Publications by authors named "Chunqin Zou"

15 Publications

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Life cycle assessment of a long-term multifunctional winter wheat-summer maize rotation system on the North China Plain under sustainable P management.

Sci Total Environ 2021 Aug 17;783:147039. Epub 2021 Apr 17.

College of Resources and Environmental Science, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing 100193, China. Electronic address:

In sustainable agriculture, sufficient crop yields and nutrients must be produced while maintaining environmental protection. Considering the role of phosphorus (P) fertilizer in influencing crops yield and environmental security, life cycle assessment was used to examine the environmental impacts of long-term P application on the grain yield and nutritional quality of winter wheat and summer maize. Thus, a long-term field experiment with six P application rates for winter wheat (0, 25, 50, 100, 200, and 400 kg P ha) and summer maize (0, 12.5, 25, 50, 100, and 200 kg P ha) was conducted on the North China Plain (NCP). The results showed that the cradle-to-farm gate eutrophication potential (EP), energy depletion (ED), and P depletion (PD) were significantly affected by the P application rate applied in winter wheat and summer maize production. The critical P rate required to ensure food security for wheat and maize was in line with the optimal rate for sustainable environmental development in terms of grain production and nutrient levels. On the NCP, the ED and PD of summer maize with optimized P management over 10 years were less than those of winter wheat regardless of using yield or nutrient level as the functional unit. However, the EP of the nutrient supply in winter wheat was less than that in summer maize under optimized P fertilization. The specific nutritional components that limited improvements in environment of wheat and maize production under the optimal P rate were energy (calories) and protein, respectively. In conclusion, in a multifunctional winter wheat-summer maize rotation system, optimized P fertilization (50 kg ha for winter wheat and 25 kg ha for summer maize) combined with the planting of high-yield wheat varieties and high-protein maize varieties showed great potential to reduce the environmental impacts of wheat and maize production.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147039DOI Listing
August 2021

Soil Microbial Composition and Gene Abundance Are Sensitive to Phosphorus Level in a Long-Term Wheat-Maize Crop System.

Front Microbiol 2020 14;11:605955. Epub 2021 Jan 14.

College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, China.

Microbes associated with phosphorus (P) cycling are intrinsic to soil P transformation and availability for plant use but are also influenced by the application of P fertilizer. Nevertheless, the variability in soil P in the field means that integrative analyses of soil P cycling, microbial composition, and microbial functional genes related to P cycling remain very challenging. In the present study in the North China Plain, we subjected the bacterial and fungal communities to amplicon sequencing analysis and characterized the alkaline phosphatase ( encoding bacterial alkaline phosphatase in a long-term field experiment (10 years) with six mineral P fertilization rates up to 200 kg P ha. Long-term P fertilization increased soil available P, inorganic P, and total P, while soil organic P increased until the applied P rate reached 25 kg ha and then decreased. The fungal alpha-diversity decreased as P rate increased, while there were no significant effects on bacterial alpha-diversity. Community compositions of bacteria and fungi were significantly affected by P rates at order and family levels. The number of keystone taxa decreased from 10 to 3 OTUs under increasing P rates from 0 to 200 kg ha. The gene copy numbers of the biomarker of the alkaline phosphatase was higher at moderate P rates (25 and 50 kg ha) than at low (0 and 12.5 kg ha) and high (100 and 200 kg ha) rates of P fertilization, and was positively correlated with soil organic P concentration. One of the keystone taxa named BacOTU3771 belonging to Xanthomonadales was positively correlated with potential functional genes encoding enzymes such as glycerophosphoryl diester phosphodiesterase, acid phosphatase and negatively correlated with guinoprotein glucose dehydrogenase. Altogether, the results show the systematic effect of P gradient fertilization on P forms, the microbial community structure, keystone taxa, and functional genes associated with P cycling and highlight the potential of moderate rates of P fertilization to maintain microbial community composition, specific taxa, and levels of functional genes to achieve and sustain soil health.
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http://dx.doi.org/10.3389/fmicb.2020.605955DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7873961PMC
January 2021

Simultaneous Biofortification of Rice With Zinc, Iodine, Iron and Selenium Through Foliar Treatment of a Micronutrient Cocktail in Five Countries.

