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1.
Mechanisms of exogenous nitric oxide and 24-epibrassinolide alleviating chlorosis of peanut plants under iron deficiency 总被引：1，自引：1，他引：0
Iron(Fe) is a crucial transition metal for all living organisms including plants; however, Fe deficiency frequently occurs in plant because only a small portion of Fe is bioavailable in soil in recent years. To cope with Fe deficiency, plants have evolved a wide range of adaptive responses from changes in morphology to altered physiology. To understand the role of nitric oxide(NO) and 24-epibrassinolide(EBR) in alleviating chlorosis induced by Fe deficiency in peanut(Arachis hypogaea L.) plants, we determined the concentration of chlorophylls, the activation, uptake, and translocation of Fe, the activities of key enzymes, such as ferric-chelate reductase(FCR),proton-translocating adenosine triphosphatase(H~+-ATPase), and antioxidant enzymes, and the accumulation of reactive oxygen species(ROS) and malondialdehyde(MDA) of peanut plants under Fe sufficiency(100 μmol L~(-1)ethylenediaminetetraacetic acid(EDTA)-Fe) and Fe deficiency(0 μmol L~(-1)EDTA-Fe). We also investigated the production of NO in peanut plants subjected to Fe deficiency with foliar application of sodium nitroprusside(SNP), a donor of NO, and/or EBR. The results showed that Fe deficiency resulted in severe chlorosis and oxidative stress, significantly decreased the concentration of chlorophylls and active Fe, and significantly increased NO production. Foliar application of NO and/or EBR increased the activity of antioxidant enzymes, superoxide dismutase,peroxidase, and catalase, and decreased the ROS and MDA concentrations, thus enhancing the resistance of plants to oxidative stress.Application of NO also significantly increased Fe translocation from the roots to the shoots and enhanced the transfer of Fe from the cell wall fraction to the cell organelle and soluble fractions. Consequently, the concentrations of available Fe and chlorophylls in the leaves were elevated. Furthermore, the activities of H~+-ATPase and FCR were enhanced in the Fe-deficient plants. Simultaneously,there was a significant increase in NO production, especially in the plants that received NO, regardless of Fe supply. These suggest that NO or EBR, and, especially, their combination are effective in alleviating plant chlorosis induced by Fe deficiency. 相似文献
2.
Siderophore-Producing Rhizobacteria as a Promising Tool for Empowering Plants to Cope with Iron Limitation in Saline Soils: A Review 总被引：1，自引：0，他引：1
Iron (Fe) bioavailability to plants is reduced in saline soils; however, the exact mechanisms underlying this effect are not yet completely understood. Siderophore-expressing rhizobacteria may represent a promising alternative to chemical fertilizers by simultaneously tackling salt-stress effects and Fe limitation in saline soils. In addition to draught, plants growing in arid soils face two other major challenges:high salinity and Fe deficiency. Salinity attenuates growth, affects plant physiology, and causes nutrient imbalance, which is, in fact, one of the major consequences of saline stress. Iron is a micronutrient essential for plant development, and it is required by several metalloenzymes involved in photosynthesis and respiration. Iron deficiency is associated with chlorosis and low crop productivity. The role of microbial siderophores in Fe supply to plants and the effect of plant growth-promoting rhizobacteria (PGPR) on the mitigation of saline stress in crop culture are well documented. However, the dual effect of siderophore-producing PGPR, both on salt stress and Fe limitation, is still poorly explored. This review provides a critical overview of the combined effects of Fe limitation and soil salinization as challenges to modern agriculture and intends to summarize some indirect evidence that argues in favour of siderophore-producing PGPR as biofertilization agents in salinized soils. Recent developments and future perspectives on the use of PGPR are discussed as clues to sustainable agricultural practices in the context of present and future climate change scenarios. 相似文献
3.
