Biomedical subjects

Fusuo Zhang

Publications and source records attributed to Fusuo Zhang.

At least 19 recordsLinked to original sources

PubMed2006

Transpiration, and nitrogen uptake and flow in two maize (Zea mays L.) inbred lines as affected by nitrogen supply.

BACKGROUND AND AIMS: The influence of two nitrogen (N) levels on growth, water relations, and N uptake and flow was investigated in two different inbred lines of maize (N-efficient Zi330 and N-inefficient Chen94-11) to analyse the differences in N uptake and cycling within a plant. METHODS: Xylem sap from different leaves of the inbred lines cultured in quartz sand was collected by application of pressure to the root system. Plant transpiration was measured on a daily basis by weighing five pots of each of the treatments. KEY RESULTS: N-efficient Zi330 had a higher relative growth rate and water-use efficiency at both high (4 mm) and low (0.08 mm) N levels. At a high N level, the amount of N taken up was similar for the two inbred lines; the amount of N transported in the xylem and retranslocated in the phloem was slight greater in Chen94-11 than in Zi330. At a low N level, however, the total amount of N taken up, transported in the xylem and retranslocated in the phloem of Zi330 was 2.2, 2.7 and 2.7 times more, respectively, than that of Chen94-11. Independent of inbred line and N level, the amounts of N transported in the xylem and cycled in the phloem were far more than that taken up by roots at the same time. Low N supply shifted NO(3)(-1) reduction towards the roots. The major nitrogenous compound in the xylem sap was NO(3)(-1), when plants grew at the high N level, while amino acid-N was predominant when plants grew at the low N level. CONCLUSIONS: The N-efficient maize inbred line Zi330 had a higher ability to take up N and cycle N within the plant than N-inefficient Chen94-11 when grown under N-deficiency.

Nitrogen↗

PubMed2006

Nicotine synthesis in Nicotiana tabacum L. induced by mechanical wounding is regulated by auxin.

The effects of different kinds of mechanical wounding on nicotine production in tobacco plants were compared, with sand or hydroponics culture under controlled conditions. Both removal of the shoot apex and damage of the youngest unfolded leaves nos 1 and 2 by a comb-like brusher with 720 punctures caused an increase in nicotine concentration in whole plants at day 3, and reached its highest level at day 6. The nicotine concentration induced by excision of the shoot apex was much higher than that induced by leaf wounding. Both treatments also caused an increase in jasmonic acid (JA) concentration within 90 min in the shoot, followed by an increase in the roots (210 min), in which the JA concentration induced by leaf wounding was significantly higher than that induced by excision of the shoot apex. The increase in nicotine concentration occurred throughout the whole plant, especially in the shoot, while the increase in JA concentration in the shoot was restricted to the damaged tissues, and was not observed in the adjacent tissues. Removal of the lateral buds that emerged after excision of the shoot apex caused a further increase in nicotine concentrations in the plant tissues. Removal of mature leaves, however, did not cause any changes in nicotine concentration in the plant, even though the degree of wounding in this case was comparable with that occurring with apex removal. The results suggest that the nicotine production in tobacco plants was not correlated with the degree of wounding (cut-surface or punctures), but was highly dependent on the removal of apical meristems and hence on the major sources of auxin in the plant. Furthermore, immediate application of 1-naphthylacetic acid (NAA) on the cut surface after removing the shoot apex completely inhibited the increase both in nicotine in whole plants and in JA in the damaged stem segment and roots. Application of an auxin transport inhibitor around the stem directly under the shoot apex of intact plants also caused an increase in nicotine concentration in the whole plant. The results strongly suggest that auxin serves as a negative signal to regulate nicotine synthesis in roots of tobacco plants.

Cyclopentanes↗

PubMed2006

Comparative proteome analyses of maize (Zea mays L.) primary roots prior to lateral root initiation reveal differential protein expression in the lateral root initiation mutant rum1.

