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51.
Interaction between CO2 enrichment and salinity stress in the C4 non-halophyte Andropogon glomeratus (Walter) BSP 总被引:2,自引:2,他引:0
Abstract Increasing atmospheric CO2 may result in alleviation of salinity stress in salt-sensitive plants. In order to assess the effect of enriched CO2 on salinity stress in Andropogon glomeratus, a C4 non-halophyte found in the higher regions of salt marshes, plants were grown at 350, 500, and 650 cm3 m?3 CO2 with 0 or 100 mol m?3 NaCl watering treatments. Increases in leaf area and biomass with increasing CO2 were measured in salt-stressed plants, while decreases in these same parameters were measured in non-salt-stressed plants. Tillering increased substantially with increasing CO2 in salt-stressed plants, resulting in the increased biomass. Six weeks following initiation of treatments, there was no difference in photosynthesis on a leaf area basis with increasing CO2 in salt-stressed plants, although short-term increases probably occurred. Stomatal conductance decreased with increasing CO2 in salt-stressed plants, resulting in higher water-use efficiency, and may have improved the diurnal water status of the plants. Concentrations of Na+ and Cl? were higher in salt stressed-plants while the converse was found for K +. There were no differences in leaf ion content between CO2 treatments in the salt-stressed plants. Decreases in photosynthesis in salt-stressed plants occurred primarily as a result of decreased internal (non-stomatal) conductance. 相似文献
52.
The relationship between respiration and temperature in leaves of the arctic plant Saxifraga cernua 总被引:4,自引:4,他引:0
Abstract Saxifraga cernua, a perennial herb distributed throughout the arctic and subarctic regions, shows high levels of dark respiration. The amount of respiration exhibited by leaves and whole plants at any temperature is influenced by the pretreatment temperature. Plants grown at 10°C typically show higher dark respiration rates than plants grown at 20°C. The levels of alternative-pathway respiration (or cyanide-insensitive respiration) in leaves of S. cernua grown at high and low temperatures were assessed by treating leaf discs with 0.25 mol m?3 salicylhydroxamic acid during measurements of oxygen consumption. Alternative pathway respiration accounted for up to 75% of the total respiration. Tissues from 20°C-grown plants yielded a Q10 of 3.37 for normal respiration, and of 0.97 for alternative-pathway respiration. Tissues from 10°C-grown plants yielded a Q10 of 2.55 for normal respiration, and of 0.79 for alternative-pathway respiration. The alternative pathway does not appear to be as temperature sensitive as the normal cytochrome pathway. A simple energy model was used to predict the temperature gain expected from these high rates of alternative-pathway respiration. The model shows that less than 0.02°C can be gained by leaves experiencing these high respiration rates. 相似文献
53.
M. J. J. van Haaren J. T. Pronk R. A. Schilperoort P. J. J. Hooykaas 《Plant molecular biology》1987,8(1):95-104
Summary Border fragments of the octopine Ti-plasmid were tested for their ability to restore tumorigenicity of an avirulent mutant carrying a deleted right border. It was found that neither introduction of left border fragments nor that of small right border fragments at the position of the deletion resulted in a complete restoration of oncogenicity. However, insertion of a larger right border fragment in the deletion mutant gave fully oncogenic strains. In the latter case sequences to the right side of the right border repeat were found to be responsible for a complete restoration of oncogenicity. Also a left border repeat inserted together with this enhancer sequence fully restored the oncogenicity of the deletion mutant. The enhancer-sequence on itself was not able to mediate the transfer of the T-region to the plant cell. Border fragments inserted in inverted orientation in the deletion mutant were able to mediate the transfer of the T-region to the plant cell, but at a reduced frequency. 相似文献
54.
R. J. M. van Veen H. den Dulk-Ras R. A. Schilperoort P. J. J. Hooykaas 《Plant molecular biology》1987,8(1):105-108
Summary The chromosomal genes chvA and chvB of Agrobacterium tumefaciens, which mediate attachment to plant cells, were found to be essential not only for tumour induction but also for the formation of root nodules on plants. 相似文献
55.
Yongru Sun Berthold M. Heil Günter Kahl Hans Willy Kohlenbach 《Plant Cell, Tissue and Organ Culture》1987,8(1):91-100
Calli were initiated from flower buds, gynoecia and inflorescence segments of Haworthia magnifica v. Poelln. and subcultured on solid medium. Two liquid culture steps were necessary to prepare the calli for the isolation of protoplasts capable of sustained cell divisions. Plants were regenerated from protoplast-derived calli. The influence of both the osmolality of the culture media and exudates on the viability of protoplasts and protoplast-derived cell colonies is briefly discussed. 相似文献
56.
