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1.
A greenhouse experiment was carried out to determine plant growth,reactive oxygen species(ROS) metabolism in roots and functions of plasma membrane(PM) and tonoplast in cucumber seedlings(Cucumis sativus L.cv.Xintaimici) treated with 40 μmol L-1 CuSO 4.5H2O,which were either ungrafted or grafted onto the rootstock(Cucurbita ficifolia).Cu treatment inhibited growth,induced significant accumulation of H2O2 and led to serious lipid peroxidation in cucumber roots,and the ROS-scavenging enzymes activities in grafted seedlings roots were significantly higher than that of ungrafted plants,thus less accumulation in grafted cucumber roots induced by Cu.As a result,lipid peroxidation in roots decreased.Furthermore,the activities of H+-ATPase,H+-PPase and Ca2+-ATPase in PM and/or tonoplast in grafted cucumber seedlings under Cu stress were obviously higher than that in ungrafted plants,resulting into higher ability in grafted plants to expulse the excess H+,promote the cytoplasm alkalinization,regulate the intracellular Ca2+ concentration and brought the cytoplasma concentration of free Ca2+ to extremely low level under Cu stress.  相似文献   

2.
[Objective] The study aimed to reveal the effects of hypergravity on salt tolerance of wheat seedlings. [Method] The seed germination rate (Gr) and germination index (Gi) of wheat seedlings were measured under hypergravity of 600×g or 1 000×g for 4 h and under the stress of 0.4% or 0.9% salt solution. The catalase (CAT) activity and malondialdehyde (MDA) content of wheat seedlings were also measured under 0.4% salt stress. [Result] Compared with seedlings in CK group (no hypergravity or salt stress),the Gr and Gi of the seedlings in salt stress treatment decreased to different extents; while the Gr and Gi of the seedlings in treatment group (hypergravity and salt stress) increased compared with that in salt stress group. CAT in seedlings of hypergravity treatment was higher than that of CK group and 0.4% salt treatment group,meanwhile the MDA showed an opposite result. [Conclusion] Hypergravity could enhance the salt resistance of wheat in specific range,and hypergravity of 600×g for 4 h performed better than that of 1 000×g for 4 h.  相似文献   

3.
[Objective] The aim of this study was to provide the theoretical basis for screening and utilizing salt-tolerant tomato varieties as well as for cultivating salt-resistance.[Method] Salinity tolerance of tomato during seed germination under simple salt sodium chloride and double salt calcium nitrate or sodium chloride stress were studied by Petri dish culturing.[Result] As the two kinds salt concentration increased,the germination regularity,the germination rate,the germination index and the growing vigor index of tomato seedlings decreased,but the germination losing rate increased.When salt concentration was from 0.2% to 0.4%,there was little difference among all indexes under two kinds of salt stress.However,when salt concentration was from 0.6% to 1.0%,the difference among all indexes under two kinds of salt stress was significant.[Conclusion] Salinity tolerance of tomato seeds under double salt calcium nitrate or sodium chloride stress was higher than that under simple salt sodium chloride stress.  相似文献   

4.
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5.
不同盐胁迫处理下番茄种子萌发期的耐盐性研究(英文)   总被引：16，自引：3，他引：13  
[Objective] The aim of this study was to provide the theoretical basis for screening and utilizing salt-tolerant tomato varieties as well as for cultivating salt-resistance.[Method] Salinity tolerance of tomato during seed germination under simple salt sodium chloride and double salt calcium nitrate or sodium chloride stress were studied by Petri dish culturing.[Result] As the two kinds salt concentration increased,the germination regularity,the germination rate,the germination index and the growing vigor index of tomato seedlings decreased,but the germination losing rate increased.When salt concentration was from 0.2% to 0.4%,there was little difference among all indexes under two kinds of salt stress.However,when salt concentration was from 0.6% to 1.0%,the difference among all indexes under two kinds of salt stress was significant.[Conclusion] Salinity tolerance of tomato seeds under double salt calcium nitrate or sodium chloride stress was higher than that under simple salt sodium chloride stress.  相似文献   

6.
[Objective] The aim of this study was to provide the theoretical basis for screening and utilizing salt-tolerant tomato varieties as well as for cultivating salt-resistance.[Method] Salinity tolerance of tomato during seed germination under simple salt sodium chloride and double salt calcium nitrate or sodium chloride stress were studied by Petri dish culturing.[Result] As the two kinds salt concentration increased,the germination regularity,the germination rate,the germination index and the growing vigor index of tomato seedlings decreased,but the germination losing rate increased.When salt concentration was from 0.2% to 0.4%,there was little difference among all indexes under two kinds of salt stress.However,when salt concentration was from 0.6% to 1.0%,the difference among all indexes under two kinds of salt stress was significant.[Conclusion] Salinity tolerance of tomato seeds under double salt calcium nitrate or sodium chloride stress was higher than that under simple salt sodium chloride stress.  相似文献   

