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Journal of Integrative Agriculture 2014年第9期13卷 1900-1908页

作者： AN Xia DUAN Feng-ying GUO Song CHEN Fan-jun YUAN Li-xing GU Ri-liang department of plant nutrition Center for ResourcesEnvironment and Food SecurityChina Agricultural University

Aldehyde dehydrogenases（ALDHs） represent a large protein family, which includes several members that catalyze the oxidation of an aldehyde to its corresponding carboxylic acid in plants. Genes encoding members of the ALDH7 subfamily have been suggested to play important roles in various stress adaptations in plants. In this study, quantitative RT-PCR analysis revealed that a maize ALDH7 subfamily member（ZmALDH7B6） was constitutively expressed in various organs, including roots, leaves, immature ears, tassels, and developing seeds. The abundance of ZmALDH7B6 mRNA transcripts in maize roots was increased by ammonium, NaCl, and mannitol treatments. To further analyze tissue-specific and stress-induced expression patterns, the 1.5-kb 5′-flanking ZmALDH7B6 promoter region was fused to the β-glucuronidase（GUS） reporter gene and introduced into maize plants. In roots of independent transgenic lines, there was significant induction of GUS activity in response to ammonium supply, confirming ammonium-dependent expression of ZmALDH7B6 at the transcript level. Histochemical staining showed that GUS activity driven by the ZmALDH7B6 promoter was mainly localized in the vascular tissues of maize roots. These results suggested that ZmALDH7B6 is induced by multiple environmental stresses in maize roots, and may play a role in detoxifying aldehydes, particularly in vascular tissue.

关键词： abiotic stress aldehyde dehydrogenase gene expression promoter transgenic maize

Comparison of N uptake and internal use efficiency in two tobacco varieties

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The Crop Journal 2015年第1期3卷 80-86页

作者： Wan Teng Wenqing Li Chunjian Li department of plant nutrition China Agricultural University Fujian Institute of Tobacco Agricultural Science

To explain the observation in field experiments that tobacco variety CB-1 was more nitrogen(N)-efficient than K326, the influence of two N levels on growth, N uptake and N flow within plants of the two tobacco varieties was studied. Xylem sap from the upper and lower leaves of both tobacco varieties cultured in quartz sand was collected by application of pressure to the root system. CB-1 took up more N with smaller roots at both high(HN, 10 mmol L-1) and low(LN, 1 mmol L-1) N levels, and built up more new tissues in upper leaves especially at LN level,than K326. Both varieties showed luxury N uptake, and CB-1 accumulated significantly less NO-3in new tissues than K326, when grown at the HN level. At both N levels, the amount of xylem-transported N and phloem-cycled N from shoot to root in K326 was greater than those in CB-1, indicating higher N use efficiency in CB-1 shoots than in K326 shoots. The major nitrogenous compound in the xylem sap was NO-3irrespective of N level and variety. Low N supply did not cause more NO-3reduction in the root. The results indicated that the N-efficient tobacco variety CB-1 was more efficient in both N uptake by smaller roots and N utilization in shoots, especially when grown at the LN level.

关键词： Nitrogen uptake Nitrogen cycling Nitrogen use efficiency Nicotiana tabacum

Fine Root Patterning and Balanced Inorganic Phosphorus Distribution in the Soil Indicate Distinctive Adaptation of Maize plants to Phosphorus Deficiency

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Pedosphere 2012年第6期22卷 870-877页

作者： ZHANG Yu YU Peng PENG Yun-Feng LI Xue-Xiun CHEN Fan-Jun LI Chun-Jian Key Laboratory of plant-Soil Interactions Ministry of EducationDepartment of Plant NutritionChina Agricultural UniversityBeijing 100193(China)

plants have diverse strategies to cope with phosphorus （P） deficiency. To better understand how maize responds to P deficiency, a field experiment with two P levels, 0 and 100 kg P205 ha-1 （P0 and P100, respectively）, was carried out as a part of a long-term Pfertilizer field trial. plant and soil analyses showed that P-deficient maize reduced its growth rate, increased P use efficiency, and formed more thin roots with the diameter less than 0.6 mm at jointing and silking stages, compared to the plants treated with P100. Further, there were no differences in major inorganic P fractions （Ca2-P, Cas-P, Al-P, Fe-P, occluded P and Ca10-P） between the rhizospheric and bulk soils at each harvest, even when soil Olsen-P was only 1.38 mg kg-1. These results suggested that maize responded to P deficiency by reducing the internal P demand for growth and increasing P acquisition ability by favorable root morphological alteration at low carbon cost.