The embryonically preformed primary root is the first root type of maize that emerges after germination. In this study the abundant soluble proteins of 2.5-day-old primary roots of wild-type and lateral root mutant rum1 seedlings were compared before the initiation of lateral roots. In CBB-stained 2-D gels, among 350 detected proteins 14 were identified as differentially accumulated (>twofold change; t-test: 95% significance) in wild-type versus rum1 primary roots. These proteins which were identified via ESI MS/MS are encoded by 12 different genes. Functionally, these proteins are involved in lignin biosynthesis, defense, and the citrate cycle. Nine of these genes were further analyzed at the RNA expression level. This study represents the first comparative proteomic analysis of maize primary roots prior to lateral root initiation and will contribute to a better understanding of the molecular basis of root development in cereals.

Blotting, Northern↗

PubMed2006

Nutritional and osmotic roles of nitrate in a euhalophyte and a xerophyte in saline conditions.

The effects of salinity and nitrogen (N) on growth and the role of NO3- in osmotic adjustment in the leaf-succulent euhalophyte Suaeda physophora and the stem-succulent xerophyte Haloxylon persicum were evaluated. Seedlings were exposed to 1 or 300 mm NaCl in 0.05, 1 or 10 mm NO3- -N treatments for 24 d. At 10 mm NO3-, 300 mm NaCl had no adverse effect on the concentration of NO3-, the content of organic N, and the estimated contribution of NO3- to osmotic potential in leaves of S. physophora, but markedly reduced these in stems of H. persicum. At 300 mm NaCl, more NO3- but less Cl- and Na+ were involved in osmotic adjustment in leaves of S. physophora compared with that in stems of H. persicum. The contribution of NO3- to osmotic potential was much higher in S. physophora, but lower in H. persicum, than that of amino acids at 300 mm NaCl. The nutritional and osmotic roles of NO3- -N seem to be more important in the euhalophyte S. physophora than in the xerophyte H. persicum under saline conditions. These characteristics may determine the natural distributions of the two species in saline or arid environments.

Amino Acids↗

PubMed2006

[Absorption and distribution of nitrogen from 15N labelled urea applied at core-hardening stage in winter jujube].

The study with pot experiment showed that at the rapid-swelling stage of winter jujube fruit, the percent of nitrogen derived from fertilizer (Ndff%) was the highest (10.64%) in fine roots, followed by new-growth nutritive organs. The absorbed urea-15N decreased in leaves and deciduous supers, and accumulated preferentially in root systems after harvest. The Ndff% in coarse roots was the highest (3.69%) before budding stage, while that in new-growth organs (new branches, deciduous supers, leaves and flowers) was the highest at full-blooming stage. The urea-15N applied at core-hardening stage mainly allocated in nutritive organs (leaves, deciduous supers, roots) in the first year, with the distribution rate 54.01% in root systems in winter, which was higher than that in branches (45.99%). The 15N stored in main branches changed drastically from post-harvest to budding stage. Main branches could be regarded as the 'target organs' of N storage, while coarse roots were the 'long-term sink' of N storage. The N reserve distributed preferentially in contiguity organs, and the distribution center changed with the growth and development of winter jujube in next spring.

Absorption↗

PubMed2006

[Estimation parameters of nitrogen balance in stock farming system of China].

The study of nitrogen (N) balance in stock farming system is the basis of nutrient management in animal husbandry production, and the determination of N cycling parameters is the foundation of this study. Through documents checking and data collecting, this paper analyzed the items and values of input/output parameters of N cycling in stock farming system, and ascertained the estimation parameters of N balance in the system, which could offer the theoretical foundation for nutrient management in animal husbandry production.

Animal Husbandry↗

PubMed2005

Root distribution and interactions between intercropped species.

Even though ecologists and agronomists have considered the spatial root distribution of plants to be important for interspecific interactions in natural and agricultural ecosystems, few experimental studies have quantified patterns of root distribution dynamics and their impacts on interspecific interactions. A field experiment was conducted to investigate the relationship between root distribution and interspecific interactions between intercropped plants. Roots were sampled twice by auger and twice by the monolith method in wheat (Triticum aestivum L.)/maize (Zea mays L.) and faba bean (Vicia faba L.)/maize intercropping and in sole wheat, maize, and faba bean up to 100 cm depth in the soil profile. The results showed that the roots of intercropped wheat spread under maize plants, and had much greater root length density (RLD) at all soil depths than sole wheat. The roots of maize intercropped with wheat were limited laterally, but had a greater RLD than sole-cropped maize. The RLD of maize intercropped with faba bean at different soil depths was influenced by intercropping to a smaller extent compared to maize intercropped with wheat. Faba bean had a relatively shallow root distribution, and the roots of intercropped maize spread underneath them. The results support the hypotheses that the overyielding of species showing benefit in the asymmetric interspecific facilitation results from greater lateral deployment of roots and increased RLD, and that compatibility of the spatial root distribution of intercropped species contributes to symmetric interspecific facilitation in the faba bean/maize intercropping.