植物吸收和转运铁的分子生理机制研究进展 总被引：7，自引：2，他引：5
铁是植物正常生命活动过程中的必需微量元素之一。由于土壤中铁的有效性很低,导致植物极易缺铁,不仅影响作物的产量和品质,而且影响人类微量元素健康,因此如何通过生物强化达到人类铁营养状况改善的目的是目前该研究领域关注的热点。本文就近5年来植物铁吸收、体内转运、子粒中积累等重要生物过程的分子生理机制的研究进展进行了详细阐述,其中对水稻兼备机理I和机理II铁吸收机制有了新的认识,而且发现YSL蛋白家族在植物铁吸收、转运和子粒积累过程中的重要性。同时,讨论了利用上述机制的研究结果通过基因工程和农学措施改善植物铁营养和提高作物子粒铁富集的技术途径。 相似文献
4.
不同供磷水平对饭豆体内铁有效性的影响 总被引：1，自引：0，他引：1
都韶婷 《植物营养与肥料学报》2010,16(1):247-251
采用溶液培养试验研究了低铁条件下（1 μmol/L FeEDTA）不同供磷水平P 3、30和300 μmol/L对饭豆叶绿素含量、生物量、铁含量以及质外体铁的影响。结果表明,饭豆叶片叶绿素含量及根系干重均随磷处理浓度的增加而显著降低; 低磷处理的植株地上部的铁含量明显高于中磷和高磷处理。随着供磷水平的增加,地上部和根系总铁量的比值呈降低趋势,说明铁由根系向地上部的转运显著减少,从而加剧了植株缺铁症状。进一步分析发现,低磷处理的根系质外体铁含量显著低于中磷和高磷处理。说明在铁吸收过程中,供磷水平增加促使铁在根系质外体空间中的固定,不利于根系中的铁转运至地上部,这可能是磷是对铁产生拮抗作用造成植物铁营养不利的原因之一。 相似文献
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6.
Salinity adversely affects plant growth, photosynthesis, and availability of nutrients including iron. Rice (Oryza sativa L.) is susceptible to soil salinity and highly prone to iron (Fe) deficiency due to lower release of Fe‐chelating compounds under saline conditions. In order to investigate the effects of salinity and low iron supply on growth, photosynthesis, and ionic composition of five rice genotypes (KS‐282, Basmati Pak, Shaheen Basmati, KSK‐434 and 99417), a solution culture experiment was conducted with four treatments (control, 50 mM NaCl, Fe‐deficient, and 50 mM NaCl + Fe‐deficient). Salinity and Fe deficiency reduced shoot and root growth, photosynthetic and transpiration rates, chlorophyll concentration, and stomatal conductance. The reduction in all these parameters was more in the interactive treatment of salinity and low Fe supply. Moreover, a significant increase in shoot and root Na+ with corresponding decrease in K+ and Fe concentrations was also observed in the combined salinity and Fe‐deficiency treatment. Among the tested genotypes, Basmati Pak was the most sensitive genotype both under salt stress and Fe deficiency. The genotype KS‐282 performed better than other genotypes under salinity stress alone, whereas Shaheen Basmati was the best genotype under Fe deficiency in terms of all the studied parameters. 相似文献
7.
微生物在植物铁营养中的潜在作用 总被引：4，自引：1，他引：4
根据近十多年来相关研究成果讨论了土壤微生物在植物根系吸收铁中可能的作用机理。这种机理可能包括缺铁植物根系分泌小分子有机化合物,如酚类和黄素类等化合物,这些化合物作为抑菌剂和(或)作为微生物生长的碳源物质来影响根际(Rhizosphere)微生物的群落结构,并在植物根际诱导形成特异性微生物种群,此类特异性微生物转而通过分泌高铁载体(Siderophore),增加土壤中铁的生物有效性,从而提高了根系对铁的吸收。此外,与植物根系共生的一些微生物也会改善植物的铁营养,这种作用可能包括:根瘤菌(Rhizobium)的结瘤作用,增强植物耐缺铁的生理响应;根系感染的菌根真菌通过增加植物根系的养分吸收面积和分泌对铁具有螯合作用的物质来改善植物的铁营养。本文在讨论这种可能的微生物作用机制的基础上,指出今后的研究方向和有待解决的问题。 相似文献
8.
