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Durzan DJ. Female parthenogenetic apomixis and androsporogenetic parthenogenesis in embryonal cells of Araucaria angustifolia: interpolation of progenesis and asexual heterospory in an artificial sporangium. SEXUAL PLANT REPRODUCTION 2012; 25:227-246. [PMID: 22669467 DOI: 10.1007/s00497-012-0189-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 05/16/2012] [Indexed: 06/01/2023]
Abstract
Cell fate, development timing and occurrence of reproductive versus apomictic development in gymnosperms are shown to be influenced by culture conditions in vitro. In this study, female parthenogenetic apomixis (fPA), androsporogenetic parthenogenesis (mAP) and progenesis were demonstrated using embryonal initials of Araucaria angustifolia in scaled-up cell suspensions passing through a single-cell bottleneck in darkness and in an artificial sporangium (AS). Expression was based on defined nutrition, hormones and feedforward-adaptive feedback process controls at 23-25 °C and in darkness. In fPA, the nucleus of an embryonal initial undergoes endomitosis and amitosis, forming a diploid egg-equivalent and an apoptotic ventral canal nucleus in a transdifferentiated archegonial tube. Discharge of egg-equivalent cells as parthenospores and their dispersal into the aqueous culture medium were followed by free-nuclear conifer-type proembryogenesis. This replaced the plesiomorphic and central features of proembryogenesis in Araucariaceae. Protoplasmic fusions of embryonal initials were used to reconstruct heterokaryotic expressions of fPA in multiwell plates. In mAP, restitutional meiosis (automixis) was responsible for androsporogenesis and the discharge of monads, dyads, tetrads and polyads. In a display of progenesis, reproductive development was brought to an earlier ontogenetic stage and expressed by embryonal initials. Colchicine increased polyploidy, but androspore formation became aberrant and fragmented. Aberrant automixis led to the formation of chromosomal bouquets, which contributed to genomic silencing in embryonal initials, cytomixis and the formation of pycnotic micronucleated cells. Dispersal of female and male parthenospores displayed heteromorphic asexual heterospory in an aqueous environment.
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Affiliation(s)
- Don J Durzan
- University of California, Plant Sciences, Davis, CA 95616, USA.
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Krishnen G, Kecskés ML, Rose MT, Geelan-Small P, Amprayn KO, Pereg L, Kennedy IR. Field monitoring of plant-growth-promoting rhizobacteria by colony immunoblotting. Can J Microbiol 2011; 57:914-22. [DOI: 10.1139/w11-059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Inoculant plant-growth-promoting bacteria are emerging as an important component of sustainable agriculture. There is a need to develop inexpensive methods for enumerating these organisms after their application in the field, to better understand their survival and impacts on yields. Immunoblotting is one potential method to measure viable cells, but the high cost of the conventionally used nylon membranes makes this method prohibitive. In this study, less expensive alternative materials such as filter papers, glossy photo papers, and transparencies for the purpose of colony immunoblotting were evaluated and the best substance was chosen for further studies. Whatman filter paper No. 541 combined with a 0.01 mol·L–1 H2SO4 rinsing step gave similar results to nylon membranes but <20% of the overall cost of the original colony immunoblotting assay. The application of the modified immunoblot method was tested on nonsterile clay soil samples that were spiked with high numbers (>107 CFU·g–1) of the plant-growth-promoting bacteria Pseudomonas fluorescens , Azospirillum brasilense , or Rhizobium leguminosarum . The modified protocol allowed the identification and recovery of over 50% of the inoculated cells of all three strains, amidst a background of the native soil microflora. Subsequently, the survival of P. fluorescens was successfully monitored for several months after application to field-grown rice at Jerilderie, New South Wales, Australia, thus validating the procedure.
