scholarly journals Response of Nicotiana alata to Insertion of an Autoregulated Senescence- inhibition Gene

2001 ◽  
Vol 126 (5) ◽  
pp. 523-530 ◽  
Author(s):  
Kenneth R. Schroeder ◽  
Dennis P. Stimart ◽  
Erik V. Nordheim
Keyword(s):  
Dry Weight ◽  
Biological Study ◽  
Nicotiana Alata ◽  
Isopentenyl Transferase ◽  
Shoot Dry Weight ◽  
New Information ◽  
Polymerase Chain ◽  
Selection For ◽  
Senesced Leaves

Nicotiana alata Link and Otto (Jasmine tobacco) was transformed with an autoregulated senescence-inhibition gene construct PSAG12-IPT encoding isopentenyl transferase via Agrobacterium-mediated transformation. Transformation was confirmed by polymerase chain reaction. Transgenic plants exhibited up to 2- to 4-fold fewer senesced leaves, 29% longer in situ flower life, 26% more shoot dry weight, and a 32% to 50% reduction in flowers per branch. Additionally, transgenics were 28% shorter and had up to 174% more branches, indicative of cytokinin overproduction and a lack of tight autoregulation of PSAG12-IPT. Variation among independent transgenics suggests selection for enhanced PSAG12-IPT is feasible. Our observations of increased branching and in situ flower longevity, as well as reduced plant height and flowers per branch provide new information on PSAG12-IPT and its potential value for biological study and horticultural application.

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.

Bidirectional Selection for Nitrogenase Activity and Shoot Dry Weight Among Late Generation Progenies of a Virginia x Spanish Peanut Cross1

1986 ◽  
Vol 13 (2) ◽  
pp. 86-89 ◽  
Author(s):  
S. Arrendell ◽  
J. C. Wynne ◽  
G. H. Elkan ◽  
T. J. Schneeweis
Keyword(s):  
Nitrogen Fixation ◽  
Plant Growth ◽  
Growth Habit ◽  
Nitrogenase Activity ◽  
Dry Weight ◽  
Fruit Weight ◽  
Shoot Dry Weight ◽  
Plant Growth Habit ◽  
The Mean ◽  
Selection For

Abstract Improvement of the host contribution to nitrogen fixation has been proposed as a method of increasing nitrogen fixation. Significant variability and generally high broad-sense heritability estimates (.60 ± .27 to .82 ± .26 for nitrogenase activity and .53 ± .29 to .85 ± .26 for shoot dry weight) have been reported for F2-derived families from a cross between the Virginia (Arachis hypogaea L. ssp. hypogaea var. hypogaea) cultivar NC 6 and the Spanish (ssp. fastigiata Waldron vulgaris Harz.) breeding line 922, indicating selection for increased nigtogen fixation should be effective in this population. Lines from this population were chosen randomly from F2-derived families selected for high and low nitrogenase activity and high and low shoot dry weight after evaluation at three dates and two locations in each of 2 years (F5 and F6 generations). This study's objectives were to evaluate the N2-fixing ability of the selected lines and to evaluate the association between plant growth habit and N2 fixation. Twenty-four lines in each of the four selection groups and the parents, NC 6 and 922, were evaluated at two sampling dates and two locations. Mean nitrogenase activity of lines selected for increased nitrogenase activity was significantly greater than the mean of the lines selected for low nitrogenase activity. Improved nitrogenase activity was associated with increased fruit weight. The fruit weight mean of the group selected for increased fruit weight. The fruit weight mean of the group selected for increased nitrogenase activity was 39% greater than the mean of the group selected for low nitrogenase activity. Mean shoot dry weight of lines selected for increased shoot dry weight was significantly greater than the mean of the lines selected for low shoot dry weight; however, the fruit weight means of these two groups did not differ. It was hypothesized that selection for increased N2 fixation in a population derived from a cross between Virginia and Spanish types would eliminate genotypes with Spanish growth habit. Groups selected for high nitrogenase activity and for high shoot dry weight had longer and wider leaflets, longer cotyledonary laterals and greater main stem height than did their respective low selection groups. However, these traits chosen to characterize plant growth habit were inadequate in discriminating parental growth habits. Consequently, the data neither substantiated nor refuted the hypothesis.