The development of iron deficiency symptoms (growth depression and yellowing of the youngest leaves) and the distribution of iron between roots and leaves were investigated in different vine cultivars (Silvaner, Riparia 1G and SO4) grown in calcareous soils. As a control treatment all cultivars were also grown in an acidic soil. Only the cultivars Silvaner and Riparia 1G showed yellowing of the youngest leaves under calcareous soil conditions at the end of the cultivation period. All cultivars including SO4 showed severe shoot growth depression, by 50 % and higher, before yellowing started or without leaf yellowing in the cultivar SO4. Depression of shoot growth occurred independently from that of root growth. In a further treatment the effect of Fe‐EDDHA spraying onto the shoot growth of the cultivar Silvaner after cultivation in calcareous soil was investigated. Prior to Fe application plants were non‐chlorotic, but showed pronounced shoot growth depression. Spraying led to a significant increase in shoot length, though leaf growth was not increased. Accordingly, depression of shoot growth of non‐chlorotic plants under calcareous soil conditions and with ample supply of nutrients and water has been evidenced to be at least partly an iron deficiency symptom. We suggest that plant growth only partially recovered because of dramatic apoplastic leaf Fe inactivation and/ or a high apoplastic pH which may directly impair growth. Since growth was impaired before the youngest leaves showed chlorosis we assume that meristematic growth is more sensitively affected by Fe deficiency than is chlorophyll synthesis and chloroplast development. In spite of high Fe concentrations in roots and leaves of the vines grown in calcareous soils plants suffered from Fe deficiency. The finding of high Fe concentrations also in young, but growth retarded green leaves is a further indication that iron deficiency chlorosis in calcareous soils is caused by primary leaf Fe inactivation. However, in future, only a rigorous study of the dynamic changes of iron and chlorophyll concentration, leaf growth and apoplastic pH at the cellular level during leaf development and yellowing will provide causal insights between leaf iron inactivation, growth depression, and leaf chlorosis.<?show $6#> 相似文献
9.
Abstract Stimulatory effects of humic substances (HS) on plant growth have been observed and widely documented. Studies have often shown positive effects on seed germination, root initiation and total plant biomass. The consistency of these observations has been uncertain, predominantly due to the lack of understanding of the plant growth promotion mechanism. Often these effects have been attributed to a direct effect of plant growth hormones; whereas in other instances the term “hormone-like activity” has been used to describe the plant growth stimulation (Chen and Aviad, Humic Substances in Soil and Crop Sciences: Selected Readings, American Society of Agronomy, Soil Science Society of America, 1990; Nardi et al., Humic Substances in Terrestrial Ecosystems, Elsevier Science B.V., 1996). Yet, investigators have been unable to prove that plant growth regulators are present in HS preparations, or the evidence provided remains unconvincing. An alternative hypothesis suggesting that growth enhancement of plants grown in nutrient solution (NS) containing HS is the result of improved micronutrient availability, Fe in particular, has been postulated and tested in the present study. Nutrient solutions containing N, P, K, Ca, Mg, S, B, Mo, Cu, Mn, Zn, and Fe at concentrations considered to be optimal for plant growth were tested for solubility of the Fe, Zn, and Mn, 7 days after preparation. In addition to control solutions at pH values of 5, 6, 7, and 7.5, 0 to 200 mg L?1 of leonardite humic acid (HA) were added to the solutions and they were tested for Fe and Zn solubility. The HA greatly enhanced the maintenance in solution of Fe, in all the tested solutions, and Zn at pH 7.5. Mn mostly remained in solution in its inorganic forms. Plant growth experiments were carried out on both dicotyledonous plants (melons and soybean) and monocotytedonous Poaceae plants (ryegrass), due to the major difference in their Fe uptake mechanism. Plants grown in the absence of Fe exhibited severe Fe deficiency that could only partially be corrected with the addition of mineral Fe salts. The addition of HA or fulvic acid (FA) without addition of Fe, and Zn resulted in partial growth enhancement and correction of Fe deficiency, or none of the two, in the various experiments. This suggests that the growth enhancement effect observed in solutions containing Fe, Zn, and HS was related to the micronutrients rather than to phytohormones. However, the addition of Fe, Zn and either EDTA, HA or FA resulted in healthy, chlorophyll rich plants and enhanced growth, thereby providing evidence that improved Fe, and possibly Zn nutrition is a major mechanism of plant growth stimulation by HS. The use of the term hormone-like activity could be the result of the similarity of the physiological effects obtained in plants enjoying sufficient supply of Fe and Zn. 相似文献
10.
