共查询到20条相似文献,搜索用时 15 毫秒
1.
- Seedling establishment is a critical step in environment colonisation by higher plants that frequently occurs under adverse conditions. Thus, we carried out an integrated analysis of seedling growth, water status, ion accumulation, reserve mobilisation, metabolite partitioning and hydrolase activity during seedling establishment of the native Caatinga species Piptadenia moniliformis (Benth.) Luckow & R.W. Jobson under salinity.
- Two‐day‐old seedlings were cultivated in vitro for 4 days in water agar (control) or supplemented with 50 or 100 mm NaCl. Biochemical determinations were performed according to standard spectrophotometric protocols.
- We found that 100 mm NaCl stimulated starch degradation, amylase activity and soluble sugar accumulation, but limited storage protein hydrolysis in the cotyledons of P. moniliformis seedlings. Although Na+ accumulation in the seedling affected K+ partitioning between different organs, it was not possible to associate the salt‐induced changes in reserve mobilisation with Na+ toxicity, or water status, in the cotyledons. Remarkably, we found that starch content increased in the roots of P. moniliformis seedlings under 100 mm NaCl, probably in response to the toxic effects of Na+.
- The mobilisation of carbon and nitrogen reserves is independently regulated in P. moniliformis seedlings under salt stress. The salt‐induced delay in seedling establishment and the resulting changes in the source–sink relationship may lead to storage protein retention in the cotyledons. Possibly, the intensification of starch mobilisation in the cotyledons supported starch accumulation in the root as a potential mechanism to mitigate Na+ toxicity.
相似文献
2.
Black cumin (Nigella sativa L.) is considered as a noteworthy herbal medicine. However, no study has been conducted on the physiological adaptive mechanism of it to salinity stress, especially under in vitro condition. To this aim, the callus cultures of ten different genotypes of N. sativa were applied to evaluate the changes occurring in biochemical traits under salinity stress. The calluses were exposed to the in vitro salt stress using different sodium chloride concentrations (0, 84, and 250 mM). A reduction occurred in the content of K+ and callus growth by enhancing the NaCl concentration. However, most of the content of Na+ (4 mgg− 1 DW), malondialdehyde (1.38 μmolg− 1 FW), total phenolic content (1.18 mg GAEg−1 FW), thymol (25.26 mgg− 1 DW), total flavonoids content (0.06 mg QEg− 1 FW), total flavonols (TFL) content (0.023 mg QEg− 1 FW), total anthocyanins (Ant) (0.05 μmol g− 1 FW) and DPPH activity (58.17%) was observed at 250 mM of NaCl. In fact, two secondary metabolites including TFL and Ant can be considered as the major contributors to the potential antioxidant activity of N. sativa at the callus level. The elicitation through NaCl opens new avenues for the selection of best dosages of NaCl for the enhancement of commercially important secondary metabolites, in superior genotypes (Nig1 and Nig2) of N. sativa at cellular level. 相似文献
3.
Two arsenic (As) hyperaccumulators ( Pteris multifida and Pteris vittata) and a non-hyperaccumulator ( Pteris semipinnata) were exposed to different As concentrations under hydroponic conditions. Five flavonoids in these fern species were determined by high-performance liquid chromatography (HPLC). Flavonoid production in P. multifida and P. semipinnata was also studied in 0 and 20 mg As L −1 treatments at different cultivation times. No significant differences were observed regarding the contents of quercetin, isoquercitrin and kaempferol in the fronds. The contents of rutin, quercetin, kaempferol and total flavonoids were also not significantly different in the roots of the three fern species under the same As treatment. However, significant differences were observed in contents of rutin, quercetin, hyperin, kaempferol and total flavonoids over time in the 20 mg As L −1 treatment. In general, the changes in flavonoid contents in the As hyperaccumulators were not directly related to As accumulation. 相似文献
4.
- Brassica insularis is a protected plant that grows on both coastal and inland cliffs in the western Mediterranean Basin. The objective of this study was to test if any variability exists in the salt stress response during seed germination and seedling development in this species relative to its provenance habitat.