Front Plant Sci 2020 13;11:589835. Epub 2020 Nov 13.

Faculty of Engineering and Natural Sciences, Sabancı University, Istanbul, Turkey.

Widespread malnutrition of zinc (Zn), iodine (I), iron (Fe) and selenium (Se), known as hidden hunger, represents a predominant cause of several health complications in human populations where rice ( L.) is the major staple food. Therefore, increasing concentrations of these micronutrients in rice grain represents a sustainable solution to hidden hunger. This study aimed at enhancing concentration of Zn, I, Fe and Se in rice grains by agronomic biofortification. We evaluated effects of foliar application of Zn, I, Fe and Se on grain yield and grain concentration of these micronutrients in rice grown at 21 field sites during 2015 to 2017 in Brazil, China, India, Pakistan and Thailand. Experimental treatments were: (i) local control (LC); (ii) foliar Zn; (iii) foliar I; and (iv) foliar micronutrient cocktail (i.e., Zn + I + Fe + Se). Foliar-applied Zn, I, Fe or Se did not affect rice grain yield. However, brown rice Zn increased with foliar Zn and micronutrient cocktail treatments at all except three field sites. On average, brown rice Zn increased from 21.4 mg kg to 28.1 mg kg with the application of Zn alone and to 26.8 mg kg with the micronutrient cocktail solution. Brown rice I showed particular enhancements and increased from 11 μg kg to 204 μg kg with the application of I alone and to 181 μg kg with the cocktail. Grain Se also responded very positively to foliar spray of micronutrients and increased from 95 to 380 μg kg. By contrast, grain Fe was increased by the same cocktail spray at only two sites. There was no relationship between soil extractable concentrations of these micronutrients with their grain concentrations. The results demonstrate that irrespective of the rice cultivars used and the diverse soil conditions existing in five major rice-producing countries, the foliar application of the micronutrient cocktail solution was highly effective in increasing grain Zn, I and Se. Adoption of this agronomic practice in the target countries would contribute significantly to the daily micronutrient intake and alleviation of micronutrient malnutrition in human populations.
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http://dx.doi.org/10.3389/fpls.2020.589835DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7691665PMC
November 2020

Integrated systematic approach increase greenhouse tomato yield and reduce environmental losses.

J Environ Manage 2020 Jul 16;266:110569. Epub 2020 Apr 16.

College of Resources and Environment, Academy of Agricultural Sciences, Southwest University, Chongqing, 400716, China; Chongqing Key Laboratory of Efficient Utilization of Soil and Fertilizer Resources, Southwest University, Chongqing, 400716, China. Electronic address:

High input - high output greenhouse vegetable systems are responsible for nutrient surpluses and environmental losses. Integrated strategies that improve soil, crop and nutrient management are needed to ensure more sustainable production systems. We conducted a two-year field experiment to evaluate the potential of integrated soil-crop system management (ISSM) practices to improve the productivity and environmental outcomes from an intensive greenhouse tomato production system in the Yangtze River Basin, China. Four treatments were tested: i) farmers' practice (FP); ii) soil remediation (SR), where lime nitrogen with compost addition was the only management strategy; iii) a treatment that combined soil remediation with optimized crop planting density (SRCO), which increased planting density for improving crop yield; and iv) integrated soil-crop system management (ISSM), as a systematic integrated approach, which included the combined optimization of soil remediation, crop optimization, and nutrient management. In the integrated soil-crop system management treatment, nutrient management was optimized through adoption of the most appropriate type (formula) of fertilizer for the crop, rate and application timing of synthetic fertilizer, and by substituting poultry manure with compost. Our results indicated that the fruit yield of the integrated soil-crop system management treatment was 104 t ha, 13.4%-37.3% higher than that of the other three treatments. The mean reactive nitrogen loss (81.1 kg N ha) and the greenhouse gas emissions (6495 kg CO-eq ha) in the farmers' practice treatment were much higher than in the other three treatments (reactive nitrogen loss: 47.9-54.3 kg N ha; and greenhouse gas emissions: 4926-5468 kg CO-eq ha, respectively). The mean nitrogen and carbon footprints of the integrated soil-crop system management treatment were significantly lower than those of other treatments, as a result of both the lower fertilizer nitrogen use and the greater yield. This study indicates that integrated soil-crop system management could produce greater yields and increase net profit with reduced nitrogen inputs, whilst reducing the environmental cost associated with conventional farmers' practice in plastic-greenhouse vegetable production systems.
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http://dx.doi.org/10.1016/j.jenvman.2020.110569DOI Listing
July 2020