《Communications in Soil Science and Plant Analysis》2012,43(9):1065-1081
Abstract Problems are invariably encountered when attempts are made to explain the variability in Bray percent yields or plant response in terms of soil or plant iron (Fe). To resolve this inconsistency, the present investigation was initiated to identify a combination of soil extractable Fe, soil properties and form of plant Fe that may be used as a measure of Fe deficiency. The study involved 16 diverse soils, using upland rice (Oryza sativa L.) as the test crop and Fe‐EDDHA [ferric ethylenediamine di (o‐hydroxyl‐phenyl acetic acid)] as source of Fe. The results showed that Bray percent yields were neither related to DTPA (diethylenetriamine pentaacetic acid) or EDTA (ethylenediamine tetraacetic acid) extractable Fe nor with total plant Fe. Even the inclusion of pH, lime, organic carbon and clay data in the regression equations was of no value. However, Bray percent yields were significantly and positively (r = 0.57* ) associated with ferrous Fe (Fe2+) in 40‐day‐old rice plants. The explanation concerning variability in Bray percent yields obtained on diverse soils could be increased about one and half 2 times (R2= 0.59*) if the contribution of lime and soil pH was also incorporated in the stepwise regression analysis. The individual contribution to R of lime, pi respectively. Thus, it appears that Fe2+ concentration in plants (along with soil pH) may identify Fe deficiency. The critical limit to separate Fe deficient from green rice plants was set at 45 ug Fe2+/g in the leaves. 相似文献
11.
Iron deficiency decreases the amount of photosynthetic pigments in higher plants, and also results in characteristic changes in the relative photosynthetic pigment composition. Iron deficient plants exhibit a relative increase in xanthophylls, largely attributable to pigments within the xanthophyll cycle, violaxanthin, antheraxanthin, and zeaxanthin. Furthermore, the xanthophyll cycle functions in Fe‐deficient plants, but not in other yellow, carotenoid enriched‐materials, such as etiolated or senescing leaves. When Fe‐deficient leaves are illuminated, part of the violaxanthin is converted into antheraxanthin and zeaxanthin. When Fe‐deficient leaves are placed in the dark, the cycle reverts back to violaxanthin. In this paper we present further data on this cycle and discuss the possible relevance of pigment changes as an alternative mechanism for the dissipation of excess energy. The possibility of using characteristic pigment changes as a tool for monitoring Fe status in higher plants is discussed. 相似文献
12.
Yuanjie Dong Weifeng Chen Fengzhen Liu 《Communications in Soil Science and Plant Analysis》2016,47(22):2490-2505
Salicylic acid (SA) and nitric oxide (NO), which are known as important signaling molecules in plants, could be promising compounds for the reduction in stress sensitivity. The aim of the present work was to study the physiological changes in peanut (Arachis hypogaea L.) seedlings grown in growth medium that contained 0.1 mM SA, 0.25 mM sodium nitroprusside (SNP, a NO donor), or in full (SA+SNP) or half [1/2 (SA+SNP)] combined strengths under iron (Fe) deficiency. After 21 days of treatment, Fe deficiency significantly inhibited peanut plant growth, destroyed photosynthetic system, and caused oxidative damages. Addition of SA, SNP, and 1/2 (SA+SNP), especially SA+SNP, alleviated the stress, increased the contents of chlorophylls, and promoted plant growth. They improved Fe uptake, transport, and availability in peanut plants by increasing the activities of H+-ATPase and ferric chelate reductase (FCR), and promoting Fe translocation from cell wall to cell organelle and soluble fraction in leaves. Furthermore, they also effectively mitigated oxidative damages by increasing the activities of antioxidant enzymes in peanut leaves and roots. The results from the present study indicate that application of SA, SNP, or 1/2 (SA+SNP) can overcome the adverse effect of Fe deficiency, but the combined application of SA+SNP is more effective in alleviating Fe deficiency stress. 相似文献
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《Journal of plant nutrition》2013,36(5):737-749
ABSTRACT Iron (Fe) deficiency is one of the major abiotic stresses affecting fruit tree crops growing in calcareous soils in the Mediterranean region. A better understanding of changes in the growth and physiological characteristics of grapevine plants during the development of Fe deficiency will help to improve Fe fertilizer management recommendations. An experiment was conducted in field conditions to determine the effects of Fe deficiency during vegetative growth on leaf photosynthesis, dry matter accumulation, pigments, and other physiological parameters. Iron deficiency considerably decreased leaf net photosynthetic rate, leaf area, and dry matter accumulation. Depressed photosynthesis and plant growth resulted in increased fruit abscission and changes in dry matter among plant tissues. The results help explain the effects of Fe deficiency on suppression of grapevine growth and yield and provide information for improving the diagnosis of Fe deficiency in grapevine production. 相似文献
15.
