Primary Product Of Photosynthesis Research Articles

Role of miRNAs in sucrose stress response, reactive oxygen species, and anthocyanin biosynthesis in Arabidopsis thaliana.

In plants, sucrose is the main transported disaccharide that is the primary product of photosynthesis and controls a multitude of aspects of the plant life cycle including structure, growth, development, and stress response. Sucrose is a signaling molecule facilitating various stress adaptations by crosstalk with other hormones, but the molecular mechanisms are not well understood. Accumulation of high sucrose concentrations is a hallmark of many abiotic and biotic stresses, resulting in the accumulation of reactive oxygen species and secondary metabolite anthocyanins that have antioxidant properties. Previous studies have shown that several MYeloBlastosis family/MYB transcription factors are positive and negative regulators of sucrose-induced anthocyanin accumulation and subject to microRNA (miRNA)-mediated post-transcriptional silencing, consistent with the notion that miRNAs may be "nodes" in crosstalk signaling by virtue of their sequence-guided targeting of different homologous family members. In this study, we endeavored to uncover by deep sequencing small RNA and mRNA transcriptomes the effects of exogenous high sucrose stress on miRNA abundances and their validated target transcripts in Arabidopsis. We focused on genotype-by-treatment effects of high sucrose stress in Production of Anthocyanin Pigment 1-Dominant/pap1-D, an activation-tagged dominant allele of MYB75 transcription factor, a positive effector of secondary metabolite anthocyanin pathway. In the process, we discovered links to reactive oxygen species signaling through miR158/161/173-targeted Pentatrico Peptide Repeat genes and two novel non-canonical targets of high sucrose-induced miR408 and miR398b*(star), relevant to carbon metabolic fluxes: Flavonoid 3'-Hydroxlase (F3'H), an important enzyme in determining the B-ring hydroxylation pattern of flavonoids, and ORANGE a post-translational regulator of Phytoene Synthase expression, respectively. Taken together, our results contribute to understanding the molecular mechanisms of carbon flux shifts from primary to secondary metabolites in response to high sugar stress.

VvSnRK1-VvSS3 regulates sugar accumulation during grape berry ripening in response to abscisic acid

Sugar is the primary product of photosynthesis and is mainly transported in plants as sucrose. Sucrose synthase 3 (VvSS3) and SNF1-related protein kinase 1 (VvSnRK1) are both critical enzymes in the metabolism of sugar in plants but are not clear about the relationship between VvSS3 and VvSnRK1 in the regulation of sugar metabolism. In this study, the spatiotemporal expression of VvSS3 and VvSnRK1 was measured during three stages of grape berry development from hard nucleolus phase to maturation phase. Our results indicated that VvSS3 and VvSnRK1 isoforms overexpressed at the beginning veraison and sugar accumulation occurred at ripening stage. We also provided transgenic calli of overexpressed VvSS3 using Agrobacterium GV3101-mediated transformation and found VvSS3 is localized in cell membrane. Furthermore, up-regulation of VvSnRK1s occurred with overexpression of VvSS3 but abscisic acid (ABA) exogenous down-regulated VvSnRK1s expression. VvSS3-overexpressed transgenic calli also increased the accumulation of soluble sugar and anthocyanin content by increasing the expression of genes related to anthocyanin and ABA synthesis. Furthermore, the interaction of VvSS3 with VvSnRK1β was confirmed by yeast two-hybrid (Y2H) and Bimolecular fluorescence complementation (BiFC). These results suggest that the VvSS3 gene has an important role in sugar accumulation during fruit ripening in grapevines.

Sugars and Organic Acids in 25 Strawberry Cultivars: Qualitative and Quantitative Evaluation.

(1) The nutritional quality of strawberry (Fragaria × ananassa Duch) fruits, among others, is largely maintained by the presence of soluble sugars and organic acids. As the primary products of photosynthesis, they are energy depots in plants, necessary for the construction of cell constituents, but also serve as precursors of aromatic compounds and signaling molecules. (2) In this study, fruits of 25 strawberry cultivars were qualitatively and quantitatively characterized concerning individual sugars and organic acids by HPLC, FT-ICR-MS, and MS imaging analysis. In addition, the total quality index (TQI), as a novel mathematical model, was used to compare all individual parameters evaluated to obtain a quantitative single score, as an indicator of overall fruit quality. (3) Regardless of a large number of cultivars and monitored parameters that were studded, several cultivars stood out in terms of selected primary metabolites, such as 'Rumba', 'Jeny', and 'Sandra', while the latter had the best TQI score. (4) Intercultivar variations in sugars and organic acids profiles, along with other bioactive compounds, should be considered for selection of promising cultivars with improved naturally occurring nutraceutical traits. Besides the search for a pleasant taste, increased awareness of healthy nutrition resulted in heightening consumer demand for high-quality fruit.