Simultaneous Biofortification of Wheat with Zinc, Iodine, Selenium, and Iron through Foliar Treatment of a Micronutrient Cocktail in Six Countries.

J Agric Food Chem 2019 Jul 15;67(29):8096-8106. Epub 2019 Jul 15.

Faculty of Engineering and Natural Sciences , Sabanci University , 34956 Istanbul , Turkey.

Field experiments were conducted on wheat to study the effects of foliar-applied iodine(I) alone, Zn (zinc) alone, and a micronutrient cocktail solution containing I, Zn, Se (selenium), and Fe (iron) on grain yield and grain concentrations of micronutrients. Plants were grown over 2 years in China, India, Mexico, Pakistan, South Africa, and Turkey. Grain-Zn was increased from 28.6 mg kg to 46.0 mg kg with Zn-spray and 47.1 mg kg with micronutrient cocktail spray. Foliar-applied I and micronutrient cocktail increased grain I from 24 μg kg to 361 μg kg and 249 μg kg, respectively. Micronutrient cocktail also increased grain-Se from 90 μg kg to 338 μg kg in all countries. Average increase in grain-Fe by micronutrient cocktail solution was about 12%. The results obtained demonstrated that foliar application of a cocktail micronutrient solution represents an effective strategy to biofortify wheat simultaneously with Zn, I, Se and partly with Fe without yield trade-off in wheat.
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http://dx.doi.org/10.1021/acs.jafc.9b01829DOI Listing
July 2019

The effects of controlled release urea on maize productivity and reactive nitrogen losses: A meta-analysis.

Environ Pollut 2019 Mar 23;246:559-565. Epub 2018 Dec 23.

College of Resources and Environment, Academy of Agricultural Science, Southwest University, Chongqing, 400716, PR China. Electronic address:

Application of controlled release urea (CRU) is recommended to reduce the undesirable environmental effects resulting from urea application. However, the overall effects of CRU on maize productivity and reactive nitrogen (N) losses remain unclear. Our global meta-analysis based on 866 observations of 120 studies indicated that application of CRU instead of urea (same N rate) increased maize yield by 5.3% and nitrogen use efficiency (NUE) by 24.1%, and significantly decreased nitrous oxide (NO) emission, N leaching and ammonia (NH) volatilization by 23.8%, 27.1% and 39.4%, respectively. The increase of NUE and reduction of NO emission by CRU application were greater with medium and high N rates (150 ≤ N < 200 and N ≥ 200 kg N ha) than with low N rates. The reduction in NO emission and N leaching with CRU application were enhanced when soil organic carbon (SOC) content was <15.0 g kg, and soil texture was medium or coarse. The reduction in NO emission and NH volatilization with CRU were greater in soils with pH ≥ 6.0. We concluded that use of CRU should be encouraged for maize production, especially on light-textured soils with low organic matter content.
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http://dx.doi.org/10.1016/j.envpol.2018.12.059DOI Listing
March 2019

Nitrate leaching from open-field and greenhouse vegetable systems in China: a meta-analysis.

