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1.
Interaction between atmospheric and pedospheric nitrogen nutrition in spruce (Picea abies L. Karst) seedlings 总被引:6,自引:2,他引:4
The effect of NO2 fumigation on root N uptake and metabolism was investigated in 3-month-old spruce (Picea abics L. Karst) seedlings. In a first experiment, the contribution of NO2 to the plant N budget was measured during a 48 h fumigation with 100mm3m?3 NO2. Plants were pre-treated with various nutrient solutions containing NO2 and NH4+, NO3? only or no nitrogen source for 1 week prior to the beginning of fumigation. Absence of NH4+ in the solution for 6d led to an increased capacity for NO3? uptake, whereas the absence of both ions caused a decrease in the plant N concentration, with no change in NO3? uptake. In fumigated plants, NO2 uptake accounted for 20–40% of NO3? uptake. Root NO3? uptake in plants supplied with NH4+plus NO3? solutions was decreased by NO2 fumigation, whereas it was not significantly altered in the other treatments. In a second experiment, spruce seedlings were grown on a solution containing both NO2 and NH4+ and were fumigated or not with 100mm3m?3 NO2 for 7 weeks. Fumigated plants accumulated less dry matter, especially in the roots. Fluxes of the two N species were estimated from their accumulations in shoots and roots, xylem exudate analysis and 15N labelling. Root NH4+ uptake was approximately three times higher than NO3? uptake. Nitrogen dioxide uptake represented 10–15% of the total N budget of the plants. In control plants, N assimilation occurred mainly in the roots and organic nitrogen was the main form of N transported to the shoot. Phloem transport of organic nitrogen accounted for 17% of its xylem transport. In fumigated plants, neither NO3? nor NH4+ accumulated in the shoot, showing that all the absorbed NO2 was assimilated. Root NO3? reduction was reduced whereas organic nitrogen transport in the phloem increased by a factor of 3 in NO2-fimugated as compared with control plants. The significance of the results for the regulation of whole-plant N utilization is discussed. 相似文献
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EMMA DESPLAND MARIA GUNDERSEN SIMON P. DAOUST BRIAN J. MADER NATHALIE DELVAS PAUL J. ALBERT ERIC BAUCE 《Physiological Entomology》2011,36(1):39-46
The pattern of feeding of Eastern spruce budworm Choristoneura fumiferana (Clem.) (Lepidoptera, Tortricidae) is compared on foliage from white spruce Picea glauca (Moench) Voss. (Pinaceae) trees previously determined to be susceptible and resistant to defoliation by budworm. No differences are observed in electrophysiological responses from taste sensilla to aqueous extracts of the two foliage types, nor is there a preference for either extract type in a choice test. Acetone extracts from the two foliage types are both preferred to a control sucrose solution, although neither elicits a preference relative to the other. These results suggest that there is no difference in phagostimulatory power of internal leaf contents of the two foliage types. Longer‐term observation of feeding behaviour in a no‐choice situation shows no difference in meal duration, confirming the lack of difference in phagostimulatory power. However, on average, intermeal intervals are twice as long on the resistant foliage, leading to an overall lower food consumption during the assay. This result suggests an anti‐digestive or toxic effect of the resistant foliage that slows behaviour and limits food intake. Previous research has shown that waxes of the resistant foliage deter initiation of feeding by the spruce budworm and that this foliage contains higher levels of tannins and monoterpenes. The data suggest that the resistant foliage contains a post‐ingestive second line of defence against the spruce budworm. 相似文献
4.
Foliar uptake and release of inorganic nitrogen compounds in Pinus sylvestris L. and Picea abies (L.) Karst. 总被引:2,自引:0,他引:2
E.J. WILSON 《The New phytologist》1992,120(3):407-416
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Effects of ozone and elevated atmospheric carbon dioxide on carbohydrate metabolism of spruce needles. Catabolic and detoxification pathways 总被引:5,自引:0,他引:5
We have studied the effects of ozone, carbon dioxide and ozone combined with carbon dioxide fumigations on catabolic and detoxification pathways in spruce ( Picea abies [L.] Karst.) needles. The results obtained showed an increase in the activities of three enzymes involved in the detoxification pathway, superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (AscPOD, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) when trees were exposed to ozone and to ozone‐carbon dioxide treatments. In these two treatments, the fraction of SOD activity due to the chloroplastic isoform was increased (1.5‐fold). In the needles of trees exposed to ozone and to ozone‐carbon dioxide fumigation, an increase in the activities of glucose‐6‐phosphate dehydrogenase (G‐6‐PDH, EC 1.1.1.49) showed that the cell had the capacity to produce more NADPH necessary for the detoxification. Stimulation of other enzymes of catabolic pathways (fumarase [EC 4.2.1.2], phosphofructokinase [PFK, EC 2.7.1.1] and phosphoenolpyruvate carboxylase [PEPC, EC 4.1.1.31]), was also observed making it possible for the cell to provide the reducing power necessary for detoxification as well as energy and carbon skeletons involved in the repair processes.