- Variability among three populations in the salt stress effects on seed germination and recovery under different temperatures was evaluated. The effect of nebulisation of a salt solution on seedling development was evaluated between populations growing at different distances from the sea.
- Seeds of B. insularis could germinate at NaCl concentrations up to 200 mm . Seed viability was negatively affected by salt, and recovery ability decreased with increasing temperature or salinity. Inter‐population variability was detected in salt response during the seed germination phase, as well as in seedling salt spray tolerance. The inland population seedlings had drastically decreased survival and life span and failed to survive to the end of the experiment. In contrast, at least 90% of the coastal seedlings survived, even when sprayed at the highest frequency with salt solution.
- This study allowed investigation of two natural factors, soil salinity and marine aerosols, widely present in the B. insularis habitat, and provided the first insights into ecology of this protected species and its distribution in the Mediterranean. These results might be useful in understanding the actual distributions of other species with the same ecology that experience these same abiotic parameters.
相似文献
5.
- Salinity is now an increasingly serious environmental issue that affects the growth and yield of many plants.
- In the present work, the influence of inoculation with the symbiotic fungus, Piriformospora indica, on gas exchange, water potential, osmolyte content, Na/K ratio and chlorophyll fluorescence of tomato plants under three salinity levels (0, 50, 100 and 150 mm NaCl) and three time periods (5, 10 and 15 days after exposure to salt) was investigated.
- Results indicate that P. indica inoculation improved growth parameters of tomato under salinity stress. This symbiotic fungus significantly increased photosynthetic pigment content under salinity, and more proline and glycine betaine accumulated in inoculated roots than in non‐inoculated roots. P. indica further significantly improved K+ content and reduced Na+ level under salinity treatment. After inoculation with the endophytic fungus, leaf physiological parameters, such as water potential, net photosynthesis, stomatal conductance and transpiration, were all higher under the salt concentrations and durations compared with controls without P. indica. With increasing salt level and salt treatment duration, values of F0 and qP increased but Fm, Fv/Fm, F′v/F′m and NPQ declined in the controls, while inoculation with P. indica improved these values.
- The results indicate that the negative effects of NaCl on tomato plants were alleviated after P. indica inoculation, probably by improving physiological parameters such as water status and photosynthesis.
相似文献
6.
The effects of 28-homobrassinolide (28-homoBL) on seedling growth, lipid peroxidation and antioxidative enzyme activities
in the seedlings of Zea mays L. (var. Partap-1) under salt (NaCl) stress were studied. The surface-sterilized seeds were germinated in petriplates containing
different concentrations of NaCl (25, 50, 75 and 100 mM) only, 28-homoBL (10 −7, 10 −9 and 10 −11 M) only and NaCl supplemented with 28-homoBL for 7 days. The activities of superoxide dismutase (SOD, EC 1.15.1.1), guaiacol
peroxidase (POD, EC 1.11.1.7), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APOX, EC 1.11.1.11) and glutathione reductase
(EC 1.6.4.2) were analysed in 7 day-old seedlings. It was observed that 28-homoBL treatments reduced the toxicity of salt
on seedling growth considerably. Lipid peroxidation level was significantly increased under saline stress, but lowered with
28-homoBL applications revealing less oxidative damage. Further 28-homoBL treatments to the seedlings showed an enhancement
in activities of SOD, POD, CAT and APOX. The activities of all antioxidative enzymes were further increased in seedlings treated
with solution containing 28-homoBL and salt together as compared to seedlings treated with different concentration of salt
solution only. 相似文献
7.
- Coastal salt marsh plants employ various combinations of morphological and physiological adaptations to survive under saline conditions. Little information is available on salinity tolerance mechanisms of Halopeplis perfoliata, a C3 stem succulent halophyte.
- We investigated the growth, photosynthesis and antioxidant defence mechanisms of H. perfoliata under saline conditions (0, 150, 300 and 600 mM NaCl) in an open greenhouse.
