Changes of sensitive microbial community in oil polluted soil in the coastal area in Shandong, China for ecorestoration.

Oil spills have an important threat to the ecological security and human health, for example the important oil field and coastal wetland Yellow River Delta is facing the dual problems of oil pollution and salinization. Therefore, the purpose of this study was to analyze the changes of soil microbial community and physicochemical properties, including pH value, total organic carbon (TOC), total petroleum hydrocarbons (TPHs) and electrical conductivity under the combined effect of petroleum and salinization. The soil properties results showed that the petroleum addition promoted the increase of TOC from 2.31 ± 0.59 mg/kg to 7.04 ± 0.42 mg/kg (r > 0.95, P < 0.1, R2 > 0.9), TPHs from 9.18 ± 0.07 mg/kg to 33.09 ± 4.61 mg/kg (r > 0.9, P < 0.05, R2 > 0.9) significantly. At the initial stage hydrocarbons caused the increase of soil salt content and the decrease of pH. Salt addition increased soil salt from 2.46 ± 0.13 g/kg to 15.12 ± 0.21 g/kg (r > 0.8, P > 0.1, R2 > 0.95), but it had no direct effect on other soil properties. It was found that the nitrate reducing bacteria Halorhodospiraceae with potential petroleum degradation ability and the anaerobic bacteria Lactobacilliceae appeared after adding crude oil. The salt tolerant bacteria Halobacilli and the stone oil degrading bacteria Immundisolidcharacter appeared in the high salt and low salt environments respectively. The aerobic bacteria Acidimicrobiaceae, Hyphomonas and the nonoil efficient Peptoccaceae disappeared in the process of salinization and oil pollution. Lactobacilliceae can ferment carbohydrate, fatty acid or ester to produce lactic acid, acetic acid and fumaric acid to provide metabolic substrate for other microorganisms. The above results showed that sensitive microorganisms were easy to be affected by pollution to indicate soil conditions, while tolerant microorganisms could potentially use oil to achieve bioremediation. The soil properties and microbial results provided data support and theoretical basis for further understanding the pollution mechanism of oil and salinization combined stress on soil.

Salinity Tolerance Mechanism of Osmotin and Osmotin-like Proteins: A Promising Candidate for Enhancing Plant Salt Tolerance.

INTRODUCTION: Salt stress is one of the most important abiotic stress factors which severely affect agricultural production. Osmotins and OLPs (osmotin like proteins) are kinds of proteins which were produced during plant adapting to the environmental stress. OBJECTIVE: These proteins were closely related to osmotic regulation and resistance stress. They are widely distributed in plants. Their expression for these genes was induced by salt stress, which played important roles in plants responding to salt stress. CONCLUSION: During salt stress, osmotin can help accumulate proline, and quench reactive oxygen species and free radicals.

The therapeutic effect of hydrogen-rich saline on the rheological behavior of leukocytes in mesentery capillary of rats with high-voltage electrical burn / 国际检验医学杂志

Objective To investigate the therapeutic effect of hydrogen-rich saline on the rheological behavior of leukocytes in mesentery capillary of rats with high-voltage electrical burn .Methods 180 rats were randomly divided into four groups :burn injury plus normal saline group ,burn injury plus hydrogen-rich saline group ,sham plus normal saline group ,and burn injury plus papaver-ine group .The rats were received saline ,hydrogen-rich saline ,saline ,papaverine at different time points after scald respectively .The changes of rheological behavior of leukocytes in mesentery capillary of rats before and after the injury were investigated .Results The rheological behavior of leukocytes in mesentery capillary of the control group were observed no significant change (P>0 .05) . In experimental group the rolling white blood cell count ,the number of leukocyte adhesion ,the length of contact of leukocyte-endo-thelial cell at each phase after injury were higher than those at 15 min before injury (P<0 .05);leukocyte rolling speed after injury is lower than that before injury (P<0 .05) .In treatment group and positive control group ,the rolling white blood cell count ,the number of leukocyte adhesion ,the length of contact of leukocyte-endothelial cell at each phase after injury were higher than those at 15 min before injury (P<0 .05) ,but compared with the experimental group ,the increase range was lower (P<0 .05) .leukocyte rolling speed after injury is lower than that before injury (P<0 .05) ,and compared with the experimental group ,the reduction was lower (P<0 .05) .Conclusion The hydrogen-rich brine can effectively reduce the changes of rheological behavior of leukocytes in mesentery capillary of rats caused by high-voltage electrical burn ,and have a protective effect on rat mesenteric .