Agriculture↗

PubMed2005

Strategies for adaptation of Suaeda physophora, Haloxylon ammodendron and Haloxylon persicum to a saline environment during seed-germination stage.

BACKGROUND AND AIMS: Germination is very important for plant establishment in arid regions. The strategies taken by halophytes during the seed germination stage to adapt to saline environments in an arid zone were investigated in Suaeda physophora (euhalophyte), Haloxylon ammodendron (xero-halophyte) and Haloxylon persicum (xerophyte). METHODS: Seeds of S. physophora, H. ammodendron and H. persicum were exposed to a range of iso-osmotic NaCl and PEG solutions. Seed germination in, and recovery germination from, high NaCl were recorded. The effects of iso-osmotic NaCl and PEG on seed water uptake and changes in ion content were measured. In addition, the structure of seeds and Na+ distribution in the seed coat and embryos of dry seeds were investigated. KEY RESULTS: The relative increase in fresh weight of germinating seeds was markedly reduced in -2.24 MPa PEG compared with that in -2.24 MPa NaCl, while the opposite trend was found in concentration of K+ during the initial 9 h for all species. Haloxylon ammodendron and S. physophora had a higher recovery germination from -3.13 MPa NaCl compared with H. persicum. Seeds of all species had no endosperm. More Na+ was compartmentalized in the seed coats of the two halophytic species compared with that in the xerophyte H. persicum. CONCLUSIONS: The effect of NaCl on seed germination was due to both osmotic stress and ion toxicity for the three species. High soil salinity and a high content of Na+ in seeds may induce more seeds to remain ungerminated in S. physophora and H. ammodendron. Morphological structure and adaptation to salinity during seed germination may determine the geographical distribution of H. ammodendron and S. physophora in certain saline regions.

Adaptation, Physiological↗

PubMed2005

[Physiological characteristics of nitrogen nutrition and stress-resistance of film-mulched rice in various ecological regions of Zhejiang Province].

The study showed that different ecological environment and cultivation system in various ecological regions of Zhejiang Province resulted in some different physiological characteristics of nitrogen nutrition and stress-resistance, especially in the aspect of NO3(-)-N and NH4+-N concentrations, between film-mulched and conventional flooded rice. Owing to the heat stress in Hangjiahu plain, the NO3(-)-N concentration of film-mulched rice decreased to some extent, but NH4+-N concentration increased markedly at tillering, jointing and booting stages, compared to conventional flooded rice. In Jinqu basin, the NO3(-)-N concentration of film-mulched rice at booting stage was higher, while the NH4+-N concentration in its roots was notably lower than those of conventional flooded rice, with NH4+-N concentration in its basal stems and leaves somewhat increased. Generally, the glutamine synthetase (GS) and nitrate reductase (NR) activities in film-mulched rice leaves were enhanced at booting stage, while malondiadehyde (MDA), soluble sugar (SS) and proline (Pro) concentrations had little changes. In conclusion, film-mulched cultivation was beneficial to the rice growth and its high yielding.

Biomass↗

PubMed2005

[Nitrogen balance and its effects on nitrate-N concentration of groundwater in three intensive cropping systems of North China].