Environ Sci Pollut Res Int 2018 Nov 4;25(31):31007-31016. Epub 2018 Sep 4.

College of Resources and Environment, Southwest University, Chongqing, 400716, China.

The potential for nitrate leaching in Chinese vegetable systems is substantial because of high inputs of nitrogen (N) fertilizer and water. To quantify the nitrate leaching and identify the key controlling factors in Chinese vegetable systems, we conducted a meta-analysis that included 221 data sets from 18 field studies. The results revealed that nitrate leaching over the entire crop growing season in Chinese vegetable systems was very high and averaged 79.1 kg N ha and primarily resulted from extremely high N fertilizer inputs (in average 423 kg N ha). Nitrate leaching was, on the average, 63.9% greater in the greenhouse systems (98.0 kg N ha) than in open-field systems (59.8 kg N ha). The leaching factor, defined as the proportion of the quantity of N applied to soils that was lost due to nitrate leaching, averaged 14.6% overall and was significantly lower in greenhouse systems (10.9%) than in open-field systems (18.4%). This difference appears to be due to lower of the total water inputs (irrigation + precipitation) in greenhouse systems. Nitrate leaching increased with water input, the number of growing days, and the N rate. The nitrate leaching response to increasing N rate was linear. The leaching factor significantly increased with water input but was not affected by the N rate or the number of growing days. Compared with application of synthetic fertilizer alone, the application of manure alone or manure plus synthetic fertilizer significantly reduced both the nitrate leaching and the leaching factor in open-field and greenhouse systems. These results suggest that nitrate leaching in Chinese vegetable systems can be reduced by optimizing rates of N and water supply to synchronize crop needs. Application of mixed synthetic N fertilizer and manure is more effective in reducing nitrate leaching, compared to synthetic N only.
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http://dx.doi.org/10.1007/s11356-018-3082-zDOI Listing
November 2018

Nitrous oxide emissions in Chinese vegetable systems: A meta-analysis.

Environ Pollut 2018 Aug 16;239:375-383. Epub 2018 Apr 16.

Academy of Agricultural Sciences, Southwest University, Chongqing, 400716, China; College of Resources and Environment, Southwest University, Chongqing, 400716, China. Electronic address:

China accounts for more than half of the world's vegetable production, and identifying the contribution of vegetable production to nitrous oxide (NO) emissions in China is therefore important. We performed a meta-analysis that included 153 field measurements of NO emissions from 21 field studies in China. Our goal was to quantify NO emissions and fertilizer nitrogen (N) based-emission factors (EFs) in Chinese vegetable systems and to clarify the effects of rates and types of N fertilizer in both open-field and greenhouse systems. The results indicated that the intensive vegetable systems in China had an average NO emission of 3.91 kg NO-N ha and an EF of 0.69%. Although the EF was lower than the IPCC default value of 1.0%, the average NO emission was generally greater than in other cropping systems due to greater input of N fertilizers. The EFs were similar in greenhouse vs. open-field systems but NO emissions were about 1.4 times greater in greenhouses. The EFs were not affected by N rate, but NO emissions for both open-field and greenhouse systems increased with N rate. The total and fertilizer-induced NO emissions, as well as EFs, were unaffected by the type of fertilizers in greenhouse system under same N rates. In addition to providing basic information about NO emissions from Chinese vegetable systems, the results suggest that NO emissions could be reduced without reducing yields by treating vegetable systems in China with a combination of synthetic N fertilizer and manure at optimized economic rates.
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http://dx.doi.org/10.1016/j.envpol.2018.03.090DOI Listing
August 2018

Characterization of QTLs for Root Traits of Wheat Grown under Different Nitrogen and Phosphorus Supply Levels.

Front Plant Sci 2017 11;8:2096. Epub 2017 Dec 11.

State Key Laboratory for Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Sciences, Chinese Academy of Sciences, Beijing, China.

