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1.
氮素形态及HCO3——对豌豆铁素营养的影响 总被引：11，自引：0，他引：11
在水培条件下研究了NO3-N ,NH4-N及添加HCO3-和HEPES对豌豆铁营养的影响。与NO3-N相比 ,供应NH4-N时豌豆根系铁还原力上升较早 ,铁还原酶活性显著较高 ,铁向地上部转移较多。供应NH4-N时培养Sparkle的营养液pH下降较快 ,而培养E107营养液 pH受氮源形态的影响较小。对根系质外体铁的利用 ,以NH4-N为氮源时 ,两种豌豆经过 15天后都全部利用 ;供应NO3-N的E107能全部利用 ,Sparkle也利用了约 3/4 ;以HCO3-缓冲时E107利用了约 3/4 ,而Sparkle则几乎不能利用。但是生长在HCO3-缓冲的营养液中的豌豆根系结构完好 ,转移到低pH环境中后铁还原力不仅没有降低 ,反而比对照有所提高。HCO3-和HEPES对豌豆铁营养的影响相似。表明HCO3-对豌豆铁营养的影响不是破坏了根系的结构和功能 ,而主要是通过提高根际 pH值 ,抑制了根系铁还原酶活性的作用 ,从而降低了对铁的吸收利用能力。氮素形态对豌豆铁营养的影响主要是通过影响质外体 pH起作用的。 相似文献
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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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NaCl胁迫下珠眉海棠苹果中Na~+的组织细胞定位研究 总被引：4，自引：0，他引：4
本试验研究了水培条件下NaCl胁迫下珠眉海棠苹果组织细胞中Na+的分布及可能的耐盐机制。结果表明 :在一定NaCl胁迫浓度范围内 ,根系中Na+浓度高于地上部 ,根系对Na+有一定的再吸收作用 ,这是珠眉海棠耐盐的重要机制 ;当NaCl胁迫浓度达到一定阀值后 ,根、叶细胞Na+大量积累 ,当细胞液泡不再接纳Na+时 ,Na+大量积累于胞质和质外体 ,使质外体渗透势大大降低 ,胞质水分外流 ,破坏细胞膜系统和胞质新陈代谢 ,造成伤害。 相似文献
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磷饥饿诱导水稻根表铁膜形成机理初探 总被引：11，自引：1，他引：10
采用溶液培养的方法,初步探索了磷饥饿诱导水稻根表铁膜形成的机理。磷饥饿24h后水稻的根表出现了明显的红棕色物质的沉积,扫描电镜的能谱分析结果显示,红棕色物质是铁的氧化物。针对这一现象,首先研究了没有水稻生长的正常磷营养液和缺磷营养液的变化,结果表明二者之间全波长的扫描图谱没有出现差异。采用酸碱混合指示剂的琼脂染色方法,观察了水稻根系表面及根际pH值的变化情况,并分别测定了正常磷营养（P）和缺磷（P0）2种条件下水稻的根系活力。结果看出,缺磷时水稻根系活力高于磷营养正常的处理,尤其是基因型Jin23A,其P和P0处理间根系活力差异极显著。水稻根表三价铁的浓度高于二价铁,并且缺磷根系表面三价铁和二价铁浓度均明显高于供磷处理;缺磷处理水稻根质外体沉积的铁浓度也明显高于供磷处理。因此,初步确定磷饥饿诱导水稻根表铁膜形成是生物学基础上的化学反应过程。 相似文献
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不同磷效率小麦对低铁胁迫的基因型差异 总被引：5，自引：2，他引：5
用营养液培养方法研究了不同磷效率小麦幼苗对低铁胁迫的基因型差异。结果表明,低铁胁迫(-Fe)对磷高效基因型小麦生长的抑制作用显著大于对磷低效基因型。低铁处理下,磷高效基因型81(85)-5-3-3-3、Xiaoyan54和Taihe-5025的植株地上部干重平均比正常供铁(+Fe)处理下降55.2%;磷低效基因型Jinghe90-Jian-17、NC37和Jing41平均33.0%。低铁胁迫显著降低了磷高效基因型小麦的叶片叶绿素含量,3个磷高效基因型的叶绿素a、叶绿素b和叶绿素a+b含量分别降低了35.6%、35.3%和35.3%,磷低效基因型分别降低了16.8%、7.7%和11.9%。低铁胁迫对小麦的根系生长、根系吸磷量和磷利用效率均未产生明显的影响,但显著降低了磷高效基因型小麦的植株地上部吸磷量和根效率比。与正常供铁的处理相比,磷高效和磷低效基因型小麦的地上部吸磷量和根效率比在低铁处理中平均降低了55.0%、54.9%和32.5%、36.4%。磷高效基因型小麦植株体内积累的磷量明显高于磷低效基因型,这是磷高效基因型不耐低铁的主要原因。磷效率越高,对低铁的反应越敏感。 相似文献
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采用分根技术、营养液培养方法 ,研究缺铁条件下供应不同形态氮素对玉米苗期体内不同铁库中铁再利用的影响。结果表明 ,缺铁条件下 ,玉米新生叶片铁营养状况不仅受体内铁库强度大小的影响 ,而且也受外界调节措施—氮素形态的调节。研究发现 ,与NO3-N相比 ,不考虑根细胞质外体铁库时 ,供应NH4-N可使初生叶中 32 %的铁再利用 ,考虑根系铁库时 ,初生叶铁变化不明显 ,而可使根系 40 %的铁转移至地上部。无论根系是否有铁库 ,缺铁条件下 ,NH4-N能提高新叶活性铁含量和伤流液中铁浓度。 相似文献
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玉米自交系苗期耐低磷的根系生理特性研究 总被引：5，自引：1，他引：4
以磷高效型04419和磷低效型04065玉米自交系为材料,研究了砂培试验条件下,二者在需磷临界期(苗期)的根系生理特性差异。低磷处理下,4～8叶期磷低效型04065玉米根系酸性磷酸酶(APase)活性显著高于磷高效型04419玉米,而其根系磷含量显著低于04419,表明根系APase水平能够反映不同基因型玉米磷效率的差异。当低磷处理至6～8叶期,除根冠比外,二者根系APase、根系活力、根系丙二醛(MDA)、根系总长和干物质积累差异显著,表明不同基因型玉米对低磷的耐受能力是多种生理反应综合作用的结果。 相似文献
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In order to study the iron (Fe) distribution pattern in bean plants with different Fe nutritional status, french bean (Phaseolus vulgaris L.) seedlings were precultured in a complete nutrient solution with 8x10‐5 M FeEDTA for five days. Thereafter, plants were further supplied with 8x10‐5 M FeEDTA (Fe‐sufficient) or with only 2x10‐6 M FeEDTA (Fe‐deficient) for another eight days. At this stage, the Fe‐deficient plants had much lower chlorophyll contents and lower dry weight of the leaves but higher reducing capacity of the roots compared with the Fe‐sufficient plants. For studies on short‐term distribution of Fe, the Fe‐sufficient plants were supplied 8x10‐5 M 59FeEDTA (specific activity 9.9 GBq/mol) and the Fe‐deficient plants 1x106 M 59FeEDTA (specific activity 98.8 GBq/mol). The plants were harvested after 4 and 24 hours. Despite a much lower supply of 59FeEDTA/(factor 80), the Fe‐deficient plants took up significantly more 59Fe but translocated less to the shoots (14.6% after 24 h) compared with the Fe‐sufficient plants (29.4% after 24 h). However, regardless of the Fe nutritional status of the plants, the majority of 59Fe was translocated in the primary leaves. Our results demonstrate a similar distribution patterns of root‐derived 59Fe in the shoots of Fe‐sufficient and Fe‐deficient plants, and thus, no preferential direct translocation of Fe to the shoot apex in the Fe‐deficient plants. 相似文献