- Optimal shoot succulence, projected shoot area and relative growth rate were obtained in the low (150 mm NaCl) salinity treatment, while growth was inhibited at the highest salinity (600 mm NaCl). The CO2 compensation point and carbon isotope composition of biomass confirmed C3 photosynthesis. Increases in salinity did not affect the photosynthetic pigment content or maximum quantum efficiency of PSII of H. perfoliata. Assimilation of CO2 (A) also remained unaffected by salinity. A modest effect on some gas exchange and photochemistry parameters was observed at 600 mm NaCl. With increasing salinity, there was a continual increase in respiration, suggesting utilisation of energy to cope with saline conditions. Under 300 and 600 mm NaCl, there was an increase in H2O2 and MDA with a concomitant rise in AsA, GR content and CAT activity.
- Hence, H. perfoliata appears to be an obligate halophyte that can grow up to seawater salinities by modulating photosynthetic gas exchange, photochemistry and the antioxidant defence systems.
相似文献
8.
- Acetylcholine (ACh) is believed to improve plant growth. However, regulation at biochemical and molecular levels is largely unknown.
- The present study investigated the impact of exogenously applied ACh (10 µm ) on growth and chlorophyll metabolism in hydroponically grown Nicotiana benthamiana under salt stress (150 mm NaCl).
- Salinity reduced root hydraulic conductivity while ACh‐treated seedlings exhibited a significant increase, resulting in increased relative water content. Salinity induced a reduction in chlorophyll biosynthetic intermediates, such as protoporphyrin‐IX, Mg‐photoporphyrin‐IX and protochlorophyllide, which were significantly ameliorated in the presence of ACh. This influence of ACh on chlorophyll synthesis was confirmed by up‐regulation of HEMA1, CHLH, CAO and POR genes. Gas exchange parameters, i.e. stomatal conductance, internal CO2 concentration and transpiration rate, increased with ACh, thereby alleviating the salinity effects on photosynthesis. In addition, the salinity‐induced enhancement of lipid peroxidation declined after ACh treatment through modulation of the activity of the assayed antioxidant enzymes (superoxide dismutase and peroxidase). Importantly, ACh significantly reduced the uptake of Na and increased uptake of K, resulting in a decline in the Na/K ratio.
- Results of the present study indicate that ACh can be effective in ameliorating NaCl‐induced osmotic stress, altering chlorophyll metabolism and thus photosynthesis by maintaining ion homeostasis, hydraulic conductivity and water balance.
相似文献
9.
Soil salinization is a global issue impeding horticulture production and is approaching an alarming status due to climate change and urbanization. Breeding salt-tolerant rootstock varieties is an ideal strategy to mitigate stress due to salinity in mango and other perennial fruit species. Stress combating strategies employed by seedlings of 7 mango were studied under saline conditions (200 mM NaCl, EC: > 4.0 dSm−1, pH 8.5) in pot experiments. Significantly high accumulation of proline (19.07 µg g−1 FW in Bappakai), glycine betaine (55.11 µg g−1 FW in 13–1), and total sugars (17.33 mg g−1 FW in Kurukkan) were found to be the common mechanism employed by the tolerant cultivars to counter the osmotic stress, under suboptimal conditions. Non-enzymatic antioxidants viz., tannins (17.18 mg g−1), phenols (18.68 mg g−1), and anthocyanins (1.59 mg g−1) were increased in seedling of "13–1", the salt-resistant cultivar from Israel. Reactive oxygen species (ROS) regulation by increased activity of superoxide dismutase and catalase in the two polyembryonic cultivars of Indian origin (Kurukkan and Nekkare) suggests their potential use as rootstocks to combat oxidative stress. The tolerance index of various cultivars was calculated by averaging the scores of morphological stress indicators, and its correlation with studied parameters suggests that salinity resilience is more tightly linked to enhanced catalase accumulation (r2 = 0.8361) that is reduced ionic stress. This evidence assign the role of osmotic stress alleviation and redox regulation in salt tolerance mechanism operational in native Indian cultivars, Nekkare and Kurukkan at par with known salt tolerant rootstocks. 相似文献
10.
