoleptic characteristics and the total glycoalkaloids content of edible potato tubers depending on a cultivation technology and storage

Glycoalkaloid Composition and Flavonoid Content as Driving Forces of Phytotoxicity in Diploid Potato.

Despite their advantages, biotechnological and omic techniques have not been applied often to characterize phytotoxicity in depth. Here, we show the distribution of phytotoxicity and glycoalkaloid content in a diploid potato population and try to clarify the source of variability of phytotoxicity among plants whose leaf extracts have a high glycoalkaloid content against the test plant species, mustard. Six glycoalkaloids were recognized in the potato leaf extracts: solasonine, solamargine, α-solanine, α-chaconine, leptinine I, and leptine II. The glycoalkaloid profiles of the progeny of the group with high phytotoxicity differed from those of the progeny of the group with low phytotoxicity, which stimulated mustard growth. RNA sequencing analysis revealed that the upregulated flavonol synthase/flavonone 3-hydroxylase-like gene was expressed in the progeny of the low phytotoxicity group, stimulating plant growth. We concluded that the metabolic shift among potato progeny may be a source of different physiological responses in mustard. The composition of glycoalkaloids, rather than the total glycoalkaloid content itself, in potato leaf extracts, may be a driving force of phytotoxicity. We suggest that, in addition to glycoalkaloids, other metabolites may shape phytotoxicity, and we assume that these metabolites may be flavonoids.

Toxicological Effects on Selected Tissues of Rats Fed Glycoalkaloid-Rich and Light-Exposed Solanum Tuberosum

Background: Exposure of potato tubers to light causes accumulation of glycioalkaloids in the tubers and overdose of glycoalkaoids are associated with some toxicity. This study aims to investigate the effect of consuming sunlight exposed tubers of Irish potato on some selected tissues of rats.
 Methods:Freshly harvested tubers of Solnum tuberosum were purchased from a farmland and were randomly grouped into five groups. Groups 1- 4 consisted of tubers exposed to sunlight (including visible and invisible light e.g. ultraviolet) for a period of 1, 2, 3, and 4 week(s), respectively, while group 5 served as the control and consisted of freshly harvested tubers of Irish potato that have not been exposed to sunlight. The glycoalkaloids content was determined in both the non-exposed (control) and sunlight exposed tubers. Thereafter the tubers were formulated as diet and administered to rats. Biochemical analyses on serum lipid profile, enzymes of selected tissues (serum, liver, and kidney) and lipid peroxidation were carried out.
 Results: The results showed that the total glycoalkaloids content of the exposed sunlight groups (230, 250, 270, and 300 mg/kg fresh weight, respectively) significantly increased compared to the control group (100 mg/kg fresh weight). A significant reduction (P < 0.05) in activities of alanine aminotransferase, aspartate aminotransferase and a significant upsurge (P < 0.05) in alkaline phosphatase activity was observed in the selected tissues of sunlight-exposed potato tuber animal groups compared to the (non-exposed) group. Lipid peroxidation assessment revealed a significant upsurge (P < 0.05) in malondialdehyde formation and a mild alteration in serum lipid profile.
 Conclusion: The study concluded that consumption of sunlight exposed Solanum tuberosum tubers may pose a threat on vital organs of the body irrespective of duration of exposure.

A Review on Greening and Glycoalkaloids in Potato Tubers: Potential Solutions.

Greening is an undesirable trait that develops in potatoes upon light exposure. This condition lowers market value, increases tuber waste in retail stores, and consequently influences the price of product in the long run. When potatoes are subjected to artificial light, the amyloplast converts into chloroplast. Although the development of total glycoalkaloids (TGA) is independent of light, the greening induced by exposure of potato to artificial light is an indication of probable TGA acceleration, which could be present in a low amount initially. Several research studies on optimum postharvest factors (temperature, lighting condition, relative humidity, pretreatment, storage air composition, and packaging) have been carried out to avoid greening and TGA development. This current review highlights major postharvest factors and summarizes past research regarding cause of greening and TGA development in potatoes in retail stores. Additionally, it also portrays the potential solutions that could help mitigate this problem, ultimately reducing wastage and achieving food security.