Effect of UV-B radiation on chlorophyll fluorescence, photosynthetic activity and relative chlorophyll content of five different corn hybrids

This research presents an experimental study of the effect of UV-B radiation (7.5 Wm−2) on the change of the total concentration of chlorophyll ΔChl and energy that a plant can store during the process of photosynthesis. The aim was to investigate the effect of UV-B radiation to spectral lines of five genetically different corn hybrids and find the lines with better resistance. Chlorophyll fluorescence from plant leaves was used as experimental method. The plants were exposed to UV-B radiation for 19 days. The following results were obtained: a) there is a significant variation between different corn hybrids regarding the effect of UV-B radiation, b) an indicative element of change in the functioning of the photosynthetic apparatus is represented in variations in the relative composition of photosynthetic pigments, c) regardless of what may be the cause of the change of the plant's ability to deposit a part of absorbed energy in the primary products of photosynthesis, it has been shown that two out of five investigated corn hybrids show great resistance to UV-B radiation, and d) relative change of photosynthesis can be used as a measure of the plant's resistance to the harmful effect of UV-B radiation.

Sorbitol immersion accelerates the deposition of suberin polyphenolic and lignin at wounds of potato tubers by activating phenylpropanoid metabolism

Sorbitol is the primary product of photosynthesis and sugar metabolism in plants. However, the mechanism by which sorbitol treatment affects potato tuber wound healing remains unclear. This study showed that sorbitol treatment reduced weight loss and disease index (inoculated with Fusarium sulphureum) of tubers during healing. Sorbitol also facilitated the accumulation of suberin polyphenolic (SPP) and lignin at the wounded sites. Sorbitol treatment activated the activities of phenylalanine ammonia-lyase (PAL), 4-coumaryl-CoA ligase (4CL), cinnamic acid-4-hydroxylase (C4H), and cinnamyl alcohol dehydrogenase (CAD), and increased the levels of individual phenolic acids and lignin monomers. In addition, sorbitol treatment increased the H2O2 level and peroxidase (POD) activity. It was suggested that sorbitol treatment could activate phenylpropanoid metabolism, and promote SPP and lignin deposition at the wound sites of potato tubers.

Transcription Factor CitERF16 Is Involved in Citrus Fruit Sucrose Accumulation by Activating CitSWEET11d.

Sugars are the primary products of photosynthesis and play an important role in plant growth and development. They contribute to sweetness and flavor of fleshy fruits and are pivotal to fruit quality, and their translocation and allocation are mainly dependent on sugar transporters. Genome-wide characterization of Satsuma mandarin identified eighteen SWEET family members that encode transporters which facilitate diffusion of sugar across cell membranes. Analysis of the expression profiles in tissues of mandarin fruit at different developmental stages showed that CitSWEET11d transcripts were significantly correlated with sucrose accumulation. Further studies indicated that overexpression of CitSWEET11d in citrus callus and tomato fruit showed a higher sucrose level compared to wild-type, suggesting that CitSWEET11d could enhance sucrose accumulation. In addition, we identified an ERF transcription factor CitERF16 by yeast one-hybrid screening assay which could directly bind to the DRE cis-element on the promoter of CitSWEET11d. Overexpression of CitERF16 in citrus callus significantly induced CitSWEET11d expression and elevated sucrose content, suggesting that CitERF16 acts as a positive regulator to promote sucrose accumulation via trans-activation of CitSWEET11d expression.

13C/12C Carbon Isotope Fractionation between Atmospheric Carbon Dioxide and Photosynthesis Products in Plant Leaves As Affected by the Spectral Composition of Lighting Environment

We investigate the effects that the spectral composition of radiation that plants are exposed to during their development has on the fractionation of carbon isotopes between atmospheric carbon dioxide and the primary products of photosynthesis in plant tissues. The difference in carbon isotope composition between carbon in air near the leaves and carbon in the leaves varies in the range of 7 to 19 depending on the spectral composition of incident light, with an increase in the red component resulting in enrichment of the leaves with the light isotope 12C. This differences are (i) the measure of isotope fractionation during the vital activity of plants and (ii) the rate of carbon assimilation due to photosynthetic reactions.