Selecting three main intensive cropping systems of North China, i.e., wheat-maize rotation, plastic greenhouse vegetable, and apple orchard as test objectives, this paper studied their nitrogen (N) budget, soil nitrate-N accumulation, and year-round dynamics of groundwater nitrate-N concentration. The results showed that in plastic greenhouse vegetable cropping system, the annual N input from chemical fertilizers, manure, and irrigation was 1358, 1881 and 402 kg x hm(-2), being 2.5, 37.5 and 83.8 folds of the corresponding items in wheat-maize cropping system, and 2.1, 10.4 and 68.2 folds in orchard, respectively, and its total N input amounted to 3656 kg x hm(-2), being 5.8 times of the wheat-maize cropping system, and 4.2 times of the orchard. The wet deposition N in the three cropping systems ranged from 14.2 kg x hm(-2) to 18.9 kg x hm(-2). The N output by wheat-maize, greenhouse vegetable and orchard was 280,329 and 121 kg x hm(-2), the N surplus was 349, 3327 and 746 kg x hm(-2), and the remained nitrate-N after harvest amounted to 221-275, 1173 and 613 kg x hm(-2) in 0-90 cm soil layer, and 213-242, 1032 and 976 kg x hm(-2) in 90-180 cm soil layer, respectively. Crop field had a comparatively even distribution of nitrate N in its 0-180 cm soil profile, and a sharp increase of nitrate N throughout the soil profile were found in both greenhouse vegetable and orchard fields. There was an evident nitrate leaching in all three cropping systems. The groundwater in shallow well (< 15 m) was severely contaminated in greenhouse vegetable area, with the nitrate-N concentration in 99% of the samples exceeding the maximum permissible limit for drinking water (10 mg x L(-1)), while 5% of the samples in deep well in vegetable area and in shallow well in orchard and 1% of the samples in deep well in wheat-maize field were exceeded the limit. The nitrate-N concentration exponentially decreased with well depth (m) in greenhouse vegetable area.

Crops, Agricultural↗

PubMed2005

[Effects of N fertilization on winter wheat grain yield and its crude protein content and apparent N losses].

Field experiments were conducted at four sites in 2002 to study the effects of N fertilization on winter wheat yield and its crude protein content and apparent N losses. The results showed that at these sites, the N application rate for maximum grain yield was 0, 0, 79 and 118 kg x hm(-2), and that for maximum grain crude protein content was 122, 100, 127 and 174 kg x hm(-2), respectively. The residual nitrate-N content in 0 approximately 90 cm soil layer after harvest was linearly increased, while the apparent N losses during wheat growth season was exponentially increased with increasing N application rate. Under the N application rate for maximum yield, soil residual nitrate-N content ranged from 86 to 115 kg x hm(-2) and apparent N losses ranged from 2 to 32 kg x hm(-2), which were much lower than the residual nitrate-N content (106 approximately 168 kg x hm(-2))and apparent N losses(14 approximately 56 kg x hm(-2)) when the maximum grain crude protein content was achieved. The results showed that the maximum wheat grain yield and the environment effects of N fertilization could be harmonized by an optimized N application rate, but, if considering the importance of wheat grain protein, more research in the future should be needed.

Biomass↗

PubMed2005

Utilization and management of organic wastes in Chinese agriculture: past, present and perspectives.

Recycling and composting of organic materials such as animal waste, crop residues and green manures has a long tradition in China. In the past, the application of organic manures guaranteed a high return of organic materials and plant mineral nutrients and thus maintained soil fertility and crop yield. As a result of rapid economic development coupled with the increasing urbanization and labour costs, the recycling rate of organic materials in Chinese agriculture has dramatically declined during the last two decades, in particular in the more developed eastern and southeastern provinces of China. Improper handling and storage of the organic wastes is causing severe air and water pollution. Because farmers are using increasing amounts of mineral fertilizer, only 47% of the cropland is still receiving organic manure, which accounted for 18% of N, 28% of P and 75% of K in the total nutrient input in 2000. Nowadays, the average proportion of nutrients (N+P+K) supplemented by organic manure in Chinese cropland is only 35% of the total amount of nutrients from both inorganic and organic sources. In China, one of the major causes is the increasing de-coupling of animal and plant production. This is occurring at a time when "re-coupling" is partly being considered in Western countries as a means to improve soil fertility and reduce pollution from animal husbandry. Re-coupling of modern animal and plant production is urgently needed in China. A comprehensive plan to develop intensive animal husbandry while taking into account the environmental impact of liquid and gaseous emissions and the nutrient requirements of the crops as well as the organic carbon requirements of the soil are absolutely necessary. As a consequence of a stronger consideration of ecological aspects in agriculture, a range of environmental standards has been issued and various legal initiatives are being taken in China. Their enforcement should be strictly monitored.

Agriculture↗

PubMed2004

Nitrogen fertilization, soil nitrate accumulation, and policy recommendations in several agricultural regions of China.

