scholarly journals Unique Plant Material for Studying Woody-plant Nitrogen Metabolism

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 442E-442
Author(s):  
Gary D. Coleman ◽  
Brent L. Black ◽  
Leslie H. Fuchigami
Keyword(s):  
Nitrogen Metabolism ◽  
Dry Weight ◽  
Stem Length ◽  
Wild Type ◽  
Plant Nitrogen ◽  
Woody Perennials ◽  
N Storage ◽  
Series Of Experiments ◽  
Bark Storage Protein ◽  
Nitrate Fertilization

Temperate woody perennials produce proteins in the stem for seasonal nitrogen (N) storage. In Populus species, this seasonal N storage occurs primarily as a 32-kDa Bark Storage Protein (BSP), which can accumulate to 50% of total bark proteins during the winter. Plants of the Populus tremula × Populus alba (clone 717) were transformed with the BSP cDNA in antisense orientation (fused to a constitutive promoter), and regenerated lines were screened. Several independent antisense-BSP (A-BSP) lines were selected, which, after 4 weeks of SD photoperiod, showed 70% to 90% reduction in total BSP accumulation compared to the wild-type (WT). A series of experiments were conducted to compare LD growth of one A-BSP line to that of the WT. A-BSP plants showed reduced growth at both 5 and 50 mM ammonium nitrate fertilization. However, the higher N rate eventually resulted in toxicity in WT, but not in A-BSP plants. A-BSP plants grown hydroponically (0.5x Hoagland1s) showed altered partitioning with reduced stem length and increased leaf area (Leaf:stem dry-weight ratios were 14.8 and 20.9 for ABSP and WT, respectively). Partitioning to the roots was not different between A-BSP and WT. Proposed functions of BSP in seasonal and LD nitrogen metabolism will be discussed.

Effects of an Autoregulatory Senescence-inhibitor Gene Construct on Nicotiana alata Link and Otto.

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 519d-519 ◽  
Author(s):  
Kenneth R. Schroeder ◽  
Dennis P. Stimart
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Plant Height ◽  
Dry Weight ◽  
Nicotiana Alata ◽  
Wild Type ◽  
Gene Encoding ◽  
Delayed Senescence ◽  
Gene Construct ◽  
Shoot Dry Weight ◽  
Inhibitor System

Nicotiana alata Link and Otto. was transformed via Agrobacterium tumefaciens encoding a senescence-specific promoter SAG12 cloned from Arabidopsis thaliana fused to a Agrobacterium tumefaciens gene encoding isopentenyl transferase (IPT) that catalyzes cytokinin synthesis. This was considered an autoregulatory senescence-inhibitor system. In 1996, we reported delayed senescence of intact flowers by 2 to 6 d and delayed leaf senescence of transgenic vs. wild-type N. alata. Further evaluations in 1997 revealed several other interesting effects of the SAG12-IPT gene construct. Measurement of chlorophyll content of mature leaves showed higher levels of both chlorophyll a and b in transgenic material under normal fertilization and truncated fertilization regimes. At 4 to 5 months of age transgenic plants expressed differences in plant height, branching, and dry weight. Plant height was reduced by 3 to 13 cm; branch counts increased 2 to 3 fold; and shoot dry weight increased up to 11 g over wild-type N. alata. These observations indicate the system is not tightly autoregulated and may prove useful to the floriculture industry for producing compact and more floriferous plants.

scholarly journals Overexpression of vesicle-associated membrane protein PttVAP27-17 as a tool to improve biomass production and the overall saccharification yields in Populus trees

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Madhavi Latha Gandla ◽  
Niklas Mähler ◽  
Sacha Escamez ◽  
Tomas Skotare ◽  
Ogonna Obudulu ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Biomass Production ◽  
Enzymatic Saccharification ◽  
Dry Weight ◽  
Populus Tremula ◽  
Transgenic Trees ◽  
Wild Type ◽  
Glucose Yield ◽  
Transgenic Lines ◽  
Wild Type Control