7.
The investigation was conducted to determine physiological criteria of early selection for salt tolerant leguminous plants. Plants were subjected to 5 levels of salt stress at the roots （0, 50, 100,150 and 200 mM NaCI）. Results showed that sodium chloride had an underrating effect on growth of stems and seed germination of the species studied. The germination rates of seeds of Glycine max and Phaseolus vulgaris （sensitive glyeophytes） were affected from 3 g/L of NaCl, with critical thresholds at 9 and 12 g/L respectively. In contrast, critical thresholds with Mucunapoggei （facultative halophyte）, Vigna unguiculata （moderately tolerant glycophyte） and P. adenanthus （natural halophyte） was found to be above 21 g/L. The reduction of stems growth rate were not significant in P. adenanthus whereas in M. poggei and V. unguiculata this inhibition was observed just when nutritive solutions were enriched with 200 mM. The lipid contents were reduced in all the species under salt stress, whereas proteins and proline contents in the leaves were substantially increased in tolerant species （M. poggei, P. adenanthus and V. unguiculata）. In contrast, proteins and leaf proline contents were negatively affected by salt concentration to G. max and P. vulgaris. Seed germination, proteins and proline could be used as physiological criteria of early selection for salt tolerant leguminous plants.  相似文献   

8.
To study the relations between DNA methylation and abiotic stress responses in cotton （Gossypium hirsutum L.）,the methylation-sensitive amplified polymorphism （MSAP） method was used to investigate the differences in methylation level and the change of cytosine methylation patterns under salt （NaCl） stress in two different salt-tolerant cotton lines.The results showed that the number of the cytosine methylation of CCGG sites in high salt-tolerant cotton line was less than that in low salt-tolerant line.Under salt stress,extensive cytosine methylation alterations including hypermethylation and demethylation as well as the potential conversion of methylation types occurred in the salt-treated cotton line compared with the corresponding control.Interestingly,salt stress-induced demethylation loci that occurred in high salt- tolerant cotton line were greater than those in low salt-tolerant cotton line,however,salt stress-induced hypermethylation loci in the high salt-tolerant cotton line were less than those in low salttolerant cotton line.It suggested that the demethylation positively contributed to salt tolerance and the hypermethylation had negative effect on salt tolerance in cotton.  相似文献   

9.
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10.
When maize seedlings were subjected to salt stress,a decline in root xylem pressure was observed within seconds,followed by a gradual increase in Na＋ deposition in the seedlings.The magnitude of xylem pressure response was positively correlated with,but not proportional to the intensity of the stress.A continuous recording of the xylem pressure profile showed that self-regulation of the xylem pressure existed before and after the imposition of salt stress when the environmental conditions were relatively stable.The salt induced increase in xylem tension dominated the total water potential of the plant when the salt stress was mild,but the osmotic potential became more prominent when the NaCl concentration in the root bathing solution was raised to over 100 mol m-3.The average transpiration rate of the seedlings dropped by 40% when the NaCl concentration in the root ambient was increased to 150 mol m-3.Although salt stress resulted in the decline of both the xylem pressure potential and the osmotic potential in the root xylem,the changes in the total water potential of the root xylem solution were always smaller than the changes in the water （osmotic） potentials of the solution bathing the root.An analysis to the water relations of maize seedlings showed that not only the water potential components,but the radial reflection coefficient of the roots was also dependent on the level of salinity.When the NaCl level in the root bathing solution was raised from 25 to 150 mol m-3,the radial reflection coefficient of the root declined from 0.43 to 0.31.This small change resulted in a remarkable increase in the normalised relative NaCl absorption by 2.4 times,indicating that the radial reflection coefficient of root played a very important role in regulating the absorption of NaCl in maize seedlings under salt stress.  相似文献   

