Evaluation of in vivo and in vitro efficacy of solasonine/solamargine-loaded lipid-polymer hybrid nanoparticles against bladder cancer.

Solasonine (SS) and solamargine (SM) are alkaloids known for their antioxidant and anticancer properties, which can be further enhanced by encapsulating them in nanoparticles. This led to a study on the potential therapeutic benefits of SS and SM against bladder cancer when encapsulated in lipid-polymer hybrid nanoparticles (LPHNP). The LPHNP loaded with SS/SM were prepared using the emulsion and sonication method and their physical-chemical properties characterized. The biological effects of these nanoparticles were then tested in both 2D and 3D bladder cancer cell culture models, as well as in a syngeneic orthotopic mouse model based on the MB49 cell line and ethanol epithelial injury. The LPHNP-SS/SM had an average size of 130 nm, a polydispersity index of 0.22 and a positive zeta potential, indicating the presence of chitosan coating on the nanoparticle surface. The dispersion of LPHNP-SS/SM was found to be monodispersed with a span index of 0.539, as measured by nanoparticle tracking analysis (NTA). The recrystallization index, calculated from DSC data, was higher for the LPHNP-SS/SM compared to LPHNPs alone, confirming the presence of alkaloids within the lipid matrix. The encapsulation efficiency (EE%) was also high, with 91.08 % for SS and 88.35 % for SM. Morphological analysis by AFM and Cryo-TEM revealed that the nanoparticles had a spherical shape and core-shell structure. The study showed that the LPHNP-SS/SM exhibited mucoadhesive properties by physically interacting with mucin, suggesting a potential improvement in interaction with mucous membrane. Both the free and nanoencapsulated SS/SM demonstrated dose-dependent cytotoxicity against bladder cancer cell lines after 24 and 72 h of treatment. In 3D bladder cell culture, the nanoencapsulated SS/SM showed an IC50 two-fold lower than free SS/SM. In vivo studies, the LPHNP-SS/SM displayed an antitumoral effect at high doses, leading to a significant reduction in bladder volume compared to the positive control. However, there were observed instances of systemic toxicity and liver damage, indicated by elevated levels of transaminases (TGO and TGP). Overall, these results indicate that the LPHNPs effectively encapsulated SS/SM, showing high encapsulation efficiency and stability, along with promising in vitro and in vivo antitumoral effects against bladder cancer. Further evaluation of its systemic toxicity effects is necessary to ensure its safety and efficacy for potential clinical application.

Potato Berries as a Valuable Source of Compounds Potentially Applicable in Crop Protection and Pharmaceutical Sectors: A Review.

Potato (Solanum tuberosum) is a major agricultural crop cultivated worldwide. To meet market demand, breeding programs focus on enhancing important agricultural traits such as disease resistance and improvement of tuber palatability. However, while potato tubers get a lot of attention from research, potato berries are mostly overlooked due to their level of toxicity and lack of usefulness for the food production sector. Generally, they remain unused in the production fields after harvesting the tuber. These berries are toxic due to high levels of glycoalkaloids, which might confer some interesting bioactivities. Berries of various solanaceous species contain bioactive secondary metabolites, suggesting that potato berries might contain similarly valuable metabolites. Therefore, possible applications of potato berries, e.g., in the protection of plants against pests and pathogens, as well as the medical exploitation of their anti-inflammatory, anticarcinogenic, and antifungal properties, are plausible. The presence of valuable compounds in potato berries could also contribute to the bioeconomy by providing a novel use for otherwise discarded agricultural side streams. Here we review the potential use of these berries for the extraction of compounds that can be exploited to produce pharmaceuticals and plant protection products.

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.

Enhancement of production of glycoalkaloids by elicitors along with characterization of gene expression of pathways in Solanum xanthocarpum.

