Acetolactate Synthase Activity in Developing Maize (<i>Zea mays</i> L.) Kernels

Muhitch, Michael J.

doi:10.1104/pp.86.1.23

Cited by 33 publications

(18 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1; FE Below, unpublished data). In the current study, 14.3 mM N elicited a maximum response in the activity of many of the enzymes surveyed and many activities were comparable to that found in similarly aged kernels grown in vivo (6,13,18,19,21). Despite this likeness, kernels which develop on the plant undoubtedly receive a N supply in excess of an 'effective' 15 mM.…”

Section: Enzyme Activitiesmentioning

confidence: 62%

See 1 more Smart Citation

Response of Enzymes and Storage Proteins of Maize Endosperm to Nitrogen Supply

Singletary¹,

Doehlert²,

Wilson³

et al. 1990

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

To examine the effects of N nutrition upon endosperm development, maize (Zea mays) kernels were grown in vitro with either 0, 3.6, 7.1, 14.3, or 35.7 millimolar N. Kernels were harvested at 20 days after pollination for determination of enzyme activities and again at maturity for quantification of storage products and electrophoretic separation of zeins. Endosperm dry weight, starch, zein-N, and nonzein-N all increased in mature kemels as N supply increased from zero to 14.3 millimolar. The activities of sucrose synthase, aldolase, phosphoglucomutase, glutamatepyruvate transaminase, glutamate-oxaloacetate transaminase, and acetolactate synthase increased from 1-to 2.5-fold with increasing N supply. Adenosine diphosphate-glucose pyrophosphorylase and both ATP-and PPi-dependent phosphofructokinases increased to lesser extents, while no significant response was detected for hexose kinases and glutamine synthetase. Nitrogen-induced changes in enzyme activities were often highly correlated with changes in final starch and/or zein-N contents. Separation of zeins indicated that these peptides were proportionately enhanced by N supply, with the exception of C-zein, which was relatively insensitive to N. These data indicate that at least a portion of the yield increase in maize produced by N fertilization is induced by a modification of kernel metabolism in response to N supply.

show abstract

Section: Enzyme Activitiesmentioning

confidence: 62%

“…For both enzymes, reactions were initiated by the addition of oxoglutarate, and corrections were made for substrate-independent NADH oxidation. GS (EC 6.3.1.2) and ALS (EC 4.1.3.18) assays have been described previously ( 17,18).…”

Section: Enzyme Extraction and Assaymentioning

confidence: 99%

Response of Enzymes and Storage Proteins of Maize Endosperm to Nitrogen Supply

Singletary¹,

Doehlert²,

Wilson³

et al. 1990

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…126 ALS activities from both embryonic and endosperm tissues of developing maize kernels are inhibited. 120 Little information has been published about the 1,2,4-triazolo[l,S-a]-pyrimidines. 132 Their adverse effects on soybean cell growth are reversed by added valine, leucine, and isoleucine; inhibition of plant ALS is associated with noncovalent binding of the inhibitor.…”

Section: Herbicides As Als Inhibitorsmentioning

confidence: 99%

“…119 In developing maize kernels, ALS activity in the endosperm increases rapidly during the early stages of seed formation whereas embryonic activity rises more gradually and throughout development; the ALS activity from both sources is subject to leucine/valine feedback inhibition. 120 In crude extracts, the ALS from many plant sources is unstable and difficult to purify; the recent successful expression of Arabidopsis ALS in E. coli offers the possibility of purifying relatively large amounts of a plant ALS for detailed structural investigations. 121…”

Section: Enzymologymentioning

confidence: 99%

Amino Acid Synthesis

Mousdale

Coggins

1991

Target Sites for Herbicide Action

View full text Add to dashboard Cite

.1. AMINO ACID BIOSYNTHESIS IN PLANTSGreen plants share with most microbial species the capacity to synthesize all the major amino acids; the few exceptions are parasitic and depend on the nitrogen metabolism of the host plant. In addition, many nonprotein "uncommon" amino acids are produced, and frequently accumulated, in large amounts in a range of species; these are important in plant/plant, plant/ insect, and plant/ animal relationships. 1 The amino acids essential for mammalian diets are phenylalanine, tryptophan, lysine, leucine, isoleucine, valine, threonine, and methionine for adults, with the addition of arginine and histidine for immature animals (the third aromatic amino acid required for protein synthesis, tyrosine, can be formed metabolically, given an adequate dietary intake of phenylalanine). The biosynthetic routes for these 10 amino acids are particularly attractive targets for toxicologically safe herbicides and for pesticides aimed at plant pathogens; the potential for antibiotics may be more limited because medicinally important microorganisms tend to inhabit nutritionally rich habitats.The general outline of the pathways of amino acid biosynthesis is shown in Figure 2.1. It should be stressed that the detailed enzymology of these pathways is far better understood in bacteria and some eucaryotic microorganisms than in higher plants; indeed, in most plant species, information on the relevant enzymology is fragmentary. 2 As will be seen later,

show abstract

“…Acetolactate synthase activity was tested as described previously (Muhitch, 1988), using leucine and valine (10 mM each) as inhibitors of acetolactate synthase to obtain specific activity as recommended. The specific acetolactate synthase activity is defined as the part of the measured activity that can be inhibited by the presence of leucine and valine.…”

Section: Methodsmentioning

confidence: 99%

New insight into the photoheterotrophic growth of the isocytrate lyase-lacking purple bacterium Rhodospirillum rubrum on acetate

et al. 2015

View full text Add to dashboard Cite

Purple non-sulfur bacteria are well known for their metabolic versatility. One of these bacteria, Rhodospirillum rubrum S1H, has been selected by the European Space Agency to ensure the photoheterotrophic assimilation of volatile fatty acids in its regenerative life support system, MELiSSA. Here, we combined proteomic analysis with bacterial growth analysis and enzymatic activity assays in order to better understand acetate photoassimilation. In this isocitrate lyaselacking organism, the assimilation of two-carbon compounds cannot occur through the glyoxylate shunt, and the citramalate cycle has been proposed to fill this role, while, in Rhodobacter sphaeroides, the ethylmalonyl-CoA pathway is used for acetate assimilation. Using proteomic analysis, we were able to identify and quantify more than 1700 unique proteins, representing almost one-half of the theoretical proteome of the strain. Our data reveal that a pyruvate : ferredoxin oxidoreductase (NifJ) could be used for the direct assimilation of acetyl-CoA through pyruvate, potentially representing a new redox-balancing reaction. We additionally propose that the ethylmalonyl-CoA pathway could also be involved in acetate assimilation by the examined strain, since specific enzymes of this pathway were all upregulated and activity of crotonyl-CoA reductase/carboxylase was increased in acetate conditions. Surprisingly, we also observed marked upregulation of glutaryl-CoA dehydrogenase, which could be a component of a new pathway for acetate photoassimilation. Finally, our data suggest that citramalate could be an intermediate of the branched-chain amino acid biosynthesis pathway, which is activated during acetate assimilation, rather than a metabolite of the so-called citramalate cycle.

show abstract

Acetolactate Synthase Activity in Developing Maize (Zea mays L.) Kernels

Cited by 33 publications

References 16 publications

Response of Enzymes and Storage Proteins of Maize Endosperm to Nitrogen Supply

Response of Enzymes and Storage Proteins of Maize Endosperm to Nitrogen Supply

Amino Acid Synthesis

New insight into the photoheterotrophic growth of the isocytrate lyase-lacking purple bacterium Rhodospirillum rubrum on acetate

Contact Info

Product

Resources

About