11.
[Objective] The study aimed to reveal the effects of hypergravity on salt tolerance of wheat seedlings. [Method] The seed germination rate (Gr) and germination index (Gi) of wheat seedlings were measured under hypergravity of 600×g or 1 000×g for 4 h and under the stress of 0.4% or 0.9% salt solution. The catalase (CAT) activity and malondialdehyde (MDA) content of wheat seedlings were also measured under 0.4% salt stress. [Result] Compared with seedlings in CK group (no hypergravity or salt stress),the Gr and Gi of the seedlings in salt stress treatment decreased to different extents; while the Gr and Gi of the seedlings in treatment group (hypergravity and salt stress) increased compared with that in salt stress group. CAT in seedlings of hypergravity treatment was higher than that of CK group and 0.4% salt treatment group,meanwhile the MDA showed an opposite result. [Conclusion] Hypergravity could enhance the salt resistance of wheat in specific range,and hypergravity of 600×g for 4 h performed better than that of 1 000×g for 4 h.  相似文献   

12.
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13.
To reveal the insecticidal mechanism of terpinen-4-ol, the activity of Na＋,K＋-ATPase in insects tested were determined in vivo and in vitro. The results showed that terpinen-4-ol and its ester derivatives had strong contact activity to housefly and the contact toxicities of its derivatives except Z3 were all superior or equivalent to terpinen-4-ol. All the 7 compounds had strong inhibition towards activity of Na＋,K＋-ATPase. With poisoning symptom exacerbating, the inhibition rates were gradually increased. In vitro, the IC50 of terpinen-4-ol, Z1, Z2, Z4, Z5, and Z6 was 155.89, 197.98, 96.02, 121.36, 124.85, and 153.74 μg mL% respectively. There was well correlation between the LDs0 of terpinen-4-ol derivatives to housefly and the IC50 of terpinen-4-ol derivatives to Na＋,K＋-ATPase in housefly. In conclusion, Na＋,K＋-ATPase was likely the target of terpinen-4-ol against insects.  相似文献   

14.
To investigate the effects of a plant autotoxin, cinnamic acid, on bacterial communities in the rhizosphere soil of cucumber seedlings under salt stress, we used cucumber as the experimental material, cinnamic acid as the autotoxin, and NaCl to apply salt stress. Bacterial communities in the rhizosphere soil were analyzed using polymerase chain reaction （PCR）, denaturing gradient gel electrophoresis （DGGE）, and clone sequencing. Salt stress decreased the diversity of bacterial species in rhizosphere soil of cucumber seedlings at several growth stages. Cinnamic acid exacerbated the effects of salt stress at high concentrations, but alleviated its effects at low concentrations. Cloning and sequencing results indicated that DGGE bands amplified from soil samples showed high homology to uncultured bacterial species. Cinnamic acid at 50 mg kg^-1 soil improved cucumber growth and was the most effective treatment to alleviate the effects of salt stress on bacterial communities.  相似文献   

15.
The present investigation was carried out to investigate the effect of heat stress and revival on some antioxidative enzymes and metabolites in leaves of the wheat （Triticum aestivum L.） seedlings of heat susceptible （cv. WH 147 and HS 277） and heat tolerant （cv. WH 1021 and HW 2045） cultivars. Seven days old seedlings grown at 25 ℃ were exposed to 40 ℃ for 6 h and these seedlings were again brought to 25 ℃. The observations were recorded in the leaves of control, stressed and revived seedlings on 2nd and 4th day of revival. For the selection ofthermo-tolerant cultivars, screening of the thirty-six cultivars was done based on wilting of primary leaf and values of chlorophyll fluorescence. The MDA （malondialdehyde） and H2O2 concentration in leaves of wheat seedlings increased at the high temperature. There was enhancement in the activities of antioxidative enzymes, viz. CAT （catalase）, POX （peroxidase）, GR （glutathione reductase） and APX （ascorbate peroxidase） in leaves of the tolerant and susceptible cultivars under heat stress, however, higher percent increase was observed in tolerant cultivars. Heat stress increased the SOD （superoxide dismutase） activity in tolerant cultivars but activity declined in susceptible cultivars. On revival, the activities of the CAT, POX and GR declined in comparison to stressed seedlings but remained higher as compared to control. Ascorbate peroxidase activity remained higher on 2nd day and 4th day of revival in all the cultivars.  相似文献   

