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41.
42.
以黑龙江野生白三叶、瑞文德、普通红三叶和杂三叶为研究对象,通过盆栽控水形成5个干旱梯度,测定土壤相对含水量、叶片相对含水量、水势、游离脯氨酸含量、可溶性蛋白质含量、可溶性糖含量的变化.结果表明:随着土壤干旱时间的延长,三叶草叶片游离脯氨酸、可溶性蛋白质和可溶性糖含量都呈明显增加趋势,并且品种间表现不同.从渗透调节物质与叶片水分的相关分析上看,三种物质与叶片水势、叶片相对含水量都呈负相关.游离脯氨酸、可溶性糖和可溶性蛋白质三种物质在水分胁迫时的渗透调节作用是协同的,各物质之间在处理的整个进程中都表现出正相关关系. 相似文献
43.
Raúl Laiz-Carrin Susana Sangiao-Alvarellos Jos M. Guzmn María P. Martín del Río Jos L. Soengas Juan M. Mancera 《Aquaculture (Amsterdam, Netherlands)》2005,250(3-4):849-861
The influence of three different environmental salinities (seawater, SW: 38 ppt salinity; brackish water, BW: 12 ppt; and low salinity water, LSW: 6 ppt salinity) on the growth, osmoregulation and metabolism of young gilthead sea bream (Sparus aurata L.) was studied over a period of 100 days. 480 inmature fish (20 g mean body weight) were randomly divided into six tanks of 2500 l (80 fish per tank) and maintained under three different salinities (38 ppt, 12 ppt and 6 ppt) in an open system. Every three weeks, 10 fish from each tank were anesthetized, weighed and lenghed. At the end of experiment, 10 fish from each tank were anesthetized, weighed and sampled for plasma, brain, gill and liver. Gill Na+, K+-ATPase activity, plasma osmolality, ions (sodium and chloride), glucose, lactate, protein and triglyceride, and hepatosomatic index were examined. In addition, levels of glycogen, lactate, ATP and activities of potential regulatory enzymes (hexokinase, pyruvate kinase, glycogen phosphorylase, and glucose 6-phosphate dehydrogenase) were assesed in liver, brain, and gill. BW-acclimated fish showed a better growth with respect to SW- or LSW-acclimated fish (12 > 38 > 6 ppt). The same relationship was observed for weight gain and specific growth rate. Osmoregulatory parameters in plasma (osmolality, Na+ and Cl− levels) were similar in SW- and BW-acclimated fish but significantly higher than those of LSW-acclimated fish. Gill Na+, K+-ATPase activity showed lower values in intermediate salinity (6 > 38 > 12 ppt). No changes were observed in metabolic parameters analyzed in plasma, whereas only minor changes were observed in metabolic parameters of liver, gills and brain that could be correlated with the higher growth rates observed in fish acclimated to BW, which do not allow us to attribute the best growth rate observed at 12 ppt to lower metabolic rates in that salinity. 相似文献
44.
木麻黄幼苗渗透调节物对酸雨胁迫的响应研究 总被引:2,自引:0,他引:2
对模拟pH2 .5~4 .5酸雨胁迫3个月后木麻黄幼苗渗透调节物含量测定结果表明,pH4 .0~4 .5酸雨胁迫后木麻黄幼苗小枝可溶性糖含量显著低于对照,但(pH2 .5~3.5 )酸雨胁迫后其含量显著高于对照;与对照相比酸雨胁迫使木麻黄幼苗小枝可溶性蛋白质含量增加,游离脯氨酸和谷胱甘肽含量则极显著增加。酸雨胁迫下木麻黄幼苗具有积累较高浓度的有机渗透调节物及改善渗透调节的生理应答能力 相似文献
45.
Gaëlle SaladinChristian Magné Christophe Clément 《Pesticide biochemistry and physiology》2003,77(3):125-137
The effects of the fungicides fludioxonil and pyrimethanil were evaluated on grapevine leaves using in vitro-grown plantlets, fruiting cuttings, and plants grown in vineyards. In vitro, both water content and osmotic potential decreased in treated leaves. Moreover, carbohydrate accumulated, suggesting that plantlets could react to the stress through an active osmoregulation process by uptaking sugars from the medium. Besides, pyrimethanil stimulated the accumulation of proteins, whereas no significant effect was observed using fludioxonil. The cuttings exhibited similar responses than in vitro though they appeared to be more tolerant since half of the studied parameters recovered 10 days after treatment. In vineyard, both fungicides modified leaf water content and carbohydrate levels, whereas nitrogenous compounds accumulated transiently. These results suggest that in vineyard-grown plants, a strong sugar translocation from mature leaves to sink organs occurs transiently, as well as a protein synthesis and a stimulation of soil nitrogen uptake. 相似文献
46.
Aaron G. Schultz Jillian M. Healy Paul L. Jones Tes Toop 《Aquaculture (Amsterdam, Netherlands)》2008,280(1-4):45-52
This study examined the osmoregulatory capability of Murray cod, Maccullochella peelii peelii, affected by chronic ulcerative dermatopathy (CUD) in intensive aquaculture. This condition appears to arise only in facilities utilizing groundwater, with the causative agent suggested to be a water-borne factor. Healthy Murray cod (~ 700 g) were transferred to a CUD-affected farm to monitor the progression of the syndrome and began to show signs of CUD after approximately five months. In order to evaluate possible effects of CUD on osmoregulation; plasma electrolyte concentrations, osmolality, and Na+,K+-ATPase activities were measured, and gill histology and immunohistochemistry were analyzed. Plasma electrolyte concentrations and osmolality of CUD-affected Murray cod were consistent with reference values determined for non CUD-affected fish. A greater number of gill mucous cells were observed in Murray cod cultured at the CUD-affected farm compared to non CUD-affected fish. We also found an un-identified cell type that was present solely in the gills of CUD-affected Murray cod. Gill Na+,K+-ATPase activity was significantly higher in severely CUD-affected Murray cod compared to individuals transferred to the CUD-affected farm. While there appeared to be some minor changes in the gills of CUD-affected fish, this study demonstrated that Murray cod were able to effectively osmoregulate, although, perhaps at an energetic cost. 相似文献
47.
