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Deng L, Pan Y, Chen X, Chen G, Hu Z. Small RNAs were involved in homozygous state-associated silencing of a marker gene (Neomycin phosphotransferase II: nptII) in transgenic tomato plants. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 68:8-15. [PMID: 23612328 DOI: 10.1016/j.plaphy.2013.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 03/26/2013] [Indexed: 06/02/2023]
Abstract
Homozygous state-associated co-suppression is not a very common phenomenon. In our experiments, two transgenic plants 3A29 and 1195A were constructed by being transformed with the constructs pBIN-353A and pBIN119A containing nptII gene as a marker respectively. The homozygous progeny from these two independent transgenic lines 3A29 and 1195A, displayed kanamycin-sensitivity and produced a short main root without any lateral roots as untransformed control (wild-type) seedlings when germinated on kanamycin media. For the seedlings derived from putative hemizygous plants, the percentage of the seedlings showing normal growth on kanamycin media was about 50% and lower than the expected percentage (75%). Southern analysis of the genomic DNA confirmed that the homozygous and hemizygous plants derived from the same lines contained the same multiple nptII transgenes, which were located on the same site of chromosome. Northern analysis suggested that the marker nptII gene was expressed in the primary and the hemizygous transformants, but it was silenced in the homozygous transgenic plants. Further Northern analysis indicated that antisense and sense small nptII-derived RNAs were present in the transgenic plants and the blotting signal of nptII-derived small RNA was much higher in the homozygous transgenic plants than that of hemizygous transgenic plants. Additionally, read-through transcripts from the TRAMP gene to the nptII gene were detected. These results suggest that the read-through transcripts may be involved in homozygous state-associated silencing of the nptII transgene in transgenic tomato plants and a certain threshold level of the nptII-derived small RNAs is required for the homozygous state-associated co-suppression of the nptII transgene.
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Affiliation(s)
- Lei Deng
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Campus A, 174 Shapingba Main Street, Chongqing 400044, People's Republic of China
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Wiebke-Strohm B, Pasquali G, Margis-Pinheiro M, Bencke M, Bücker-Neto L, Becker-Ritt AB, Martinelli AHS, Rechenmacher C, Polacco JC, Stolf R, Marcelino FC, Abdelnoor RV, Homrich MS, Del Ponte EM, Carlini CR, De Carvalho MCCG, Bodanese-Zanettini MH. Ubiquitous urease affects soybean susceptibility to fungi. PLANT MOLECULAR BIOLOGY 2012; 79:75-87. [PMID: 22382992 PMCID: PMC3332383 DOI: 10.1007/s11103-012-9894-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Accepted: 02/11/2012] [Indexed: 05/09/2023]
Abstract
The soybean ubiquitous urease (encoded by GmEu4) is responsible for recycling metabolically derived urea. Additional biological roles have been demonstrated for plant ureases, notably in toxicity to other organisms. However, urease enzymatic activity is not related to its toxicity. The role of GmEu4 in soybean susceptibility to fungi was investigated in this study. A differential expression pattern of GmEu4 was observed in susceptible and resistant genotypes of soybeans over the course of a Phakopsora pachyrhizi infection, especially 24 h after infection. Twenty-nine adult, transgenic soybean plants, representing six independently transformed lines, were obtained. Although the initial aim of this study was to overexpress GmEu4, the transgenic plants exhibited GmEu4 co-suppression and decreased ureolytic activity. The growth of Rhizoctonia solani, Phomopsis sp., and Penicillium herguei in media containing a crude protein extract from either transgenic or non-transgenic leaves was evaluated. The fungal growth was higher in the protein extracts from transgenic urease-deprived plants than in extracts from non-transgenic controls. When infected by P. pachyrhizi uredospores, detached leaves of urease-deprived plants developed a significantly higher number of lesions, pustules and erupted pustules than leaves of non-transgenic plants containing normal levels of the enzyme. The results of the present work show that the soybean plants were more susceptible to fungi in the absence of urease. It was not possible to overexpress active GmEu4. For future work, overexpression of urease fungitoxic peptides could be attempted as an alternative approach.