Фракционирование изотопов углерода -=SUP=-13-=/SUP=-С/-=SUP=-12-=/SUP=-С из углекислого газа атмосферы в продукты фотосинтеза в листьях растений в зависимости от спектральных характеристик световой среды

We have studied influence of the light with various spectral characteristics, coming to plants during its growth, on the distribution of carbon isotopes between atmospheric carbon dioxide and the primary products of photosynthesis in plant leaves, using the developed set of methods and laboratory setups. The difference between the carbon isotopic composition in the air near the plants and in their leaves varies from 7 to 19 ‰, increase in the red component of the spectrum resulting in leave enrichment with light carbon isotope 12C. This difference reflects the degree of isotope fractionation during the plant life, characterizes the rate of carbon assimilation due to photosynthetic reactions, and can be used as a phytomonitoring parameter.

Geographic pattern and effects of climate and taxonomy on nonstructural carbohydrates of Artemisia species and their close relatives across northern China

Nonstructural carbohydrates (NSCs) are the primary products of photosynthesis and have implications for determining the carbon (C) limitation under current environmental conditions and the impact of climate change on the C balance in ecosystems. Yet, heretofore little was known about how climate and taxonomy affect NSC at the regional or global scale. We explored geographic patterns and effects of climate and taxonomy on the NSC in the aboveground organs of Artemisia species and their close relatives from 65 sites across northern China. Hierarchical linear models (HLMs) showed that sugar concentration decreased with increasing altitude and that the response of NSC to the altitudinal gradient differed among species. NSC concentration was affected by climate of the warmest quarter rather than annual climate. Sugar and starch concentrations differed significantly among species. Within the NSC C pool, species identity explained more of the total variance of sugar C than that of starch C. Our results show that the NSC pattern at a large geographical scale differs from that at the local scale. As a temporary storage of C, NSCs appear to be a direct product of the photosynthetic process rather than to function as protectants against environmental stresses during the growing season at the regional scale. Therefore, different species, even among closely related taxa, may vary in their adaptation to environmental gradients via the physiological adjustment of NSCs at the regional scale.

Starch Phosphorylase: An Overview of Biochemical Characterization, Immobilization and Peptide Mapping

Starch phosphorylase (EC 2.4.1.1) is the key enzyme which catalyzes the reversible conversion of starch and inorganic phosphate into glucose-1-phosphate (G-1-P) and has been reported in many higher plants. It can be exploited for industrial purposes for tailoring starch and for the synthesis of biopolymers which may be useful in food industry and are also of clinical importance. Starch in the form of insoluble granules accumulates in chloroplasts as the primary product of photosynthesis. Multiple forms of the enzyme have been reported in different plant tissues which have been predicted to have different roles in starch metabolism. Here, various biochemical properties have Review Article Jain et al.; BBJ, 5(3): 103-122, 2015; Article no.BBJ.2015.011 104 been reviewed. Various techniques for enzyme immobilization have been discussed. Besides, reports on immobilization of starch phosphorylase from different sources and on different solid matrices have also been reviewed. Peptide mapping reports of various proteins have also been assessed in this review.

Genetic analysis of sugar-related traits in rice grain

Sugar is the primary product of photosynthesis in plant and plays a critical role in regulating plant growth and development. In this study, quantitative trait loci (QTLs) for total soluble sugar, sucrose, and fructose contents in rice grain were identified using a double haploid population derived from a cross between japonica CJ06 and indica TN1. A total of 17 QTLs, including four QTLs for total soluble sugar content, seven QTLs for sucrose content, and six QTLs for fructose content, were detected on chromosome 1, 3, 4, 5, 6, and 8, with the LOD ranges from 2.61 to 3.85. Furthermore, among the determined varieties, we found that the total soluble sugar content in japonica showed higher than that in indica. Comparative genetic analysis showed that starch synthesis related gene is presumably involved in sugar-related metabolic activity in rice grain.