Discolouration of Potato Tubers Under Retail Light: Cultivar Variations and Effect of Different Packaging Materials for Folva Potatoes Stored at 20 and 6 °C

Light exposure of potatoes induces formation of both chlorophyll (greening) and of toxic glycoalkaloids (GAs). Greening leads to rejection by consumers and thus to food waste and economic loss. The aim of this study was to (1) study light sensitivity with respect to colour changes and GA development for different Norwegian grown potato cultivars stored at 20 °C and (2) evaluate the light protective effect of selected packaging materials on colour development in cv. Folva at 6 °C and 20 °C. Potatoes of seven cultivars were stored under LED illumination for 4 days at 20 °C. Changes in colour were measured during storage by Minolta Chroma meter and by visually assessing the limit for unacceptable change of colour. The tested cultivars became unacceptable at different times (24–60 h) and differed both in absolute colour values and relative changes of values. The levels of total glycoalkaloids in cultivars with and without light exposure did not correspond well to the changes in colour. Potatoes of cultivar Folva were packaged in materials with different light barrier properties, followed by LED illumination for 4 days at 20 °C and 18 days at 6 °C. None of the tested packaging types provided sufficient protection from light. All potatoes at 20 °C were unacceptably green after 2 days in light (16 h/day) while the potatoes at 6 °C were unacceptably green after 9 days. Packaging material for potatoes cv. Folva should aim for a total light transmittance below 0.02 W/m2 to avoid development of green colour during light exposure at 20 °C in grocery stores.

Glycoalkaloids in leaves and potato tubers depending on herbicide application with biostimulants

The aim of the study was to determine the influence of herbicide application with biostimulants on total glycoalkaloid (TGA) content in potato leaves and tubers. The study was based on a two-factor field experiment established in a split-plot arrangement in three replications. The factors were as follows: factor I – two cultivars of edible potato – Oberon and Malaga; factor II – five methods of using herbicide and biostimulants: 1. control object; 2. herbicide clomazone + metribuzin (Avatar 293 ZC); 3. herbicide clomazone + metribuzin and biostimulant PlonoStart; 4. herbicide clomazone + metribuzin and biostimulant Aminoplant; 5. herbicide clomazone + metribuzin and biostimulant Agro-Sorb Folium. The herbicide clomazone + metribuzin significantly increased the concentration of glycoalkaloids in potato leaves, and the herbicide used together with the biostimulant Aminoplant significantly reduced the content of TGA in potato leaves compared to the control. The herbicide whether applied with the biostimulants (PlonoStart, Aminoplant, Agro-Sorb Folium) contributed to a reduction in the concentration of glycoalkaloids in tubers compared to the control. Leaves and tubers of the cultivar Malaga were characterised by a significantly lower TGA content than the cultivar Oberon.

Effect of environment and peeling in the glycoalkaloid concentration of disease-resistant and heat-tolerant potato clones

The effect of environment and peeling on the glycoalkaloid concentration of late blight-resistant and heat-tolerant potato clones was determined by ultraperformance liquid chromatography (UPLC). Significant variation due to clone, environment and clone x environment (G x E) interaction was found. Total glycoalkaloids (TGA) concentration in raw unpeeled tubers ranged from 1.37 to 33.35 mg / 100 g on a fresh weight basis (FW). The α-chaconine, α-solanine and TGA concentrations of all the late blight-resistant and heat-tolerant clones and varieties evaluated in this study were higher under heat stress conditions. The clones 398098.570, 398192.213 and 398208.219 have less than 10 mg / 100 g FW of glycoalkaloids under heat stress conditions and are recommended for distribution. TGA concentration of clones and varieties was reduced from 5 to 73% with a mean reduction of 33% after peeling. However, under heat stress conditions, clones 398098.203 and 398098.204 presented unsafe levels of TGA even after peeling and have been removed from the list of late blight-resistant and heat-tolerant clones recommended for distribution. Peeling reduced the TGA concentration of clone 393371.58 to a safe level when grown under heat stress conditions.

Effect of Storage Conditions on Biologically Active Compounds in Purple-Fleshed Potatoes

Abstract Potatoes (Solanum tuberosum L.) are an important crop. They are a source of natural phenolic compounds with high biological activity. Stress factors may decrease phenolic concentration and increase concentration of the toxin glycoalkaloid as a result of plant self-protection against stress. The aim of the current study was to evaluate the effect of storage under light on the concentration of biologically active compounds in purple-fleshed potatoes. The purple-fleshed potato variety ‘Blue Congo’ was harvested from test fields of the Institute of Agricultural Resources and Economics in Latvia. Storage under light was performed in a climate chamber ICH110 (Memmert GmbH + Co. KG, Germany) with constant pre-set relative air humidity 85%, temperature +22 °C, and full-spectrum light (Eecoo, 1200 W, LED) intensity of 2000 lux and total time seven days. Total phenolic concentration, antioxidant activity and total glycoalkaloid concentration was measured using spectrophotometry, and moisture was determined according to standard LVS 272:2000. Storage under artificial light of purple-fleshed variety ‘Blue Congo’ potatoes caused decrease of total phenolic concentration and antioxidant activity, no change in moisture level, and increase of total glycoalkaloid concentration.