Solanum xanthocarpum fruits are used in the treatment of cough, fever, and heart disorders. It possesses antipyretic, hypotensive, antiasthmatic, aphrodisiac and antianaphylactic properties. In the present study, 24 elicitors (both biotic and abiotic) were used to enhance the production of glycoalkaloids in cell cultures of S. xanthocarpum. Four concentrations of elicitors were added into the MS culture medium. The maximum accumulation (5.56-fold higher than control) of demissidine was induced by sodium nitroprusside at 50 mM concentration whereas the highest growth of cell biomass (4.51-fold higher than control) stimulated by systemin at 30 mM concentration. A total of 17 genes of biosynthetic pathways of glycoalkaloids were characterized from the cells of S. xanthocarpum. The greater accumulation of demissidine was confirmed with the expression analysis of 11 key biosynthetic pathway enzymes e.g., acetoacetic-CoA thiolase, 3- hydroxy 3-methyl glutaryl synthase, ß-hydroxy ß-methylglutaryl CoA reductase, mevalonate kinase, farnesyl diphosphate synthase, squalene synthase, squalene epoxidase, squalene-2,3- epoxide cyclase, cycloartenol synthase, UDP-glucose: solanidine glucosyltransferase and UDP-rhamnose: solanidine rhamno-galactosyl transferase. The maximum expression levels of UDP-rhamnose: solanidine rhamno-galactosyl transferase gene was recorded in this study.

A comprehensive approach to the monitoring of steroidal glycoalkaloids in foods of plant origin.

Steroidal glycoalkaloids (GAs) are toxins produced by solanaceous plants. As there are no fully standardized methods for their extraction and determination in food, the research aimed to: (1) develop and critically compare methods based on gas (GC) and liquid (LC) chromatography, including their coupling with mass spectrometry, and (2) to develop and optimize a universal GA extraction method. Hyphenated techniques proved to be the most useful in GA analysis: LC-MS was the most sensitive one, while GC-MS offered the highest chromatographic resolution. It was proven that quantitative results obtained using different analytical techniques cannot be directly compared. New extraction method that is more efficient than the AOAC method (997.13) was then designed and optimized. It was characterized by higher absolute recovery (99% and 34%, respectively) and allowed to extract much more GAs from the same material (e.g. 21.2 ± 1.4 and 11.82 ± 0.97 mg g-1 of potato tubers, respectively).

Steroidal scaffold decorations in Solanum alkaloid biosynthesis.

Steroidal glycoalkaloids (SGAs) are specialized metabolites produced by hundreds of Solanum species, including important vegetable crops such as tomato, potato and eggplant. Though SGAs are better known for their role in defence in plants and 'anti-nutritional' effects (e.g., toxicity and bitterness) to humans, many of these molecules have documented anti-cancer, anti-microbial, anti-inflammatory, anti-viral and anti-pyretic activities. Among these, α-solasonine and α-solamargine isolated from black nightshade (Solanum nigrum), are reported to have potent anti-tumor, anti-proliferative and anti-inflammatory activities. Notably, α-solasonine and α-solamargine, along with the core steroidal aglycone solasodine are the most widespread SGAs produced among the Solanum plants. However, it is still unknown how plants synthesize these bioactive steroidal molecules. Through comparative metabolomic-transcriptome guided approach, biosynthetic logic, combinatorial expression in Nicotiana benthamiana and functional recombinant enzyme assays, here we report the discovery of 12 enzymes from S. nigrum that converts the staring cholesterol precursor to solasodine aglycone, and the downstream α-solasonine, α-solamargine and malonyl-solamargine SGA products. We further identified 6 enzymes from cultivated eggplant that catalyse the production of α-solasonine, α-solamargine and malonyl-solamargine SGAs from solasodine aglycone, via glycosylation and atypical malonylation decorations. Our work provides the gene tool box and platform for engineering the production of high value, steroidal bioactive molecules in heterologous hosts using synthetic biology.

Health Benefits of the Alkaloids from Lobeira (Solanum lycocarpum St. Hill): A Comprehensive Review.

