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1.
Stable transformation of the cotton plastid genome and maternal inheritance of transgenes 总被引:23,自引:0,他引:23
Chloroplast genetic engineering overcomes concerns of gene containment, low levels of transgene expression, gene silencing, positional and pleiotropic effects or presence of vector sequences in transformed genomes. Several therapeutic proteins and agronomic traits have been highly expressed via the tobacco chloroplast genome but extending this concept to important crops has been a major challenge; lack of 100 homologous species-specific chloroplast transformation vectors containing suitable selectable markers, ability to regulate transgene expression in developing plastids and inadequate tissue culture systems via somatic embryogenesis are major challenges. We employed a Double Gene/Single Selection (DGSS) plastid transformation vector that harbors two selectable marker genes (aphA-6 and nptII) to detoxify the same antibiotic by two enzymes, irrespective of the type of tissues or plastids; by combining this with an efficient regeneration system via somatic embryogenesis, cotton plastid transformation was achieved for the first time. The DGSS transformation vector is at least 8-fold (1 event/2.4 bombarded plates) more efficient than Single Gene/Single Selection (SGSS) vector (aphA-6; 1 event per 20 bombarded plates). Chloroplast transgenic lines were fertile, flowered and set seeds similar to untransformed plants. Transgenes stably integrated into the cotton chloroplast genome were maternally inherited and were not transmitted via pollen when out-crossed with untransformed female plants. Cotton is one of the most important genetically modified crops ($ 120 billion US annual economy). Successful transformation of the chloroplast genome should address concerns about transgene escape, insects developing resistance, inadequate insect control and promote public acceptance of genetically modified cotton. 相似文献
2.
Relationships among 37 North American octoploid strawberry populations were studied by evaluating 44 morphological traits and 36 randomly amplified polymorphic DNA (RAPD) markers. Both data sets were analyzed by principal components analysis and UPGMA clustering based on genetic distances. Morphological data defined five groups: east of the Missouri River (Fragaria virginiana ssp. virginiana), the Black Hills (F. virginiana ssp. virginiana and ssp. glauca), from the eastern Cascades to the eastern Rocky Mountains (F. virginiana ssp. glauca), the western Cascades and Olympic Peninsula (F. virginiana ssp. platypetala), and the Pacific coast (F. chiloensis). Canonical discriminant analysis clearly discriminated populations into these provenances, suggesting that these groups are morphologically distinct. RAPD data defined three groups, one with F. virginiana ssp. virginiana and ssp. glauca, another with F. chiloensis, and a third with F. virginiana ssp. platypetala. The latter was more similar to F. chiloensis than F. virginiana, suggesting it is likely a subspecies of F. chiloensis. All octoploid North American strawberries have likely derived from a common ancestor and have differentiated into F. chiloensis and F. virginiana by adapting to moister and drier environments, respectively. 相似文献
3.
Meyer S 《American journal of botany》1997,84(4):471-477
Chrysothamnus nauseosus (Asteraceae) is a complex polymorphic shrub species widely distributed in western North America. In a study of 86 populations belonging to 15 subspecies, achene mass varied among populations over a sevenfold range. Achene mass was closely correlated with capitulum size at the subspecies level, varied little between wild-growing and common-garden-grown members of a population, and was under strong genetic control. Subspecies with the heaviest achenes are restricted to specialized edaphic environments (dunes and badlands) or late seral montane riparian communities, while subspecies that are widely distributed and that occur in early seral habitats have less heavy achenes. Selection on achene mass has apparently been a notable feature of the adaptive radiation of Chrysothamnus nauseosus into the wide array of habitats it currently occupies. Within a wild population, achene mass was greater for plants fruiting in midautumn than for plants fruiting early or late in the autumn, and this same trend was observed within individual plants in garden populations, indicating environmental control, perhaps through resource limitation. Highly significant between-plant differences in achene mass were found in both wild and garden populations, suggesting that within-population genetic variation is sufficient to permit continuing selection. 相似文献
4.