A pot study was conducted to determine the effects of arbuscular mycorrhizal (AM) fungi ( Glomus mosseae and Paraglomus occultum) and salt (NaCl) stress on growth, photosynthesis, root morphology and ionic balance of citrus ( Citrus tangerine Hort. ex Tanaka) seedlings. Eighty-five-day-old seedlings were exposed to 100 mM NaCl for 60 days to induce salt stress.
Mycorrhizal colonization of citrus seedlings was not affected by salinity when associated with P. occultum, but significantly decreased when with G. mosseae. Compared with the non-mycorrhizal controls, mycorrhizal seedlings generally had greater plant height, stem diameter, shoot,
root and total plant biomass, photosynthetic rate, transpiration rate and stomatal conductance under the 0 and 100 mM NaCl
stresses. Root length, root projected area and root surface area were also higher in the mycorrhizal than in the non-mycorrhizal
seedlings, but higher root volume in seedlings with G. mosseae. Leaf Na + concentrations were significantly decreased, but leaf K + and Mg 2+ concentrations and the K +/Na + ratio were increased when seedlings with both G. mosseae and P. occultum. Under the salt stress, Na + concentrations were increased but K + concentrations decreased in the mycorrhizal seedlings. Under the salt stress, Ca 2+ concentrations were increased in the seedlings with P. occultum or without AM fungi (AMF), but decreased with G. mosseae. Ratios of both Ca 2+/Na + and Mg 2+/Na + were also increased in seedlings with G. mosseae under the non-salinity stress, while only the Mg 2+/Na + ratio was increased in seedlings with P. occultum under the salt stress. Our results suggested that salt tolerance of citrus seedlings could be enhanced by associated AMF
with better plant growth, root morphology, photosynthesis and ionic balance. 相似文献
11.
- Salt stress negatively affects growth and development of plants. However, it is hypothesized that plant growth‐promoting endophytic bacteria can greatly alleviate the adverse effects of salinity and can promote growth and development of plants. In the present research, we aimed to isolate endophytic bacteria from halotolerant plants and evaluate their capacity for promoting crop plant growth.
- The bacterial endophytes were isolated from selected plants inhabiting sand dunes at Pohang beach, screened for plant growth‐promoting traits and applied to rice seedlings under salt stress (NaCl; 150 mm ).
- Out of 59 endophytic bacterial isolates, only six isolates, i.e. Curtobacterium oceanosedimentum SAK1, Curtobacterium luteum SAK2, Enterobacter ludwigii SAK5, Bacillus cereus SA1, Micrococcus yunnanensis SA2, Enterobacter tabaci SA3, resulted in a significant increase in the growth of Waito‐C rice. The cultural filtrates of bacterial endophytes were tested for phytohormones, including indole‐3‐acetic acid, gibberellins and organic acids. Inoculation of the selected strains considerably reduced the amount of endogenous ABA in rice plants under NaCl stress, however, they increased GSH and sugar content. Similarly, these strains augmented the expression of flavin monooxygenase (OsYUCCA1) and auxin efflux carrier (OsPIN1) genes under salt stress.
- In conclusion, the pragmatic application of the above selected bacterial strains alleviated the adverse effects of NaCl stress and enhanced rice growth attributes by producing various phytohormones.
相似文献
12.