Abstract Background Bioconversion of wood into bioproducts and biofuels is hindered by the recalcitrance of woody raw material to bioprocesses such as enzymatic saccharification. Targeted modification of the chemical composition of the feedstock can improve saccharification but this gain is often abrogated by concomitant reduction in tree growth. Results In this study, we report on transgenic hybrid aspen (Populus tremula × tremuloides) lines that showed potential to increase biomass production both in the greenhouse and after 5 years of growth in the field. The transgenic lines carried an overexpression construct for Populus tremula × tremuloides vesicle-associated membrane protein (VAMP)-associated protein PttVAP27-17 that was selected from a gene-mining program for novel regulators of wood formation. Analytical-scale enzymatic saccharification without any pretreatment revealed for all greenhouse-grown transgenic lines, compared to the wild type, a 20–44% increase in the glucose yield per dry weight after enzymatic saccharification, even though it was statistically significant only for one line. The glucose yield after enzymatic saccharification with a prior hydrothermal pretreatment step with sulfuric acid was not increased in the greenhouse-grown transgenic trees on a dry-weight basis, but increased by 26–50% when calculated on a whole biomass basis in comparison to the wild-type control. Tendencies to increased glucose yields by up to 24% were present on a whole tree biomass basis after acidic pretreatment and enzymatic saccharification also in the transgenic trees grown for 5 years on the field when compared to the wild-type control. Conclusions The results demonstrate the usefulness of gene-mining programs to identify novel genes with the potential to improve biofuel production in tree biotechnology programs. Furthermore, multi-omic analyses, including transcriptomic, proteomic and metabolomic analyses, performed here provide a toolbox for future studies on the function of VAP27 proteins in plants.

scholarly journals Reducing Substrate Moisture Content during Greenhouse Production of Poinsettia Improves Postproduction Quality and Economic Value

HortScience ◽  
2018 ◽  
Vol 53 (11) ◽  
pp. 1618-1628
Author(s):  
Yanjun Guo ◽  
Terri Starman ◽  
Charles Hall
Keyword(s):  
Moisture Content ◽  
Economic Value ◽  
Growth Index ◽  
Dry Weight ◽  
Leaf Number ◽  
Stem Length ◽  
Total Production ◽  
Greenhouse Production ◽  
Ethylene Concentration ◽  
Substrate Moisture

The objective was to determine the effect of substrate moisture content (SMC) during poinsettia (Euphorbia pulcherrima) greenhouse production on plant quality, postproduction longevity, and economic value. Two experiments were conducted, one in 2016 with ‘Freedom Red’ and the other in 2017 with ‘Christmas Eve Red’. Treatments included two SMC levels (20% or 40%) applied in four timing of application combinations. Total production (TP) time was 14 (2016) or 12 (2017) weeks in which vegetative production (VP) occurred from week 33 (2016) or 35 (2017) to week 39 and reproductive production (RP) continued from week 40 to 47. The four timing of application treatments were 40/40 = TP at 40% SMC; 20/40 = VP at 20% + RP at 40%; 40/20 = VP at 40% + RP at 20%; 20/20 = TP at 20% SMC. After simulated shipping in the dark, plants were evaluated in a simulated retail environment with two packaging treatments: no sleeve covering or plastic perforated plant sleeves covering container and plant. At the end of greenhouse production, plants grown in 20% SMC during RP (20/20 and 40/20) had shorter bract internode length, stem length, and smaller growth index (GI), decreased shoot and root dry weight (DW), and bract and leaf surface area compared with those in 40% SMC during RP (40/40 and 20/40). Photosynthetic rate was higher when plants were watered at 40% SMC regardless of production stage compared with those in 20% SMC. Leaf thickness, petiole thickness, total bract and leaf number were unaffected by SMC treatments. Plants in 20% SMC during RP (20/20 or 40/20) had earlier bract coloring despite days to anthesis being the same for all SMC treatments. Compared with 40/40, 40/20, and 20/20 could save 44.2% or 43.6%, respectively, irrigation and fertilizer usage, and 39.1% and 47.8%, respectively, labor time. During postharvest, ethylene concentration was unaffected by packaging method. Sleeved plants, regardless of SMC treatment, received lower light intensity in the middle of the plant canopy, causing plants to have lower total leaf number due to abscission and SPAD reading at the end of postproduction. The 40/40 treatment abscised more bracts during five weeks (in 2016) of postproduction and with no sleeve had higher number of bracts with bract edge burn (BEB). In summary, reducing SMC to 20% during TP or RP reduced water usage during production and produced more compact plants with increased postproduction quality.