Assessment of a 1H high-resolution magic angle spinning NMR spectroscopy procedure for free sugars quantification in intact plant tissue

In most plants, sucrose is the primary product of photosynthesis, the transport form of assimilated carbon, and also one of the main factors determining sweetness in fresh fruits. Traditional methods for sugar quantification (mainly sucrose, glucose and fructose) require obtaining crude plant extracts, which sometimes involve substantial sample manipulation, making the process time-consuming and increasing the risk of sample degradation. Here, we describe and validate a fast method to determine sugar content in intact plant tissue by using high-resolution magic angle spinning nuclear magnetic resonance spectroscopy (HR-MAS NMR). The HR-MAS NMR method was used for quantifying sucrose, glucose and fructose in mesocarp tissues from melon fruits (Cucumis melo var. reticulatus and Cucumis melo var. cantalupensis). The resulting sugar content varied among individual melons, ranging from 1.4 to 7.3g of sucrose, 0.4-2.5g of glucose; and 0.73-2.83g of fructose (values per 100g fw). These values were in agreement with those described in the literature for melon fruit tissue, and no significant differences were found when comparing them with those obtained using the traditional, enzymatic procedure, on melon tissue extracts. The HR-MAS NMR method offers a fast (usually <30min) and sensitive method for sugar quantification in intact plant tissues, it requires a small amount of tissue (typically 50mg fw) and avoids the interferences and risks associated with obtaining plant extracts. Furthermore, this method might also allow the quantification of additional metabolites detectable in the plant tissue NMR spectrum.

Paradigm of Monoterpene (β-phellandrene) Hydrocarbons Production via Photosynthesis in Cyanobacteria

A direct “photosynthesis-to-fuels” approach envisions application of a single organism, absorbing sunlight, photosynthesizing, and converting the primary products of photosynthesis into ready-made fuel. The work reported here applied this concept for the photosynthetic generation of monoterpene (β-phellandrene) hydrocarbons in the unicellular cyanobacteria Synechocystis sp. PCC 6803. Heterologous expression of a codon-optimized Lavandula angustifolia β-phellandrene synthase (β-PHLS) gene in Synechocystis enabled photosynthetic generation of β-phellandrene in these microorganisms. β-phellandrene accumulation occurred constitutively and in tandem with biomass accumulation, generated from sunlight, CO2, and H2O. Results showed that β-phellandrene diffused through the plasma membrane and cell wall of the cyanobacteria and accumulated on the surface of the liquid culture. Spontaneous β-phellandrene separation from the biomass and its removal from the liquid phase alleviated product inhibition of cellular metabolism and enabled a continuous production process. The work showed that oxygenic photosynthesis can be directed to generate monoterpene hydrocarbons, while consuming CO2, without a prior requirement for the harvesting, dewatering, and processing of the respective biomass.

Glucose Determination by Biosensors

Sugars constitute a class of biocomponents, which can reach in plants an amount of almost 50% of their dried weight. Glucose, fructose and saccharose are found in significant amounts in fruits and honey. Glucose or dextrose occurs naturally in fruits and vegetables as the primary product of photosynthesis. Most ingested carbohydrates (saccharose, lactose, starch) are converted to glucose during digestion, and this is the form of sugar that is transported in the bloodstream. Sugars in diet can be naturally occurring or added, and contribute largely to the nutritional value of the foodstuffs in which they are found or incorporated. Naturally occurring sugars are found in fruits and honey (glucose, fructose, saccharose) and milk (lactose). The major sources of added sugars are soft drinks, fruit juices, chocolate, candies, cakes, cookies, pies, dairy desserts and milk products (ice cream, sweetened yogurt and sweetened milk). Glucose can be manufactured from starch by enzymatic or acidic hydrolysis. Glucose represents a key analyte in many fields, like food analysis or biomedical analysis. Its determination can rely on its reducing character, using the titrimetric methods Luff-Schoorl, Bertrand or Somogyi [1] or by colorimetric methods [2]. Nevertheless, these methods are characterized by reduced selectivity and necessitate previous precipitation of proteins, which could interfere in the analysis [2]. Under this circumstances, biosensors represent a viable alternative to laborious and time consuming conventional techniques. Biosensors are sophisticated analytical instruments which incorporate a biorecognition element (e.g. enzyme, nucleic acid, antibody, whole cell), in close contact to a transducer. The latter senses the changes that take place in the system, as a result of the substrate (analyte)-biocatalyst (enzyme) interaction. The transduced parameter can be electrical (current intensity, potential/pH difference), optical (absorbance, reflectance, fluorescence, luminiscence), thermal, piezoelectrical [3-6]. Among biosensors, enzyme electrode combine the specificity and selectivity imparted by the biomolecule, to the accuracy, sensitivity and rapidity of the physico-chemical transduction (e.g. electrochemical, optical) and necessitate minimum sample pre-treatment [3-6], thus being preferred to the previously mentioned classical techniques. The enzyme electrodes, the most commonly used biosensor type, can use various detection techniques: electrochemical (potentiometric, amperometric, conductometric), optical, thermal, piezoelectrical, the first mentioned being the most widely employed [4]. Enzyme immobilization in biosensor construction provide the advantages of repetitive enzyme use, biocatalyst stabilization, cost diminution. Many techniques have been used for enzyme immobilization: physical adsorbtion, gel entrapment, covalent coupling with or without crosslinking, or the construction of chemically modified electrodes based on carbon paste, carbon nanotubes, composite materials, screen printing or sol-gel technique [3-5].