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G. Jagnow 《植物养料与土壤学杂志》1983,146(2):217-227
Root samples of 11 non-cultivated monocotyledonous and 7 dicotyledonous species taken during a wet summer had low mean nitrogenase activities of 10.2 and 7.1 nmol C2H4·g?1 DW·h?1 after preincubation at pO2 0.02, respectively. Maxima of 139–169 nmol·g?1·h?1 were observed with Agrostis vulgaris and Agropyron repens on a sandy soil poor in Corg. Three of 6 early, but none of 4 late fodder maize cultivars had a very low activity up to 0.5 nmol·g?1h?1. Oat, rye and wheat roots from plots with organic or mineral N fertilizers had activities between 1.3 and 7.3 nmol·g?1h?1 at flowering, which were not correlated with their Azospirillum populations (102-107·g?1 after preincubation). Winter wheat and barley roots given 0, 40, 80 and 120 kg. ha?1 NH4NO3-N in 0–3 applications had mean activities of 0.08, 4.06, 0.09 and 0.08 nmol or 1.77, 2.67, 0.36 and 0.23 nmol C2H4g?1·h?1 after flowering, respectively. An appreciable part of this activity could be removed by root washing. In preincubated rhizosphere soil of wheat and barley populations of N2-fixing, facultative anaerobic Klebsiella and Enterobacter spp. were 10–100 times higher than those of Azospirillum sp., both being higher in O N than in 80 kg N·ha?1 trials. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(3):507-518
Studies have reported significant differences in nitrate accumulation among genotypes within a crop species, but the reason for these differences is not clear. This study investigated nitrate (NO3) efflux from roots of two oilseed rape cultivars (Brassica napus L. cvs. ZY821 and D89) and the relationship between nitrate efflux and plant nitrate accumulation. Nitrate efflux was estimated by measuring nitrate released from roots into nitrate-free nutrient solutions 58 days after sowing. The solutions were buffered with either 2.0 mM (n-morpholino) ethanesulfonic acid (MES) or 0.05 mM phosphate. Whole-plant and petiole nitrate accumulations were significantly greater for ZY821 compared to D89. Nitrate efflux varied diurnally, and the difference between cultivars was greater in the morning than in the afternoon. Data suggested that the relatively high pH of the phosphate-buffered solutions increased nitrate efflux rates from oilseed rape plants; therefore phosphate buffer should not be used when making direct determinations of nitrate efflux. Maximum cumulative nitrate efflux was 0.97 μmol g?1 fresh-weight (FW) root for ZY821 and 1.9 μmol g?1 FW root for D89. Maximum nitrate efflux rate was 0.084 μmol g?1 FW min?1 for ZY821 and 0.097 μmol g?1 FW min?1 for D89. These results indicated that between the two cultivars, ZY821 had the greatest petiole nitrate nitrogen concentration and the lowest total nitrate efflux. We suggest that cultivars with low nitrate efflux rates are able to translocate and store greater amounts of nitrate in aboveground plant organs, especially in petioles. 相似文献
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《Journal of plant nutrition》2013,36(12):2425-2437