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Affiliation(s)
- Beatriz Wiebke-Strohm
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Giancarlo Pasquali
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, UFRGS, Porto Alegre, Brazil
| | - Márcia Margis-Pinheiro
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Marta Bencke
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Lauro Bücker-Neto
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Arlete B. Becker-Ritt
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, UFRGS, Porto Alegre, Brazil
| | - Anne H. S. Martinelli
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, UFRGS, Porto Alegre, Brazil
| | - Ciliana Rechenmacher
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | | | - Renata Stolf
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Soja, Londrina, Brazil
| | | | | | - Milena S. Homrich
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Emerson M. Del Ponte
- Departamento de Fitossanidade, Faculdade de Agronomia, UFRGS, Porto Alegre, Brazil
| | - Celia R. Carlini
- Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, UFRGS, Porto Alegre, Brazil
| | | | - Maria Helena Bodanese-Zanettini
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
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Cooper JL, Till BJ, Laport RG, Darlow MC, Kleffner JM, Jamai A, El-Mellouki T, Liu S, Ritchie R, Nielsen N, Bilyeu KD, Meksem K, Comai L, Henikoff S. TILLING to detect induced mutations in soybean. BMC PLANT BIOLOGY 2008; 8:9. [PMID: 18218134 PMCID: PMC2266751 DOI: 10.1186/1471-2229-8-9] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Accepted: 01/24/2008] [Indexed: 05/18/2023]
Abstract
BACKGROUND Soybean (Glycine max L. Merr.) is an important nitrogen-fixing crop that provides much of the world's protein and oil. However, the available tools for investigation of soybean gene function are limited. Nevertheless, chemical mutagenesis can be applied to soybean followed by screening for mutations in a target of interest using a strategy known as Targeting Induced Local Lesions IN Genomes (TILLING). We have applied TILLING to four mutagenized soybean populations, three of which were treated with ethyl methanesulfonate (EMS) and one with N-nitroso-N-methylurea (NMU). RESULTS We screened seven targets in each population and discovered a total of 116 induced mutations. The NMU-treated population and one EMS mutagenized population had similar mutation density (approximately 1/140 kb), while another EMS population had a mutation density of approximately 1/250 kb. The remaining population had a mutation density of approximately 1/550 kb. Because of soybean's polyploid history, PCR amplification of multiple targets could impede mutation discovery. Indeed, one set of primers tested in this study amplified more than a single target and produced low quality data. To address this problem, we removed an extraneous target by pretreating genomic DNA with a restriction enzyme. Digestion of the template eliminated amplification of the extraneous target and allowed the identification of four additional mutant alleles compared to untreated template. CONCLUSION The development of four independent populations with considerable mutation density, together with an additional method for screening closely related targets, indicates that soybean is a suitable organism for high-throughput mutation discovery even with its extensively duplicated genome.
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Affiliation(s)
| | - Bradley J Till
- Fred Hutchinson Cancer Research Center, Seattle, WA 98107, USA
- Department of Biology, University of Washington, Box 355325, Seattle, WA 98195, USA
| | - Robert G Laport
- Fred Hutchinson Cancer Research Center, Seattle, WA 98107, USA
| | | | - Justin M Kleffner
- National Center for Soybean Biotechnology, Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Aziz Jamai
- Department of Plant Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901, USA
| | - Tarik El-Mellouki
- Department of Plant Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901, USA
| | - Shiming Liu
- Department of Plant Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901, USA
| | - Rae Ritchie
- USDA-ARS Crop Production and Pest Control Research Unit, Purdue University, West Lafayette, IN 47907, USA
| | - Niels Nielsen
- USDA-ARS Crop Production and Pest Control Research Unit, Purdue University, West Lafayette, IN 47907, USA
| | | | - Khalid Meksem
- Department of Plant Soil and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901, USA
| | - Luca Comai
- Department of Biology, University of Washington, Box 355325, Seattle, WA 98195, USA
- Current address: Department of Plant Biology and Genome Center, UC Davis, Davis, CA 95616, USA
| | - Steven Henikoff
- Fred Hutchinson Cancer Research Center, Seattle, WA 98107, USA
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