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PubMed1991

Potential Role of Pyrophosphate:Fructose 6-Phosphate Phosphotransferase in Carbohydrate Metabolism of Cold Stored Tubers of Solanum tuberosum cv Bintje.

To gain a better understanding of the mechanism of cold induced sweetening, sugar accumulation in potato, Solanum tuberosum cv Bintje, was compared to the maximum activity of inorganic pyrophosphate (PPi):fructose 6-phosphate 1-phosphotransferase (EC 2.7.1.90) and the concentration of two regulatory metabolites. Mature tubers accumulated reducing sugars and sucrose at an almost linear rate of 13.4 and 5.2 micromole per day per gram dry weight at 2 degrees C and 4.5 and 1.3 micromole per day per gram dry weight, respectively, at 4 degrees C. During storage at 8 degrees C sugar accumulation was nil. Sugar accumulation was preceded by a lag phase of about 4 days. The accumulation of reducing sugars persisted for at least 4 weeks, whereas sucrose accumulation declined after 2 weeks of storage. The ratio of glucose:fructose changed concomitantly with sugar increase from 65:35 to equimolarity. The maximum activity of PPi:fructose 6-phosphate 1-phosphotransferase was 2.51 and 2.25 units per gram dry weight during storage at 2 and 8 degrees C, respectively. The temperature coefficient of this enzyme from potatoes kept at 2 or 8 degrees C was 2.12 and 2.48, respectively. The endogenous concentration of fructose 2,6-biphosphate increased from 0.15 to 1 nanomole per gram dry weight during storage at 2 and 4 degrees C but remained the same throughout storage at 8 degrees C. After exposure to 2 degrees C an initial increase in the concentration of PPi was observed from 4.0 to 5.6 nanomoles per gram dry weight. Pyrophosphate concentration did not change during storage at 4 degrees C but decreased slightly at 8 degrees C. All observed changes became annulled after transfer of cold stored tubers to 18 degrees C. These data strongly indicate that PPi:fructose 6-phosphate 1-phosphotransferase can be fully operational in cold stored potato tubers and the lack of increase in PPi concentration supports the functioning of this enzyme during sugar accumulation.

Journal Article↗
PubMed1992

Potato Tuber UDP-Glucose:Protein Transglucosylase Catalyzes Its Own Glucosylation.

Potato (Solanum tuberosum L.) tuber UDP-glucose:protein transglucosylase (UPTG) (EC 2.4.1.112) is involved in the first of a two-step mechanism proposed for protein-bound alpha-glucan synthesis by catalyzing the covalent attachment of a single glucose residue to an acceptor protein. The resulting glucosylated 38-kilodalton polypeptide would then serve as a primer for enzymic glucan chain elongation during the second step. In the present report, we describe the fast protein liquid chromatography purification of UPTG from a membrane pellet of potato tuber. An apparently close association of UPTG, phosphorylase, and starch synthase was observed under native conditions during different purification steps. Enrichment of a 38-kilodalton polypeptide was found throughout enzyme purification. It is now shown that the purified UPTG, with an apparent molecular mass of 38 kilodaltons, undergoes self-glucosylation in a UDP-glucose- and Mn(2+)-dependent reaction. Therefore, it is concluded that UPTG is the enzyme and at the same time the priming protein required for the biogenesis of protein-bound alpha-glucan in potato tuber.

Journal Article↗
PubMed2004

Kinetics of labelling of organic and amino acids in potato tubers by gas chromatography-mass spectrometry following incubation in (13)C labelled isotopes.

Metabolic pathways of primary metabolism of discs isolated from potato tubers were evaluated by the use of a gas chromatography-mass spectrometry (GC-MS) method generated specifically for this purpose. After testing several possible methods including chemical ionization, it was decided for reasons of sensitivity, reproducibility and speed to use electron impact ionization-based GC-MS analysis. The specific labelling and label accumulation of over 30 metabolites including a broad number of sugars, organic and amino acids was analysed following the incubation of tuber discs in [U-(13)C]glucose. The reproducibility of this method was similar to that found for other GC-MS-based analyses and comparison of flux estimates from this method with those obtained from parallel, yet less comprehensive, radiolabel experiments revealed close agreement. Therefore, the novel method allows quantitatively evaluation of a broad range of metabolic pathways without the need for laborious (and potentially inaccurate), chemical fractionation procedures commonly used in the estimation of fluxes following incubation in radiolabelled substrates. As a first experiment the GC-MS method has been applied to compare the metabolism of wild type and well-characterized transgenic potato tubers exhibiting an enhanced sucrose mobilization. The fact that this method is able to rapidly yield further comprehensive information into primary metabolism illustrates its power as a further phenotyping tool for the analysis of plant metabolism.

