The chemical diversity and distribution of glucosinolates and isothiocyanates among plants

Acyl lipids in Arabidopsis and all other plants have a myriad of diverse functions. These include providing the core diffusion barrier of the membranes that separates cells and subcellular organelles. This function alone involves more than 10 membrane lipid classes, including the phospholipids, galactolipids, and sphingolipids, and within each class the variations in acyl chain composition expand the number of structures to several hundred possible molecular species. Acyl lipids in the form of triacylglycerol account for 35% of the weight of Arabidopsis seeds and represent their major form of carbon and energy storage. A layer of cutin and cuticular waxes that restricts the loss of water and provides protection from invasions by pathogens and other stresses covers the entire aerial surface of Arabidopsis. Similar functions are provided by suberin and its associated waxes that are localized in roots, seed coats, and abscission zones and are produced in response to wounding. This chapter focuses on the metabolic pathways that are associated with the biosynthesis and degradation of the acyl lipids mentioned above. These pathways, enzymes, and genes are also presented in detail in an associated website (ARALIP: http://aralip.plantbiology.msu.edu/). Protocols and methods used for analysis of Arabidopsis lipids are provided. Finally, a detailed summary of the composition of Arabidopsis lipids is provided in three figures and 15 tables.

/pdf/acyl-lipid-metabolism-2156uh7qdu.pdf

Acyl-Lipid Metabolism

Variation of glucosinolate accumulation among different organs and developmental stages of Arabidopsis thaliana.

https://www.cell.com/trends/plant-science/pdf/S1360-1385(10)00031-2.pdf

Biosynthesis of glucosinolates – gene discovery and beyond

Diversity, distribution and roles of osmoprotective compounds accumulated in halophytes under abiotic stress

Leaf and seed extracts of Arabidopsis thaliana var. Columbia contain a large number of glucosinolates, representing close to 2 5 % of those known to occur in nature. The glucosinolates, in the form of their desulphated analogs, are separated by reversed-phase, high-performance liquid chromatography (HPLC). Seventeen are identified using thermospray liquid chromatography/mass spectrometry (TSP LC/MS). Additional glucosinolates, present in trace amounts, are identified as isothiocyanates by electron impact and chemical ionization gas chromatography/MS (GC/MS). In total, 23 glucosinolates are detected and these include four series of homologs and analogs. Fifteen possess aliphatic side chains, of which six contain ωmethylthioalkyl and six contain ω-methylsulphinylalkyl side chains; eight possess aromatic side chains, of which four constitute an homologous series of benzoic acid esters and three possess 3-indolylmethyl-based structures. Sixteen of the glucosinolates are detected in Arabidopsis thaliana for the first time and three of these, 4-hydroxybutyl glucosinolate, 5-benzoyloxypentyl glucosinolate, and 6-benzoyloxyhexyl glucosinolate, represent novel plant constituents. In radish, esterification of the thioglucosyl moiety by sinapic acid is also known to occur (1,2) . A l l can be hydrolyzed by the enzyme myrosinase to give D-glucose, sulphate, and a variety o f products derived from the aglycone moiety, including iso­ thiocyanates, nitriles, and other products (3) . Glucosinolates have been reported in 11 plant families and within the Cruciferae * NRCC Communication No. 29493 they have been found in all species examined (4 ) . Glucosinolates, as a class o f plant constituents, are o f major importance to several vegetable crops due to the flavor com­ ponents (isothiocyanates or mustard oils) generated by hydroly­ sis when the plant tissues are crushed. The hydrolytic products of some glucosinolates exhibit toxic effects in mammals and, thus, have limited the usefulness of some Cruciferae species as fodder (1 ) . Information concerning the biosynthetic pathway of glucosinolates and the genes that encode the enzymes involved in their synthesis could facilitate the genetic engineering of altered glucosinolate levels in crops. One approach to obtain­ ing such information is through the analysis of mutants. As part of a program on the genetic manipulation of glucosinolate levels in crop plants, the present authors plan to take advantage of the speed and versatility of genetic analysis in the small crucifer Arabidopsis thaliana ( L . ) Heynh to isolate and characterize mutants deficient in glucosinolate biosynthesis (5 ) . A necessary first step was to determine the natural composition of gluco­ sinolates in leaf and seed tissue of wild type plants and to adopt a method that would be amenable for their analysis in individual