Carbon sequestration and Jerusalem artichoke biomass under nitrogen applications in coastal saline zone in the northern region of Jiangsu, China.

Agriculture is an important source of greenhouse gases, but can also be a significant sink. Nitrogen fertilization is effective in increasing agricultural production and carbon storage. We explored the effects of different rates of nitrogen fertilization on biomass, carbon density, and carbon sequestration in fields under the cultivation of Jerusalem artichoke as well as in soil in a coastal saline zone for two years. Five nitrogen fertilization rates were tested (in guream(-2)): 4 (N1), 8 (N2), 12 (N3), 16 (N4), and 0 (control, CK). The biomass of different organs of Jerusalem artichoke during the growth cycle was significantly higher in N2 than the other treatments. Under different nitrogen treatments, carbon density in organs of Jerusalem artichoke ranged from 336 to 419gCkg(-1). Carbon sequestration in Jerusalem artichoke was higher in treatments with nitrogen fertilization compared to the CK treatment. The highest carbon sequestration was found in the N2 treatment. Soil carbon content was higher in the 0-10cm than 10-20cm layer, with nitrogen fertilization increasing carbon content in both soil layers. The highest soil carbon sequestration was measured in the N2 treatment. Carbon sequestration in both soil and Jerusalem artichoke residue was increased by nitrogen fertilization depending on the rates in the coastal saline zone studied.

Soil characterization and differential patterns of heavy metal accumulation in woody plants grown in coal gangue wastelands in Shaanxi, China.

Soil contamination by heavy metals in coal mine wastelands is a significant environmental issue in most developing countries. The purpose of this study is to evaluate contamination characteristics in the coal mine wastelands of Sanlidong coal mine, Tongchuan, China. To achieve this goal, we conducted field sampling work, followed by further analysis of the properties of soil contamination and accumulation characteristics in woody plants. At this site, the pH value ranged from 4.41 to 7.88, and the nutrient content of the soil rose gradually with the time after deposition due to the weathering effect improving the soil quality. Meanwhile, the levels of Cd, Cr, Cu, Ni, and Zn gradually decreased with the passage time. Generally, heavy metal contamination was found to be more serious in the discharge refuse area, with Cd contamination at moderate or heavy levels; Ni, Zn, and Cu contamination at light levels; and with no Cr contamination. The geoaccumulation index (I geo) was highest for Cd (2.38-3.14), followed by Ni, Zn, Cu, and Cr. Heavy metals accumulated on the lower slopes and spread to the surrounding areas via hydrodynamic effects and wind. According to transfer and enrichment coefficient analyses, Robinia pseudoacacia, Ulmus pumila, and Hippophae rhamnoides with considerable biomass could be used as pollution-resistant tree species for vegetation restoration. This study provided a theoretical basis for the restoration of the ecological environment in the mining area. This report described a link between heavy metal contamination of soils and growth dynamics of woody plants in China.

Effects of Early Treatment with Mouse Nerve Growth Factor on Wound Healing in Aged Patients with Elec-tric Burn / 中国药房

OBJECTIVE:To explore the effects of early treatment with mouse nerve growth factor on the wound healing in aged patients with electric burn. METHODS:78 elderly patients with electric burn were divided into control group and observation group by random number table method,with 39 cases in each group. Control group was given routine method for electric burn, and observation group was additionally given Mouse nerve growth factor for injection 30 μg dissolved in 2 ml 0.9% Sodium chlo-ride injection within 24 h,im,qd,on the basis of control group. Treatment course of 2 groups lasted for 2 weeks. Clinical effica-cies of 2 groups were compared as well as VAS score before treatment,3,5,7 days after treatment. The survival rate of skin flaps and the rate of wound healing 3,5,7 days after treatment,the recovery of wound scar,the value of wound blood perfusion,the time of complete wound healing and the occurrence of ADR were also compared. RESULTS:The total effective rate of observation group(94.9%)was significantly higher than that of control group(66.7%),with statistical significance(P<0.05). 3,5,7 days after treatment,VAS score of observation group was significantly lower than that of control group,and the survival rate of skin flaps and the rate of wound healing were significantly higher than those of control group,with statistical significance(P<0.05). Af-ter treatment,VSS score of observation group was significantly lower than that of control group,while the value of wound blood perfusion was significantly higher than that of control group;the time of complete wound healing was significantly lower than that of control group,with statistical significance (P<0.05). No obvious ADR was found in 2 groups. CONCLUSIONS:Early treat-ment with mouse nerve growth factor for elderly patients with electric burns can effectively lower the VAS and VSS score,improve the survival rate of skin flaps and the rate of wound healing,increase the value of wound blood perfusion and shorten the time of complete wound healing with good clinical efficacy and safety.