铁、镁、锌营养胁迫对植物体内活性氧代谢影响机制 总被引：7，自引：2，他引：7
活性氧是植物体内常见的一类自由基,对植物有很强的伤害。本文总结了铁、镁、锌元素胁迫影响植物体内活性氧代谢机制。铁对于催化植物体内的Haber-Weiss反应产生活性氧具有重要作用。镁诱导植物体内活性氧代谢失调与光氧化有密切关系。缺锌条件下,植物体内活性氧含量升高,其机制是多方面的:NADPH氧化酶氧化能力提高,O2产生增多;体内铁浓度升高,增强了铁诱导的活性氧的产生;光氧化伤害加重;清除系统活性降低。 相似文献
16.
Masatake KANAI Midori HIRAI Masaaki YOSHIBA Toshiaki TADANO Kyoko HIGUCHI 《Soil Science and Plant Nutrition》2009,55(2):271-276
Iron deficiency stress causes a severe reduction in plant growth. Although Fe deficiency causes an imbalance in divalent heavy metal nutrients, the mechanisms underlying the growth reduction caused by this imbalance remain unclear. We investigated Zn uptake and accumulation in maize under Fe-deficient conditions. Under Fe-deficient conditions, Zn uptake was 15-fold higher and Zn accumulation was 16-fold higher than that under normal nutrient conditions. The Zn content of maize leaves under Fe-deficient conditions was >0.4 mg g−1 dry weight, which was higher than the content of plants grown in a nutrient solution containing 50 µM ZnCl2 . Plant growth under conditions of both Fe and Zn deficiency was significantly higher than that under only Fe-deficient conditions. Moreover, Fe deficiency increased the thiol content of the plant. These results indicate that Fe deficiency causes excess uptake and accumulation of Zn, and that the stress resulting from the Zn overload accelerates growth reduction in maize. 相似文献
17.
Emin Bülent Erenolu 《植物养料与土壤学杂志》2019,182(3):496-501
The present study aimed to test the contribution of the iron (Fe) deficiency‐induced uptake system to zinc (Zn) and copper (Cu) uptake by using bread wheat (Triticum aestivum cv. Bezostaja). For this purpose, two different uptake experiments, long‐term and short‐term, were set up in a nutrient solution culture under controlled growth chamber conditions. For the long‐term experiment, wheat cv. plants were grown with different concentrations of Fe or Zn. Results show that there was an uptake system induced under Fe‐limiting conditions which also contributed to Zn and Cu uptake. However, the Zn deficiency‐induced uptake mechanism affected neither Fe nor Cu uptake by wheat. Short‐term uptake experiments indicate that Fe deficiency‐induced Zn2+ uptake was more enhanced than the absorption of Zn‐phytosiderophore (PS) complexes. In addition, the Fe‐deficient plants absorbed more Zn in comparison to those plants supplied with sufficient Fe. Similar tendencies in Zn uptake under Fe deficiency in both short‐ and long‐term experiments suggest that there may be a specific Fe uptake system induced under Fe‐limiting conditions for non‐chelated metals in bread wheat. Moreover, this system also contributes to the transport of inorganic forms of some other metals, such as Zn and Cu. Although evidence is still needed involving the use of molecular biological techniques, it is hypothesized that IRT‐like proteins are responsible for this uptake system. Moreover, the release of Fe deficiency‐induced phytosiderophores and uptake of Fe(III)‐phytosiderophore complexes may not be the only mechanisms involved in the adaptation of wheat to Fe‐limiting conditions. 相似文献
18.