Abstract Pot and rhizobox experiments were carried out to investigate the iron availability in intercropped peanut and maize as affected by soil moisture. Results from pot experiment showed that the root growth of peanuts were significantly inhibited at 25% soil water content compared to those at 15% soil water content. The chlorophyll content in the new leaves of intercropped peanut decreased and leaves became chlorotic at 25% soil water content. There were no significant differences in the active iron concentration in new leaves of peanut between 15% and 25% soil water content. The soil pH were higher in peanut rhizosphere than in bulk soil at the early, middle, and harvest stages for both 15% and 25% soil water content. The soil bicarbonate content was also higher in peanut rhizosphere than in bulk soil for both 15% and 25% soil water content. There was significant difference in soil bicarbonate of peanut rhizosphere between 15% and 25% soil water content at the harvest stage. The available iron content in both rhizosphere soil and bulk soil were lower than 3.5 mg kg?1 in all growth stages at both 15% and 25% soil water content. Results from rhizobox experiment showed that citric acid, maleic acid, and fumaric acid in exudates of peanuts significantly increased at 25% soil water content compared to that at 15% soil water content. The apoplastic iron content of peanut roots decreased by 0.216 and 0.409 µmol g?1 fresh weight?1 (FW) from the 28th growth day to 42nd growth day at 25% and 15% soil water content, respectively. The mobilizing ability of apoplastic iron in intercropped peanuts at 15% soil water content was 20.1% higher compared to that at 25% soil water content. It is concluded that improvement of iron nutrition of peanuts with intercropping with maize could be affected by soil moisture condition. 相似文献
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Shah Alam Fumihito Akiha Shigeru Kamei Shigenao Kawai 《Soil Science and Plant Nutrition》2013,59(3):457-461
The release of phytosiderophore (PS) from roots of Fe-deficient graminaceous plants follows a distinct diurnal rhythm with maximum release rates occurring usually 3 to 4 hours after the onset of light. However, it remains to be determined whether absorption of the PS-Fe3+ complex shows a diurnal rhythmicity similar to that of PS release, Barley plants grown with or without 10 µM FeEDTA for 7 days were fed with ferreted PS (10 µM labelled with 59Fe) at 4-h intervals to study the diurnal variations in the absorption and transloca tion of 59Fe, The absorption of 59Fe, irrespective of the Fe nutritional status of the plants, was higher during the day and lower during the night but did not show any peak throughout the day-night cycle. On the other hand, the translocation of 59Fe into shoots of Fe-deficient plants was lower than that of Fe-sufficient plants, while the Fe nutritional status of the plants did not affect the absorption of 59Fe by roots, The formation of root apoplastic 59Fe was lower during the day and higher during the night, regardless of the Fe nutritional status of plants. Our results showed that the absorption of the PS-Fe3+ complex by roots did not follow the PS release pattern. 相似文献