Effects of modified Sijunzi decoction on the expression of p53 and Bcl-2 in burn-induced esophageal lesion / 中国生化药物杂志

Objective To establish burn-induced esophageal lesion model by adding NaOH with different concentrations in rabbits, and investigate the effect of modified sijunzi decoction on the p53 and Bcl-2.Methods After injection with different concentrations of NaOH, esophagus was dissected and observed anatomically.Rabbits were given a gavage of modified Sijunzi decoction daily for 20 days, and then were injected with NaOH.Esophageal epithelium isolated from each group was observed by hematoxylin-eosin staining.p53 and Bcl-2 protein and mRNA expression was measured with western blot and qRT-PCR, respectively.Results The degree of corrosion of esophageal epithelium was positively correlated with the concentration of NaOH.p53 protein and mRNA levels were increased after NaOH challenge; this increase was inhibited by treatment with modified Sijunzi decoction.Additionally, NaOH decreased Bcl-2 protein and mRNA, which was attenuated by modified Sijunzi decoction.Conclusion Modified sijunzi decoction can relieve the esophageal alkali burning in a dose-dependent manner, suggesting that modified Sijunzi decoction may be a useful strategy to treat chemical injuries in esophageal tissue.

Gene regulation of iron-deficiency responses is associated with carbon monoxide and heme oxydase 1 in Chlamydomonas reinhardtii.

Carbon monoxide (CO) as an endogenous gaseous molecule regulates a variety of biological processes in animals. However, CO regulating nutrient stress responses in green alga is largely unknown. On the other hand, heme oxydase (HO1 as a rate-limiting enzyme of the first step for heme degration and to catalyze heme into biliverdin (BV), which is concomitant with releasing of CO and ferrous ions, probably participates in the process of CO-regulating response to nutrient stress in green alga. In this paper, we described an observation that CO could regulate iron-homeostasis in iron-starving Chlamydomonas reinhardtii. Exogenous CO at 8 µM was able to prevent the iron deficient-inducing chlorosis and improve chlorophyll accumulation. Expression pattern of FOX1, FTR1 and ferredoxin was up-regulated by CO exposure in iron-deficient mediam. treatment with external CO increasing iron accumulation in iron-deficient C. reinhardtii. Moreover, to get insights into the regulatory role of HO1, we constructed a transgenic alga overexpressing HO1 and HO1 knock-out mutants. The results show that there was no significant influence on chlorosis with HO1 overexpression of C. reinhardtii under iron-deficiency and the chlorophyll accumulation, and gene expression associated with iron deficiency of mutant were greatly improved. Otherwise, those results from HO1 knock-out mutants were opposite to HO1 overexpression mutants. Finally, CO exposure induced NO accumulation in cells. However, such an action could be blocked by NO scavenger cPTIO. These results indicate that CO/HO1 may play an important role in improving green algae adaptation to iron deficiency or cross-talking with NO under the iron deficiency.

Advances and prospects: biotechnologically improving crop water use efficiency.

