Lack of Glyphosate Resistance Gene Transfer from Roundup Ready® Soybean to Bradyrhizobium japonicum under Field and Laboratory Conditions

2011 ◽  
Vol 66 (11-12) ◽  
pp. 595-604
Author(s):  
Laura Arango Isaza ◽  
Katja Opelt ◽  
Tobias Wagner ◽  
Elke Mattes ◽  
Evi Bieber ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Dna Sequence ◽  
Bradyrhizobium Japonicum ◽  
Natural Transformation ◽  
Roundup Ready ◽  
Laboratory Conditions ◽  
Epsps Gene ◽  
Field And Laboratory Conditions ◽  
Japonicum Strain ◽  
Cp4 Epsps

A fi eld study was conducted at the Russell E. Larson Agricultural Research Center to determine the effect of transgenic glyphosate-resistant soybean in combination with herbicide (Roundup) application on its endosymbiont Bradyrhizobium japonicum. DNA of bacteroids from isolated nodules was analysed for the presence of the transgenic 5-enolpyruvylshikimate- 3-phosphate synthase (CP4-EPSPS) DNA sequence using polymerase chain reaction (PCR). To further assess the likelihood that the EPSPS gene may be transferred from the Roundup Ready® (RR) soybean to B. japonicum, we have examined the natural transformation efficiency of B. japonicum strain 110spc4. Analyses of nodules showed the presence of the transgenic EPSPS DNA sequence. In bacteroids that were isolated from nodules of transgenic soybean plants and then cultivated in the presence of glyphosate this sequence could not be detected. This indicates that no stable horizontal gene transfer (HGT) of the EPSPS gene had occurred under field conditions. Under laboratory conditions, no natural transformation was detected in B. japonicum strain 110spc4 in the presence of various amounts of recombinant plasmid DNA. Our results indicate that no natural competence state exists in B. japonicum 110spc4. Results from field and laboratory studies indicate the lack of functional transfer of the CP4-EPSPS gene from glyphosate-tolerant soybean treated with glyphosate to root-associated B. japonicum

scholarly journals An Evolutionary Link between Natural Transformation and CRISPR Adaptive Immunity

mBio ◽  
2012 ◽  
Vol 3 (5) ◽  
Author(s):  
Peter Jorth ◽  
Marvin Whiteley
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Bacterial Diversity ◽  
Natural Transformation ◽  
Bacterial Species ◽  
Comparative Genomic ◽  
Content Type ◽  
Immune Systems ◽  
Adaptive Immune ◽  
Adaptive Immune Systems

ABSTRACTNatural transformation by competent bacteria is a primary means of horizontal gene transfer; however, evidence that competence drives bacterial diversity and evolution has remained elusive. To test this theory, we used a retrospective comparative genomic approach to analyze the evolutionary history ofAggregatibacter actinomycetemcomitans, a bacterial species with both competent and noncompetent sister strains. Through comparative genomic analyses, we reveal that competence is evolutionarily linked to genomic diversity and speciation. Competence loss occurs frequently during evolution and is followed by the loss of clustered regularly interspaced short palindromic repeats (CRISPRs), bacterial adaptive immune systems that protect against parasitic DNA. Relative to noncompetent strains, competent bacteria have larger genomes containing multiple rearrangements. In contrast, noncompetent bacterial genomes are extremely stable but paradoxically susceptible to infective DNA elements, which contribute to noncompetent strain genetic diversity. Moreover, incomplete noncompetent strain CRISPR immune systems are enriched for self-targeting elements, which suggests that the CRISPRs have been co-opted for bacterial gene regulation, similar to eukaryotic microRNAs derived from the antiviral RNA interference pathway.IMPORTANCEThe human microbiome is rich with thousands of diverse bacterial species. One mechanism driving this diversity is horizontal gene transfer by natural transformation, whereby naturally competent bacteria take up environmental DNA and incorporate new genes into their genomes. Competence is theorized to accelerate evolution; however, attempts to test this theory have proved difficult. Through genetic analyses of the human periodontal pathogenAggregatibacter actinomycetemcomitans, we have discovered an evolutionary connection between competence systems promoting gene acquisition and CRISPRs (clustered regularly interspaced short palindromic repeats), adaptive immune systems that protect bacteria against genetic parasites. We show that competentA. actinomycetemcomitansstrains have numerous redundant CRISPR immune systems, while noncompetent bacteria have lost their CRISPR immune systems because of inactivating mutations. Together, the evolutionary data linking the evolution of competence and CRISPRs reveals unique mechanisms promoting genetic heterogeneity and the rise of new bacterial species, providing insight into complex mechanisms underlying bacterial diversity in the human body.