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Affiliation(s)
- Ganisan Krishnen
- SUNFix Centre for Nitrogen Fixation, Faculty of Agriculture, Food and Natural Resources, Biomedical Building, 1 Central Avenue, Eveleigh, The University of Sydney, New South Wales 2006, Australia
- Strategic Resources Research Centre, MARDI Head Quarters, 43400 Serdang, Selangor, Malaysia
| | - Mihály L. Kecskés
- SUNFix Centre for Nitrogen Fixation, Faculty of Agriculture, Food and Natural Resources, Biomedical Building, 1 Central Avenue, Eveleigh, The University of Sydney, New South Wales 2006, Australia
| | - Michael T. Rose
- SUNFix Centre for Nitrogen Fixation, Faculty of Agriculture, Food and Natural Resources, Biomedical Building, 1 Central Avenue, Eveleigh, The University of Sydney, New South Wales 2006, Australia
| | - Peter Geelan-Small
- SUNFix Centre for Nitrogen Fixation, Faculty of Agriculture, Food and Natural Resources, Biomedical Building, 1 Central Avenue, Eveleigh, The University of Sydney, New South Wales 2006, Australia
| | - Khanok-on Amprayn
- SUNFix Centre for Nitrogen Fixation, Faculty of Agriculture, Food and Natural Resources, Biomedical Building, 1 Central Avenue, Eveleigh, The University of Sydney, New South Wales 2006, Australia
| | - Lily Pereg
- School of Science and Technology, University of New England, Armidale New South Wales, Australia
| | - Ivan R. Kennedy
- SUNFix Centre for Nitrogen Fixation, Faculty of Agriculture, Food and Natural Resources, Biomedical Building, 1 Central Avenue, Eveleigh, The University of Sydney, New South Wales 2006, Australia
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Davis CK, Denman SE, Sly LI, McSweeney CS. Development of a colorimetric colony-screening assay for detection of defluorination by micro-organisms. Lett Appl Microbiol 2011; 53:417-23. [PMID: 21767280 DOI: 10.1111/j.1472-765x.2011.03123.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To develop a colorimetric colony-screening assay to facilitate the isolation of micro-organisms capable of defluorination. METHODS AND RESULTS A metal-dye chelate, zirconium-xylenol orange was used to detect fluoride ions released from a fluorinated substrate through microbial metabolism. Depolymerised zirconium reagent gave the greatest visual contrast for the presence of fluoride compared to more polymerised forms of zirconium reagent. The sensitivity of the assay was greatest when the molar ratio of depolymerised zirconium to xylenol orange was 1:2. Using depolymerised zirconium and xylenol orange (150 and 300 nmol l(-1) respectively), the assay could detect a fluoride application spot (5 mmol l(-1)) containing 50 nmoles of fluoride ions. Most media constituents were well tolerated by the assay, although phosphate ions needed to be restricted to 0.1 g l(-1) and some proteins digest to between 1 and 5 g l(-1). A microbial enrichment culture growing on solidified medium containing 20 mmol l(-1) fluoroacetate was screened using the assay, and defluorinating bacteria belonging to the genus Burkholderia isolated. CONCLUSIONS A method was developed that is sensitive, rapid and reliable for detecting defluorination by micro-organisms growing on solidified medium. SIGNIFICANCE AND IMPACT OF THE STUDY This method can be used to facilitate the isolation of micro-organisms capable of defluorination.
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Affiliation(s)
- C K Davis
- CSIRO Livestock Industries, Queensland Bioscience Precinct, St Lucia, Qld, Australia
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Fargasová A, Betina V. Acquisition of small colonies of Trichoderma viride for genetic analysis. Folia Microbiol (Praha) 1985; 30:458-61. [PMID: 4054737 DOI: 10.1007/bf02928756] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Growth and mutual interlacing of colonies of T. viride is affected by concentration of nutrients and presence of inhibitors in the culture medium. The most convenient colony restrictors were Bengal red, Ox Gall and sodium deoxycholate while L-sorbose and 2-deoxy-D-arabino-hexose were less efficient.