Glutamate synthase levels in Neurospora crassa mutants altered with respect to nitrogen metabolism

1981 ◽  
Vol 1 (2) ◽  
pp. 158-164
Author(s):  
N S Dunn-Coleman ◽  
E A Robey ◽  
A B Tomsett ◽  
R H Garrett
Keyword(s):  
Neurospora Crassa ◽  
Glutamate Dehydrogenase ◽  
Nitrogen Metabolism ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Glutamate Synthase ◽  
Wild Type ◽  
Mutant Strains ◽  
Synthase Regulation ◽  
Glutamate Biosynthesis ◽  
Glutamine Limitation

Glutamate synthase catalyzes glutamate formation from 2-oxoglutarate plus glutamine and plays an essential role when glutamate biosynthesis by glutamate dehydrogenase is not possible. Glutamate synthase activity has been determined in a number of Neurospora crassa mutant strains with various defects in nitrogen metabolism. Of particular interest were two mutants phenotypically mute except in an am (biosynthetic nicotinamide adenine dinucleotide phosphate-glutamate dehydrogenase deficient, glutamate requiring) background. These mutants, i and en-am, are so-called enhancers of am; they have been redesignated herein as en(am)-1 and en(am)-2, respectively. Although glutamate synthase levels in en(am)-1 were essentially wild type, the en(am)-2 strain was devoid of glutamate synthase activity under all conditions examined, suggesting that en(am)-2 may be the structural locus for glutamate synthase. Regulation of glutamate synthase occurred to some extent, presumably in response to glutamate requirements. Glutamate starvation, as in am mutants, led to enhanced activity. In contrast, glutamine limitation, as in gln-1 mutants, depressed glutamate synthase levels.

Mating-type genes control sexual reproduction, conidial germination and virulence in Cochliobolus lunatus

2021 ◽  
Author(s):  
Kexin Liu ◽  
Jiaqi Jia ◽  
Nan Chen ◽  
Dandan Fu ◽  
Jiaying Sun ◽  
...  
Keyword(s):  
Mating Type ◽  
Pathogenic Fungus ◽  
Germination Rate ◽  
Dry Weight ◽  
Single Copy ◽  
Conidial Germination ◽  
Curvularia Lunata ◽  
Wild Type ◽  
Cochliobolus Lunatus ◽  
Mat Genes

Cochliobolus lunatus (anamorph: Curvularia lunata) is a major pathogenic fungus that causes the Curvularia leaf spot of maize. ClMAT1-1-1 and ClMAT1-2-1, the C. lunatus orthologs of Cochliobolus heterostrophus ChMAT1-1-1 and ChMAT1-2-1, were investigated in the present study to uncover their functions in C. lunatus. Southern blot analysis showed that these mating-type MAT genes exist in the C. lunatus genome as a single copy. ClMAT1-1-1 and ClMAT1-2-1 were knocked out and complemented to generate ΔClmat1-1-1 and ΔClmat1-2-1, ΔClmat1-1-1-C and ΔClmat1-2-1-C, respectively. The mutant strains had defective sexual development and failed to produce pseudothecia. There were no significant differences in growth rate or conidia production between the mutant and wild-type strains. However, the aerial mycelia and mycelial dry weight of ΔClmat1-1-1 and ΔClmat1-2-1 were lower than that of wild type, suggesting that MAT genes affect asexual development. ClMAT genes were involved in the responses to cell wall integrity and osmotic adaptation. ΔClmat1-2-1 had a lower conidial germination rate than the wild-type strain CX-3. The virulence of ΔClmat1-2-1 and ΔClmat1-1-1 was also reduced compared to the wild type. Complementary strains could restore all the phenotypes.