Heavy metal depuration in flat tree oystersisognomon alatusunder field and laboratory conditions

2004 ◽  
Vol 86 (3) ◽  
pp. 171-179 ◽  
Author(s):  
Katayon Saed ◽  
Ahmad Ismail ◽  
Hishamuddin Omar ◽  
Misri Kusnan
Keyword(s):  
Heavy Metal ◽  
Laboratory Conditions ◽  
Field And Laboratory Conditions

scholarly journals Electrical conductivity of the seed soaking solution and soybean seedling emergence

2004 ◽  
Vol 61 (2) ◽  
pp. 164-168 ◽  
Author(s):  
Roberval Daiton Vieira ◽  
Angelo Scappa Neto ◽  
Sonia Regina Mudrovitsch de Bittencourt ◽  
Maristela Panobianco
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Seedling Emergence ◽  
Soybean Seed ◽  
Accelerated Aging ◽  
Seed Vigor ◽  
Soybean Seedling ◽  
Seed Soaking ◽  
Laboratory Conditions ◽  
Field And Laboratory Conditions

Vigor of soybean [Glycine max (L.) Merrill] seeds can be evaluated by measuring the electrical conductivity (EC) of the seed soaking solution, which has shown a satisfactory relationship with field seedling emergence, but has not had aproper definition of range yet. This work studies the relationship between EC and soybean seedling emergence both in the field and laboratory conditions, using twenty two seed lots. Seed water content, standard germination and vigor (EC, accelerated aging and cold tests) were evaluated under laboratory conditions using -0.03; -0.20; -0.40 and -0.60 MPa matric potentials, and field seedling emergence was also observed. There was direct relationship between EC and field seedling emergence (FE). Under laboratory conditions, a decreasing relationship was found between EC and FE as water content in the substrate decreased. Relationships between these two parameters were also found when -0.03; -0.20 and -0.40 MPa matric potentials were used. EC tests can be used successfully to evaluate soybean seed vigor and identify lots with higher or lower field emergence potential.

scholarly journals Selección para calidad fisiológica de la semilla y rendimiento en líneas S2 derivadas de cuatro poblaciones tropicales de maíz (Zea mays L.)

2016 ◽  
Vol 7 (1) ◽  
pp. 58
Author(s):  
Enrique Navarro ◽  
Cristina Vega ◽  
Fernando Narváez ◽  
Hugo Córdova
Keyword(s):  
Genetic Variability ◽  
Grain Yield ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Agronomic Traits ◽  
Reciprocal Recurrent Selection ◽  
Laboratory Conditions ◽  
Flower Plant ◽  
Ear Height ◽  
Field And Laboratory Conditions

This study was carried out in 1993 to evaluate S2 lines from four maize tropical populations improved by reciprocal recurrent selection. These lines were evaluated under field and laboratory conditions, the latter one to determine physiology quality. The main goal was to measure genetic variability within and among populations for traits such as grain yield, vigor and germination and to select the best lines under field and laboratory conditions. The combined analysis of variance showed great genetic variability among the S2 lines within and among populations for grain yield, days to flower, plant and ear height, among others. The maximum genetic variability was observed on the lines from population 43 and pool 23 for most of the traits, although the latter showed a greater genetic variability for grain yield. Besides, it is important to mention that the above populations included the best genotypes for grain yield, germination and vigor. Taking into account the above mentionel agronomic traits, fifteen lines were selected; 2 belong to population 43* pool 20, 2 from pool 19* pool 23, 8 from population 43, and 3 from pool 23. These results confirm the genetic superiority of the lines from populations 43 and pool 23, so that these populations should be recommended for future genetic improvement by reciprocal recurrent procedures.

Annual dormancy cycles in Lesquerella fendleri (Brassicaceae) seeds stored under both field and laboratory conditions

2000 ◽  
Vol 77 (11) ◽  
pp. 1648-1654
Author(s):  
Laura A Hyatt ◽  
Ann S Evans ◽  
Carol C Baskin
Keyword(s):  
Seed Storage ◽  
Storage Conditions ◽  
Perennial Species ◽  
Lesquerella Fendleri ◽  
Laboratory Conditions ◽  
Fluctuating Environments ◽  
Growth Chambers ◽  
Field And Laboratory Conditions ◽  
Dormancy Cycles ◽  
Over Time

Patterns of germination over time were investigated in a short-lived desert perennial species, Lesquerella fendleri (Gray) S. Wats. Field-collected seeds were either buried in the field in cloth bags or stored in a glass jar under laboratory conditions. Regular germination tests were conducted under a range of alternating temperatures (buried seeds) or under differing water regimes (laboratory-stored seeds). Testing revealed Lesquerella fendleri to have an annual dormancy-nondormancy cycle, which was manifest regardless of seed storage conditions, suggesting that cycles may be partially endogenously regulated. Increasing seed germinability in field-stored seeds (maximum of 30% in year 1 and 95% in year 2) leads to the formation of a seed bank for at least 1 year and enhances the possibility of spreading germination events through time. This allows parent plants to maximize fitness in randomly fluctuating environments. The existence of two seedling flushes in the field and single germinability peaks in growth chambers suggests that dormancy cycling may support the formation of a metapopulation with subpopulations which are, although physically intermingled, genetically distinct.

Applied Zoology for Forming of Research Competence at Students of Biologists

2018 ◽  
pp. 321-341
Author(s):  
Farit Miniyarov
Keyword(s):  
Research Work ◽  
Rating System ◽  
Research Projects ◽  
Research Activity ◽  
Research Competence ◽  
Laboratory Conditions ◽  
Uniform Approach ◽  
System A ◽  
Field And Laboratory Conditions

This chapter about how to involve students of biologists in research work, using benefits of applied zoology. The first part of the chapter provides the overview of such questions as research activity of students, methods and conditions of its forming, feature for students of biologists. The second part is devoted to the step-by-step organization of research activity according to levels of readiness of students. Much attention in this part is paid to questions of applied zoology: directions and objects of researches; structure and content of laboratory works, scientific and practical and research projects; uniform approach to use of techniques of researches in field and laboratory conditions. For assessment of results of researches and formation of research competence of students such methods as rating system, a portfolio, methods of expert estimates are offered.

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