The present study investigates the regulatory role of exogenous selenium (Se) in the antioxidant defense and methylglyoxal
(MG) detoxification systems in rapeseed seedlings exposed to salt stress. Twelve-day-old seedlings, grown in Petri dishes,
were supplemented with selenium (25 μM Na 2SeO 4) and salt (100 and 200 mM NaCl) separately and in combination, and further grown for 48 h. The ascorbate (AsA) content of
the seedlings decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione
disulfide (GSSG) increased with an increase in the level of salt stress, while the GSH/GSSG ratio decreased. In addition,
the ascorbate peroxidase (APX) and glutathione S-transferase (GST) activity increased significantly with increased salt concentration (both at 100 and 200 mM NaCl), while
glutathione peroxidase (GPX) activity increased only at moderate salt stress (100 mM NaCl). Glutathione reductase (GR) activity
remained unchanged at 100 mM NaCl, while it was decreased under severe (200 mM NaCl) salt stress. Monodehydroascorbate reductase
(MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) activities decreased
upon the imposition of salt stress, whereas a sharp decrease of these activities was observed under severe salt stress (200 mM
NaCl). Concomitant increases in the levels of H 2O 2 and lipid peroxidation (MDA) were also measured. Exogenous Se treatment alone had little effect on the non-enzymatic and
enzymatic components. However, further investigation revealed that Se treatment had a synergistic effect: in salt-stressed
seedlings, it increased the AsA and GSH contents; GSH/GSSG ratio; and the activities of APX, MDHAR, DHAR, GR, GST, GPX, CAT,
Gly I, and Gly II. As a result, addition of Se in salt-stressed seedlings led to a reduction in the levels of H 2O 2 and MDA as compared to salt stress alone. These results suggest that the exogenous application of Se rendered the plants
more tolerant to salt stress-induced oxidative damage by enhancing their antioxidant defense and MG detoxification systems. 相似文献
13.
The effects of salt stress were studied on the accumulation and metabolism of proline and its correlation with Na + and K + content in shoots and callus tissue of four potato cultivars, viz., Agria, Kennebec (relatively salt tolerant), Diamant and Ajax (relatively salt sensitive). Na + and proline contents increased in all cultivars under salt stress. However, K + and protein contents decreased in response to NaCl treatments. The activities of enzymes involved in proline metabolism,
Δ 1-pyrroline-5-carboxylate synthetase (P5CS) and proline dehydrogenase (ProDH) increased and decreased, respectively, in response
to elevated NaCl concentrations. The changes of P5CS and ProDH activities in more salt sensitive cultivars (Diamant, Ajax)
were more than those in the tolerant ones. Then the stimulation of synthesis in combination with a partially increase of protein
proteolysis, a decrease in proline utilization and inhibition of oxidation resulted in high proline contents in seedlings
and calli under salt stress. In callus tissue, reduced growth and cell size may be partially responsible for high proline
accumulation in response to high NaCl levels. However, although the basic proline contents in the seedlings of more salt tolerant
cultivars were higher than the sensitive ones, a clear relationship was not generally observed between accumulation of proline
and salt tolerance in potato. 相似文献
15.
The inevitable exposure of crop plants to salt stress is a major environmental problem emerged from the presence of excess
NaCl radicals in the soil. Handling the problem in maize plants using a biological agent was the main interest of the present
study. The non-pathogenic, halophytic, facultative aerobic bacterium Geobacillus caldoxylosilyticus IRD that was isolated from Marakopara pond in the Atoll Tikehau (French Polynesian, 2005) and found tolerant to salt stress
until 3.5% NaCl (w/v). An artificial symbiosis was achieved by inoculating Geobacillus sp. into 5-day-old maize cultivars of triple hybrids (321 and 310) and singlet hybrids (10 and 162). Thereafter, maize seedlings
were exposed to 350 mmol NaCl for 10 days. The data revealed that Geobacillus sp. had interacted with salinized maize and improved maize overall growth, dry weight and relative water content. Na + accumulation was six times less and Cl − accumulation was 13 times less in the tips of salinized maize seedlings upon Geobacillus sp. inoculation. Salinized maize without Geobacillus viewed decayed cortical cells of seedlings. In addition, proline content was two times higher in salinized seedlings lacking
Geobacillus. Photosynthetic pigments and antioxidant enzymes were significantly regulated upon inoculation. Beyond this study, we presented
a novel insight into a possible role of Geobacillus caldoxylosilyticus bacteria in controlling/protecting maize plants against high salt stress. 相似文献
16.
