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Silicon nutrition potentiates the antioxidant metabolism of rice plants under iron toxicity 总被引:2,自引:0,他引:2
Zahra Kiani Chalmardi Ahmad Abdolzadeh Hamid Reza Sadeghipour 《Acta Physiologiae Plantarum》2014,36(2):493-502
Iron toxicity reduces growth of rice plants in acidic lowlands. Silicon nutrition may alleviate many stresses including heavy metal toxicity in plants. In the present study, the ameliorating effects of silicon nutrition on rice (Oryza sativa L.) plants under toxic Fe levels were investigated. Plants were cultivated in greenhouse in hydroponics under different Fe treatments including 10, 50, 100, and 250 mg L?1 as Fe-EDTA and silicon nutrition including 0 and 1.5 mM sodium silicate. Iron toxicity imposed significant reduction in plant fresh weight, tiller, and leaf number. The activity of catalase, cell wall, and soluble peroxidases, and polyphenol oxidase in shoots decreased due to moderate Fe toxicity (50 and 100 mg L?1), but increased at greater Fe concentration. Ascorbate peroxidase activity increased in both roots and shoots of Fe-stressed plants. Iron toxicity led to increased tissue hydrogen peroxide and lipid peroxidation. Silicon nutrition improved plant growth under all Fe treatments and alleviated Fe toxicity symptoms, probably due to lower Fe concentration of Si-treated plants. Silicon application could improve the activity of antioxidant enzymes such as catalase, ascorbate peroxidase, and soluble peroxidase under moderate Fe toxicity, which resulted in greater hydrogen peroxide detoxification and declined lipid peroxidation. Thus, silicon nutrition could ameliorate harmful effects of Fe toxicity possibly through reduction of plant Fe concentration and improvement of antioxidant enzyme activity. 相似文献
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Zeynab Shahmoradi Fatemeh TamaskaniHamid Reza Sadeghipour Ahmad Abdolzadeh 《Journal of plant physiology》2013
Alterations in the redox state of storage proteins and the associated proteolytic processes were investigated in moist-chilled and warm-incubated walnut (Juglans regia L.) kernels prior to germination. The kernel total protein labeling with a thiol-specific fluorochrome i.e. monobromobimane (mBBr) revealed more reduction of 29–32 kDa putative glutelins, while in the soluble proteins, both putative glutelins and 41, 55 and 58 kDa globulins contained reduced disulfide bonds during mobilization. Thus, the in vivo more reduced disulfide bonds of storage proteins corresponds to greater solubility. After the in vitro reduction of walnut kernel proteins pre-treated by N-ethyl maleimide (NEM) with dithioerythrethiol (DTT) and bacterial thioredoxin, the 58 kDa putative globulin and a 6 kDa putative albumin were identified as disulfide proteins. Thioredoxin stimulated the reduction of the H2O2-oxidized 6 kDa polypeptide, but not the 58 kDa polypeptide by DTT. The solubility of 6 kDa putative albumin, 58 and 19–24 kDa putative globulins and glutelins, respectively, were increased by DTT. The in vitro specific mobilization of the 58 kDa polypeptide that occurred at pH 5.0 by the kernel endogenous protease was sensitive to the serine-protease inhibitor phenylmethylsulfonyl fluoride (PMSF) and stimulated by DTT. The specific degradation of the 58 kDa polypeptide might be achieved through thioredoxin-mediated activation of a serine protease and/or reductive unfolding of its 58 kDa polypeptide substrate. As redox changes in storage proteins occurred equally in both moist chilled and warm incubated walnut kernels, the regulatory functions of thioredoxins in promoting seed germination may be due to other germination related processes. 相似文献
3.
Silicon nutrition alleviates physiological disorders imposed by salinity in hydroponically grown canola (Brassica napus L.) plants 总被引:1,自引:0,他引:1
Mohammad Farshidi Ahmad Abdolzadeh Hamid Reza Sadeghipour 《Acta Physiologiae Plantarum》2012,34(5):1779-1788
The effects of Si nutrition on transpiration, leaf anatomy, accumulation of Na+, K+, Cl?, P, Fe and B and some reactive oxygen species related parameters were investigated in canola plants under salinity. Plants were grown hydroponically in growth chamber under controlled conditions at 0 and 100?mM NaCl each supplied with or without 1.7?mM silicon (Si) as sodium silicate. Salinity imposed significant reduction in growth parameters of plants like fresh weights of roots and shoots and leaf area. It also led to accumulation of Na+ and Cl? and a decrease in the concentration of K+, P, B and Fe. Reduction of transpiration, stomatal density and specific leaf area in leaves and an increase in leaf thickness were amongst other symptoms in salt-affected plants. Salinity led to higher concentration of hydrogen peroxide, increased lipid peroxidation and decrease of catalase and peroxidase activity, which suggests the induction of oxidative stress in plants. Silicon nutrition could prevent toxic ions (Na+ and Cl?) accumulation while higher levels of essential minerals like K+, P and Fe were maintained in plants. Consequently, silicon nutrition decreased oxidative stress in plants, evidenced by increase in antioxidant enzyme activity, reduction in hydrogen peroxide and lipid peroxidation. 相似文献
4.