关键词： inorganic phosphorus fractions phosphorus starvation rhizosphere root length root morphology

Contribution of Root Proliferation in Nutrient-Rich Soil Patches to Nutrient Uptake and Growth of Maize

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Pedosphere 2012年第6期22卷 776-784页

作者： LI Hong-Bo ZHANG Fu-Suo SHEN Jian-Bo department of plant nutrition China Agricultural UniversityKey Laboratory of Plant-Soil InteractionsMinistry of EducationBeijing 100193(China)

Root proliferation can be stimulated in a heterogeneous nutrient patch; however, the functions of the root proliferation in the nutrient-rich soil patches are not fully understood. In the present study, a two-year field experiment was conducted to examine the comparative effects of localized application of ammonium and phosphorus (P) at early or late stages on root growth, nutrient uptake, and biomass of maize (Zea mays L.) on a calcareous soil in an intensive farming system. Localized supply of ammonium and P had a more evident effect on shoot and root growth, and especially stimulated fine root development at the early seedling stage, with most of the maize roots being allocated to the nutrient-rich patch in the topsoil. Although localized ammonium and P supply at the late stage also enhanced the fine root growth, the plant roots in the patch accounted for a low proportion of the whole maize roots in the topsoil at the flowering stage. Compared with the early stage, fine root length in the short-lived nutrient patch decreased by 44%-62% and the shoot dry weight was not different between heterogeneous and homogeneous nutrient supply at the late growth stage. Localized supply of ammonium and P significantly increased N and P accumulation by maize at 35 and 47 days after sowing (DAS); however, no significant difference was found among the treatments at 82 DAS and the later growth stages. The increased nutrient uptake and plant growth was related to the higher proportion of root length in the localized nutrient-enriched patch. The results indicated that root proliferation in nutrient patches contributed more to maize growth and nutrient uptake at the early than late stages.

关键词： biomass growth stage intensive farming system localized nutrient supply root length

Profile Characteristics and Potential EnvironmentalEffect of Accumulated Phosphorusin Soils ofVegetable Fields in Beliing

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Pedosphere 2002年第2期12卷 179-184页

作者： SU DECHUN, YANG FENHE and ZHANG FUSUOdepartment of plant nutrition, China Agricultural University, Beijing 100094 (China) department of plant nutrition China Agricultural University 北京 100094

Profile characteristics of accumulated P in 10 representativesoils of vegetable fields in suburban districts of Beijing wereinvestigated. Bioavailability of the accumulated P and its potentialeffect n the environment were studied in a greenhouse pot experimentand a soil column experiment. The results showed that theconcentration of Olsen-P in the 0～20 cm soil samples of thevegetable fields ranged from 2.1 to 358.0 mg kg^-1, which was 2 to 10times higher than that of the crop field sin the suburbs of *** of the excessive phosphorus was accumulated in the topsoils.