Excessive nitrogen (N) fertilization and decreasing N recovery rates by crops have caused dramatic increases in non-point source pollution from agriculture in China. The rate of N fertilization across the country varies widely among regions and crops, depending on the stage of economic development. For example, N application rates in the eastern regions and on cash crops are far higher than in western regions of the country and on cereal crops. Moreover, N application rates in wealthier regions are higher than recommended by the Chinese Academy of Sciences. To successfully achieve environmental protection as well as high crop yields, China must formulate relevant agricultural policies to encourage farmers in economically developed areas to reduce their N fertilization rate while also issuing conventional fertilization recommendations for small-scale farming systems and the expanding cultivation of cash crops.

Agriculture↗

PubMed2004

[A preliminary study on salt contents of soil in root-canopy area of halophytes].

The results showed that among the 27 sampling sites, the salt content in rhizosphere of herbaceous halophytes increased at 7 sites and decreased at 20 sites. The variation of soil salt content in the RUE micro-area of shrubby halophytes was related to the growth status of the plants. The salt content in rhizosphere decreased a little at the early stage of plant development, but that in RUE micro-area tended to increase and accumulated most quickly at the site of the canopy edge soil. An obvious variation of salt components was found in the RUE micro-area of different types of halophytes. The Na+/K+ ratio tended to decrease in succulent halophytes and salt secrete halophytes. Among 53 sampling sites, only 14 sampling sites had a higher ratio of Na+/K+ in rhizosphere soil than in background soil, and only 10 sampling sites had a higher ratio of Na+/K+ in canopy-under soil than in background soil. However, the Na+/K+ ratio in the canopy edge soil of Tamarix and Nitraria tended to increase when they grew weakly. By contraries, the Na+/K+ ratio in the rhizosphere was higher than that in background soil at 3 of 4 sampling sites of Phragmites australia, which indicated that the Na+/K+ ratio in the rhizosphere of exclude halophytes tended to increase. The variation of SO4(2-)/Cl- ratio in the RUE micro-area was different in the 3 types of halophytes. For salt secrete halophytes, it decreased obviously in rhizosphere soil, canopy-under soil and canopy-edge soil; for succulent herbaceous halophytes, it tended to increase in rhizosphere soil; and for succulent shrubby halophytes, it tended to decrease in rhizosphere and in canopy-under soil, and tended to increase in canopy-edge soil. The SO4(2-)/Cl- ratio had no big change for exclude-halophytes. The reduction of the salts in rhizosphere of herbaceous halophytes was mainly because of their plant uptake, and the accumulation of salts in the RUE micro-area of shrubby halophytes was because the salt absorbed from the around soil returned to the RUE micro-area again. Because of the selective uptake by plant, the salt component varied with different types of halophytes. Most halophytes except Phragmites australia take more Na+, and hence the Na+/K+ ratio in the rhizosphere tends to decrease. The SO4(2-)/Cl- ratio in the RUE micro-area of salt secrete halophytes trended reduce, mainly because this type of halophyte can secrete more Cl- with its growth.

Chlorides↗

PubMed2004

[Effects of peanut mixed cropping with different gramineous plants on apoplast iron accumulation and reducing capacity of peanut].

The effects of peanut mixed cropping with five different gramineous plants on apoplast iron accumulation and reducing capacity of peanut were investigated by soil culture experiment. The results showed that mixed cropping of maize, barley, oats, wheat, and sorghum with peanut could improve iron nutrition of peanut respectively. The phytosiderophores excretion rate of barley, oats and wheat were much higher than that of maize, and the phytosiderophores excretion rate of sorghum was lower than that of maize. In comparison with peanut in monocropping the iron content in different organs of peanut mixed with maize, barley, oats, wheat and sorghum were increased. The Fe content in root apoplast of peanut mixed with five different gramineous was gradually increased and higher than that of peanut in monocropping at different growth days. At the same time, the mixed cropping systems remarkably improved the soil Fe availability in the rhizosphere and root Fe reducing capacity of peanut. The higher root Fe (III) reducing capacity and much more available Fe in the rhizospe (III) of peanut in mixed cropping played an important role in improving iron nutrition of peanut.