Liangchou Wei Richard H. Loeppert William R. Ocumpaugh 《Journal of plant nutrition》2013,36(7):1539-1549
Iron (Fe) is an essential nutrient for plants. When Fe‐deficient, most dicotyledonous and non‐graminaceous monocotyledonous plants exhibit Fe‐deficiency stress responses, which may include proton (H+) release from roots. Proton release is considered to be one of the factors contributing to plant Fe‐deficiency resistance. Several methods, including the pH‐stat, back‐titration, and pH‐drift procedures, have been used to evaluate the Fe‐deficiency induced acidification process. These methods actually determine total net acidity release, not H+ release. A method, based on the principles of chemical equilibrium, for the analysis of net free H+ release is introduced in this paper. By comparing results of the chemical equilibrium method with those of a method measuring total net acidity release, such as the back‐titration method, it is possible to determine the relative role of free H+ and organic acid to total acidity release. The pH‐stat method for analysis of total net acidity release, in which the pH of the incubation solution is held constant, eliminates the influence of pH decrease during plant incubation and thus results in a more accurate measurement of Fe‐deficiency induced acidity release. The advantages and disadvantages of each individual method are discussed. 相似文献
19.
ABSTRACT Indian mustard (Brassica juncea Czern) is a promising species for the phytoextraction of zinc (Zn), but the effectiveness of this plant can be limited by iron (Fe) deficiency under Zn-contaminated conditions. Our objectives were to determine the effects of root-applied Fe and Zn on plant growth, accumulation of Zn in plant tissues, and development of nutrient deficiencies for B. juncea. In the experiment, B. juncea was supplied 6 levels of iron ethylenediamine dihydroxyphenylacetic acid (Fe-EDDHA; 0.625 to 10.0 mg L?1) and two levels of Zn (2.0 and 4.0 mg L?1) for 3 weeks in a solution-culture experiment. Nutrient solution pH decreased with decreasing supply of Fe and increasing supply of Zn in solution, indicating that B. juncea may be an Fe-efficient plant. If plants were supplied 2.0 mg Zn L?1, plant growth was stimulated by increases in Fe supply, but plant growth was not influenced by Fe treatments if plants were supplied 4.0 mg Zn L?1. Zinc concentration in roots and shoots was suppressed by increasing levels of Fe in solution. Leaf concentrations of Cu, Mn, and P were suppressed also as Fe supply in solutions increased. Iron additions to the nutrient solution were not effective at increasing the Zn-accumulation potential of B. juncea unless plants were supplied the higher level of Zn in solution culture. Even under these conditions, Fe additions were effective only if supplied at low levels in solution culture (1.25 mg Fe L?1). Results suggest that Fe fertility has limited potential for enhancing Zn phytoextraction by B. juncea, even if plants suffer a suppression in growth from Fe deficiency. 相似文献
20.
机理Ⅰ植物铁营养的吸收转运及信号调控机制研究进展 总被引：1，自引：1，他引：0
铁是植物正常生长发育必需的微量元素之一。在通气良好的碱性或石灰性土壤中,常常因铁有效性低而难以满足植物生长发育所需,缺铁已成为继缺氮和缺磷之后农业生产所面临的又一重要的营养障碍因子。与机理Ⅱ植物相比,机理Ⅰ植物更易缺铁,因此全面了解机理Ⅰ植物的铁吸收及利用机制是分子育种改良此类植物铁营养的重要基础。基于国内外的相关研究进展,从机理Ⅰ植物的根际铁活化、根系铁吸收、木质部和韧皮部中的铁运输以及胞外和胞内铁的再利用等几方面进行综述;在此基础上,从bHLH和MYB转录因子调控网络、蛋白的泛素化修饰以及小分子化学信号调控途径等几方面,重点阐述机理Ⅰ植物铁营养吸收、转运及稳态平衡过程的调控机制;同时,对研究中存在的部分问题及未来研究方向进行简要的讨论分析。 相似文献