Extant variants of henequen (Agave fourcroydes Lem.) and wild populations of its putative ancestor A. angustifolia Haw. were grown in the Mexican state of Yucatan for 10 yr under homogeneous conditions. A statistical and numerical analysis of their patterns of morphological variation was performed as part of broader research to provide evidence of its genetic diversity, evolutionary relationships and changes under human selection. A comparison with results of a similar analysis under natural growing conditions was also made. The study indicated the following. (1) Under natural growth conditions, the three putative wild ecotypes are morphologically distinct, but under uniform conditions only populations growing in Tropical subdeciduous forest may be distinguished from the other two, thus indicating the probable existence of only two ecotypes: one growing in Coastal dunes and Tropical subdeciduous forest, and the other growing in Tropical deciduous forest. (2) This last ecotype is the most similar to cultivated variants. Within its populations, the most similar to the cultivated is that known as Chelem White, gathered by artisans for its textile use. (3) The cordage-cultivated Sac Ki and Yaax Ki differ from wild populations in four syndromes of domestication: gigantism, greater fibrosity, less thorniness, and less reproductive capacity. The lower cv of their characteristics compared with those of wild populations suggest less genetic diversity. (4) Kitam Ki is probably a textile-cultivated variant of recent introduction and/or a variant in which the artificial selection process has had different direction and intensity. (5) Improved growth conditions in the botanic garden resulted in a decreased cv, an increase in size and fiber content, and a reduction of thorniness for both wild and cultivated variants. Given that wild populations with desirable characteristics exist and that these characteristics are highly plastic and respond positively to cultivation, then selection and cultivation of populations such as those from Tropical deciduous forest may well have been the path taken by the ancient Maya during henequen domestication. 相似文献
5.
Alfonso Valiente-Banuet Alberto Rojas-Martínez María del Coro Arizmendi Patricia Dávila 《American journal of botany》1997,84(4):452-455
We document the pollination biology and mating systems of Neobuxbaumia mezcalaensis and Neobuxbaumia macrocephala, two Mexican giant columnar cacti. These two species form mixed forests in the western Tehuacan Valley, Mexico. The flowers of both N. mezcalaensis and N. macrocephala exhibit nocturnal anthesis, are self-incompatible, and are pollinated primarily by three species of nectar-feeding bats (Choeronycteris mexicana, Leptonycteris curasoae, and Leptonycteris nivalis). Neobuxbaumia mezcalaensis is androdioecious, a breeding system that appears to be uncommon among Cactaceae. Neobuxbaumia macrocephala is hermaphroditic. We hypothesize that columnar cacti show a geographical dichotomy in floral biology specialization that probably can be related to predictability in pollinator abundance. 相似文献
6.
Intra and intertribal genetic variation within a linguistic group: The Ge-speaking Indians of Brazil
F. M. Salzano J. V. Neel H. Gershowitz E. C. Migliazza 《American journal of physical anthropology》1977,47(2):337-347
A total of 562 individuals living in four villages of two Brazilian Indian tribes (Cayapo and Krahó) was studied in relation to blood groups ABO, MNSs, P, Rh, Lewis, Duffy, Kidd and Diego; haptoglobin, Gc, acid phosphatase and phosphoglucomutase types. These results were compared with those obtained previously among the Xavante, and the inhabitants of three other Cayapo villages, all of whom speak Ge languages; the ranges in gene frequencies observed in a representative series of South American Indians from all over the continent were also compiled. The Ge Indians are characterized by low frequencies ofRz, medium frequencies ofR1,R2, R0, orr,Jka andPGM11, and high frequencies ofGc2 andACPA when compared with other South American tribes. Genetic distance analyses based on six loci indicate that the intratribal variability observed among Cayapo is of the same order of magnitude as those obtained among the Xavante and Krahó, being much less pronounced than those observed among the Yanomama and Makiritare. The intertribal differences within this linguistic group are much less pronounced than those encountered among tribes that speak more differentiated languages. 相似文献
7.
Three chlorophyll-protein complexes have been resolved from blue-green algae using an improved procedure for membrane solubilization and electrophoretic fractionation. One complex has a red absorbance maximum of 676 nm and a molecular weight equivalency of 255 000 ± 15 000. A second complex has an absorbance maximum of 676 nm, a molecular weight equivalency of 118 000 ± 8000, and resembles the previously described P-700-chlorophylla-protein (CPI) of higher plants and algae. The third chlorophyll-protein has a red absorbance maximum of 671 nm and a molecular weight equivalency of 58 000 ± 5000. Blue-green algal membrane fractions enriched in Photosystem I and heterocyst cells do not contain this third chlorophyll-protein, whereas Photosystem II-enriched membrane fractions and vegetative cells do. A component of the same spectral characteristics and molecular weight equivalency was also observed in chlorophyll b-deficient mutants of barley and maize. It is hypothesized that this third complex is involved in some manner with Photosystem II. 相似文献
8.