Amino Acids↗
PubMed1990

Intraorganelle localization and substrate specificities of the mitochondrial acyl-CoA: sn-glycerol-3-phosphate O-acyltransferase and acyl-CoA: 1-acyl-sn-glycerol-3-phosphate O-acyltransferase from potato tubers and pea leaves.

The mitochondrial sn-glycerol-3-phosphate and 1-acyl-sn-glycerol-3-phosphate O-acyltransferases from potato tubers and pea leaves were investigated with respect to their intraorganelle localization, their positional and substrate specificities, and their fatty acid selectivities. In mitochondria from potato tubers both enzymes were found to be located in the outer membrane. The 1-acyl-sn-glycerol-3-phosphate O-acyltransferase of pea mitochondria showed the same intraorganelle localization whereas the sn-glycerol-3-phosphate O-acyltransferase behaved like a soluble protein of the intermembrane space. The sn-glycerol-3-phosphate O-acyltransferase of both potato and pea mitochondria used sn-glycerol-3-phosphate but not dihydroxyacetone phosphate as acyl acceptor and exclusively catalyzed the formation of 1-acyl-sn-glycerol-3-phosphate which subsequently served as substrate for the second acylation reaction at its C-2 position. Both acyltransferases of potato as well as pea mitochondria showed higher activities with acyl-CoA than with the corresponding acyl-(acyl carrier protein) thioesters. When different acyl-CoA thioesters were offered separately, the sn-glycerol-3-phosphate O-acyltransferase of potato mitochondria displayed no fatty acid specificity whereas the enzyme of pea mitochondria revealed one for saturated acyl groups. On the other hand, the mitochondrial 1-acyl-sn-glycerol-3-phosphate O-acyltransferases from both potato tubers and pea leaves were more active on unsaturated than on saturated acyl-CoA thioesters. Furthermore, these enzymes preferentially used oleoyl- and linoleoyl-CoA when they were offered in a mixture with saturated ones, although the fatty acid selectivity of the pea enzyme was less pronounced than that of the potato enzyme. The sn-glycerol-3-phosphate O-acyltransferase of potato mitochondria displayed a slight preference for saturated acyl groups.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗
PubMed1997

Typing Tuber ectomycorrhizae by polymerase chain amplification of the internal transcribed spacer of rDNA and the sequence characterized amplified region markers.

Identification of some economically important Tuber species using classical morphological characteristics is sometimes difficult. We report here the molecular characterization of a species coming from China, Tuber indicum, mistaken with Tuber melanosporum species. Using restriction analysis of the amplified internal transcribed spacer (ITS) of rDNA, ITS sequence analysis, and sequence characterized amplified region markers, with DNA from fruit bodies or mycorrhizae, genetic variation was found between these two species, allowing to differentiate and characterize them.

Ascomycota↗
PubMed2005

Effects of saponin monomer 13 of dwarf lilyturf tuber on L-type calcium currents in adult rat ventricular myocytes.

The saponin monomer 13 of dwarf lilyturf tuber (DT-13), one of the saponin monomers of dwarf lilyturf tuber, has been found to have potent cardioprotective effects. In order to investigate the effect of DT-13 on L-type calcium currents (I(Ca,L)), exploring the mechanisms of DT-13's cardioprotective effects, we directly measured the I(Ca,L) in the adult rat cardiac myocytes exposed to DT-13 using standard whole-cell patch-clamp recording technique. Our results showed that DT-13 exerted inhibitory effects on the I(Ca,L) of the single adult rat cardiac myocytes. The current density was reduced by about 38% after exposure of the cells to DT-13 (0.1 microM) for 10 minutes, from the control value of 7.46 +/- 1.31 pA/pF to 4.25 +/- 0.35 pA/pF (n = 6, p < 0.05). This I(Ca,L)-inhibiting action of DT-13 was concentration-dependent. DT-13 up-shifted the current-voltage (I-V) curve, but did not significantly affect the half activation potential (V0.5). V0.5 was from -11.8 +/- 0.9 mV in the control to -12.6 +/- 1.9 mV in the presence of DT-13 at 0.1 micromol/L. DT-13 at 0.1 microM did not markedly affect the activation of I(Ca,L), but shifted the inactivation curve of I(Ca,L) to the left. In combination with previous reports, these results suggest that there might be a close relationship between the cardioprotective effects of dwarf lilyturf tuber and the inhibitory effects of DT-13 on L-type calcium currents.