关键词： accumulated P bioavailability environment vegetable fields

Responses of Aerobic Rice (Oryza sativa L.) to Iron Deficiency

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Journal of Integrative Agriculture 2012年第6期11卷 938-945页

作者： SHI Rong-li HAO Hong-mei FAN Xiao-yun Md Rezaul Karim ZHANG Fu-SUO ZOU Chun-qin Key Laboratory of plant-Soil Interaction Ministry of Education/Center for ResourcesEnvironment and Food SecurityDepartment of Plant NutritionChina Agricultural University

Aerobic rice has the advantage of saving water. Most published work has focused on improving its yield, while few reported on its micronutrient status. In fact, Fe deficiency is a common nutritional problem in the production of aerobic rice. Short- term hydroponic culture experiments were conducted to study the response of aerobic rice to Fe deficiency and the effect of root exudates from Fe-deficient wheat on its Fe uptake ability. The results indicate that the amount of phytosiderophores （PS） released from aerobic rice did not increase under Fe deficient conditions. The Fe（III） reducing capacity of Fe-deficient aerobic rice did not increase and the solution pH did not decrease significantly. What＇s more, no obvious swelling was observed in the root tips. Aerobic rice did not show special responses to improve their Fe nutrition under Fe deficiency as both strategy I and II plants though they were very sensitive to Fe deficiency. This may be a reason which causes Fe deficiency problem in aerobic rice. However, root exudates from Fe-deficient wheat （PSw） could improve its Fe nutrition in the presence of insoluble Fe（OH）3. This suggests that aerobic rice could utilize Fe activated by PSw.

关键词： aerobic rice Fe(III)-reduction iron nutrition phytosiderophore release root tip swelling

Influence of silicon on microdistribution of mineral ions in roots of salt-stressed barley as associated with salt tolerance in plants

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Science China(Life Sciences) 2002年第3期45卷 298-308页

作者：丁瑞兴梁永超 department of plant nutrition College of Natural Resources and Environmental Sciences Nanjing Agricultural University Nanjing China

Two contrasting barley (Hordeum vulgare L.) cultivars: Kepin No.7 (salt sensitive), and Jian 4 (salt tolerant) were grown hydroponically to investigate the microdistribution of mineral ions in roots as affected by silicon (Si) with respect to salt tolerance. The experiment was undertaken consisting of two treatments with 3 replicates: (i) 120 mmol·L-1 NaCI alone (referred to as Si-NaCI+), (ii) 120 mmol·L-1 NaCI + 1.0 mmol·L-1 Si (as potassium silicate) (referred to as Si+NaCI+). plant root tips were harvested for microanalysis using an energy dispersive X-ray microanalyzer (EDX) 30 d after transplanting. Higher Cl and Na X-ray peaks were recorded in the root epidermal, cortical and stelar cells of roots for the treatment Si-NaCI+ with the majorities of Na and Cl being accumulated in epidermal and cortical cells, while relatively low K peaks were observed regardless of the barley cultivars used. By contrast, considerably higher K peaks were detected in the epidermal, cortical and stelar cells of the roots for the treatment Si+NaCI+, but lower Cl and Na peaks were also observed for this treatment with both Na and Cl ions being evenly distributed in the epidermal, cortical and stelar cells. These findings directly support our previous finding, which showed that Si depressed the uptake of sodium but enhanced the uptake of potassium by salt-stressed barley. We believe that one of the possible mechanisms involved in Si-enhancement of salt tolerance in barley is attributed to the Si-induced changes in the uptake and microdistribution of mineral ions in plants.

关键词： barley, energy dispersive X-ray microanalysis, ion uptake and microdistribution, salt stress, silicon.

Fractionation of Zn,Cd and Pb in a Tropical Soil After Nine-Year Sewage Sludge Applications

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Pedosphere 2010年第5期20卷 545-556页

作者： T.A.R.NOGUEIRA W.J.MELO I.M.FONSECA S.A.MARCUSSI G.M.P.MELO M.O.MARQUES department of plant nutrition Center for Nuclear Energy in AgricultureUniversity of Sao Paulo department of Technology Sao Paulo State University