16.
In this study, we investigated the effect of exogenous sodium benzoate on wheat seedlings(Yangmai 16) grown under heavy metal stress. The results showed that 2.4 mmol kg~(–1) of heavy metals significantly inhibited growth and delayed emergence of wheat seedlings. Under compound heavy metal stress, application of 2–4 g L~(–1) sodium benzoate significantly increased(P0.01) chlorophyll content and chlorophyll fluorescence parameters F_v/F_m and F_v/F_o of wheat, compared to the control(water treatment). Further analysis showed that application of 2–4 g L~(–1) sodium benzoate alleviated osmotic stress by promoting the accumulation of osmolytes such as soluble proteins and free proline, increased the activity of superoxide dismutase(SOD) and reduced malondialdehyde content(MDA). In contrast, higher concentrations of sodium benzoate solution(6 g L~(–1)) inhibited the growth of wheat seedlings and even caused damage to seedlings. Correlation analysis showed that when the sodium benzoate concentration was in the range of 1.97–3.12 g L~(–1)(2016) and 1.58–3.27 g L~(–1)(2017), values of chlorophyll and its components, root activity, SOD activity, soluble protein, and free proline content were the highest. When the sodium benzoate concentration was raised to 2.59 g L~(–1)(2016) or 3.02 g L~(–1)(2017), MDA content was the lowest. Ultimately, exogenous sodium benzoate(2–4 g L~(–1)) facilitates root development and improves the root activity of wheat seedlings grown under compound heavy metals stress, thereby effectively alleviating the damage of compound heavy metal stress in wheat seedlings.  相似文献   

17.
Alfalfa （Medicago sativa L.） is an important forage crop in the world and it is of great signiifcance for the improvement of its salt tolerance. To improve salt tolerance in alfalfa, a rice ascorbate peroxidase gene （OsAPX2） was introduced into alfalfa using Agrobacterium tumefaciens-mediated transformation with marker gene bar. The different T-DNA insertions in T1 transgenic alfalfa were identiifed by Southern hybridization. Three independent T2 transgenic lines were selected for stress analysis and the results showed that all of them were salt tolerant compared with wild-type plants. The transgenic plants had low levels of H2O2, malondialdehyde and relative electrical conductivity under salt and drought stresses. Moreover, the contents of chlorophyll and proline, and APX activity were high in transgenic plants under salt and drought stresses. Taken together, the overexpression of OsAPX2 enhances salt tolerance in alfalfa through scavenging reactive oxygen species.  相似文献   

18.
[Objective] The aim of this study is to reveal the salt resistance of castor. [Method] Under salt stress, the growth, osmotic potential, chlorophyll fluorescence parameters, Na~+ and K~+ uptakes and transports in the seedlings of two Ricinus communis varieties (cultivar castor ‘Zibi 6’ and wild castor which grew naturally in coastal saline-alkali land), were comparatively studied. [Result] Wild castor preformed better in halophilism than that of cultivar castor Zibi 6 under the NaCl treatment. One of the salt tolerant mechanisms of castor is to improve K~+ uptake and transport to overground portion, thus to maintain K~+/Na~+ homeostasis in leaves; on the other hand, the high stability of Photoreaction System Ⅱ (PS Ⅱ) plays a key role in maintaining the leaf photosynthetic rate under salt stress. [Conclusion] The results of this study provided theoretical basis for the extension and application of castor in saline beach.  相似文献   

19.
The growth situation and peroxidase (POD) of seedlings of two tomato cultivars were investigated under the stress of different concentrations of Cu2+ and Cd2+. The toxicity differences of Cu2+ and Cd2+ to tomato seedlings and the corresponding differences between two tomato cultivars were observed through the stress trial with the above two heavy metal ions. The results showed that low concentration of Cu2+ and Cd2+ could promote the growth and could enhance the POD activity of tomato seedlings,while high concentration Cu2+ and Cd2+ could inhibit seedling growth and POD activity of tomato seedlings. Cd2+ functioned more obviously than that of Cu2+,two tomato cultivars also presented difference in response to heavy metal stress.  相似文献   

20.
To better understand the effect and mechanism of cold tolerant seed-coating agents on the cold tolerance of rice seedlings, the physiological and biochemical effects of four cold tolerant seed-coating agents （HET, YKJ, YKZYJ, and the ABA seed coating agents） on two early indica rice varieties were studied under chilling stress. The results showed that the rice seedlings treated with cold tolerant seed-coating agents under chilling stress maintained dramatically higher root vigor, POD, CAT and SOD activities, and chlorophyll content, had lower MDA content and electrolyte leakage, and accumulated more soluble sugar and free proline, when compared with the control without the treatment, and finally showed lower plant injury rate. It was indicated that the cold tolerant seed coating agent improved the ability of rice seedlings in resisting to chilling stress. YKZYJ was ranked the first in terms of the efficiency in cold tolerance among the four cold tolerant seed-coating agents tested.  相似文献   

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