Bio-water saving can be defined as the reduction of crop water consumption employing biological measures. This is the focus of efforts to save water in agriculture. Different levels of water-use efficiency (WUE) have been developed. The genetic diversity of WUE has been confirmed in several crops. WUE is the basis of bio-watering and physiological WUE is the key. The degree to develop physiological WUE potential decides the performance of bio-watering in the field. During this process, fine management is important. Thus bio-watering is closely related to WUE. Crop WUE has improved and evolved as a result of breeding programs. Many WUE genes have been located in different genomic and aneuploid materials and have been mapped by various molecular markers in a number of crops. Two genes, (Erecta and alx8), which control water use efficiency; have been cloned in Arabidopsis thaliana. Eleven WUE genes have been identified by microarray analysis. Six genes associated with drought resistance and photosynthesis have been transfered into crops which have resulted in improving WUE and drought resistance. WUE is important on the basis of functional identification of more drought resistant gene resources. The popularity on the industrial-scale of transgenic plants is still in its infancy and one of the reasons for this is the lack of knowledge regarding molecular mechanisms and it is a very immature technology. Enhanced agricultural practices and the theoretical aspects of improving crop WUE have been developed and are discussed in this review paper. Rapid progress will be made in bio-water savings and that crop WUE can be substantially improved under both favorable and unfavorable water-limited environments. This will be achieved by a combination of traditional breeding techniques and the introduction of modern biotechnology.

Pentoxifylline for random flap survival: Evaluation using laser-Doppler blood reperfusion image / 中国组织工程研究

BACKGROUND: Pentoxifylline (PTX), as an effective drug to improve blood rheology, has been used as a vasodilator for the treatment of vascular diseases and peripheral vascular disease science 1960s. But the role of PTX on skin blood flow to improve flap survival remains still unclear. OBJECTIVE: Through the clinical application of PTX therapy, the dynamic observation of random flap to understand that the PTX can promote flap survival and improve blood circulation of flap. METHODS: A total of 39 patients (27 males and 12 females aging 7-54 years) with skin tissue defect undergoing random flap repairing were selected from Department of Burn and Plastic Surgery, First Hospital of Hebei Medical University. The 39 cases were randomly divided into control group and drug group. Patients in the drug group were given intravenous injection of 250 mL PTX at day 2 after random flap operation, once a day, until 14 days after flap repairing surgery. On the first day after flap pedicle surgery, 250 mL PTX sodium chloride injection was intravenously given, once a day, until 7 days after flap pedicle surgery. The control group was not given PTX treatment. The value of blood perfusion (PU) was measured using laser-Doppler blood reperfusion image after flap transplantation, before and after pedicle division. RESULTS AND CONCLUSION: All 39 patients were completely cured and discharged, with no interruption experiments. Before pedicle division, PU value at distal flap in both drug and control groups were increased obviously, and the PU value in the drug group was significantly higher than control group (P < 0.05); after pedicle division, the PU value in the two groups were decreased, and there was no significant difference between the two groups (P > 0.05). Prior to pedicle division, the PU value of pedicle was gradually decreased and then increased in the drug group, and that in the control group was gradually increased. On the seventh day, the PU value of pedicle was stable in the drug group, and there was no significant difference between the two groups (P> 0.05); after pedicle division immediately, the PU values of pedicle were decreased in the two groups, and then the increase in the drug group was remarkable compared to control group (P < 0.05). Two sets of random flaps all survived, and skin defects were successfully repaired after pedicle division. PTX can markedly increase blood perfusion after random flap transplantation, promote flap survival and pedicle division in an early stage, and effectively shorten the healing time.

Random flap microcirculation and pedicle division timing: Can laser Doppler imaging evaluate them? / 中国组织工程研究

BACKGROUND: Random flap as a primary means of wound healing, is widely used at present, its blood circulation to establish the situation is also researched a lot, but not yet the system of random skin flap perfusion were observed and measured. In addition, the timing of pedicle division of a pedicle flap random is also a hot topic, but not yet a mature clinical testing method has been discovered to determine the best timing.OBJECTIVE: By means of laser Doppler blood perfusion imaging, this study was designed to dynamically observe random flap microcirculation, to understand the changes on random flap blood flow, and to determine the best timing of pedicle division. METHODS: A total of 18 cases were divided into traditional pedicle division group and early pedicle division group. Pedicle flap blood perfusion values were statistically measured immediately after surgery, at 3, 7,11,15, and 19 days after surgery, before division, immediately after division, and at 24 hours after pedicle division, 8-9 phases in total.RESULTS AND CONCLUSION: Distal blood perfusion value was increased with the time prolongation in both groups; while, the blood perfusion in various time phases was significantly different from that after surgery (P < 0.05); but, the blood perfusion was decreased immediately after surgery, which was still significantly compared with traditional pedicle division group (P< 0.05). There was no significant different in blood perfusion between early pedicle division and immediate after surgery of pedicle division (P > 0.05), but there was significant difference between 24 hours after pedicle division and immediate after surgery of pedicle division (P< 0.05). Blood perfusion values were less changed in both groups (P> 0.05). The ratio of both groups peaked before pedicle division and then gradually decreased after pedicle division. The best timing of pedicle division was the ratio of 1.2.

