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1.
J Biotechnol ; 214: 182-91, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26432336

RESUMO

A droplet-vitrification procedure is described for cryopreservation of Malus shoot tips. Survival patterns, recovery types, histological observations, and genetic integrity were compared for Malus shoot tips cryopreserved using this droplet-vitrification procedure and an encapsulation-dehydration procedure that was previously reported by us. In both procedures, three types of shoot tip recovery were observed following cryopreservation: callus formation without shoot regrowth, leaf formation without shoot regrowth, and shoot regrowth. Three categories of histological observations were also identified in cross-sections of shoot tips recovered after cryopreservation using the two cryogenic procedures. In category 1, almost all of the cells (94-95%) in the apical dome (AD) were damaged or killed and only some cells (30-32%) in the leaf primordia (LPs) survived. In category 2, only a few cells (18-20%) in the AD and some cells (30-31%) in the LPs survived. In category 3, majority of the cells (60-62%) in the AD and some cells (30-33%) in the LPs survived. These data suggest that shoot regrowth is correlated to the presence of a majority of surviving cells in the AD after liquid nitrogen exposure. No polymorphic bands were detected by inter-simple sequence repeats or by random amplified polymorphic DNA assessments, and ploidy levels analyzed by flow cytometry were unchanged when plants recovered after cryoexposure were compared to controls. The droplet-vitrification procedure appears to be robust since seven genotypes representing four Malus species and one hybrid recovered shoots following cryopreservation. Mean shoot regrowth levels of these seven genotypes were 48% in the droplet-vitrification method, which were lower than those (61%) in the encapsulation-dehydration procedure reported in our previous study, suggesting the latter may be preferred for routine cryobanking applications for Malus shoot tips.


Assuntos
Criopreservação/métodos , Dessecação/métodos , Malus/citologia , Malus/fisiologia , Brotos de Planta/citologia , Brotos de Planta/fisiologia , DNA de Plantas/análise , DNA de Plantas/genética , Malus/genética , Vitrificação
2.
Biotechnol Adv ; 32(3): 583-95, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24681087

RESUMO

Rapid increases in human populations provide a great challenge to ensure that adequate quantities of food are available. Sustainable development of agricultural production by breeding more productive cultivars and by increasing the productive potential of existing cultivars can help meet this demand. The present paper provides information on the potential uses of cryogenic techniques in ensuring food security, including: (1) long-term conservation of a diverse germplasm and successful establishment of cryo-banks; (2) maintenance of the regenerative ability of embryogenic tissues that are frequently the target for genetic transformation; (3) enhancement of genetic transformation and plant regeneration of transformed cells, and safe, long-term conservation for transgenic materials; (4) production and maintenance of viable protoplasts for transformation and somatic hybridization; and (5) efficient production of pathogen-free plants. These roles demonstrate that cryogenic technologies offer opportunities to ensure food security.


Assuntos
Biotecnologia , Cruzamento , Criopreservação , Plantas , Abastecimento de Alimentos , Engenharia Genética
3.
Theor Appl Genet ; 125(7): 1413-23, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22733447

RESUMO

Phytic acid (myo-inositol 1, 2, 3, 4, 5, 6 hexakisphosphate) is an important constituent of soybean meal. Since phytic acid and its mineral salts (phytates) are almost indigestible for monogastrics, their abundance in grain food/feed causes nutritional and environmental problems; interest in breeding low phytic acid has therefore increased considerably. Based on gene mapping and the characteristics of inositol polyphosphates profile in the seeds of a soybean mutant line Gm-lpa-ZC-2, the soybean ortholog of inositol 1,3,4,5,6 pentakisphosphate (InsP(5)) 2-kinase (IPK1), which transforms InsP(5) into phytic acid, was first hypothesized as the candidate gene responsible for the low phytic acid alteration in Gm-lpa-ZC-2. One IPK1 ortholog (Glyma14g07880, GmIPK1) was then identified in the mapped region on chromosome 14. Sequencing revealed a G → A point mutation in the genomic DNA sequence and the exclusion of the entire fifth exon in the cDNA sequence of GmIPK1 in Gm-lpa-ZC-2 compared with its wild-type progenitor Zhechun No. 3. The excluded exon encodes 37 amino acids that spread across two conserved IPK1 motifs. Furthermore, complete co-segregation of low phytic acid phenotype with the G → A mutation was observed in the F(2) population of ZC-lpa x Zhexiandou No. 4 (a wild-type cultivar). Put together, the G → A point mutation affected the pre-mRNA splicing and resulted in the exclusion of the fifth exon of GmIPK1 which is expected to disrupt the GmIPK1 functionality, leading to low phytic acid level in Gm-lpa-ZC-2. Gm-lpa-ZC-2, would be a good germplasm source in low phytic acid soybean breeding.


Assuntos
Éxons/genética , Mutação/genética , Ácido Fítico/metabolismo , Sítios de Splice de RNA/genética , Homologia de Sequência de Aminoácidos , Soja/enzimologia , Soja/genética , Sequência de Bases , Cruzamentos Genéticos , DNA Complementar/genética , DNA de Plantas/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Homozigoto , Dados de Sequência Molecular , Fenótipo , Fosfatos/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Mapeamento Físico do Cromossomo , Sementes/genética , Sementes/metabolismo , Soja/embriologia , Transcrição Genética
4.
J Agric Food Chem ; 57(9): 3632-8, 2009 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-19323582

RESUMO

Reduction of phytic acid in soybean seeds has the potential to improve the nutritional value of soybean meal and lessen phosphorus pollution in large scale animal farming. The objective of this study was to assess the effect of two new low phytic acid (LPA) mutations on seed quality and nutritional traits. Multilocation/season comparative analyses showed that the two mutations did not affect the concentration of crude protein, any of the individual amino acids, crude oil, and individual saturated fatty acids. Among other traits, Gm-lpa-TW75-1 had consistently higher sucrose contents (+47.4-86.1%) and lower raffinose contents (-74.2 to -84.3%) than those of wild type (WT) parent Taiwan 75; Gm-lpa-ZC-2 had higher total isoflavone contents (3038.8-4305.4 microg/g) than its parent Zhechun # 3 (1583.6-2644.9 microg/g) in all environments. Further tests of homozygous F(3) progenies of the cross Gm-lpa-ZC-2 x Wuxing # 4 (WT variety) showed that LPA lines had a mean content of total isoflavone significantly higher than WT lines. This study demonstrated that two LPA mutant genes have no negative effects on seed quality and nutritional traits; they instead have the potential to improve a few other properties. Therefore, these two mutant genes are valuable genetic resources for breeding high quality soybean varieties.


Assuntos
Mutação , Valor Nutritivo , Ácido Fítico/análise , Sementes/genética , Soja/genética , Cruzamento , Ácidos Graxos/análise , Isoflavonas/análise , Oligossacarídeos/análise , Óleos Vegetais/análise , Proteínas de Plantas/análise , Rafinose/análise , Estações do Ano , Sementes/química , Soja/química , Sacarose/análise
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