Solanum is the largest genus within the Solanaceae family and has garnered considerable attention in chemical and biological investigations over the past 30 years. In this context, lobeira or "fruta-do-lobo" (Solanum lycocarpum St. Hill), a species predominantly found in the Brazilian Cerrado, stands out. Beyond the interesting nutritional composition of the fruits, various parts of the lobeira plant have been used in folk medicine as hypoglycemic, sedative, diuretic, antiepileptic, and antispasmodic agents. These health-beneficial effects have been correlated with various bioactive compounds found in the plant, particularly alkaloids. In this review, we summarize the alkaloid composition of the lobeira plant and its biological activities that have been reported in the scientific literature in the last decades. The compiled data showed that lobeira plants and fruits contain a wide range of alkaloids, with steroidal glycoalkaloid solamargine and solasonine being the major ones. These alkaloids, but not limited to them, contribute to different biological activities verified in alkaloid-rich extracts/fractions from the lobeira, including antioxidant, anti-inflammatory, anticancer, antigenotoxic, antidiabetic, antinociceptive, and antiparasitic effects. Despite the encouraging results, additional research, especially toxicological, pre-clinical, and clinical trials, is essential to validate these human health benefits and ensure consumers' safety and well-being.

Structural Impact of Steroidal Glycoalkaloids: Barrier Integrity, Permeability, Metabolism, and Uptake in Intestinal Cells.

SCOPE: Potato tubers represent an essential food component all over the world and an important supplier of carbohydrates, fiber, and valuable proteins. However, besides their health promoting effects, potatoes contain α-solanine and α-chaconine, which are toxic steroidal glycoalkaloids (SGAs). Other solanaceous plants like eggplants and tomatoes produce SGAs as well, different in their chemical structure. This study aims to investigate toxic effects (cholinesterase inhibition, membrane, and barrier disruption), permeability, metabolism, and structure-activity relationships of SGAs. METHODS AND RESULTS: α-solanine, α-chaconine, α-solasonine, α-solamargine, α-tomatine, and their respective aglycones solanidine, solasodine, and tomatidine are analyzed using Ellman assay, cellular impedance spectroscopy, cell extraction, and Caco-2 intestinal model. Additionally, metabolism is analyzed by HPLC-MS techniques. The study observes dependencies of barrier disrupting potential and cellular uptake on the carbohydrate moiety of SGAs, while permeability and acetylcholinesterase (AChE) inhibition are dominated by the steroid backbone. SGAs show low permeabilities across Caco-2 monolayers in subtoxic concentrations. In contrast, their respective aglycones reveal higher permeabilities, but are extensively metabolized. CONCLUSION: Besides structure-activity relationships, this study provides new information on the overall effects of steroidal alkaloids on intestinal cells and closes a gap of knowledge for the metabolic pathway from oral uptake to final excretion.

Agri-Food Waste Recycling for Healthy Remedies: Biomedical Potential of Nutraceuticals from Unripe Tomatoes (Solanum lycopersicum L.).

Unripe tomatoes represent an agri-food waste resulting from industrial by-processing products of tomatoes, yielding products with a high content of bioactive compounds with potential nutraceutical properties. The food-matrix biological properties are attributed to the high steroidal glycoalkaloid (SGA) content. Among them, α-tomatine is the main SGA reported in unripe green tomatoes. This review provides an overview of the main chemical and pharmacological features of α-tomatine and green tomato extracts. The extraction processes and methods employed in SGA identification and the quantification are discussed. Special attention was given to the methods used in α-tomatine qualitative and quantitative analyses, including the extraction procedures and the clean-up methods applied in the analysis of Solanum lycopersicum L. extracts. Finally, the health-beneficial properties and the pharmacokinetics and toxicological aspects of SGAs and α-tomatine-containing extracts are considered in depth. In particular, the relevant results of the main in vivo and in vitro studies reporting the therapeutic properties and the mechanisms of action were described in detail.

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

INTRODUCTION: 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. OBJECTIVES: This study aimed to systemically evaluate the phytochemical profile, quantification, and bioactivities of polyphenolics and glycoalkaloids in different parts of S. nigrum L. RESULTS: 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. CONCLUSION: This is the first study to systematically differentiate between polyphenolic and glycoalkaloid profiles from different parts of S. nigrum L.

Phytochemical investigation and antioxidant properties of unripe tomato cultivars (Solanum lycopersicum L.).