When carbon dioxide alone was applied, no effects could be detected on these enzyme activities. However, when carbon dioxide was combined with ozone, the effect of ozone on trees was less than that induced by ozone alone, suggesting that elevated atmospheric carbon dioxide concentrations may to some extent protect plants from ozone injury. 相似文献
When carbon dioxide alone was applied, no effects could be detected on these enzyme activities. However, when carbon dioxide was combined with ozone, the effect of ozone on trees was less than that induced by ozone alone, suggesting that elevated atmospheric carbon dioxide concentrations may to some extent protect plants from ozone injury. 相似文献
7.
Seasonal changes of some water relations parameters of Norway spruce shoots ( Picea abies [L.] Karst.) were studied during two experiments using the pressure-volume analysis. For each experiment only shoots of a single tree were used.
During the first study, the course of the turgor loss point (as bulk osmotic pressure when turgor first reaches zero, πp) of shoots developed in late 1986 vegetation period, were measured in 1987. The turgor loss point decreased temporarily from –2.5 MPa at the beginning of the year to –3.3 MPa at the end of March, but then increased to the original level for the rest of the year.
During the second study, water relations parameters were measured in late summer 1987 and in late winter 1988. Winter shoots at full water saturation contained up to 20% less water than in late summer. Accordingly, the bulk osmotic pressure at full water saturation (πp ) decreased from –1.7 MPa in late summer to –1.9 MPa in winter, πp decreased also from –2.2 MPa to –2.8 MPa. However, the amount of osmotically active substances (mOsmol, N) remained unchanged. The relative amount of apoplastic water in the total shoot water content appeared to drop insignificantly from 17% to 15%.
The results show that the decrease in πo and πp in late winter is not due to an accumulation of osmotically active substances in the vacuoles but is due to a decrease in tissue water content. The temporary reduction of the symplastic volume by deposition of osmotically inert substances seems to be the most probable cause of this phenomenon. 相似文献
During the first study, the course of the turgor loss point (as bulk osmotic pressure when turgor first reaches zero, πp) of shoots developed in late 1986 vegetation period, were measured in 1987. The turgor loss point decreased temporarily from –2.5 MPa at the beginning of the year to –3.3 MPa at the end of March, but then increased to the original level for the rest of the year.
During the second study, water relations parameters were measured in late summer 1987 and in late winter 1988. Winter shoots at full water saturation contained up to 20% less water than in late summer. Accordingly, the bulk osmotic pressure at full water saturation (π
The results show that the decrease in π
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9.
Rise and demise of cold-climate Picea abies forest in Sweden 总被引:1,自引:0,他引:1
LEIF KULLMAN 《The New phytologist》1996,134(2):243-256
10.
Response of Picea rubens seedlings to intermittent mist varying in acidity, and in concentrations of sulfur-, and nitrogen-containing pollutants 总被引:7,自引:0,他引:7
Jay S. Jacobson Twylene Bethard Laurence I. Heller James P. Lassoie 《Physiologia plantarum》1990,78(4):595-601
Two-year-old red spruce seedlings ( Picea rubens Sarg .) growing in. field chambers were repeatedly exposed to acidic mist with a factorial combination of 3 fluctuating levels of acidity: median pH values of 3.0 (range of 2.5 to 3.5), 3.5 (range of 3.0 to 4.0), and 4.0 (range of 3.5 to 4.5). and 3 ion compositions: sulfate. nitrate and ammonium, and a combination of all 3 ions. The experiment was performed during the growing season over a period of 3.5 months. Mist exposures were intermittent with 5 wet-dry cycles for each 16-h overnight exposure period, Foliar necrosis occurred on seedlings treated with the most acidic mist and was most severe when the mist contained sulfate. At a median pH of 3.5, a value close to that of cloud water occurring in the eastern United States, injury developed with sulfuric acid mist, but not. when the mist contained nitric acid. The combination of high acidity and sulfate significantly decreased volume of aboveground tissues, while high acidity and nitrate increased volume. Root and needle dry weights were not affected. However, high acidity of mist was associated with increased leader shoot length. These results indicate, that there is a risk of foliar injury and changes in growth of red spruce with cloud water at a median acidity of pH 3.5 or below, especially when there are high concentrations of sulfate and low concentrations of nitrate. 相似文献