scholarly journals Competitiveness of Bradyrhizobium japonicum inoculation strain for soybean nodule occupancy  

2022 ◽  
Author(s):  
Dragana Miljakovic ◽  
Jelena Marinković ◽  
Maja Ignjatov ◽  
Dragana Milosević ◽  
Zorica Nikolić ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Bradyrhizobium Japonicum ◽  
Dry Weight ◽  
Soil Conditions ◽  
Nodule Occupancy ◽  
Enterobacterial Repetitive Intergenic Consensus ◽  
Shoot Dry Weight ◽  
Soybean Nodule ◽  
Commercial Inoculant ◽  
Selection For

The competitiveness of Bradyrhizobium japonicum inoculation strain against indigenous rhizobia was examined in a soil pot experiment. The effect of inoculation strain was evaluated under different soil conditions: with or without previously grown soybean and applied commercial inoculant. Molecular identification of inoculation strain and investigated rhizobial isolates, obtained from nodules representing inoculated treatments, was performed based on 16S rDNA and enterobacterial repetitive intergenic consensus (ERIC) sequencing. Inoculation strain showed a significant effect on the investigated parameters in both soils. Higher nodule occupancy (45% vs. 18%), nodule number (111% vs. 5%), nodule dry weight (49% vs. 9%), shoot length (15% vs. 7%), root length (31% vs. 13%), shoot dry weight (34% vs. 11%), shoot nitrogen content (27% vs. 2%), and nodule nitrogen content (9% vs. 5%) was detected in soil without previously grown soybean and applied commercial inoculant. Soil had a significant effect on the shoot, root and nodule nitrogen content, while interaction of experimental factors significantly altered dry weight and nitrogen content of shoots, roots and nodules, as well as number of nodules. Nodulation parameters were significantly related with shoot dry weight, shoot and nodule nitrogen content. Symbiotic performance of inoculation strains in the field could be improved through co-selection for their competitiveness and effectiveness.  

scholarly journals Susceptibility of four grapevine rootstocks to Cylindrocladiella parva

2013 ◽  
Vol 66 ◽  
pp. 249-253 ◽  
Author(s):  
D.S. Brown ◽  
M.V. Jaspers ◽  
H.J. Ridgway ◽  
C.J. Barclay ◽  
E.E. Jones
Keyword(s):  
Dry Weight ◽  
Conidial Suspension ◽  
Sterile Water ◽  
Rooted Cuttings ◽  
Root Dry Weight ◽  
Shoot Dry Weight ◽  
Foot Disease ◽  
Black Foot ◽  
Black Foot Disease

The susceptibility of four common grapevine rootstocks (10114 Schwarzmann 5C and Riparia Gloire) to Cylindrocladiella parva (black foot disease) infection was assessed in a pot experiment The roots of 4monthold callused rooted cuttings were wounded in situ and inoculated with 50 ml C parva conidial suspension (106/ml) or sterile water (controls) After 6 months of growth shoot dry weight was significantly higher for control plants (242 g) than for those inoculated with C parva (165 g) but did not differ between rootstock varieties Root dry weight was not significantly affected by C parva inoculation but root dry weight of 10114 was significantly higher than other rootstocks Incidence and severity of trunk infection were significantly affected by rootstock variety being lowest in rootstock 10114 plants than other rootstocks None of the rootstocks tested was resistant to this pathogen

scholarly journals Advances in the diagnosis and treatment of leprosy

2002 ◽  
Vol 4 (15) ◽  
pp. 1-14 ◽  
Author(s):  
Vishwa M. Katoch
Keyword(s):  
Direct Detection ◽  
Genomic Structure ◽  
In Situ Hybridisation ◽  
Technological Advances ◽  
New Information ◽  
Rna Targeting ◽  
Polymerase Chain ◽  
Monitoring Treatment ◽  
Effective Drugs