Monireh Zarei-Ghadikolaee Ahmad Abdolzadeh Hamid Reza Sadeghipour 《Trees - Structure and Function》2010,24(3):425-433
The activities of arginase, glutamine synthetase (GS) and glutamate dehydrogenase (GDH) were studied in both moist chilled
(5°C) and warm (27°C) incubated walnut (Juglans regia. L) kernels to asses whether the non-germinability of dormant kernels is associated with failure in amino acid metabolism.
Warm-incubated kernels showed low germination (25%), whereas cold-stratified kernels displayed germination up to 61%. Arginase
activity increased about twofold in imbibed kernels. It remained at a high level in cold-stratified kernels from mid-period
of incubation onwards; however, in warm-incubated kernels the activity declined after an initial increase so that by 20 days,
it was negligible. No significant differences in GS activity occurred between cold-stratified and warm-incubated kernels,
but the activity of GDH was significantly more in kernels incubated at warm conditions. Thin-layer chromatographic separation
of polyamines revealed greater ammonia, spermidine and an unknown polyamine accumulation in warm-incubated kernels. Thus,
the declined rate of walnut kernel germination under warm conditions is mainly correlated with rapid inactivation of arginase,
greater levels of ammonia and alterations in kernel polyamine composition. The enhanced activity of GDH in warm-incubated
kernels implies that catabolic deamination of amino acids and their subsequent respiration is the favored pathway ongoing
under warm conditions. This situation compromises germination-specific metabolism of amino acids which likely to operate better
at lower temperatures during cold stratification of kernels. 相似文献
5.
Change in uptake, transport and accumulation of ions in Nerium oleander (rosebay) as affected by different nitrogen sources and salinity 总被引:1,自引:0,他引:1
Background and Aims
The source of nitrogen plays an important role in salt tolerance of plants. In this study, the effects of NaCl on net uptake, accumulation and transport of ions were investigated in Nerium oleander with ammonium or nitrate as the nitrogen source in order to analyse differences in uptake and cycling of ions within plants.Methods
Plants were grown in a greenhouse in hydroponics under different salt treatments (control vs. 100 mm NaCl) with ammonium or nitrate as the nitrogen source, and changes in ion concentration in plants, xylem sap exuded from roots and stems, and phloem sap were determined.Key Results
Plant weight, leaf area and photosynthetic rate showed a higher salt tolerance of nitrate-fed plants compared with that of ammonium-fed plants. The total amount of Na+ transported in the xylem in roots, accumulated in the shoot and retranslocated in the phloem of ammonium-fed plants under salt treatment was 1·8, 1·9 and 2·7 times more, respectively, than that of nitrate-treated plants. However, the amount of Na+ accumulated in roots in nitrate-fed plants was about 1·5 times higher than that in ammonium-fed plants. Similarly, Cl− transport via the xylem to the shoot and its retranslocation via the phloem (Cl− cycling) were far greater with ammonium treatment than with nitrate treatment under conditions of salinity. The uptake and accumulation of K+ in shoots decreased more due to salinity in ammonium-fed plants compared with nitrate-fed plants. In contrast, K+ cycling in shoots increased due to salinity, with higher rates in the ammonium-treated plants.Conclusions
The faster growth of nitrate-fed plants under conditions of salinity was associated with a lower transport and accumulation of Na+ and Cl− in the shoot, whereas in ammonium-fed plants accumulation and cycling of Na+ and Cl− in shoots probably caused harmful effects and reduced growth of plants.Key words: Mineral cycling, Nerium oleander, nitrogen source, salinity, xylem and phloem transport 相似文献6.
Effects of phosphorus supply on growth, phosphate concentration and cluster-root formation in three Lupinus species 总被引:1,自引:0,他引:1
Background and Aims
In some lupin species, phosphate deficiency induces cluster-root formation, which enhances P uptake by increasing root surface area and, more importantly, the release of root exudates which enhances P availability.Methods
Three species of Lupinus, L. albus, L. atlanticus and L. micranthus, with inherently different relative growth rates were cultivated under hydroponics in a greenhouse at four phosphate concentrations (1, 10, 50 and 150 µm) to compare the role of internal P in regulating cluster-root formation.Key Results
The highest growth rate was observed in L. atlanticus, followed by L. albus and L. micranthus. At 1 µm P, cluster-root formation was markedly induced in all three species. The highest P uptake and accumulation was observed in L. micranthus, followed by L. atlanticus and then L. albus. Inhibition of cluster-root formation was severe at 10 µm P in L. atlanticus, but occurred stepwise with increasing P concentration in the root medium in L. albus.Conclusions
In L. atlanticus and L. albus cluster-root formation was suppressed by P treatments above 10 µm, indicating a P-inducible regulating system for cluster-root formation, as expected. By contrast, production of cluster roots in L. micranthus, in spite of a high internal P concentration, indicated a lower sensitivity to P status, which allowed P-toxicity symptoms to develop. 相似文献7.
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