- Miscanthus sinensis Anderss. is a good candidate for C4 bioenergy crop development for marginal lands. As one of the characteristics of marginal lands, salinization is a major limitation to agricultural production. The present work aimed to investigate the possible factors involved in the tolerance of M. sinensis C4 photosynthesis to salinity stress.
- Seedlings of two accessions (salt‐tolerant ‘JM0119’ and salt‐sensitive ‘JM0099’) were subjected to 0 mm NaCl (control) or 250 mm NaCl (salt stress treatment) for 2 weeks. The chlorophyll content, parameters of photosynthesis and chlorophyll a fluorescence, activity of C4 enzymes and expression of C4 genes were measured.
- The results showed that photosynthesis rate, transpiration rate, chlorophyll content, PSII operating efficiency, coefficient of photochemical quenching, activity of phosphoenolpyruvate carboxylase (PEPC) and pyruvate, orthophosphate dikinase (PPDK) and gene expression of PEPC and PPDK under salinity were higher after long‐term salinity exposure in ‘JM0119’ than in ‘JM0099’, while activity of NADP‐malate dehydrogenase (NADP‐MDH) and NADP‐malic enzyme (NADP‐ME), together with expression of NADP‐MDH and NADP‐ME, were much higher in ‘JM0099’ than in ‘JM0119’.
- In conclusion, the increased photosynthetic capacity under long‐term salt stress in the salt‐tolerant relative to the salt‐sensitive M. sinensis accession was mainly associated with non‐stomatal factors, such as reduced chlorophyll loss, higher PSII operating efficiency, enhanced activity of PEPC and PPDK and relatively lower activity of NADP‐ME.
相似文献
17.
To examine the effects of salt stress on dark-grown wheat ( Triticum aestivum), seedlings of the salt-tolerant cultivar Sids 1 and the susceptible cultivar Giza 168 were grown in darkness for 14 days
in nutrient solution with and without 200 mM of supplementary salt (100 mM of NaCl and 100 mM of KCl). During this time, we
monitored their protochlorophyllide (Pchlide) contents, ratios of photoactive to non-photoactive forms of Pchlide (from 655/633-nm
emission ratios in their 77 K fluorescence emission spectra) and (following flash irradiation) ratios of newly formed chlorophyllide
(Chlide) to non-photoactive Pchlide. In addition, the accumulation of chlorophyll a in leaf sections was monitored during prolonged (24 h) irradiation. The results depended on the developmental state of the
seedlings. However, the salt stress treatment caused marked increases in both Pchlide contents in dark-grown leaves and in
Chlide contents following irradiation of leaf sections of both cultivars. The ratio of phototransformable to non-phototransformable
Pchlide and the abundance of newly formed Chlide were also increased by the salt stress. Further, leaves of salt-stressed
seedlings consistently accumulated more chlorophyll a than leaves of unstressed seedlings when floating on the nutrient solution (with or without supplementary salt) in continuous
white light. The findings are consistent with the hypothesis that increased levels of the long-wavelength form of Pchlide
contribute to protective mechanisms against salt stress. 相似文献
18.
Growth, photosynthesis, and Na +, K +, Ca 2+, and Mg 2+ distributions were examined in two-year-old hydroponically cultured Populus nigra and Populus alba cuttings exposed to salt stress (0, 50, or 100 mM NaCl) for four or six weeks and to nonaeration stress for one or three weeks,
followed by a three-week aeration period in 2/5 Hoagland solution. Salt stress with 100 mM NaCl totally inhibited height increase
in P. nigra cuttings. Combined salinity and nonaeration inhibited height increase to a greater degree than either stress alone in both
species. Simple salt stress did not affect diameter increase in P. alba, whereas combined high salinity (100 mM NaCl) and nonaeration inhibited diameter increase. Growth and biomass accumulation
were more sensitive to salt stress in P. nigra cuttings than in P. alba, although P. alba showed a more rapid decrease in photosynthesis in response to nonaeration stress. Ion distributions in the leaves and roots
differed between species. P. alba was superior to P. nigra in terms of Na + exclusion capacity, such that most of the absorbed Na + was confined to the root system, with little reaching the leaves. The distributions of K +, Ca 2+, and Mg 2+ in the leaves and roots of each species under the two stressors were also analyzed. The lower Na +/K + ratio in leaves indicated that P. alba was more tolerant to salt stress than P. nigra. 相似文献
19.