Leprosy is a chronic infectious disease caused by Mycobacterium leprae that mainly affects the skin and peripheral nerves. Over recent years, many important advances have been made in developing molecular diagnostics, in identifying highly effective drugs and designing multidrug regimens for treatment, and in unravelling the genomic structure and functions of the leprosy bacillus. Using the new information about specific sequences of M. leprae, several gene probes and gene amplification systems for confirming diagnosis and monitoring treatment have been developed. Among these, polymerase chain reaction (PCR)-based methods have been useful in confirming the diagnosis in paucibacillary leprosy (where few bacilli are present). RNA-targeting systems for monitoring the progress of treatment, in situ hybridisation techniques for analysing specimens with nonspecific histological features, and molecular methods for direct detection of rifampicin/dapsone resistance are other major technological advances with immense applied value. Several effective regimens for the treatment of leprosy have been developed, which include rifampicin, clofazimine and dapsone as core drugs. Although these regimens are generally satisfactory, limitations in terms of persisting activity and late reactions/relapses in paucibacillary leprosy, and persistence of dead and/or live organisms in multibacillary forms of the disease, have been observed.

scholarly journals Selecting forage grasses for improved nitrate retention - a progress report

2007 ◽  
pp. 207-211 ◽  
Author(s):  
S.N. Nichols ◽  
J.R. Crush
Keyword(s):  
Perennial Ryegrass ◽  
Dry Weight ◽  
Root Diameter ◽  
Italian Ryegrass ◽  
Forage Grasses ◽  
Nitrate Retention ◽  
Shoot Dry Weight ◽  
Shoot Size ◽  
Selection For ◽  
Nitrogen Demand

Significant variation for both root diameter and shoot dry weight was found among 20 commercially available hybrid and Italian ryegrass cultivars screened for root diameter. Nitrate interception by four selected cultivars was then compared with perennial ryegrass in a lysimeter trial. The shoot size of selected cultivars was significantly higher than perennial ryegrass. Drainage volumes from hybrid/Italian ryegrasses were half that of perennial ryegrass and contained significantly less nitrate. 15N absorption was also significantly higher for thin (79- 80%) and thick rooted (75-76%) hybrid/Italian cultivars than for the perennial ryegrass (63%). Root diameter of the different hybrid/Italian cultivars did not have a major impact on nitrogen interception and leaching. However the concept of a large, winter active grass with high nitrogen demand during periods of high leaching activity is supported by this study. Further selection for finer roots could increase the nitrogen interception ability of these plants without compromising shoot growth. Keywords: leaching, nitrate, roots, ryegrass

scholarly journals Air-filled Porosity, Gas Relative Diffusivity, and Tortuosity: Indices of Prunus ×cistena sp. Growth in Peat Substrates

1996 ◽  
Vol 121 (2) ◽  
pp. 236-242 ◽  
Author(s):  
Suzanne E. Allaire ◽  
Jean Caron ◽  
Isabelle Duchesne ◽  
Léon-Étienne Parent ◽  
Jacques-André Rioux
Keyword(s):  
Plant Growth ◽  
Chemical Properties ◽  
Dry Weight ◽  
Gas Diffusion ◽  
Water Desorption ◽  
Tortuosity Factor ◽  
Shoot Dry Weight ◽  
Relative Diffusivity ◽  
Chemical Factors

A 2-year experiment with Prunus ×cistena sp. was conducted in pots using seven substrates composed of various proportions of primarily peat, compost and bark. Peat substrates significantly affected root and shoot dry weight. Water desorption characteristics and saturated hydraulic conductivity were measured in situ to estimate the pore tortuosity factor and the relative gas diffusion coefficient. The pH, electrical conductivity, C/N ratio, total and hydrolyzable N, as well as NO3--N and NH4+-N in solution were also measured. Estimates of the physical properties suggest that a lack of aeration limited plant growth. Plant growth was significantly correlated with both the gas relative diffusivity and the pore tortuosity factor. Among the chemical factors, pH and soil nitrate level were also correlated with plant growth. No significant correlation was found between plant growth and air-filled porosity or any other measured chemical properties. This study indicates that an index of gas-exchange dynamics could be a useful complementary diagnostic tool to guide substrate manufacturing.