Baldisserotto B Copatti CE Gomes LC Chagas EC Brinn RP Roubach R 《Fish physiology and biochemistry》2008,34(4):405-412
Fishes that live in the Amazon environment may be exposed to several kinds of water: black water (BW), acidic black water
(pH 3.5) (ABW) and white water (WW), among others. The aim of the present study was to analyze net ion fluxes in the facultative
air-breather Hoplosternum littorale (tamoata) and the obligate air-breather Arapaima gigas (pirarucu) exposed to different types of water. Fishes were acclimated in well water and later placed in individual chambers
containing one type of water for ion flux measurements. After 4 h, the water in the chambers was replaced by a different type
of water. The transfer of both species to ABW (independent of previous water exposure) increased net ion loss. Tamoatas transferred
from ABW to BW or WW presented a net ion influx, but pirarucus showed only small changes on net ion efflux. These results
allow us to conclude that tamoatas and pirarucus present differences in terms of ion regulation but that the general aspects
of the ion flux are similar: (1) exposure to ABW led to net ion loss; (2) transfer from BW to WW or vice-versa induced only
minor changes on net ion fluxes. These observations demonstrate that any osmoregulatory difficulties encountered by either
species during changes between these latter two waters can be easily overcome. 相似文献
48.
干旱胁迫对苣荬菜抗氧化酶和渗透调节物质的影响 总被引:9,自引:4,他引:9
为探究野生苣荬菜(Sonchus brachyotus DC.)抗旱能力,用盆栽控制浇水模拟干旱的方法,研究了不同程度干旱胁迫下苣卖菜幼苗对干旱胁迫的响应。结果表明:随着干旱胁迫程度的加深,苣荬菜叶片相对含水量逐渐降低,质膜透性、丙二醛(MDA)含量升高,轻度干旱胁迫下以上3种指标与对照相比差异不显著(P<0.05)。超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性升高,SOD,POD活性在重度干旱条件下稍有下降,但仍高于对照。可溶性有机渗透调节物质脯氨酸、可溶性糖含量、可溶性蛋白含量持续上升,尤以脯氨酸上升幅度最大,重度干旱时达对照的11.06倍,表明苣荬菜有一定的抗旱能力。 相似文献
49.
不同土壤水分条件下硅对紫花苜蓿生理特性及品质的影响 总被引:1,自引:0,他引:1
采用盆栽试验研究了不同土壤水分条件下硅对紫花苜蓿生理特性及品质的影响.结果表明:土壤含水量为饱和含水量的80%和35%时,外源性硅对紫花苜蓿地上生物量没有显著影响,而土壤含水量为饱和含水量的50%和65%时,外源性硅显著增加了紫花苜蓿地上生物量;土壤含水量为饱和含水量的80%时外源性硅对紫花苜蓿叶片SOD活性、丙二醛和脯氨酸含量没有显著影响,土壤含水量为饱和含水量的65%时外源性硅显著降低了紫花苜蓿叶片SOD活性,而对丙二醛和脯氨酸含量没有影响,土壤含水量小于或等于饱和含水量50%时外源性硅显著降低了紫花苜蓿茎叶SOD活性、丙二醛和脯氨酸含量(P<0.05);添加硅对紫花苜蓿茎叶比、粗纤维、粗蛋白质和类胡萝卜素含量没有显著影响.说明添加外源性硅提高了紫花苜蓿遭受水分亏缺胁迫时的抗氧化能力,减轻了水分亏缺对紫花苜蓿的伤害程度,但对紫花苜蓿牧草品质影响不大. 相似文献
50.
M. Y. Tsuzuki K. Ogawa C. A. Strü ssmann M. Maita F. Takashima 《Aquaculture (Amsterdam, Netherlands)》2001,200(3-4):349-362
Mortality and physiological responses (plasma cortisol, glucose, osmolality, ions Na+ and Cl− and hematocrit values) were examined in adult pejerrey Odontesthes bonariensis subjected to transport or crowding and subsequent recovery for 1 week at 0, 5 and 20 ppt NaCl. Two experiments were conducted using fish from different hatcheries; the following responses were consistent for both stocks. Mortality was observed only during post-stress recovery at 0 and 20 ppt NaCl but not at 5 ppt. During recovery, blood cortisol and glucose were generally higher, whereas osmolality and blood electrolytes (Na+ and Cl−) were lower at 0 ppt than at the other salinities. A salinity of 5 ppt NaCl could not prevent the rise in cortisol and glucose levels caused by the stress of transport, but during recovery, it prevented further increases in these features and/or accelerated their return to basal levels. This salinity also helped maintain stable blood electrolyte levels. During recovery at 20 ppt NaCl, osmolality and blood ions increased, whereas plasma cortisol and glucose generally decreased. Hematocrit values were lower at 20 ppt than at the other salinities. These results suggest that freshwater is not an adequate medium for post-stress recovery and that the presence of NaCl in the water either decreases the secretion of cortisol or promotes its clearance in O. bonariensis. 相似文献