scholarly journals Formate-Dependent H2 Production by the Mesophilic Methanogen Methanococcus maripaludis

2008 ◽  
Vol 74 (21) ◽  
pp. 6584-6590 ◽  
Author(s):  
Boguslaw Lupa ◽  
Erik L. Hendrickson ◽  
John A. Leigh ◽  
William B. Whitman
Keyword(s):  
Dry Weight ◽  
Maximal Activity ◽  
Growth Conditions ◽  
H2 Production ◽  
Resting Cells ◽  
Wild Type ◽  
Methanococcus Maripaludis ◽  
Gene Encoding ◽  
Major Pathway ◽  
Key Enzyme

ABSTRACT Methanococcus maripaludis, an H2- and formate-utilizing methanogen, produced H2 at high rates from formate. The rates and kinetics of H2 production depended upon the growth conditions, and H2 availability during growth was a major factor. Specific activities of resting cells grown with formate or H2 were 0.4 to 1.4 U�mg−1 (dry weight). H2 production in formate-grown cells followed Michaelis-Menten kinetics, and the concentration of formate required for half-maximal activity (Kf ) was 3.6 mM. In contrast, in H2-grown cells this process followed sigmoidal kinetics, and the Kf was 9 mM. A key enzyme for formate-dependent H2 production was formate dehydrogenase, Fdh. H2 production and growth were severely reduced in a mutant containing a deletion of the gene encoding the Fdh1 isozyme, indicating that it was the primary Fdh. In contrast, a mutant containing a deletion of the gene encoding the Fdh2 isozyme possessed near-wild-type activities, indicating that this isozyme did not play a major role. H2 production by a mutant containing a deletion of the coenzyme F420-reducing hydrogenase Fru was also severely reduced, suggesting that the major pathway of H2 production comprised Fdh1 and Fru. Because a Δfru-Δfrc mutant retained 10% of the wild-type activity, an additional pathway is present. Mutants possessing deletions of the gene encoding the F420-dependent methylene-H4MTP dehydrogenase (Mtd) or the H2-forming methylene-H4MTP dehydrogenase (Hmd) also possessed reduced activity, which suggested that this second pathway was comprised of Fdh1-Mtd-Hmd. In contrast to H2 production, the cellular rates of methanogenesis were unaffected in these mutants, which suggested that the observed H2 production was not a direct intermediate of methanogenesis. In conclusion, high rates of formate-dependent H2 production demonstrated the potential of M. maripaludis for the microbial production of H2 from formate.

scholarly journals A Fatty Acyl Coenzyme A Reductase Promotes Wax Ester Accumulation in Rhodococcus jostii RHA1

2017 ◽  
Vol 83 (20) ◽  
Author(s):  
James Round ◽  
Raphael Roccor ◽  
Shu-Nan Li ◽  
Lindsay D. Eltis
Keyword(s):  
Specific Activity ◽  
Dry Weight ◽  
Fatty Acyl ◽  
Wax Esters ◽  
Wax Ester ◽  
Wild Type ◽  
Considerable Potential ◽  
Commodity Chemicals ◽  
Acyl Coenzyme A ◽  
Rhodococcus Jostii