/pdf/hplc-separation-of-glucosinolates-from-leaves-and-seeds-of-59wyrttlq7.pdf

HPLC Separation of Glucosinolates from Leaves and Seeds of Arabidopsis thaliana and Their Identification Using Thermospray Liquid Chramatography/Mass Spectrometry

A simple enzymatic method for the preparation of radiolabeled erucoyl-CoA and other long-chain fatty acyl-CoAs and their characterization by mass spectrometry☆

Erucic acid (22:1) was chosen as a marker to study triacylglycerol (TAG) biosynthesis in a Brassica napus L. cv Reston microspore-derived (MD) embryo culture system. TAGs accumulating during embryo development exhibited changes in acyl composition similar to those observed in developing zygotic embryos of the same cv, particularly with respect to erucic and eicosenoic acids. However, MD embryos showed a much higher rate of incorporation of 14C-erucoyl moieties into TAGs in vitro than zygotic embryos. Homogenates of early-late cotyledonary stage MD embryos (14-29 days in culture) were assessed for the ability to incorporate 22:1 and 18:1 (oleoyl) moieties into glycerolipids. In the presence of [1-14C]22:1-coenzyme A (CoA) and various acyl acceptors, including glycerol-3-phosphate (G-3-P), radiolabeled erucoyl moieties were rapidly incorporated into the TAG fraction, but virtually excluded from other Kennedy Pathway intermediates as well as complex polar lipids. This pattern of erucoyl incorporation was unchanged during time course experiments or upon incubation of homogenates with chemicals known to inhibit Kennedy Pathway enzymes. In marked contrast, parallel experiments conducted using [1-14C]18:1-CoA and G-3-P indicated that 14C oleoyl moieties were incorporated into lyso-phosphatidic acids, phosphatidic acids, diacylglycerols, and TAGs of the Kennedy Pathway, as well as other complex polar lipids, such as phosphatidylcholines and phosphatidylethanolamines. When supplied with l-[2-3H(N)]G-3-P and [1-14C]22:1-CoA, the radiolabeled TAG pool contained both isotopes, indicating G-3-P to be a true acceptor of erucoyl moieties. Radio-high-performance liquid chromatography, argentation thin-layer chromatography/gas chromatography-mass spectrometry, and stereospecific analyses of radiolabeled TAGs indicated that 22:1 was selectively incorporated into the sn-3 position by a highly active diacylglycerol acyltransferase (DGAT; EC 2.3.1.20), while oleoyl moieties were inserted into the sn-1 and sn-2 positions. In the presence of sn-1,2-dierucin and [1-14C]22:1-CoA, homogenates and microsomal preparations were able to produce radiolabeled trierucin, a TAG not found endogenously in this species. A 105,000g pellet fraction contained 22:1-CoA:DGAT exhibiting the highest specific activity. The rate of 22:1-CoA:DGAT activity in vitro could more than account for the maximal rate of TAG biosynthesis observed in vivo during embryo development. In double label experiments, G-3-P was shown to stimulate the conversion of [3H]phosphatidylcholines to [3H]diacylglycerols, which subsequently acted as acceptors for 14C erucoyl moieties. In vitro, 22:1 moieties did not enter the sn-1 position of TAGs by a postsynthetic modification or transacylation of preformed TAGs.

https://www.jstor.org/stable/pdfplus/4273794.pdf

Triacylglycerol Bioassembly in Microspore-Derived Embryos of Brassica napus L. cv Reston'

The South-western USA and Northern Mexico one-seeded Junipers: their volatile oils and evolution

Identification of Lower Terpenoids from Gas-Chromatography-Mass Spectral Data by On-Line Computer Method

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Lawrence Hogge

Author Tools

Chat about Author