High performance Nanogold™-in situ hybridzation and its use in the detection of hybridized and PCR-amplified microscopical preparations

1996 ◽  
Vol 54 ◽  
pp. 896-897
Author(s):  
G. W. Hacker ◽  
I. Zehbe ◽  
J. Hainfeld ◽  
A.-H. Graf ◽  
C. Hauser-Kronberger ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Messenger Rna ◽  
High Performance ◽  
Detection System ◽  
Direct Methods ◽  
Genetic Alterations ◽  
Chain Reaction ◽  
Protein Encoding ◽  
Polymerase Chain

In situ hybridization (ISH) with biotin-labeled probes is increasingly used in histology, histopathology and molecular biology, to detect genetic nucleic acid sequences of interest, such as viruses, genetic alterations and peptide-/protein-encoding messenger RNA (mRNA). In situ polymerase chain reaction (PCR) (PCR in situ hybridization = PISH) and the new in situ self-sustained sequence replication-based amplification (3SR) method even allow the detection of single copies of DNA or RNA in cytological and histological material. However, there is a number of considerable problems with the in situ PCR methods available today: False positives due to mis-priming of DNA breakdown products contained in several types of cells causing non-specific incorporation of label in direct methods, and re-diffusion artefacts of amplicons into previously negative cells have been observed. To avoid these problems, super-sensitive ISH procedures can be used, and it is well known that the sensitivity and outcome of these methods partially depend on the detection system used.

Cell Size and Pretransplant Nutritional Conditioning Influences Early Vine Growth and Yield of Transplanted Watermelon

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 594e-594
Author(s):  
Charles J. Graham
Keyword(s):  
Cell Volume ◽  
Significant Influence ◽  
Field Performance ◽  
Dry Weight ◽  
Soluble Solids ◽  
Growth And Yield ◽  
Average Weight ◽  
Shoot Dry Weight ◽  
Solids Concentration ◽  
Soluble Solids Concentration

Research is needed to better understand the influence of cell volume and fertility on watermelon transplant size and field performance in order to determine the most economic production practices. `Jubilee' watermelon transplants were grown using a 4 x 4 factorial experimental design consisting of 4 cell volumes (30.7, 65.5, 147.5, and 349.6 cm3) and 4 fertility rates (0, 1/4, 1/2, and full-strength Hoagland's solution). Transplant shoot dry weight significantly increased as cell volume and fertility increased. Increasing cell volume linearly increased watermelon number/ha and tons/ha for early and total harvest in 1995. The average weight per watermelon significantly increased for early-harvested fruit but not for total harvest as cell volume increased in 1995. Soluble solids concentration linearly increased with increasing cell volume for early and total harvests in 1995. Cell volume had no significant influence on the harvest parameters measured in 1997. In 1995, increasing fertility linearly increased watermelon number/ha and tons/ha for early harvests. Increasing fertility increased the soluble solids concentration linearly for early-harvested watermelons in 1997 but not in 1995. Fertility rate had no significant influence on any of the other harvest parameters measured in 1995 and 1997. The growing conditions and disease pressure in 1997 reduced melons/ha, yield, and soluble solids content when compared to 1995 values. The half-strength Hoagland's solution produced the greatest number of watermelons/ha, tons/ha, and the highest soluble solids concentration in 1995 and 1997. Pretransplant nutritional conditioning had no significant effect on total `Jubilee' watermelon production in Louisiana for 1995 and 1997.

Sign in / Sign up

Export Citation Format

Share Document