ABSTRACT Many rhodococci are oleaginous and, as such, have considerable potential for the sustainable production of lipid-based commodity chemicals. Herein, we demonstrated that Rhodococcus jostii RHA1, a soil bacterium that catabolizes a wide range of organic compounds, produced wax esters (WEs) up to 0.0002% of its cellular dry weight during exponential growth on glucose. These WEs were fully saturated and contained primarily 31 to 34 carbon atoms. Moreover, they were present at higher levels during exponential growth than under lipid-accumulating conditions. Bioinformatics analyses revealed that RHA1 contains a gene encoding a putative fatty acyl coenzyme A (acyl-CoA) reductase (FcrA). The purified enzyme catalyzed the NADPH-dependent transformation of stearoyl-CoA to stearyl alcohol with a specific activity of 45 ± 3 nmol/mg · min and dodecanal to dodecanol with a specific activity of 5,300 ± 300 nmol/mg · min. Deletion of fcrA did not affect WE accumulation when grown in either carbon- or nitrogen-limited medium. However, the ΔfcrA mutant accumulated less than 20% of the amount of WEs as the wild-type strain under conditions of nitric oxide stress. A strain of RHA1 overproducing FcrA accumulated WEs to ∼13% cellular dry weight under lipid-accumulating conditions, and their acyl moieties had longer average chain lengths than those in wild-type cells (C17 versus C16). The results provide insight into the biosynthesis of WEs in rhodococci and facilitate the development of this genus for the production of high-value neutral lipids. IMPORTANCE Among the best-studied oleaginous bacteria, rhodococci have considerable potential for the sustainable production of lipid-based commodity chemicals, such as wax esters. However, many aspects of lipid synthesis in these bacteria are poorly understood. The current study identifies a key enzyme in wax ester synthesis in rhodococci and exploits it to significantly improve the yield of wax esters in bacteria. In so doing, this work contributes to the development of novel bioprocesses for an important class of oleochemicals that may ultimately allow us to phase out their unsustainable production from sources such as petroleum and palm oil.

Perineal muscles: possible androgen regulation of glucocorticoid receptor sites in the rat

1984 ◽  
Vol 102 (2) ◽  
pp. 225-229 ◽  
Author(s):  
D. C. DuBois ◽  
R. R. Almon
Keyword(s):  
Glucocorticoid Receptor ◽  
Dry Weight ◽  
Levator Ani ◽  
Intact Male ◽  
Receptor Sites ◽  
Muscle Complex ◽  
Androgen Withdrawal ◽  
Androgen Regulation ◽  
Series Of Experiments ◽  
Plateau Level

ABSTRACT The glucocorticoid receptor population of the androgen-dependent levator ani–bulbo cavernosus muscle complex in response to both androgen withdrawal and androgen replacement was examined in rats. (1) After castration the concentration of receptor sites more than doubled. The increase in the sites began within the first 24 h after castration and reached a plateau level within 7 days. (2) Parallel dry weight studies demonstrated that no loss in muscle mass is observed until 48 h after castration. (3) In a second series of experiments, both the regrowth of the muscle and the number of receptor sites in response to androgen injections were examined. By day 11 of injection, the muscle had increased in dry weight to a point where it was equal to the size of this muscle in normal intact male controls. (4) During this process, the concentration of receptor sites began to decline 5 days after the beginning of injections and reached control or below control values by 11 days. J. Endocr. (1984) 102, 225–229

Control of Stem Elongation by Gibberellin A1: Evidence From Genetic Studies Including the Slender Mutant sln

1993 ◽  
Vol 20 (5) ◽  
pp. 585 ◽  
Author(s):  
JJ Ross ◽  
JB Reid ◽  
SM Swain
Keyword(s):  
Stem Elongation ◽  
Stem Length ◽  
Wild Type ◽  
Garden Pea ◽  
Genetic Studies ◽  
Developing Seed ◽  
In The Wild ◽  
Pea Mutant ◽  
Gibberellin A1 ◽  
Prohexadione Calcium