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The effects of calcium (Ca) deficiency on cation uptake and concentration of xylem sap from tomato roots after excision of the aerial parts, were studied. The measurements were made on tomato plants grown on nutrient solutions with +Ca or without‐Ca, over a period of 48 hours. Calcium deficiency entailed a significant increase of the flux of xylem sap between the 6th and 14th hour on the first day after excision. In spite of the lack of Ca in the nutrient solution, the Ca concentration in xylem sap was unaffected in regard to that of excised roots with +Ca. The maintenance of the Ca concentration in xylem sap of plants grown on a Ca deficient solution was related to a reuse of the Ca from the apoplastic root stores. So, this regulation indicates a possible translocation of the Ca available in the root supply and a mobility of this element out of the roots only during the early stages of exposure to a Ca deficiency. The presence of NH4 + in xylem sap with both +Ca and‐Ca treatments confirms the nitrogenous reduction activity of tomato roots. The accumulation of free ammonium 24 h after excision in both xylem saps (+Ca and‐Ca) is likely to be evidence of an alteration process of protein synthesis which is related to the depletion of the root water soluble carbohydrate supply. 相似文献
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Amith R. Devireddy Madhuri A. Inupakutika David Willmon Prathusha Kakarla Naveen Puppala 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(3):245-251
Antibiotics from various sources such as livestock waste are being accumulated in the soil. The excessive uptake of antimicrobial agents by plants has been a major concern as it is currently unknown how plants respond to the presence of antibiotics in agricultural lands. The objectives were to analyze the alteration of trigonelline (TRG) biosynthesized by plants in response to various antibiotic stresses and to evaluate the ability of peanut (Arachis hypogaea L.) plants to resist the deleterious impacts of antibiotic uptake. Three veterinary antibiotics used in this study were tetracycline, streptomycin sulfate, and chloramphenicol in the concentrations of 2.5 and 5 mg L?1. Mean TRG amounts were 53.4 ± 1.6 and 59.9 ± 1.1 μg·g?1 dry weight (DW) in Spanish as treated with growth chloramphenicol and streptomycin at 2.5 mg·L?1, respectively, and were significantly (p ≤ .05) different compared to the control (40.4 ± 1.6 μg·g?1 DW) of Spanish. Spanish genotype treated with chloramphenicol at 5 mg·L?1 had a mean TRG amount of 41.0 ± 1.0 μg·g?1 DW and improved yield, with the average pod number of 29.6 ± 7.6 and pod weight of 20.1 ± 6.1 g. TRG was continuously biosynthesized and increased under antibiotic stress up to 12.7% at full pod (R4 growth stage) and 139.1% at beginning maturity (R7), but declined 20.2% at the harvest stage (R8) in all combined genotypes when compared with TRG amounts (21.7 ± 0.6 μg·g?1 DW) at the flowering R1 stage. 相似文献
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The development of stinging nettle (Urtica dioica L.) grown on culture solution containing with either ammonium or nitrate ions, or urea, was investigated under iron deficiency conditions, and with added FeEDTA or FeCto. Both seed‐cultured and vegetatively‐cultured stinging nettle plants produced normally developed green shoots when nitrate and 4 μM FeEDTA or FeCto were supplied. Stinging nettle plants were able to utilize Fe‐citrate, Fe‐ascorbate, and Fe‐malate effectively at the same concentration as well. When K3Fe(CN)6 was supplied, which is impermeable to the plasmalemma, and therefore is used to measure the reductive capacity of the roots, stinging nettle plants became chlorotic because the complex was stable at the pH of the culture solution. Urea did not induce chlorosis but inhibited growth. The plants died when ammonium was supplied as a sole N source. Applying bicarbonate and ammonium together prevented the plants from dying, but the plants became chlorotic. Total exclusion of iron from the culture solution resulted in iron‐deficiency stress reactions as has been described for other dicotyledonous plants (Strategy II). 相似文献