Arachis↗

PubMed2004

[Effect of reduced N application on N utilization and balance in winter wheat-summer maize cropping system].

A field trial on a calcareous soil was carried out at an experimental station of China Agricultural University with the objective of assessing the effect of reduced nitrogen application on N utilization and N balance in a winter wheat-summer maize cropping system. Before this study, the trial has been conducted for one rotation cycle of wheat and maize with four-fixed N rates of 0, 120, 240 and 360 N kg.hm-2 per crop. In this study, each plot was divided into two sub-plots for two N application rates: normal N application(original rate) and reduced N application(reduced rate). The results showed that the grain yields of wheat and maize reached the platform at N rate of 120 kg.hm-2(N120), and then almost kept the same level regardless of the further increase of N rate(N240 and N360). The N uptake by wheat and maize followed the similar tendency like their yield. The grain yield and N uptake of wheat were not significantly declined with the half reduction of original N rate except the treatment N120. However, the same items in maize significantly declined with the further reduction of N fertilizer to zero. The residual NO3-N(main source of mineral N) in reduced N sub-plots was significantly lower in 0-1 m soil layer, but not different in 1-2 m soil layer compared with those receiving original N rate, indicating that 1-2 m soil NO3-N could hardly be utilized by crops. N balance calculation further showed that the N recovery by crops could be largely raised by the reduction of N fertilizer, while the apparent N loss rate decreased in wheat-maize rotation, respectively. Thus, the reduction of fertilizer N under high N rate can significantly increase N use efficiency and reduce NO3-N accumulation and apparent N loss.

Crops, Agricultural↗

PubMed2004

[Formation of iron plaque on root surface and its effect on plant nutrition and ecological environment].

This paper illustrated the conditions of iron plaque formation on root surface, the morphology, mineralogical composition and deposition site of the plaque, and its function as a Fe reservoir in supplying Fe nutrient and affecting the uptake of other nutrients such as phosphorus and zinc. The environmental and ecological role of the plaque in inhibiting the uptake and translocation of heavy metals such as Cu, Ni, Cd and As through absorption or co-precipitation was called external tolerance mechanism, while its competition with heavy metals for metabolically sensitive sites in plants was called internal tolerance mechanisms. These two mechanisms help plant survive in high acidic and low carbon environment.

Ecosystem↗

PubMed2003

[Effect of different cultivation practices on Fe and Cd content in iron plaque outside rice root and Cd content in rice root].

The effects of different cultivation practices-traditional flooding (TF), film mulching (FM), straw mulching (SM), and wetting cultivation (WC)-on Cd concentrations in Indica and Japonica roots and on Cd and Fe concentrations in iron plaque outside the roots were studied at different growth stages (tillering, booting, filling and harvest) with a Cd-polluted soil. The results showed that in all practices, the mean Fe concentration in iron plaque and the mean Cd concentration in roots of Japonica at tillering stage were 6.37 mg.mg-1 and 25.49 mg.kg-1, and greater than those of Indica, which were 4.52 mg.mg-1 and 16.37 mg.kg-1 respectively; at booting stage, the mean Fe and Cd concentrations in iron plaque and the mean Cd concentrations of Japonica were 1.60, 16.35 and 54.68 mg.kg-1, and greater than those of Indica, which were 1.06 mg.mg-1, 9.56 and 43.31 mg.kg-1, respectively; at filling stage, the Fe concentrations in iron plaque of Japonica in SM and WC were 0.89 and 1.00 mg.mg-1, and those of Indica were 0.63 and 0.30 mg.mg-1; in all practices, the mean Cd concentrations in iron plaque and root of Japonica were 15.23 and 73.68 mg.kg-1, and those of Indica were 3.46 and 52.38 mg.kg-1; at harvest stage, the Fe concentration in iron was plaque of Indica in TF was 1.21 mg.mg-1 and that of Japonica was 0.65 mg.mg-1, but that of Japonica in SM was 0.94 mg.mg-1 and that of Indica in SM was 0.55 mg.mg-1; the Cd concentration in iron plaque of Japonica in WC was 7.96 mg.kg-1, and that of Indica was 5.09 mg.kg-1; the mean Cd concentration in root of Japonica was 54.53 mg.kg-1 and that of Indica was 35.91 mg.kg-1 in all practices.

Cadmium↗