Animals↗
PubMed1990

Long-term reno-cardiovascular effects of orally administered aconiti tuber in humans.

The reno-cardiovascular effects of Aconiti Tuber were studied. In a controlled, double-blind, and randomized clinical trial, it was found that in 9 months, Aconiti Tuber, after preparation (120 degrees C, 40 min), (1) had no apparent adverse effects, (2) showed positive inotropic, positive chronotropic, and vasodilator effects, (3) increased renal blood flow, and glomerular filtration rate, Na+/Cl-/K+ excretions. The renal function test results could be interpreted as secondary to hemodynamic changes. We conclude that specially prepared Aconiti Tuber may be a promising cardiotonic agent.

Adult↗
PubMed1996

'Normolipidemic' tendinous and tuberous xanthomatosis.

BACKGROUND: Multiple tendinous and tuberous xanthomas are characteristically associated with hyperlipidemic states. However, normolipidemic tendinous and tuberous xanthomas have been reported in the literature, with normal levels of cholesterol, cholestanol and plant sterols. OBJECTIVE AND METHOD: To delineate the disorder and to suggest its likely origin, a case of apparently normolipidemic severe tuberous and tendinous xanthomatosis was studied. Several lipoprotein and lipid analyses, clinical tests and histological studies were performed over a period of 5 years in the propositus and his family. RESULTS: At the first lipid analysis, no quantitative or qualitative alterations of the lipoprotein fractions or of the apoproteins AI, B, CII, CIII, E were detected in the propositus and xanthomatosis was classified as normolipidemic. During the follow-up, the patient showed a nonconstant hypertriglyceridemia and/or hypercholesterolemia associated with the presence of small and dense VLDL and LDL. An increase in apo-B was observed. There was an unusual quantity of conjugated dienes of arachidonic acid in the plasma and in the LDLs of the patient, present only in small traces in the control population. The family study and the long follow-up of the lipid analysis of the propositus were compatible with the diagnosis of familial combined hyperlipidemia. CONCLUSION: Our data highlight the importance of a critical review of studies regarding normolipidemic xanthomatosis, since only after an extensive follow-up and sequential analyses of lipoprotein fractions is it possible to exclude the presence of time variables and complex lipoprotein abnormalities.

Achilles Tendon↗
PubMed1983

Comparable surges of luteinizing hormone induced by preoptic or medial basal tuberal electrical stimulation in spontaneously persistent estrous or cyclic proestrous rats.

A previous report demonstrated in cyclic proestrous rats electrically stimulated in the medial preoptic area (MPOA) or the arcuate nucleus-median eminence (ARC/ME) region a close parallel in the progressive increase of serum LH with increasing stimulation time. The present report compares the LH surges induced in middle aged spontaneously persistent estrous (SPE) rats by electrical stimulation of the two regions. Electrical parameters were those previously used. In Series I, MPOA stimulation of SPE rats for 60 min or ARC/ME stimulation for 45 min produced serum LH concentrations 60 and 90 min after stimulation began that were essentially identical to those in proestrous rats similarly treated. In Series II, stimulations were prolonged to 120 min to determine whether LH would continue to rise with the longer stimulation. These rats were all chosen from one shipment and all were born on the same day. Sequential blood samples were taken before stimulation and 60, 90, 120, and 150 min after stimulation began. SPE rats were stimulated in either the MPOA or the ARC/ME and, for comparison, a few proestrous rats that had remained cyclic were stimulated in the MPOA. LH concentrations in these cyclic rats rose more abruptly than in the previous study to amounts significantly higher at both 60 and 90 min, but by 120 min the respective means were not significantly different. In the SPE rats, the 60-min LH levels resembled those in Series I. They continued to rise during the second hour, but only to average levels approximately half those attained in proestrous rats stimulated for 120 min. The comparative increments in MPOA-stimulated and ARC/ME-stimulated rats were similar, although all means in the latter were somewhat higher. The results agree with previous indications that stimulation of either the MPOA or the ARC/ME activates the rostral or caudal portions of a unitary preoptic-tuberal system. Although the tendency of SPE rats to release smaller amounts of LH may result from age-related lowered pituitary responsiveness to LHRH, only future study can determine whether a given degree of preoptic-tuberal stimulation releases equivalent amounts of LHRH in SPE and proestrous rats. Nevertheless, the absence of spontaneous LH surges in SPE points to a primary deficiency in control mechanisms impinging on the preoptic-tuberal system or in its responsiveness thereto.