In this study, high-betacyanin Suaeda salsa seedlings were developed and used to explore whether the betacyanin accumulation is related to salinity tolerance in S. salsa. After 8 days of culture, betacyanin content decreased markedly in both high-betacyanin S. salsa seedlings and the control under nonsalt stress, but the decreases were suppressed by NaCl treatments. Betacyanin content
in high-betacyanin seedlings was much higher than that in the control throughout the salt treatments. Growth of S. salsa plants was significantly promoted by NaCl treatments, and the fresh weight of high-betacyanin seedlings was much higher than
that of the control when grown in 400 mmol L −1 NaCl. Similar cell sap osmolarity and K +/Na + ratios were observed in high-betacyanin seedlings and the control. No obvious differences in V-ATPase (tonoplast H +-ATPase) activity, leaf SOD (superoxide dismutase) activity, and total chloroplast SOD (including thylakoid-bound SOD and
stroma SOD) activity were detected between high-betacyanin seedlings and the control under nonsalt stress conditions. However,
V-ATPase hydrolytic activity increased dramatically in S. salsa seedlings when subjected to different levels of NaCl, and the increases in V-ATPase activity in high-betacyanin seedlings
were much higher than that in the control. No clear pattern was observed for NaCl-dependent activity changes of P-ATPase (plasma
membrane H +-ATPase) and V-PPase (tonoplast H +-pyrophosphatase). Similar changes were demonstrated in leaf SOD activity and chloroplast SOD activity under salt stress.
Both leaf SOD activity and chloroplast SOD activity were markedly enhanced with the increase of NaCl or with time, especially
thylakoid-bound SOD activity. Furthermore, the increases in chloroplast SOD activity and thylakoid-bound SOD activity were
much higher in high-betacyanin seedlings than that in the control at different levels of NaCl treatment. The higher V-ATPase
activity, chloroplastic SOD activity, and thylakoid-bound SOD activity demonstrated in high-betacyanin seedlings, but lower
in the control, suggest that high-betacyanin S. salsa seedlings may have higher potential to be energized by the electrochemical gradient for ion uptake into the vacuole and to
scavenge O 2−• in situ produced in the chloroplasts, which may lead to higher salt tolerance than the control under salt stress. Thus, betacyanin
may be involved in salt tolerance of S. salsa. 相似文献
20.
In this study, we set out to investigate the effect of sodium chloride (NaCl) on carotenoid and flavonoid production by the black nightshade ( Solanum nigrum L.). The study was carried out under green chamber conditions using seedlings subjected to 0, 50, 100 and 150 mM NaCl for 3 weeks. The negative effect of NaCl on dry biomass production of roots and leaves were accompanied by a significant restriction in K +, Ca 2+ and Mg 2+ ion uptake and by an increase in Na + ion concentrations, the effects of which were most pronounced at the highest NaCl level. Salt stress also induced oxidative stress, according to the amplified levels of thiobarbituric acid reactive substances and relative ion leakage ratio. Expression of some related carotenoid (phytoene synthase 2 and β-lycopene cyclase) and flavonoids genes (phenylalanine ammonialyase, chalcone synthase and flavonol synthase) were induced by NaCl, followed enhanced production of β-carotene, lutein, and quercetin 3-β- d-glucoside. At the highest NaCl level (150 mM NaCl), quercetin 3-β- d-glucoside synthesis came at the expense of reduced β-carotene and lutein, while salt stress treatment affected leaf antioxidant activities to a great extent relative to the control. Our data suggest that the potential antioxidant properties of carotenoids and flavonoids and their related key genes may be efficiently involved in the restriction of salt-induced oxidative damages. 相似文献
|