Information from well-known stem length mutants, both short and elongated, is discussed in the context of criteria necessary to demonstrate that the level of GA1 controls stem elongation in wild- type plants of the garden pea. Whilst this evidence is compelling, a mutant which over-produces GA1 would afford further insight, particularly into whether GA1 levels are saturating for growth in the wild-type. In this paper we further characterise the first reported garden pea mutant (sln) which possesses elevated levels of GA1. Evidence is presented from studies using this mutant that GA1 is normally limiting for growth over the early internodes in wild-type plants. In the developing seed, the mutant sin is shown to block the metabolism of [13C, 3H]GA29 to [13C, 3H]GA29-catabolite, particularly in the testa. Associated with this there were dramatically elevated GAGA29 levels in the dry seed from sln plants (400 times) compared with seeds from Sln plants. Upon germination, it appears that some of this GAGA20 is converted to GAGA1, which leads to substantial elongation of the early internodes. This hypothesis is supported by the observation that the inhibitor of an early step in GA biosynthesis, paclobutrazol, reduces elongation of sln plants when applied to developing seeds but not when applied at the start of germination. By contrast, prohexadione-calcium (BX-112), which inhibits the step GA20 to GA1, dramatically reduces internode length of sln plants when applied to seeds at the start of germination. Finally, application of GA20 to the dry seed of a wild-type (Sln) line (before sowing) resulted in a phenocopy of the sln mutant.

CHANGES IN PEACH TREES (cv. RED HAVEN) ATTACKED BY TAPHRINA DEFORMANS, WITH PARTICULAR REFERENCE TO NITROGEN METABOLISM IN INFECTED AND NON-INFECTED LEAVES

1967 ◽  
Vol 45 (4) ◽  
pp. 459-477 ◽  
Author(s):  
Vittorio Raggi
Keyword(s):  
Amino Acids ◽  
Nitrogen Metabolism ◽  
Free Amino Acids ◽  
Free Amino ◽  
Dry Weight ◽  
Infected Tissue ◽  
Diseased Plant ◽  
Glycolytic Activity ◽  
Protein Amino Acids ◽  
Peach Trees

Some of the changes induced by Taphrina deformans on metabolism (particularly the nitrogen metabolism) of peach leaves were studied. Observations were as follows. (1) Dry weight diminishes in the infected tissues, especially at the end of the cycle, whereas it remains almost unchanged in the non-infected tissues of the diseased plant. (2) Initially, the amount of total nitrogen, per gram of dry substance is clearly greater in the infected tissues than in the control, then it becomes lower during the differentiation of the asci, especially at the stage of full sporulation. Similar variations occur also, in a more attenuated form, in the non-infected tissues. (3) A considerable increase of the glycolytic activity is observed in the infected tissue especially during the period preceding the differentiation of the asci, and an increase of respiration, even though much more restricted, is observed also in the next period. In non-invaded tissues, an increase of glycolysis is noted along with a diminution of respiration. (4) The non-infected leaves weigh more than those of the control until the differentiation of the asci; after it, they have a clear drop up to the maturity of the asci, and a further revival at the end of the disease. (5) In the infected tissues, the content of free amino acids is always higher than in the control (with a maximum after sporulation), whereas in the non-infected ones it is generally lower. (6) The more important alterations in the pool of the free amino acids in invaded tissues consist in a scarcity, in percentage of the total, of alanine and glutamic acid, especially at the end of the disease, whereas proline, ornithine, glycine, and others increase, especially during the incubation period. In particular the glutamine–asparagines– threonine group reaches the highest value when sporulation has occurred. In the non-invaded tissues, the changes are more restricted. (7) The content of protein amino acids in infected tissues is generally lower than in the control, especially in the last phases of infection whereas in the non-invaded parts it is generally higher, except in differentiation of the asci. (8) In the infected tissue, the alterations of the quantitative relationships between the single protein amino acids (in percentage of the total) are not very great, but some diminutions and increases are recorded (diminution of alanine, glycine, leucine, etc.; increase of lysine, histidine, etc.); in the non-infected tissues, no noteworthy alterations were observed.

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