A long-term field experiment was carried out in the experiment farm of the Sao Paulo State University,Brazil,to evaluate the phytoavailability of Zn,Cd and Pb in a Typic Eutrorthox soil treated with sewage sludge for nine consecutive years,using the sequential extraction and organic matter fractionation *** 2005-2006,maize(Zea mays L.) was used as test plants and the experimental design was in randomized complete blocks with four treatments and five *** treatments consisted of four sewage sludge rates(in a dry basis):0.0(control,with mineral fertilization),45.0,90.0 and 127.5 t ha-1,annually for nine *** maize sowing,the sewage sludge was manually applied to the soil and incorporated at 10 cm *** samples(0-20 cm layer) for Zn,Cd and Pb analysis were collected 60 days after *** successive applications of sewage sludge to the soil did not affect heavy metal(Cd and Pb) fractions in the soil,with exception of Zn *** Zn,Cd and Pb distributions in the soil were strongly associated with humin and residual fractions,which are characterized by stable chemical ***,Cd and Pb in the soil showed low phytoavailability after nine-year successive applications of sewage sludge to the soil.

关键词： heavy metals humic substance sequential extraction Zea mays L.

Nitrogen Under-and Over-supply Induces Distinct Protein Responses in Maize Xylem Sap

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Journal of Integrative plant Biology 2012年第6期54卷 374-387页

作者： Chengsong Liao Renyi Liu Fusuo Zhang Chunjian Li Xuexian Li department of plant nutrition College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China department of Botany and plant Sciences University of CaliforniaRiversideCA 92521USA

Xylem sap primarily transports water and mineral nutrients such as nitrogen （N） from roots to shoots in vascular plants. However, it remains largely unknown how nitrogenous compounds, especially proteins in xylem sap, respond to N under- or over-supply. We found that reducing N supply increased amino-N percentage of total N in maize （Zea mays L.） xylem sap. Proteomic analysis showed that 23 proteins in the xylem sap of maize plants, including 12 newly identified ones, differentially accumulated in response to various N supplies. Fifteen of these 23 proteins were primarily involved in general abiotic or biotic stress responses, whereas the other five proteins appeared to respond largely to N under- or over-supply, suggesting distinct protein responses in maize xylem upon N under- and over-supply. Furthermore, one putative xylanase inhibitor and two putative O-glycosyl hydrolases had preferential gene expression in shoots.

关键词： Protein response gene expression Xylem sap Zea mays nitrogen under-supply nitrogen over-supply.

Action Mechanisms of Arbuscular Mycorrhizal Fungi in Phosphorus Uptake by Capsicum annuum L.

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Pedosphere 2011年第4期21卷 502-511页

作者： M.SHARIF N.CLAASSEN department of Soil and Environmental Sciences NWFP Agricultural University department of Crop Sciences (plant nutrition) Georg-August-University Gttingen

A pot experiment was conducted to investigate the action mechanisms phorus （P） uptake of Capsicum annuum L. in a sterilized fossil Oxisol of arbuscular mycorrhizal （AM） fungi in phos- Three P levels of 0, 10 and 200 mg kg-1 soil （P0, P10 and P200, respectively） without and with AM fungal inoculation were applied as Ca（H2PO4）2-H20. Shoot dry matter yields and shoot P uptake increased significantly （P 〉 0.05） by the inoculation of AM fungi at P0 and P10. Root length and P concentration in soil solution increased with the inoculation of AM fungi but the root：shoot ratio decreased or remained constant. Around 50% roots of inoculated plants were infected by AM and the external hyphae amounted to 20 m g^-1 soil at P10 and P200. The hyphae surface area of the infected root cylinder amounted to 11 and 2 cm^2 cm^-2 root at P0 and P10, respectively. The increased P uptake of inoculated plants was mainly because of an up to 5 times higher P influx of the infected root. Model calculations showed that the root alone could not have achieved the measured P influx in both infected and non-infected roots. But the P influx for hyphae calculated by the model was even much higher than the measured one. The P uptake capacity of hyphae introduced in the model was too high. Model calculations further showed that the depletion zone around roots or hyphae was very narrow. In the case of the root only 7% of the soil volume would contribute P to the plant, while in the case of hyphae it would be 100%. The results together with the model calculations showed that the increased P uptake of AM inoculated plants could be explained partly by the increased P concentration in the soil solution and by the increased P absorbing surface area coming from the external hyphae.

关键词： hyphae mechanistic model phosphorus influx root infection root morphology