Unripe tomatoes are among the main waste produced during tomato cultivation and processing. In this study, unripe tomatoes from seven different Italian cultivars have been investigated to evaluate their nutraceutical potential. Phytochemical investigation allowed shedding light on the identification of seventy-five bioactive compounds. The highest amount of polyphenolic and glycoalkaloids along with the high level of antioxidant activities was found in the Datterini tomatoes variety. The peculiarity of this variety is the high chlorogenic acid content, being ten times higher compared to the other cultivars examined. Moreover, the total α-tomatine amount has been found substantially higher (34.699 ± 1.101 mg/g dry weight) with respect to the other tomato varieties analyzed. Furthermore, the cultivars metabolomic profiles were investigated with the PCA approach. Based on Datterini cultivar's metabolomic profile, its waste-recovery could represent a good option for further added value products in pharmaceutical and nutraceutical areas with a high α-tomatine content.

Are Growth Performance and Fecal Score in Weaning Pigs Affected by the Inclusion Level of Potato Protein Concentrate and the Enclosed Glycoalkaloids in Iso-Nitrogenous Diets?

Glycoalkaloids (GA) are anti-nutritional factors in standard potato protein concentrate (PPC) fed to piglets. Increasing levels of standard PPC was expected to affect growth performance and fecal score negatively. Seven-hundred-and-twenty pigs (7-30 kg) were fed one of the following four diets within three feeding phases (days 0-13, 13-24, and 24-45): control (CTRL), PPC standard inclusion (PPC-S; 4%, 2%, and 0%), high PPC inclusion (PPC-H; 8%, 3.5%, and 2%), and extremely high PPC inclusion (PPC-EH; 12%, 5%, and 3.5%). During days 0-13, CTRL displayed no difference in growth performance compared with the three experimental groups (PPC-S, PPC-H, and PPC-EH). During days 13-24, PPC-H achieved greater (p < 0.001) average daily feed intake (ADFI) compared to CTRL. During days 24-45, no differences between groups were observed. For the overall experimental period (0-45 days), PPC-H displayed greater average daily gain (ADG) (p = 0.010) and ADFI (p = 0.024) compared to CTRL. The feed conversion ratio (FCR) remained unaffected between the groups for all experimental periods. Increasing levels of PPC and hence GA did not affect the probability of diarrhea. In conclusion, increased standard PPC and hence increased levels of GA in isonitrogenous diets did not negatively affect growth performance nor fecal score in piglets (7-30 kg).

Metabolomic and transcriptomic analyses identify external conditions and key genes underlying high levels of toxic glycoalkaloids in tubers of stress-sensitive potato cultivars.

Introduction: High levels of toxic steroidal glycoalkaloids (SGAs) in potato tubers constitute a recognized food quality problem. Tuber SGA levels vary between potato cultivars and can increase after post-harvest stresses such as wounding and light exposure. A few cultivars, e.g., 'Magnum Bonum' and 'Lenape,' have been withdrawn from commercial sales due to excessive SGA levels during some cultivation years. However, these sudden SGA increases are diffucult to predict, and their causes are not understood. To identify external and genetic factors that underlie sudden SGA increases in certain potato cultivars, we have here in a 2-year study investigated 'Magnum Bonum' and five additional table potato cultivars for their SGA levels after wounding and light exposure. Results and methods: Results showed that 'Magnum Bonum' has an unusual strong SGA response to light exposure, but not to wounding, whereas 'Bintje' displayed an opposite regulation. Levels of calystegine alkaloids were not significantly altered by treatments, implicating independent metabolic regulation of SGA and calystegine levels also under conditions of high SGA accumulation. Metabolomic and transcriptomic analyses identified a small number of key genes whose expression correlated with SGA differences between cultivars. Overexpression of two key genes in transgenic low-SGA potato cultivars increased their leaf SGA levels significantly. Discussion: The results show that a strong response to light can underlie the SGA peaks that occasionally occur in certain potato cultivars and indicate that a between-cultivar variation in the expression of single SGA key genes can account for cultivar SGA differerences. We propose that current attempts to mitigate the SGA hazard will benefit from an increased consideration of cultivar-dependent SGA responses to post-harvest conditions, particularly light exposure. The identified key SGA genes can now be used as a molecular tool in this work.