Animals↗
PubMed1994

Anti-inflammatory activities of methanolic extract and alkaloidal components from Corydalis tuber.

A methanolic extract (CM-ext) from Corydalis tuber (Corydalis turtschaninovii Besser forma yanhusuo Y. H. Chou et C. C. Hsu) has been screened for activity in experimental models of inflammation. CM-ext (200 or 500 mg/kg, p.o.) inhibited an increase in vascular permeability in mice induced by acetic acid, and reduced acute paw edema in rats induced by compound 48/80 or carrageenin. CM-ext suppressed the development of adjuvant-induced edema in arthritic rats. CM-ext and its alkaloidal components, dehydrocorydaline, d-glaucine and l-tetrahydrocoptisine inhibited compound 48/80-induced histamine release from peritoneal mast cells of rats. Since these substances from C. tuber were found to be effective in both the acute and chronic phases of inflammation, the crude drug C. tuber can be considered to exert anti-inflammatory activity.

Alkaloids↗
PubMed1997

Inhibitory effects of dehydrocorydaline isolated from Corydalis Tuber against type I-IV allergic models.

An alkaloidal component, dehydrocorydaline (DHC) isolated from Corydalis Tuber (tuber of Corydalis turtschaninovii forma yanhusuo), has been screened for activity against types I-IV allergic reactions. In a type I allergic models, DHC at a dose of 0.5 mmol/kg, p.o. inhibited 48 h homologous passive cutaneous anaphylaxis (PCA) in rats, which is related to IgE. DHC also exhibited an inhibitory effect on antigen-induced histamine release from peritoneal mast cells. In a type II allergic model, DHC did not inhibit reversed cutaneous anaphylaxis (RCA) in rats. In a type III allergic model, DHC showed weak inhibition on direct passive arthus reaction (DPAR) in rats. Furthermore, in a type IV allergic model, DHC had inhibitory effects on the induction phase and effector phase in picryl chloride-induced contact dermatitis (PC-CD). These results indicated that DHC not only inhibits antibody-mediated allergic reactions but also influences cell-mediated allergia reactions, and the inhibitory effect of Corydalis Tuber on allergic reactions may be partially attributed to DHC.

Alkaloids↗
PubMed2000

Metabolic activity decreases as an adaptive response to low internal oxygen in growing potato tubers.

Plants lack specialised organs and circulatory systems, and oxygen can fall to low concentrations in metabolically active, dense or bulky tissues. In animals that tolerate hypoxia or anoxia, low oxygen triggers an adaptive inhibition of respiration and metabolic activity. Growing potato tubers were used to investigate whether an analogous response exists in plants. Oxygen concentrations fall below 5% in the centre of growing potato tubers. This is accompanied by a decrease of the adenylate energy status, and alterations of metabolites that are indicative of a decreased rate of glycolysis. The response to low oxygen was investigated in more detail by incubating tissue discs from growing tubers for 2 hours at a range of oxygen concentrations. When oxygen was decreased in the range between 21% and 4% there was a partial inhibition of sucrose breakdown, glycolysis and respiration. The energy status of the adenine, guanine and uridine nucleotides decreased, but pyrophosphate levels remained high. The inhibition of sucrose breakdown and glycolysis was accompanied by a small increase of sucrose, fructose, glycerate-3-phosphate, phosphenolpyruvate, and pyruvate, a decrease of the acetyl-coenzymeA:coenzymeA ratio, and a small increase of isocitrate and 2-oxoglutarate. These results indicate that carbon fluxes are inhibited at several sites, but the primary site of action of low oxygen is probably in mitochondrial electron transport. Decreasing the oxygen concentration from 21% to 4% also resulted in a partial inhibition of sucrose uptake, a strong inhibition of amino acid synthesis, a decrease of the levels of cofactors including the adenine, guanine and uridine nucleotides and coenzymeA, and attenuated the wounding-induced increase of respiration and invertase and phenylalanine lyase activity in tissue discs. Starch synthesis was maintained at high rates in low oxygen. Anoxia led to a diametrically opposed response, in which glycolysis rose 2-fold to support fermentation, starch synthesis was strongly inhibited, and the level of lactate and the lactate:pyruvate ratio and the triose-phosphate:glycerate-3-phosphate ratio increased dramatically. It is concluded that low oxygen triggers (i) a partial inhibition of respiration leading to a decrease of the cellular energy status and (ii) a parallel inhibition of a wide range of energy-consuming metabolic processes. These results have general implications for understanding the regulation of glycolysis, starch synthesis and other biosynthetic pathways in plants, and reveal a potential role for pyrophosphate in conserving energy and decreasing oxygen consumption.