The effects of proanthocyanidins on antidepressant-like behaviors and the adrenal gland in chronic stress rats / 中华行为医学与脑科学杂志

Objective To investigate the effects of proanthocyanidins on depressant-like behaviors and the structure of adrenal gland in chronic unpredictable mild stress (CUMS) rats. Methods Rats were randomly divided into 6 groups:control group, stressed group (CUMS + vehicle), three treatment groups (CUMS + proanthocyanidins 25,50,100 mg·kg-1,respectively) ,and imipramine group (CUMS + imipramine 10 mg·kg-1). Used the CUMS model in rats to investigate the effects of chronic oral administration (21 days) of proanthocyanidins and imipramine (ip) on the open-field;and forced swimming and sucrose consumption tests and the ratio of adrenal gland/body weight,and its thickness were examined by HE stain. Results Compared with control group, rats subjected to CUMS exhibited increased ratio of adrenal gland /body weight ( P < 0. 01), less sucrose consumption( P<0.01) and inhibited in the open-field test( P<0.01) as well as more despair time in the forced swimming test( P<0.01). While compared with stressed group,treatments with proanthocyanidins (25,50,100 mg·kg-1, po ,21 days) could significantly improve the activities in open-field test ((39.6±3.4) vs (49±4.5), (52.6±3.7),(54.1±1.8) ;all P<0.01) and sucrose consumption( (5.8±2.5)ml vs (8.1±3.3)ml,(8.5±4.1) ml, (9.2±2.6) ml; P < 0.05, P < 0.05, P < 0.01 respectively); Meanwhile, it could reduce the duration time in forced swimming test significantly( (103.5±10.2)s vs (83.7±8.8)s,(75.8±5.9)s,(67.2±6.5)s; all P<0.01) as well as thickness of the adrenal gland(P<0.05, P<0.01).Conclusions This study suggests that the proanthocyanidins (25,50,100 mg·kg-1) has an antidepressant-like effects in CUMS rats. The antidepressant actions of proanthocyanidins, in some degrees, may be related with the regulation of the adrenal gland's structure.

Random flap experimental study of dynamic changes of blood flow / 中国综合临床

Objective To know the establishment of the flap pedicle blood supply and the right moment of the cutting off of pedicle by means of laser Doppler blood perfusion imaging instrument on the random flap blood flow changes.Methods 20 adult healthy rabbits were divided in to four groups and each 5 have unilateral flaps.1,3,5,7,9,12,14,18 days after operation,the pedicle blood perfusion values (PU) measurement of the distal pedicle on the flap and midpoint of both ends of the pedicle were performed,and PU values were analyzed.Results Pedicle of the PU values at the different time points changed little (P＞0.05).The PU value in the distal flap reached the minimum 1 day after operation and then increased gradually [3 d (1.24±0.07),5 d (1.57±0.15),7 d (1.79±0.08),9 d(1.89±0.13),12 d(2.01±0.16),14 d(2.18±0.09) and 18 d(2.40±0.18),P＜0.05].When distal PU values/pedicle PU value≥1.2,the flap survival rate reached 99%.Conclusions The establishment of random skin flap blood circulation,as well as the ratio of PU values of distal to the pedicle flap pedicle can be used as the timing of an important indicators.

A study on differentially expressed gene screening of Chrysanthemum plants under sound stress.