Improving the Biocontrol Potential of Endophytic Bacteria Bacillus subtilis with Salicylic Acid against Phytophthora infestans-Caused Postharvest Potato Tuber Late Blight and Impact on Stored Tubers Quality

Potato (Solanum tuberosum L.) tubers are a highly important food crop in many countries due to their nutritional value and health-promoting properties. Postharvest disease caused by Phytophthora infestans leads to the significant decay of stored potatoes. The main objective of this study was to evaluate the effects of the endophytic bacteria, Bacillus subtilis (strain 10–4), or its combination with salicylic acid (SA), on some resistance and quality traits of stored Ph. infestans-infected potato tubers. The experiments were conducted using hydroponically grown potato mini-tubers, infected prior to storage with Ph. infestans, and then coated with B. subtilis, alone and in combination with SA, which were then stored for six months. The results revealed that infection with Ph. infestans significantly increased tuber late blight incidence (up to 90–100%) and oxidative and osmotic damage (i.e., malondialdehyde and proline) in tubers. These phenomena were accompanied by a decrease in starch, reducing sugars (RS), and total dry matter (TDM) contents and an increase in amylase (AMY) activity. Moreover, total glycoalkaloids (GA) (α-solanine, α-chaconine) notably increased in infected tubers, exceeding (by 1.6 times) permissible safe levels (200 mg/kg FW). Treatments with B. subtilis or its combination with SA decreased Ph. infestans-activated tuber late blight incidence (by 30–40%) and reduced oxidative and osmotic damages (i.e., malondialdehyde and proline) and AMY activity in stored, infected tubers. Additionally, these treatments decreased pathogen-activated GA accumulation and increased ascorbic acid in stored tubers. Thus, the results indicated that endophytic bacteria B. subtilis, individually, and especially in combination with SA, have the potential to increase potato postharvest resistance to late blight and improve tuber quality in long-term storage.

Fruit Composition of Eggplant Lines with Introgressions from the Wild Relative S. incanum: Interest for Breeding and Safety for Consumption

The wild species Solanum incanum has been used as a donor parent for the development of a set of eggplant introgression lines (ILs), which are of interest for breeding for stress tolerances and relevant morpho-agronomic traits but could also be useful for breeding for fruit quality, due to the generally higher content in health-promoting compounds of S. incanum. The use of eggplant ILs with introgressions from S. incanum requires ensuring that glycoalkaloids levels are below safety limits. We evaluated 25 fruit composition traits, including proximate composition, sugars, acids, phenolics, glycoalkaloids, and minerals in a set of 16 eggplant ILs with S. incanum, both parents and the F1, grown under two environments (open field and screenhouse). The results demonstrated that the parents were significantly different regarding most fruit composition traits. Large variation was found among the 16 ILs for all traits analyzed and a strong influence of the environment accounted for the variation of 17 out of the 25 traits evaluated. Although the S. incanum parent produced fruits with high levels of glycoalkaloids, the 16 ILs showed mean values of total glycoalkaloids below the currently accepted safety limit for human consumption (200 mg kg−1 fresh weight). Overall, the ILs produced fruits that are safe for consumption, with nutritional and functional quality similar to the recipient parent. Furthermore, six putative QTLs were detected spread over chromosomes 3 for crude protein, 5 for malic and total acids, and 7 for chlorogenic acid and solamargine, and potential candidate genes were spotted for most of them, which provide new relevant information for eggplant breeding.

High-Performance Liquid Chromatography-Mass Spectrometry Analysis of Glycoalkaloids from Underexploited Solanum Species and Their Acetylcholinesterase Inhibition Activity.