Two new quinolinone glycoalkaloids from Chrysanthemum indicum L. and their antimicrobial activity.

Phytochemical investigation of Chrysanthemum indicum L. yielded two new quinolinone glycoalkaloids named as Chrysanthemumsides A-B (1-2). The structures of the new compounds were elucidated by analysis of their 1D- and 2D-NMR, HRESIMS and ECD calculations. Compounds 1-4 were evaluated for antimicrobial activity against the Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans, and the data showed that compound 2 had significant antimicrobial effects (MIC 3.9 to 7.8 µg/mL).

SlERF.H6 mediates the orchestration of ethylene and gibberellin signaling that suppresses bitter-SGA biosynthesis in tomato.

Steroidal glycoalkaloids (SGAs) constitute a characteristic class of antinutritional metabolites that are found in certain Solanum species. Despite the considerable studies on SGA biosynthesis, the mechanisms of crosstalk between hormone signaling pathways that regulate SGA content still remain to be elucidated. Here, we performed a metabolic genome-wide association study (mGWAS) based on the levels of SGA metabolites and identified SlERF.H6 as a negative regulator of bitter-SGA biosynthesis. SlERF.H6 repressed the expression of SGA biosynthetic glycoalkaloid metabolism (GAME) genes and caused a subsequent decrease in the abundance of bitter SGAs. Furthermore, SlERF.H6 were shown to act downstream of GAME9, a regulator of SGA biosynthesis in tomato. We also uncovered the interplay between ethylene and gibberellin (GA) signaling in regulating SGA biosynthesis. SlERF.H6, acting as a downstream component in ethylene signaling, modulated GA content by inhibiting SlGA2ox12 expression. Increasing levels of endogenous GA12 and GA53 in SlERF.H6-OE could inhibit of GA on SGA biosynthesis. Additionally, 1-aminocyclopropane-1-carboxylic acid (ACC) treatment decreased the stability of SlERF.H6, weakening its inhibition on GAME genes and SlGA2ox12, and caused bitter-SGA accumulation. Our findings reveal a key role of SlERF.H6 in the regulation of SGA biosynthesis through the coordinated ethylene-gibberellin signaling.

Allelochemical Interactions in the Trophic System «Henosepilachna vigintioctomaculata Motschulsky-Solanum tuberosum Linneus¼.

Henosepilachna vigintioctomaculata is an intrinsic element in the agroecosystem of potato fields. The issues of relationships in the system "potato ladybird beetle-potato plant" have not yet been studied. To study the effect of potato varieties on the potato ladybird beetle, only hatched and active larvae with a hatching rate close to 100% were selected from a laboratory colony. Larvae of the first summer generation collected in potato fields were used in our study to determine the level of adrenaline in the bodies of insects, fresh potato leaves were used to study the content of glycoalkaloids, the content and activity of proteinase inhibitors. The larvae that fed on plants of varieties Belmonda, Queen Anne, Lilly, Dachny, Kazachok, Yubilyar, and Avgustin demonstrated the highest level of stress while the stress level in those that fed on variety Smak was the lowest. The damage inflicted by potato ladybird beetles on leaves of some studied potato varieties led to a progressive increase in the content of glycoalkaloids already within 24 h after the phytophages had been transferred. In most cases, the content of glycoalkoloids increased by 20% within five days. Potato ladybird beetles feeding on plants of different potato varieties caused a progressive increase in proteinase inhibitors (% of the control). Plants of variety Smak did not show a significant increase in the content of alkaloids in the herbage in response to the damage. A correlation was established between the mortality rate, the activity of proteinase inhibitors, the dynamics of glycoalkaloids, and the level of adrenaline, which could be formulated as follows: the higher the content of glycoalkaloids and the activity of proteinase inhibitors in the tissues of potato plants, the higher the level of stress in the potato ladybird beetles that feed on them.

Isomers of the Tomato Glycoalkaloids α-Tomatine and Dehydrotomatine: Relationship to Health Benefits.