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Tan ST, Maxcy RB, Thompson TL. Paper replication method for isolation of radiation-sensitive mutants. Appl Environ Microbiol 1983; 46:233-6. [PMID: 6351745 PMCID: PMC239293 DOI: 10.1128/aem.46.1.233-236.1983] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A filter paper replication system particularly useful for isolation of radiation-sensitive mutants of pigmented bacteria was devised. The fidelity of replication was high. Adhesion between a paper disk and a properly dried master plate provided adequate contact pressure. The replicas arising from this technique constitute a convenient apparatus for general application in isolation of clones sensitive to a discriminating treatment.
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Delange AM, Mishra NC. The isolation of mms- and histidine-sensitive mutants in Neurospora crassa. Genetics 1981; 97:247-59. [PMID: 6456170 PMCID: PMC1214392 DOI: 10.1093/genetics/97.2.247] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A simple method of replica plating has been used to isolate mutants of Neurospora crassa that have increased sensitivity to methyl methanesulfonate (MMS) and/or to histidine. Twelve mutants with increased sensitivity to MMS and one mutant with increased sensitivity to histidine showed Mendelian segregation of the mutant phenotypes. Three mutants were mapped to loci not previously associated with MMS sensitivity. Two other were allelic to the UV- and MMS-sensitive mutant, mei-3. Survival curves indicate that conidia (mutant or wild-type) survive on much higher concentrations of MMS at 25 degrees than at 37 degrees. In contrast, mycelial growth is more resistant to MMS at 37 degrees. The possibility of qualitatively different repair processes at these two temperatures is discussed.
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Käfer E, Perlmutter E. Isolation and genetic analysis of MMS-sensitive mus mutants of neurospora. CANADIAN JOURNAL OF GENETICS AND CYTOLOGY. JOURNAL CANADIEN DE GENETIQUE ET DE CYTOLOGIE 1980; 22:535-52. [PMID: 7237231 DOI: 10.1139/g80-060] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
With the aim of obtaining mutants that affect DNA repair or recombination, mutants sensitive to methylmethane sulfonate (MMS) have been isolated in the ascomycete Neurospora crassa. Seven of these mutants were backcrossed repeatedly to produce isogenic strains for measurements of relative mutagen sensitivities and for analysis of recombination frequencies. The new mus (mutagen sensitives) were compared to four previously known radiation-sensitive mutants which were shown to be cross-sensitive to MMS. Tests for allelism assigned the mus mutants to five new genes, mus-7 to mus-11, each mapping in a different linkage group. In homozygous crosses all mutants were sterile, except the two alleles of gene mus-10 which occasionally produced some viable ascospores. Complementation tests on MMS-media identified double mutant strains from many intercrosses. Such strains can be used for analysis of interactions between mutant alleles from different genes and of possible epistatic groupings for repair-deficient mutants in Neurospora. Four of these double mutant strains, all containing mus-8 and previously known mutants, were checked for survival on MMS media and their sensitivities were compared to those of their parental single mutant strains. Results indicate that mus-8 may be epistatic to uvs-2 which is deficient in excision repair, but not to mutants like uvs-3 that appear to be deficient in error-prone repair.
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Littlewood BS, Chia W, Metzenberg RL. Genetic control of phosphate-metabolizing enzymes in Neurospora crassa: relationships among regulatory mutations. Genetics 1975; 79:419-34. [PMID: 123873 PMCID: PMC1213282 DOI: 10.1093/genetics/79.3.419] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In Neurospora crassa, the phosphate-metabolizing enzymes are made during phosphate starvation, but not under phosphate sufficiency. The synthesis of these enzymes is controlled by three regulatory genes: pcon-nuc-2, preg and nuc-1, pcon-nuc-2 and preg are closely linked. A model of the hierarchical relationships among these regulatory genes is presented. Studies of double mutants and revertants confirm several predictions of the model. It has been found that nuc-2 (null) and pcon-c (constitutive) mutations reside in the same cistron. preg-c (constitutive) mutations are epistatic to nuc-2 mutations. nuc-1 (null) mutations are epistatic to all others.
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Selektion ausgewählterClaviceps-Stämme mit der Replica-Plating-Methode. J Basic Microbiol 1975. [DOI: 10.1002/jobm.3630150211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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