Solanum glycoalkaloids are gaining increased scientific attention due to their bioactive potential in the defense of plants against pests and pathogens. The comprehensive glycoalkaloid profiling from the leaves, stems, and roots of seven underexploited Solanum species (S. caripense, S. melanocerasum, S. muricatum, S. nigrum, S. quitoense, S. retroflexum, and S. sisymbriifolium) was conducted using high-performance liquid chromatography–time-of-flight mass spectrometry. A total of 51 glycoalkaloids were shared among the studied Solanum species, with concentrations ranging from 7 to 5.63 × 105 ng g−1. Based on the glycoalkaloid composition, plants were separated into two clusters, Cluster 1 (S. melanocerasum, S. nigrum, and S. retroflexum) and Cluster 2 (S. caripense, S. muricatum, S. quitoense, and S. sisymbriifolium). The inhibition activity of glycoalkaloid extracts on acetylcholinesterase showed a half-maximal inhibitory concentration (IC50), ranging from 0.4 (S. nigrum stems) to 344.9 µg mL−1 (S. sisymbriifolium leaves), that was not directly correlated to the total glycoalkaloid contents. This suggests that the composition of glycoalkaloids in the plant extract, rather than the total concentration, is a driver of biological activity. The study provides a framework for the bioprospecting of underexploited Solanum species for exploring bioactive glycoalkaloids and other compounds with potential pesticidal activities for the development of green bioformulation. This is the first comprehensive report on the glycoalkaloid profiles of S. retroflexum.

The MYB transcription factor LrAN2, from Lycium ruthenicum, led to enhanced accumulation of anthocyanins and modified profile of the total glycoalkaloids in potato

The MYB transcription factor LrAN2, from Lycium ruthenicum, led to enhanced accumulation of anthocyanins and modified profile of the total glycoalkaloids in potato

Indices for the Assessment of Glycoalkaloids in Potato Tubers Based on Surface Color and Chlorophyll Content

Glycoalkaloids (GAs) are toxic to humans at higher concentrations. However, studies also suggest the health benefits of GAs depending on the dose and conditions of use. Methods that have been used to determine GA content in potato tubers are destructive and time-consuming and require skilled personnel and high-performance laboratory equipment. We conducted this study to develop indices for the prediction of the level of total GAs in potato tubers at different greening stages based on surface color readings and chlorophyll (Chl) development. Color values (Hunter L*, a*, b*, a*/b*), Chls (Chl a, Chl b, and total Chls) and GA (α-solanine, α-chaconine, and total GAs) content were measured from tubers of ‘Atlantic’ and ‘Trent’ potato cultivars at three-week intervals in up to six greening stages during the storage at room conditions (22 °C, 12-h shift of light-dark cycles). The results have revealed that greening, Chls, and GA content significantly increased for the two cultivars as the stage proceeded. The toxic level of GAs (>200 mg kg−1 FW) was accumulated at the late greening stages, accompanied by the highest Chl content. Finally, indices were developed based on surface color and Chl content for estimation of the safe GA levels for the consumption of the two commercially and commonly used potato cultivars. Moreover, the developed indices could be used as basic information to adapt to other potato cultivars.

The Effect of Light Exposures on the Content of Harmful Substances in Edible Potato Tuber

Background: The impact of light on the content of undesirable substances is particularly important in the case of potatoes available in store where the tubers are exposed to continuous light access. Both washed and unwashed potatoes are available, hence the hypothesis that the amount of harmful substances stored in tubers depends not only on the time of their exposure to light, but also on whether they were washed or not. Methods: In order to verify the hypothesis, laboratory tests were carried out on the tubers of five potato varieties originating from a univariate field experiment. The aim of the study was to analyse the change in the content of total glycoalkaloids (TGA) and nitrates (V) in tubers of five potato varieties depending on the time of light exposition (0, 7, 14 days) and pretreatment of tubers. Results: It has been demonstrated that the content of glycoalkaloids and nitrates in potato tubers depended significantly on the variety, time of exposure to light and pretreatment. Most glycoalkaloids were accumulated in the tubers of the Lord (89.67 mg·kg−1) and Irga (89.05 mg·kg−1) varieties. The time of light exposure significantly influenced the increase in glycoalkaloids and nitrates in the studied potato tubers. The increase in TGA after 14 days ranged from 20.67 mg∙kg−1 for variety Vinieta to 54.67 mg∙kg−1 for variety Irga. The increase in nitrates ranged from 11.67 mg∙kg−1 for variety Bellarosa to 27.50 mg∙kg−1 for variety Irga. Exposure time affected the content of glycoalkaloids in a parabolic manner and the content of nitrates in a linear manner.

Biochemical and functional attributes of raw and boiled potato flesh and peel powders for suitability in food applications.