Environmental stress can induce differential expression of genes of flower plants. It had been found that sound stimulation had an obvious effect on the growth and development of flower plants, but it is not reported on the differentially expressed genes and their expressing characteristics under sound stimulation. This is one of the few reports in terms of using the DDRT-PCR technique for screening the differentially expressed cDNA fragments responding to sound-wave stress on Chrysanthemum. Six differentially expressed cDNA fragments were obtained. Molecular weight of fragments was from 200 to 600 bp, respectively. Among differential fragments acquired, three of them (SA3, SG7-1, and CA2) were found to be positive fragments by northern dot hybridization, whose molecular weight are 270, 580 and 370 bp, respectively. SA3 was differentially expressed and SG7-1 was preferably expressed, while CA2 was restrained by the sound wave. These results indicated that expression of some genes was turned on, meanwhile the stress restrained some genes from expression under the mode of sound-stress stimulation.

Investigation on the relationship between leaf water use efficiency and physio-biochemical traits of winter wheat under rained condition.

Different statistical methods and path analysis were used to study the relationship between leaf water use efficiency (WUE) and physio-biochemical traits for 19 wheat genotypes, including photosynthesis rate (P(n)), stomatal conductance (g(s)), transpiration rate (T(r)), intercellular concentration of carbon oxide (C(i)), leaf water potential (Psi(w)), leaf temperature, wax content, leaf relative water content (RWC), rate of water loss from excised-leaf (RWL), peroxidase (POD) and superoxide dismutase (SOD) activities. The results showed that photosynthesis rate, stomatal conductance and transpiration rate were the most important leaf WUE variables under rained conditions. Based on the results of five statistical analyses, it is reasonable to assume that high leaf WUE wheat under the rained could be obtained by selecting breeding materials with high photosynthesis rate, low transpiration rate and stomatal conductance.

Osmotic regulation of 10 wheat (Triticum aestivum L.) genotypes at soil water deficits.

Drought is a worldwide problem, seriously influencing plant (crop) productivity. Wheat is a stable food for 35% of the world population, moreover about 60% of land area on the globe belongs to arid and semi-arid zone. Wheat drought resistance is a multi-gene-controlling quantitative character and wheat final production in field is realized mainly by physiological regulation under the condition of multi-environmental factor interaction. Exploring drought resistance physiological mechanisms for different wheat genotypes is of importance to finding new drought resistance gene resources and conventional breeding and the basis for wheat drought resistance biotechnological breeding and platform. Osmotic adjustment regulation is the main component for physiological machinery of wheat drought resistance. By pot-cultivating experiments, investigation of osmotic adjustment comparison for 10 wheat genotypes at soil water deficits (75% FC, 55% FC, 45% FC, respectively), was conducted. The main results were as followed: (1) K(+) content in 10 wheat genotypes at three levels of soil water stress and at the same soil water deficit was very different. Five of these 10 wheat genotypes had higher K K(+) content under the condition of 75% FC. (2) Five of these 10 wheat genotypes possessed greater soluble sugar content at 55% FC soil water level. (3) Proline (Pro) content in five wheat genotypes was higher at 75% FC. (4) Five of these 10 wheat genotypes had lower malondialdehyde (MDA) content at 45% FC at seedling stage. Osmotic adjustment of wheat different genotypes was discussed in terms of different content of osmotic solutes.

Does Puccinelia tenuiflora have the ability of salt exudation?

The leaves surface of Puccinelia tenuiflora seedling under stress of different concentration of Na(2)CO(3) was observed with scanning electron microscopy and X-ray electron probe micro analyzer. All the results indicated that varied salts crystalline distributing in stomatal apparatus on P. tenuiflora leaves surface could be observed by means of frozen-dried sampling. In the case of no stress, these leaves had many kinds of sediments such as Na, K, Ca, Mg, Zn, Cu, Cl, P, S, Si on their surface. When there was stress of Na(2)CO(3), the percentage content of each sediment would have an non-linear relationship to stress. As the concentration of Na(2)CO(3) increased, the percentage contents of Na, Cu, Zn, P, S generally decreased while that of K, Ca, Mg, Si generally increased. The ratio of K/Na also changed the same way as the later. From these results, we concluded, under stress of alkali and salts, P. tenuiflora leaves could exude salts through their stomata or together with wax secretion and these ways might participate many regulation process of P. tenuiflora leaves cells, for example in ion balancing, osmosis regulating and water metabolizing.

Changes of anti-oxidative enzymes and MDA content under soil water deficits among 10 wheat (Triticum aestivum L.) genotypes at maturation stage.