High-performance liquid chromatography (HPLC) analysis of three commercial tomatine samples and another isolated from green tomatoes revealed the presence of two small peaks in addition to those associated with the glycoalkaloids dehydrotomatine and α-tomatine. The present study investigated the possible structures of the compounds associated with the two small peaks using HPLC-mass spectrophotometric (MS) methods. Although the two peaks elute much earlier on chromatographic columns than the elution times of the known tomato glycoalkaloids dehydrotomatine and α-tomatine, isolation of the two compounds by preparative chromatography and subsequent analysis by MS shows the two compounds have identical molecular weights, tetrasaccharide side chains, and MS and MS/MS fragmentation patterns to dehydrotomatine and α-tomatine. We suggest the two isolated compounds are isomeric forms of dehydrotomatine and α-tomatine. The analytical data indicate that widely used commercial tomatine preparations and those extracted from green tomatoes and tomato leaves consist of a mixture of α-tomatine, dehydrotomatine, an α-tomatine isomer, and a dehydrotomatine isomer in an approximate ratio of 81:15:4:1, respectively. The significance of the reported health benefits of tomatine and tomatidine is mentioned.

Steroidal glycoalkaloids contribute to anthracnose resistance in Solanum lycopersicum.

Anthracnose is a widespread plant disease caused by various species of the fungal pathogen Colletotrichum. In solanaceous plants such as tomato (Solanum lycopersicum), Colletotrichum infections exhibit a quiescent, asymptomatic state in developing fruit, followed by a transition to necrotrophic infections in ripe fruit. Through analysis of fruit tissue extracts of 95L368, a tomato breeding line that yields fruit with enhanced anthracnose resistance, we identified a role for steroidal glycoalkaloids (SGAs) in anthracnose resistance. The SGA α-tomatine and several of its derivatives accumulated at higher levels, in comparison with fruit of the susceptible tomato cultivar US28, and 95L368 fruit extracts displayed fungistatic activity against Colletotrichum. Correspondingly, ripe and unripe 95L368 fruit displayed enhanced expression of glycoalkaloid metabolic enzyme (GAME) genes, which encode key enzymes in SGA biosynthesis. Metabolomics analysis incorporating recombinant inbred lines generated from 95L368 and US28 yielded strong positive correlations between anthracnose resistance and accumulation of α-tomatine and several derivatives. Lastly, transient silencing of expression of the GAME genes GAME31 and GAME5 in anthracnose-susceptible tomato fruit yielded enhancements to anthracnose resistance. Together, our data support a role for SGAs in anthracnose defense in tomato, with a distinct SGA metabolomic profile conferring resistance to virulent Colletotrichum infections in ripe fruit.

Omics Profiles of Non-GM Tubers from Transgrafted Potato with a GM Scion.

"Transgrafting" is a grafting procedure whereby a transgenic plant body is grafted to a non-transgenic plant body. It is a novel plant breeding technology that allows non-transgenic plants to obtain benefits usually conferred to transgenic plants. Many plants regulate flowering by perceiving the day-length cycle via expression of FLOWERING LOCUS T (FT) in the leaves. The resulting FT protein is translocated to the shoot apical meristem via the phloem. In potato plants, FT is involved in the promotion of tuber formation. Here we investigated the effects of a genetically modified (GM) scion on the edible parts of the non-GM rootstock by using potato plants transformed with StSP6A, a novel potato homolog of the FT gene. Scions prepared from GM or control (wild-type) potato plants were grafted to non-GM potato rootstocks; these were designated as TN and NN plants, respectively. After tuber harvest, we observed no significant differences in potato yield between TN and NN plants. Transcriptomic analysis revealed that only one gene-with unknown function-was differentially expressed between TN and NN plants. Subsequent proteomic analysis indicated that several members of protease inhibitor families, known as anti-nutritional factors in potato, were slightly more abundant in TN plants. Metabolomic analysis revealed a slight increase in metabolite abundance in NN plants, but we observed no difference in the accumulation of steroid glycoalkaloids, toxic metabolites found in potato. Finally, we found that TN and NN plants did not differ in nutrient composition. Taken together, these results indicate that FT expression in scions had a limited effect on the metabolism of non-transgenic potato tubers.