Root is important in acquiring nutrients from soils. Developing marker-assisted selection for wheat root traits can help wheat breeders to select roots desirable for efficient acquisition of nutrients. A recombinant inbred line (RIL) population derived from wheat varieties Xiaoyan 54 and Jing 411 was used to detect QTLs for maximum root length and root dry weight (RDW) under control, low nitrogen and low phosphorus conditions in hydrophobic culture (HC). We totally detected 17 QTLs for the investigated root traits located at 13 loci on 11 chromosomes. These loci differentially expressed under different nutrient supplying levels. The RILs simultaneously harboring positive alleles or negative alleles of the most significant three QTLs for RDW, , and , were selected for soil column culture (SC) trial to verify the effects of these QTLs under soil conditions. The RILs pyramiding the positive alleles not only had significantly higher shoot dry weight, RDW, nitrogen and phosphorus uptake in all the three treatments of the HC trial, but also had significantly higher RDW distribution in both the top- and sub-soils in the SC trial than those pyramiding the negative alleles. These results suggested that QTL analysis based on hydroponic culture can provide useful information for molecular design of wheat with large and deep root system.
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http://dx.doi.org/10.3389/fpls.2017.02096DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5732362PMC
December 2017

Agronomic Approach of Zinc Biofortification Can Increase Zinc Bioavailability in Wheat Flour and thereby Reduce Zinc Deficiency in Humans.

Nutrients 2017 May 6;9(5). Epub 2017 May 6.

Key Laboratory of Plant-Soil Interactions, Ministry of Education, Center for Resources, Environment and Food Security, China Agricultural University, Beijing 100193, China.

Zinc (Zn) deficiency is a common disorder of humans in developing countries. The effect of Zn biofortification (via application of six rates of Zn fertilizer to soil) on Zn bioavailability in wheat grain and flour and its impacts on human health was evaluated. Zn bioavailability was estimated with a trivariate model that included Zn homeostasis in the human intestine. As the rate of Zn fertilization increased, the Zn concentration increased in all flour fractions, but the percentages of Zn in standard flour (25%) and bran (75%) relative to total grain Zn were constant. Phytic acid (PA) concentrations in grain and flours were unaffected by Zn biofortification. Zn bioavailability and the health impact, as indicated by disability-adjusted life years (DALYs) saved, increased with the Zn application rate and were greater in standard and refined flour than in whole grain and coarse flour. The biofortified standard and refined flour obtained with application of 50 kg/ha ZnSO₄·7H₂O met the health requirement (3 mg of Zn obtained from 300 g of wheat flour) and reduced DALYs by >20%. Although Zn biofortification increased Zn bioavailability in standard and refined flour, it did not reduce the bioavailability of iron, manganese, or copper in wheat flour.
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http://dx.doi.org/10.3390/nu9050465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5452195PMC
May 2017

Overuse of Phosphorus Fertilizer Reduces the Grain and Flour Protein Contents and Zinc Bioavailability of Winter Wheat (Triticum aestivum L.).

J Agric Food Chem 2017 Mar 16;65(8):1473-1482. Epub 2017 Feb 16.

Key Laboratory of Plant-Soil Interactions, Ministry of Education; Center for Resources, Environment and Food Security, China Agricultural University , Beijing 100193, People's Republic of China.

To supplement human dietary nutrition, it is necessary to evaluate the effects of phosphorus (P) fertilizer application on grain and flour protein contents and especially on the bioavailability of zinc (Zn). A field experiment of winter wheat with six P application rates (0, 25, 50, 100, 200, 400 kg/ha) was conducted from 2013 to 2015. The grain yield increased with P application but was not further enhanced when P rates exceeded 50 kg/ha. As P application increased, the protein concentration in grain and standard flour and the viscosity of standard flour decreased. Phosphorus and phytic acid (PA) concentrations in grain and flours increased and then plateaued, whereas Zn concentration decreased and then plateaued as P application increased from 0 to 100 kg/ha. Estimated Zn bioavailability in grain and flours decreased as P application increased from 0 to 100 kg/ha and then plateaued. Estimated Zn bioavailability was greater in standard flour, bread flour, and refined flour than in grain or coarse flour. Phosphorus supply in the intensive cropping of wheat can be optimized to simultaneously obtain high grain yields, high grain and flour protein contents, and high Zn bioavailability.
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http://dx.doi.org/10.1021/acs.jafc.6b04778DOI Listing
March 2017