Drought is a world-spread problem seriously influencing grain production and quality, the loss of which is the total for other natural disasters, with increasing global climate change making the situation more serious. Wheat is the staple food for more than 35% of world population, so wheat anti-drought physiology study is of importance to wheat production and biological breeding for the sake of coping with abiotic and biotic conditions. Much research is involved in this hot topic, but the pace of progress is not so large because of drought resistance being a multiple-gene-control quantitative character and wheat genome being larger (16,000Mb). On the other hand, stress adaptive mechanisms are quite different, with stress degree, time course, materials, soil quality status and experimental plots, thus increasing the complexity of the issue in question. Additionally, a little study is related to the whole life circle of wheat, which cannot provide a comprehensive understanding of its anti-drought machinery. We selected 10 kinds of wheat genotypes as materials, which have potential to be applied in practice, and measured change of relative physiological indices through wheat whole growing-developmental circle (i.e. seedling, tillering and maturing). Here, we reported the anti-oxidative results of maturation stage (the results of seedling and tillering stage have been published) in terms of activities of POD, SOD, CAT and MDA content as follows: (1) 10 wheat genotypes can be grouped into three kinds (A-C, respectively) according to their changing trend of the measured indices; (2) A group performed better resistance drought under the condition of treatment level 1 (appropriate level), whose activities of anti-oxidative enzymes (POD, SOD, CAT) were higher and MDA lower; (3) B group exhibited stronger anti-drought under treatment level 2 (light-stress level), whose activities of anti-oxidative enzymes were higher and MDA lower; (4) C group expressed anti-drought to some extent under treatment level 3 (serious-stress level), whose activities of anti-oxidative enzymes were stronger, MDA lower; (5) these results demonstrated that different wheat genotypes have different physiological mechanisms to adapt themselves to changing drought stress, whose molecular basis is discrete gene expression profiling (transcriptom); (6) our results also showed that the concept and method accepted and adopted by most researchers [T.C. Hsiao, Plant response to water stress, Ann. Rev. Plant Physiol. 24 (1973) 519-570], that 75% FC is a proper supply for higher plants, was doubted, because this level could not reflect the true suitable level of different wheat genotypes. The study in this respect is the key to wheat anti-drought and biological-saving water agriculture; (7) our research can provide insights into physiological mechanisms of crop anti-drought and direct practical materials for wheat anti-drought breeding; (8) the physiological study of wheat is more urgent up-to-date and molecular aspects are needed, but cannot substitute this important part. The combination of both is an important strategy and a key and (9) POD, SOD and CAT activities and MDA content of different wheat genotypes had quite different changing trend at different stages and under different soil water stress conditions, which was linked with their origin of cultivation and individual soil water threshold.

Investigation on dynamic changes of photosynthetic characteristics of 10 wheat (Triticum aestivum L.) genotypes during two vegetative-growth stages at water deficits.

Drought is a worldwide problem, seriously influencing plant (crop) productivity. Wheat is a stable food for 35% of the world population, and moreover, about 60% of land area on the globe belongs to arid and semiarid zone. Wheat drought resistance is a multi-gene controlling quantitative character and wheat final production in field is realized mainly by physiological regulation under the condition of multi-environmental factor interaction. Exploring drought resistance physiological mechanisms for different wheat genotypes is of importance to finding new drought resistance gene resources and conventional breeding, and the basis for wheat drought resistance biotechnological breeding and platform. Photosynthesis is the main component for physiological machinery of wheat assimilates conversion and wheat production. Investigation on photosynthetic characteristics of different wheat genotypes at soil water deficits also has other implications for refine physiological regulation of photosynthesis in fields and field management of crops in arid and semiarid areas. By pot-cultivating experiments, investigation of photosynthesis for 10 wheat genotypes at seedling stage and tillering stage at soil water deficits (75%FC, 55%FC and 45%FC, respectively) was conducted. The main results were as followed: developmental stages influenced wheat photosynthesis greatly and tillering stage played more roles; there were significant difference in the main photosynthetic parameters, photosynthesis rate (Photo), stomatal conductance (Cond) and transpiration rate (Tr), among 10 wheat genotypes; general photosynthesis and drought resistance in different wheat genotypes was related much to their domesticated origin soil water environment and selected generations and there was a photosynthetic threshold effect in terms of different wheat genotypes at soil water deficits.