Effects of limitation stress and of disruptive stress on induced antigrazing defense in the bladder wrack Fucus vesiculosus

We assessed the effects of light limitation and temperature shift on palatability and induced antiherbivore defense in the brown alga Fucus vesiculosus L. Incubation for 2 wk at light intensities above the compensation point of photosynthesis and in the absence of grazers increased the palatability of F. vesiculosus and its subsequent consumption by the omnivorous isopod Idotea baltica Pallas. This effect correlated with an increased C:N ratio and mannitol content in the algal tissue, presumably due to increased photosynthetic carbon fixation. Mannitol, the primary product of photosynthesis in F. vesiculosus, proved to be a feeding cue for I. baltica, and depletion of the mannitol pool may therefore account for the reduced palatability during light limitation. At light intensities above the compensation point of photosynthesis, F. vesiculosus responded with decreasing palatability when it was exposed to I. baltica grazing. Irrespective of the preceding light regime, such defense induction was prevented during incubation under light limitation. Thus, under low light, defense induction is not only inhibited, but also less necessary due to the relative absence of feeding cues. Upward or downward shifts in water temperature by approximately 10°C also inhibited inducible defense in F. vesiculosus. However, such shifts did not affect algal growth and were therefore the consequence of an impairment of specific defense-related components rather than of resource limitation, unless compensatory growth was given priority over defense.

Free galactose and galactosidase activity in the course of flax fiber development

Composition and content of free monosaccharides and β-galactosidase activity were determined in the course of development of the flax (Linum usitatissimum L.) tissues containing bast fibers. In the stem regions where the fibers were at the stage of formation of the secondary cell wall of gelatinous type, the content of free galactose was high (14 mM) and 13–20 times greater than in the upper part of the stem where the fibers were at the stage of intrusive growth. Pulse-chase experiments demonstrated the differences in the metabolism of individual low-molecular sugars. In respect to glucose and sucrose, all the examined characteristics (content, absolute and specific radioactivity, and the temporal changes of these indices) were identical in the stem regions wherein the fibers were at different stages of development. Labeled galactose was detected only in the stem regions where the fibers were at the stage of secondary cell wall formation. The specific radioactivity of glucose and sucrose reached the maximum immediately after photosynthesis in the presence of 14CO2 and changed in the same way as in the primary products of photosynthesis. The time-course of label incorporation into galactose indicated that this monosaccharide arose as a result of hydrolytic processes. At the stage of secondary cell wall formation, high activity of β-galactosidase was observed, with tissue- and stage-specific fiber β-1,4-galactan as its substrate.

Expression and cloning of the full-length cDNA for sorbitol-6-phosphate dehydrogenase and NAD-dependent sorbitol dehydrogenase from pear ( Pyrus pyrifolia N.)

Sorbitol is the primary product of photosynthesis and the major translocation form of photosynthate in the Rosaceae family, which includes pear plants. Therefore, the biosynthesis and breakdown of sorbitol is an important step in the carbohydrate metabolism of pear. In sorbitol metabolism, sorbitol-6-phosphate dehydrogenase (S6PDH) and NAD-sorbitol dehydrogenase (NAD-SDH) play key roles in biosynthesis and breakdown of sorbitol, respectively. We isolated full-length cDNAs encoding S6PDH and NAD-SDH from pear ( Pyrus pyrifolia N. cv Niitaka). PyS6PDH cDNA encodes a polypeptide consisting of 311 amino acid residues. PyNAD-SDH cDNA encodes a 371 amino acid polypeptide. The PyS6PDH gene was expressed at high levels in leaves at 30 day after full bloom (DAFB), but its expression was decreased later. Conversely, the transcripts of the PyNAD- SDH gene were detected at low levels in young leaves, but increased with age. These genes may be regulated by the transcriptional level.