Adenine Nucleotides↗
PubMedDate not supplied

Beta-1,3-glucooligosaccharide induced activation of four enzymes responsible for N-p-coumaroyloctopamine biosynthesis in potato (Solanum tuberosum cv.) tuber tissue.

Potato tuber disks, when treated with laminarin, a beta-1,3-glucooligosaccharide from Laminaria digitata, accumulate a hydroxycinnamoyl amide compound, N-p-coumaroyloctopamine (p-CO). The biosynthesis of p-CO was investigated by feeding experiments, in order to show that the precursors of N-p-coumaroyl and octopamine moieties of p-CO are L-phenylalanine and L-tyrosine, respectively. The treatment of potato tuber tissue with laminarin resulted in elevated activities of four enzymes which are putatively involved in p-CO biosynthesis: phenylalanine ammonia lyase (PAL; EC 4.3.1.5), 4-hydroxycinnamic acid:CoA ligase (4CL; EC 6.2.1.12), hydroxycinnamoyl-CoA:tyramine N-(hydroxycinnamoyl)transferase (THT; EC 2.3.1.110) and tyrosine decarboxylase (TyrDC; EC 4.1.1.25). Among these, the response of TyrDC was specific to laminarin treatment, thus indicating that the regulation of TyrDC activity is critical for the accumulation of p-CO in potato tuber tissue.

Acyltransferases↗
PubMed2001

Response of potato tuber yield to stem injury by European corn borer (Lepidoptera: Crambidae) in the Mid-Atlantic United States.

The response of potato, Solanum tuberosum L., tuber yield to stem injury by European corn borer, Ostrinia nubilalis (Hübner), larvae was investigated in the Mid-Atlantic region of the United States for 3 yr. This response was described for 'Superior', 'Atlantic', and 'Snowden' potato, which are early-season, midseason, and late-season maturing cultivars, respectively. To model the yield/injury relationship, a range of corn borer injury levels was established in the field by augmenting the natural infestation with varying densities of laboratory-reared larvae. Linear and nonlinear regression analyses (plateau and second-order polynomial models) were used to describe the relationship between yield of U.S. No. 1 grade tubers and the percentage of stems injured by corn borer larvae. The maturity of the cultivar did not affect the response of potato yield to stem injury. In nine of 14 experiments, potato tolerated high levels of corn borer injury (55-90% of stems injured) without yield loss, suggesting that control of corn borer may not be necessary. Yet, in one of five Superior tests, in two of four Atlantic tests and in two of five Snowden tests, corn borer injury significantly reduced yield. Of the five data sets in which corn borer injury reduced yield, the plateau model fit two data sets and the quadratic model fit one data set. In two of the three cases, these models accounted for nearly identical amounts of total variation in yield as that accounted for by the linear model. The linear model fit four of the five data sets, but the R2 values were low for three of the four tests (0.10, 0.18, and 0.31). The parameter or parameters that interact with corn borer injury to cause tuber yield reduction should be identified before economic injury levels and thresholds are developed.

Animals↗
PubMedDate not supplied

Tuberous xanthomas associated with olanzapine therapy and hypertriglyceridemia in the setting of a rare apolipoprotein E mutation.