Purple membrane was reacted with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide at pH 4.5 and 8.0. At pH 4.5, the reaction yields cross-linked bacteriorhodopsin. The cross-linking is inhibited by pretreatment of the membrane with papain, or by the presence of carbohydrazide or glycine ethyl ester in the reaction mixture. The product of the pH 8.0 reaction is not cross-linked, but it displays altered properties. Two measures of photochemical activity (light-induced change in proton binding (Δh?) and decay of photointermediate M) show changes indicative of slowed proton uptake. The Δh? is increased by ethyl dimethylaminopropylcarbodiimide. This increase is unaffected by pretreatment of the membrane with papain, and it is not reversed by NH2OH. However, the reaction is inhibited by millimolar concentrations of CaCl2. The altered Δh? is not apparent in detergent-solubilized membranes. Ethyl dimethylaminopropyl-carbodiimide does not appear to cause a large alteration in the membrane surface charge, as measured by Ca2+ binding.We conclude that (1) at acid pH, ethyl dimethylaminopropylcarbodiimide can be used for cross-linking or for attachment of specific probes to the C-terminal region of bacteriorhodopsin, and hence to the cytoplasmic side of the purple membrane, and (2) at alkaline pH, ethyl dimethylaminopropylcarbodiimide reacts at a different type of site and appears to inhibit the proton pump. 相似文献
9.
Trypsin treatment of solubilized coupling factor-latent ATPase from Mycobacterium phlei alters its subunit structure and functional properties. This coupling factor exhibits ATPase activity following trypsin treatment. Concurrently, both the ability of the enzyme to rebind to membranes depleted of coupling factor and its capacity for coupled phosphorylation are lost. The native alpha (64 000 dalton) subunit undergoes limited proteolytic digestion, and the delta (14 000 dalton) subunit is partially lost. During the course of tryptic proteolysis, the coupling factor molecule may exist in one of ten unique structural states (e.g. the native, ATPase-inactive molecule exists in the ααα state). Rigorous analysis of the experimental data by theoretical modeling provided information concerning the intermediate structural states leading to the fully ATPase-activated α″α″α″ state under different conditions of trypsin treatment. The theoretical models of structure-function relationships that best-represented the experimental data predicted that the native coupling factor molecule contains three copies of the α (64 000 dalton) form of the alpha subunit, that the α″ (58 000 dalton) alpha subunit species contributes maximally and the α′ (61 000 dalton) form about half-maximally to ATPase activity, that membrane rebinding ability is proportional to the number of native alpha subunits in the enzyme, and that at least one native α subunit/molecule is required for full expression of coupled phosphorylation. These results indicate an essential role for the alpha subunit in the regulation of ATPase activity and in the ability of the solubilized coupling factor to rebind to depleted membranes. 相似文献
10.
The photosynthetic electron transport and phosphorylation reactions were measured in the room temperature region in the thylakoid membranes prepared from the blue-green alga, Anacystis nidulans. The Arrhenius plot of the Hill reaction with 2,6-dichlorophenolindophenol showed a distinct break of straight lines at 21°C in the membranes from cells grown at 38°C, and at 12°C in those from cells grown at 28°C. The Arrhenius plot of the Hill reaction with ferricyanide showed a break at 13°C in the membranes from cells grown at 38°C, and at 7°C in those from cells grown at 28°C. On the other hand, the Arrhenius plot of the System I reaction with methylviologen as an electron acceptor and 2,6-dichlorophenolindophenol and ascorbate as an electron donor system was composed of a straight line in the membranes from cells grown at 28°C as well as at 38°C. The Arrhenius plot of the System II reaction measured by the ferricyanide reduction mediated by silicotungstate in the presence of 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea also showed a break at 11°C in the membranes from cells grown at 38°C.The Arrhenius plot of the phosphorylation mediated by N-methylphenazonium methylsulfate showed a break at 21°C in the membranes from cells grown at 38°C and at 12°C in those from cells grown at 28°C. The Arrhenius plot of the phosphorylation mediated by the System I reaction showed a break at 24°C in the membranes from cells grown at 38°C.The characteristic features in the Arrhenius plots of the photosynthetic electron transport and phosphorylation reactions are discussed in terms of the transition of physical phase of the thylakoid membrane lipids. 相似文献