The diurnal metabolism of leaf starch

Starch is a primary product of photosynthesis in leaves. In most plants, a large fraction of the carbon assimilated during the day is stored transiently in the chloroplast as starch for use during the subsequent night. Photosynthetic partitioning into starch is finely regulated, and the amount of carbohydrate stored is dependent on the environmental conditions, particularly day length. This regulation is applied at several levels to control the flux of carbon from the Calvin cycle into starch biosynthesis. Starch is composed primarily of branched glucans with an architecture that allows the formation of a semi-crystalline insoluble granule. Biosynthesis has been most intensively studied in non-photosynthetic starch-storing organs, such as developing seeds and tubers. Biosynthesis in leaves has received less attention, but recent reverse-genetic studies of Arabidopsis (thale cress) have produced data generally consistent with what is known for storage tissues. The pathway involves starch synthases, which elongate the glucan chains, and branching enzymes. Remarkably, enzymes that partially debranch glucans are also required for normal amylopectin synthesis. In the last decade, our understanding of starch breakdown in leaves has advanced considerably. Starch is hydrolysed to maltose and glucose at night via a pathway that requires recently discovered proteins in addition to well-known enzymes. These sugars are exported from the plastid to support sucrose synthesis, respiration and growth. In the present review we provide an overview of starch biosynthesis, starch structure and starch degradation in the leaves of plants. We focus on recent advances in each area and highlight outstanding questions.

Effect of altitude on the primary products of photosynthesis and the associated enzymes in barley and wheat

There is little information available on the primary products of photosynthesis and the change in the activity of the associated enzymes with altitude. We studied the same in varieties of barley and wheat grown at 1300 (low altitude, LA) and 4200 m (high altitude, HA) elevations above mean sea level in the western Himalayas. Plants at both the locations had similar photosynthetic rates, leaf water potential and the chlorophyll fluorescence kinetics. The short-term radio-labelling experiments in leaves showed appearance of (14)CO(2) in phosphoglyceric acid and sugar phosphates in plants at both the LA and HA, suggesting a major role of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in CO(2) fixation in the plants at two altitudes, whereas the appearance of labelled carbon in aspartate (Asp) and glutamate (Glu) at HA suggested a role of phosphoenolpyruvate carboxylase (PEPCase) in photosynthesis metabolism. Plants at HA had significantly higher activities of PEPCase, carboxylase and oxygenase activity of Rubisco, aspartate aminotransferase (AspAT), and glutamine synthetase (GS). However, the activities of malate dehydrogenase, NAD-malic enzyme and citrate synthase were similar at the two locations. Such an altered metabolism at HA suggested that PEPCase probably captured CO(2) directly from the atmosphere and/or that generated metabolically e.g. from photorespiration at HA. Higher oxygenase activity at HA suggests high photorespiratory activity. OAA thus produced could be additionally channelised for Asp synthesis using Glu as a source of ammonia. Higher GS activity ensures higher assimilation rate of NH(3) and the synthesis of Glu through GS-GOGAT (glutamine:2-oxoglutarate aminotransferase) pathway, also as supported by the appearance of radiolabel in Glu at HA. Enhanced PEPCase activity coupled with higher activities of AspAT and GS suggests a role in conserving C and N in the HA environment.

Connecting genes to metabolites by a systems biology approach

Plants are of pivotal importance to sustain life on Earth because they supply oxygen, food, energy, and many valuable metabolites. All plant constituents, including secondary metabolites, some of which are used as flavors, fragrances, colorants, or pharmaceuticals, are ultimately derived from primary products of photosynthesis through multiple enzymatic steps encoded by the genome of each plant. However, our knowledge of how both primary and secondary metabolites are synthesized and which genes are involved is far from complete. A better understanding of metabolite synthesis and the regulation thereof will be increasingly important for improving the sustainability and efficiency of useful plant production. Recently, the availability of entire genome sequences of Arabidopsis thaliana and rice and the development of functional genomics tools have allowed the elucidation of metabolite syntheses by a systems biology approach (1–3). The mining and exploitation of the data obtained from genomics and the related research areas of genomewide transcriptomics, proteomics, and metabolomics will bring us into a new era of understanding of biological systems (Fig. 1). Fig. 1. A schematic representation of a plant metabolomics platform using a systems biology approach. The platform is divided into multiple analytical approaches aimed at increased coverage of the metabolome. Data processing methods enable us to track both known and unknown metabolites, which can then be integrated from across multiple platforms. Multivariate analyses are used to find trends in data and select most relevant unknown compounds for further identification. Sulfur is one of the essential nutrients for all plants, required to synthesize the key amino acids cysteine and methionine, which in turn are needed to produce functional proteins and many secondary metabolites (4). Approximately 90% of the reduced S is bound through these amino …