Bhaskaran S. Smith R. H. Paliwal S. Schertz K. F. 《Plant Cell, Tissue and Organ Culture》1987,9(3):189-196
Plant Cell, Tissue and Organ Culture (PCTOC) - Sorghum bicolor (L.) Moench, plants were regenerated from 4 to 5 month old callus cultures originally derived from seedling explants. Somaclonal... 相似文献
57.
Y. Peleg S. Koder J. S. Rokem I. Chet I. Goldberg 《Plant Cell, Tissue and Organ Culture》1987,9(3):207-215
Production of phaseollin was measured in cell suspension cultures and whole plants of Phaseolus vulgaris. In suspension cultures phaseollin appeared when there was no further increase in cell mass. Cells transferred to a medium without auxins yielded three times higher phaseollin concentrations than cells grown in their presence. Addition of autoclaved fungal mycelia or polysaccharides as elicitors resulted in an increased phaseollin concentration in the cell suspension.In whole plants phaseollin could be detected only after the plants were challenged by a fungus which caused lesions (browning) of the upper root neck region, Rhizoctonia solani. Treatment of non-infected plants with autoclaved fungal mycelia or other elicitors did not induce phaseollin production. However, when they were added before or together with the pathogenic fungus, the elicitors further increased phaseollin concentration in the root neck regions of the plants. This indicated that the pathogenic fungus was important for the penetration of the elicitors to inner plant tissues where phaseollin (and probably other phytoalexins) is produced. 相似文献
58.
Excised young intact stigmas plus ovaries of Crocus sativus L. were cultured on Linsmaier-Skoog media supplemented with either a cytokinin or an auxin alone or in combinations. Benzyladenine and kinetin at concentrations of 0.1, 1, and 5 mgl-1 supported growth, and crocin was biosynthesized in the stigmas in vitro. Auxins had little effect. Young excised single stigmas or half ovaries were also cultured so as to form stigma-like structures in order to explore a possible new approach to industrial production of the spice, saffron. On Linsmaier-Skoog and Nitsch media supplemented with kinetin at concentration of 1 or 5 mgl-1 and alpha-naphthalene acetic acid or indole-butyric acid at concentration of 0.1 or 10 mgl-1 in combinations, stigma-like structures appeared directly and indirectly (through meristematic tissue), grew and matured. The maximum number of structures were 75 per half ovary. Three kinds of yellow pigments including crocin were tentatively identified by TLC in the stigma-like structures as was the case for the in vivo grown natural stigma, although the contents were lower.Abbreviations BA
benzyladenine
- 2,4-D
2,4-dichlorophenoxy-acetic acid
- IAA
indole-acetic acid
- IBA
indole-butyric acid
- NAA
alpha-naphthalene-acetic acid
- TLC
thin layer chromatography 相似文献
59.
60.
The effect of varied supply of P (2.5× 10−5 to 6× 10−4 M) and Zn (0 to 10−6 M) on uptake and concentrations of P and Zn was studied in cotton ( Gossypium hirsutum L. cv. Deltapine 15/21) grown in nutrient solution under controlled environmental conditions. At a given Zn supply, increasing levels of P had no significant effect on the concentrations of total Zn in plants. However, increasing levels of P induced or enhanced visual Zn deficiency symptoms when the Zn concentration in the nutrient solution was low. The concentrations of water-soluble Zn in roots and shoots constituted 60% of the total Zn concentrations for plants grown with low P and 30% for plants grown with high P. The concentration of water-soluble Zn in leaves, but not total Zn, was closely correlated with visual Zn deficiency symptoms, levels of chlorophyll, super oxide dismutase and membrane permeability. The critical deficiency concentration of water-soluble Zn in cotton leaves was in the range of 6 to 7 μg (g dry weight)−1 or about 1.0 μg (g fresh weight)−1 . The results show that high P concentrations in plant tissue decrease the physiological availability of Zn. Water-soluble Zn in the tissue appears to be a suitable indicator for Zn nutritional status in general and phosphorus-induced Zn deficiency in particular. Also in field-grown orange trees (Citrus sinensis) visual Zn deficiency symptoms in leaves were closely related to the concentration of water-soluble Zn. 相似文献