Zinc, iron, manganese and copper uptake requirement in response to nitrogen supply and the increased grain yield of summer maize.

PLoS One 2014 4;9(4):e93895. Epub 2014 Apr 4.

Center for Resources, Environment and Food Security, China Agricultural University, Beijing, China.

The relationships between grain yields and whole-plant accumulation of micronutrients such as zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) in maize (Zea mays L.) were investigated by studying their reciprocal internal efficiencies (RIEs, g of micronutrient requirement in plant dry matter per Mg of grain). Field experiments were conducted from 2008 to 2011 in North China to evaluate RIEs and shoot micronutrient accumulation dynamics during different growth stages under different yield and nitrogen (N) levels. Fe, Mn and Cu RIEs (average 64.4, 18.1 and 5.3 g, respectively) were less affected by the yield and N levels. ZnRIE increased by 15% with an increased N supply but decreased from 36.3 to 18.0 g with increasing yield. The effect of cultivars on ZnRIE was similar to that of yield ranges. The substantial decrease in ZnRIE may be attributed to an increased Zn harvest index (from 41% to 60%) and decreased Zn concentrations in straw (a 56% decrease) and grain (decreased from 16.9 to 12.2 mg kg-1) rather than greater shoot Zn accumulation. Shoot Fe, Mn and Cu accumulation at maturity tended to increase but the proportions of pre-silking shoot Fe, Cu and Zn accumulation consistently decreased (from 95% to 59%, 90% to 71% and 91% to 66%, respectively). The decrease indicated the high reproductive-stage demands for Fe, Zn and Cu with the increasing yields. Optimized N supply achieved the highest yield and tended to increase grain concentrations of micronutrients compared to no or lower N supply. Excessive N supply did not result in any increases in yield or micronutrient nutrition for shoot or grain. These results indicate that optimized N management may be an economical method of improving micronutrient concentrations in maize grain with higher grain yield.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0093895PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3976344PMC
January 2015

Senescence-induced iron mobilization in source leaves of barley (Hordeum vulgare) plants.

New Phytol 2012 Jul 16;195(2):372-383. Epub 2012 May 16.

Molecular Plant Nutrition, Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, 06466 Gatersleben, Germany.

• Retranslocation of iron (Fe) from source leaves to sinks requires soluble Fe binding forms. As much of the Fe is protein-bound and associated with the leaf nitrogen (N) status, we investigated the role of N in Fe mobilization and retranslocation under N deficiency- vs dark-induced leaf senescence. • By excluding Fe retranslocation from the apoplastic root pool, Fe concentrations in source and sink leaves from hydroponically grown barley (Hordeum vulgare) plants were determined in parallel with the concentrations of potential Fe chelators and the expression of genes involved in phytosiderophore biosynthesis. • N supply showed opposing effects on Fe pools in source leaves, inhibiting Fe export out of source leaves under N sufficiency but stimulating Fe export from source leaves under N deficiency, which partially alleviated Fe deficiency-induced chlorosis. Both triggers of leaf senescence, shading and N deficiency, enhanced NICOTIANAMINE SYNTHASE2 gene expression, soluble Fe pools in source leaves, and phytosiderophore and citrate rather than nicotianamine concentrations. • These results indicate that Fe mobilization within senescing leaves is independent of a concomitant N sink in young leaves and that phytosiderophores enhance Fe solubility in senescing source leaves, favoring subsequent Fe retranslocation.
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http://dx.doi.org/10.1111/j.1469-8137.2012.04165.xDOI Listing
July 2012

Is iron phloem mobile during senescence in trees? A reinvestigation of Rissmüller's finding of 1874.