Four different potato cultivars, namely, Kufri Chipsona 1 and Kufri Frysona (processing purpose), Kufri Jyoti and Kufri Bahar (table purpose) were converted into flesh and peel powder (raw and after boiling) and studied for their respective biochemical and functional attributes to get an idea of possible dynamics of their utilization in different food formulation as bioadditives. The 16 variants of powder obtained retained less than 10% moisture content and demonstrated 'very good' to 'fair' flowability. Peel powders recorded a higher total mineral, fiber, phenolic contents and total antioxidant activity than the flesh powders which were significantly affected by boiling. Among raw and boiled flesh powders, highest reducing and total sugars were recorded for Kufri Bahar while least was observed in Kufri Chipsona 1. Colour coordinate showed that boiling imparts brightness to flesh powder while peel powder got darkened. Boiling of the tubers resulted in an increase in the resistant starch (~ 29% maximum) and flavour (~ 180% maximum) component. Peel exhibited a total glycoalkaloid content in the range of 0.75 (Kufri Frysona) to 1.7mg/100g (Kufri Bahar) that is well within the acceptable limits. Rheological study of the flesh powders revealed a reduction of about 11-18°C in pasting temperature and about 87-90% in peak viscosity, setback, breakdown value and final viscosity upon boiling. This study revealed that the traditional processing method such as boiling can significantly modify the techno-functional characteristics of potato flesh and peel powders which can further govern their end use in various food formulations.

Effect of Magnesium Supply and Storage Time on Anti-Nutritive Compounds in Potato Tubers

The nutritional quality of potato tubers is cultivar-specific and depends on climate-soil conditions and agrotechnical practices, as well as the conditions during long-term storage. Studies were performed from 2009–2011 to determine the effects of magnesium fertilisation and storage duration on the contents of the anti-nutritive compound nitrates, nitrites and total glycoalkaloids (TGA) in potato tubers of mid-early cultivar “Bila” (Solanum tuberosum L.). Magnesium (Mg) was applied in doses of 0, 20, 40, 60, 80 and 100 kg MgO ha−1, respectively, in the form of kieserite–magnesium sulphate (26% MgO). Potato quality after harvest and after three and six months of storage was determined. The content of nitrates in tubers after harvest ranged from 303 to 356 mg kg−1 FW and nitrites from 1.59 to 1.67 mg kg−1 FW. Increasing magnesium fertilisation reduced the nitrate and nitrite content of tubers but increased TGA content. Possible explanations for the TGA increase after Mg supply are discussed. Tubers that contained less TGA after harvest also had less glycoalkaloids after storage. However, physical damage during harvest or transportation, exposure to light and bad storage conditions increase the concentrations of glycoalkaloids in tubers. The consumption of cultivar “Bila” would not exceed the acceptable daily intake of harmful substances.

Growth and alkaloid production along with expression profiles of biosynthetic pathway genes in two contrasting morphotypes of prickly and prickleless Solanum viarum Dunal.

Growth and production kinetics of three important glycoalkaloids viz. α-solanine, solanidine, and solasodine in two contrasting prickly and prickleless plants of Solanum viarum Dunal were evaluated under in vitro conditions. The prickleless plants showed improved accumulation of total glycoalkaloid content [7.11 and 6.85 mg g-1 dry weight (DW)] and growth (GI = 11.08 and 19.26) after 45 and 50 days of culture cycle, respectively. For higher biomass (91.18 g l-1) as well as glycoalkaloid (52.56 mg l-1) recovery, the prickleless plants served as highly profitable platform. All the three studied glycoalkaloids were identified and quantified by mass spectrometry and HPLC. All the three studied glycoalkaloids accumulated in age-dependent manner. The presence of two constituents, i.e., solasodine and solanidine mainly contributed for higher accumulation of total glycoalkaloid content in the prickleless plants. However, the synthesis of α-solanine was highly age specific and could be detected after 4 to 5 weeks of culture cycle in both prickle containing as well as prickleless plants of S. viarum. The higher accumulation of glycoalkaloids in prickleless plants was also supported with the expression analysis of six key pathway enzymes viz. mevalonate kinase (MVK), 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (HMGR), farnesyl diphosphate synthase (FPS), UDP-galactose/solanidine galactosyltransferase (SGT1), UDP-glucose/solanidine glucosyltransferase (SGT2), and cytochrome P450 monooxygenase (CYP). The results indicated that the plants harvested after 45 and 50 days of culture cycle accumulated maximum bioactive in-demand glycoalkaloids in the prickly and prickleless plants of S. viarum Dunal, respectively.