OBJECTIVE: To describe a patient with tuberous xanthomas and high levels of cholesterol and triglycerides, who was found to have type III hyperlipoproteinemia (HLP) and a rare apolipoprotein E (apoE) mutation. METHODS: We present a case report with extensive clinical, laboratory, and genetic documentation. RESULTS: A 33-year-old African American man presented for evaluation of hypertriglyceridemia. His medical history was remarkable for schizophrenia necessitating ongoing olanzapine therapy for the past 6 years. A few months after olanzapine treatment was begun, he noted the development of nontender, firm, papular skin lesions on his elbows and knees. His family history was negative for lipid disorders or premature vascular disease. Physical examination revealed the presence of prominent tuberous xanthomas on both elbows and knees. Results of a lipid panel demonstrated a total cholesterol level of 374 mg/dL (9.7 mmol/L) and triglycerides of 828 mg/dL (9.3 mmol/L). A work-up for causes of secondary hyper-triglyceridemia was negative. Results of apoE genotyping by a commercial laboratory showed the E3/E3 genotype, based on gene sequencing at codons 112 and 158. Because the skin lesions were typical for type III HLP, his entire apoE gene was sequenced. This analysis revealed an apoE2/E2 (arginine 145 to cysteine) mutation, previously reported to be a rare cause of type III HLP in 5 patients of African descent. Triglyceride-lowering therapy with gem-fibrozil was initiated, in addition to lifestyle modification. At follow-up several months later, total cholesterol was 276 mg/dL (7.14 mmol/L) and triglycerides were 479 mg/dL (5.41 mmol/L). CONCLUSION: We speculate that olanzapine therapy, with its known metabolic side effects, exacerbated this patient's underlying lipoprotein metabolic abnormality. To our knowledge, this is the first report of an association between olanzapine therapy and tuberous xanthomas and the sixth report of this rare apoE2/E2 (arginine 145 to cysteine) mutation in the literature.

Adult↗
PubMed2000

[Content of nitrates and glycoalcaloids in mature tubers of Polish potato].

Nitrates and glycoalcaloids (TGA) content in mature tubers of 29 potato table cultivars of different earliness were examined during 1992-1998. Excess of nitrates (more than 250 mg NaNO3/kg of product--the upper limit for food safety in Poland) was found in 24 tuber samples what makes 16% of total number (154) tested samples. Samples with the highest amounts of nitrates belonged mainly to very early and early cultivars. TGA concentrations lower than the upper limit TGA for food safety (200 mg/kg of product) were estimated in all 129 tested tuber samples. Only in 8 samples TGA content was between 100 and 140 mg/kg of product what could cause bitter taste.

Humans↗
PubMedDate not supplied

[Effect of growth regulators on proton transport through cytoplasmic membrane of potato tuber cells].

Effects of the growth regulators epibrassinolide-694 (EB), gibberellic acid (GA), and abscisic acid (ABA) on the ATP-dependent translocation of H+ through the membranes of plasma membrane vesicles of potato (Solanum tuberosum L.) tuber cells were studied. The ATP-dependent accumulation of H+ in the plasma membrane vesicles from dormant tubers was inhibited by EB and ABA and stimulated by GA. After the break of dormancy, the stimulatory effect of GA increased, the inhibitory effect of ABA decreased, and EB stimulated the accumulation of H+ in the vesicles. The data suggest that the plasma membrane H+ ATPase is a target of phytohormones that regulate the dormancy of potato tubers.

Abscisic Acid↗
PubMed2001

High-resolution metabolic phenotyping of genetically and environmentally diverse potato tuber systems. Identification of phenocopies.

We conducted a comprehensive metabolic phenotyping of potato (Solanum tuberosum L. cv Desiree) tuber tissue that had been modified either by transgenesis or exposure to different environmental conditions using a recently developed gas chromatography-mass spectrometry profiling protocol. Applying this technique, we were able to identify and quantify the major constituent metabolites of the potato tuber within a single chromatographic run. The plant systems that we selected to profile were tuber discs incubated in varying concentrations of fructose, sucrose, and mannitol and transgenic plants impaired in their starch biosynthesis. The resultant profiles were then compared, first at the level of individual metabolites and then using the statistical tools hierarchical cluster analysis and principal component analysis. These tools allowed us to assign clusters to the individual plant systems and to determine relative distances between these clusters; furthermore, analyzing the loadings of these analyses enabled identification of the most important metabolites in the definition of these clusters. The metabolic profiles of the sugar-fed discs were dramatically different from the wild-type steady-state values. When these profiles were compared with one another and also with those we assessed in previous studies, however, we were able to evaluate potential phenocopies. These comparisons highlight the importance of such an approach in the functional and qualitative assessment of diverse systems to gain insights into important mediators of metabolism.

Amino Acids↗