Plant Physiol Biochem 2011 May 9;49(5):489-93. Epub 2011 Mar 9.

Department of Plant Nutrition, China Agricultural University, Beijing 100193, PR China.

As long as 130 years ago Rissmüller reported substantial retranslocation of iron (Fe) from beech leaves (Fagus sylvatica L.) shortly before leaf fall. This rather limited report on Fe retranslocation via the phloem in plants was the reason for this research to study changes in Fe content in individual beech leaves in more detail during the vegetative period. Besides Fe, other micronutrients and particularly Ca and K, well known to differ substantially in phloem mobility, were analysed as mineral nutrient markers. In addition to beech, other deciduous and evergreen species of Angiosperms and Gymnosperms were also studied. As expected, there was no evidence of Ca retranslocation from senescent leaves, while K as a phloem mobile mineral nutrient was retranslocated in fall in deciduous but not in evergreen trees. There was no indication to support Rissmüller's finding of Fe retranslocation in any of the different species studied. From these results, we conclude that natural leaf senescence of trees during late season does not induce retranslocation of Fe and other micronutrients. Possible reasons for the absence of a distinct retranslocation of Fe in the species studied during late season senescence are the lack of a sink activity, as for example the development of seeds in annual plant species (e.g., cereals), or the presence of a root system still active enough to provide Fe and other mineral nutrients for plant demand, and both factors have to be considered in further studies. Reviewing the data in the literature on Fe and Zn retranslocation during senescence, we conclude that in principle both micronutrients are potentially phloem mobile. However, various prerequisites are needed for the occurrence of phloem mobility which were absent in the plant species studied. Regardless of this conclusion, we recommend that in general early published research data need a critical re-evaluation.
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http://dx.doi.org/10.1016/j.plaphy.2011.03.004DOI Listing
May 2011

Iron and zinc concentrations in grain and flour of winter wheat as affected by foliar application.

J Agric Food Chem 2010 Dec 12;58(23):12268-74. Epub 2010 Nov 12.

Key Laboratory of Plant-Soil Interaction, MOE, and Key Laboratory of Plant Nutrition, MOA, Department of Plant Nutrition, China Agricultural University, Beijing 100193, People's Republic of China.

Human deficiencies of iron (Fe) and zinc (Zn) are worldwide problems. Biofortification of wheat could reduce Fe and Zn deficiencies in societies that depend on wheat consumption. This study investigated the effects of foliar application of Fe with or without Zn on the concentrations of Fe and Zn in grain and especially in flour of three wheat cultivars. On average, grain Fe concentration was increased significantly from 29.5 mg kg(-1) in the control to 37.8, 35.9, or 34.9 mg kg(-1) by application of FeSO4, ferric citrate plus ZnSO4, or ferric citrate, respectively. As expected, grain Zn concentration was increased from 29.0 mg kg(-1) in the control to 45.7 or 39.6 mg kg(-1) by application of ferric citrate plus ZnSO4 or a complex of micronutrients. Although the Fe and Zn concentrations in flour were inherently lower than in bran and shorts made by experimental mill, the concentrations in flour were simultaneously increased from 10.4 to 12.4 mg kg(-1) for Fe and from 11.8 to 17.4 mg kg(-1) for Zn by application of ferric citrate plus ZnSO4. Importantly, Fe was peripherally localized within grain fractions and strictly limited to transport to endosperm, making it more difficult to increase the quantity of Fe in flour products by foliar Fe application, but the situation with Zn is promising because Zn is more readily transported to the endosperm than Fe. The current study increases the understanding of agronomic biofortification.
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http://dx.doi.org/10.1021/jf103039kDOI Listing
December 2010
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