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1.
Interaction of salinity （NaCI） and cadmium （Cd） on growth, mineral nutrients, Na and Cd accumulation in four barley genotypes differing in salt tolerance was studied in a hydroponic experiment. Cd, NaCI and their combined stresses reduced Ca and Mg concentrations in roots and shoots, K concentration in shoots, increased K and Cu concentrations in roots relative to control, but had non-significant effect on micronutrients Cu, Fe and Mn concentrations in shoot. The three stresses reduced accumulation of most tested nutrients in both roots and shoots, except NaCI and NaCl＋Cd stresses for root K and shoot Cu accumulation in salt tolerant genotypes. The salt tolerant genotypes did not have higher nutrient concentration and accumulation than the sensitive ones when exposed to Cd and NaCI stresses. In conclusion, the affecting mechanism of Cd stress on nutrients was to some extent different from salinity stress, and the NaCl＋Cd stress was not equal to additional Cd and NaCI stresses, probably due to the different valence and competitive site of Na^＋ and Cd^2＋. NaCI addition in the Cd-containing medium caused remarkable reductions in both Cd concentration and accumulation, with the extent of reduction being also dependent on genotypes. The salt-tolerant genotypes had lower Na concentration than sensitive ones.  相似文献   

2.
Objective: In addition to pH regulation, Na+/H+ exchange (NHE) has been shown to facilitate cell growth and proliferation. However, the effects of long-term inhibition of Na+/H+ exchange on cardiac structural and functional remodeling post myocardial infarction (MI) are still controversial. The present study was therefore carried out to further investigate the effects of long-term treatment with cariporide, a specific inhibitor of NHE-1, on cardiac remodeling after MI in rats; Methods: Male Wistar rats that underwent coronary ligation were randomly selected for cariporide treatment starting 6 h after induction of MI or no treatment. Treatment was continued up to 6 weeks post MI, after which, the arterial, venous and left ventricular catheters were chronically implanted. Twenty-four h later, after hemodynamic signals were recorded in conscious rats, they were sacrificed and hearts were taken out for morphological examinations; Results: Cariporide treatment decreased the heart weight and heart weight to body weight ratio (bothP<0.05), decreased left ventricular end-diastolic pressure (P<0.001), improved myocardial contractility (dP/dt max) (P<0.05) and tended to increase the survival of treated rats compared to that of untreated infarct rats; Conclusion: The results of the present study indicate that the long-term inhibition of NHE with cariporide can attenuate cardiac structural remodeling and improve left ventricular dysfunction in infarcted rats, and suggest that Na+/H+ exchange inhibition could be an effective therapeutic strategy for myocardial infarction-induced heart failure.  相似文献   

3.
Transgenic Brassica compestris L.spp.chinensis plants expressing a choline oxidase(codA) gene from Arthrobacter globiformis were obtained through Agrobacterium tumefaciens-mediated transformation.In the transgenic plants,codA gene expression and its product transportation to chloroplasts were detected by the enzyme-linked immunosorbent assay(ELISA) examination,immunogold localization,and 1 H-nuclear magnetic resonance( 1 H-NMR) . Stress tolerance was evaluated in the T3 plants under extreme temperature and salinity conditions.The plants of transgenic line 1(L1) showed significantly higher net photosynthetic rate(Pn) and Pn recovery rate under high(45°C,4 h) and low temperature(1°C,48 h) treatments,and higher photosynthetic rate under high salinity conditions(100,200,and 300 mmol/L NaCl,respectively) than the wild-type plants.The enhanced tolerance to high temperature and high salinity stresses in transgenic plants is associated with the accumulation of betaine,which is not found in the wild-type plants.Our results indicate that the introduction of codA gene from Arthrobacter globiformis into Brassica compestris L.spp.chinensis could be a potential strategy for improving the plant tolerance to multiple stresses.  相似文献   

4.

Salinity affects more than 6% of the world’s total land area, causing massive losses in crop yield. Salinity inhibits plant growth and development through osmotic and ionic stresses; however, some plants exhibit adaptations through osmotic regulation, exclusion, and translocation of accumulated Na+ or Cl-. Currently, there are no practical, economically viable methods for managing salinity, so the best practice is to grow crops with improved tolerance. Germination is the stage in a plant’s life cycle most adversely affected by salinity. Barley, the fourth most important cereal crop in the world, has outstanding salinity tolerance, relative to other cereal crops. Here, we review the genetics of salinity tolerance in barley during germination by summarizing reported quantitative trait loci (QTLs) and functional genes. The homologs of candidate genes for salinity tolerance in Arabidopsis, soybean, maize, wheat, and rice have been blasted and mapped on the barley reference genome. The genetic diversity of three reported functional gene families for salt tolerance during barley germination, namely dehydration-responsive element-binding (DREB) protein, somatic embryogenesis receptor-like kinase and aquaporin genes, is discussed. While all three gene families show great diversity in most plant species, the DREB gene family is more diverse in barley than in wheat and rice. Further to this review, a convenient method for screening for salinity tolerance at germination is needed, and the mechanisms of action of the genes involved in salt tolerance need to be identified, validated, and transferred to commercial cultivars for field production in saline soil.

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5.
The effects of salinity(50 mmol/L NaCl) and Cd(1 μmol/L CdCl2) as sole and combined on growth and photosyn-thetic parameters were studied using two soybean genotypes,Huachun 18 and NGB.The concentrations of Cd2 ,Zn2 ,Ca2 ,Mg2 ,K and Na were also determined in seeds and pods.Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate(Pn) in the treatments of salinity stress alone and combined stress(NaCl Cd),showing that it is relatively sensitive to salinity.The decrease in Pn caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency(the ratio of variable fluorescence to maximal fluorescence,Fv/Fm),whereas the decease in NGB was mainly related to reduced stomatal conductance(Gs).The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone.Greater change in the pod concentrations of Zn2 ,Ca2 ,Mg2 ,K and Na was detected under salt stress for Huachun 18 than for NGB.The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes.  相似文献   

6.
Alkaloids are plant secondary metabolites that are widely distributed in Nicotiana species and contribute greatly to the quality of tobacco leaves. Some alkaloids, such as nornicotine and myosmine, have adverse effects on human health. To reduce the content of harmful alkaloids in tobacco leaves through conventional breeding, a genetic study of the alkaloid variation among different genotypes is required. In this study, alkaloid profiles in leaves of five Nicotiana tabacum cultivars and Nicotiana tomentosiformis were investigated. Six alkaloids were identified from all six genotypes via gas chromatograph-mass spectrometry (GC-MS). Significant differences in alkaloid content were observed both among different leaf positions and among cultivars. The contents of nornicotine and myosmine were positively and significantly correlated (R 2=0.881), and were also separated from those of other alkaloids by clustering. Thus, the genotype plays a major role in alkaloid accumulation, indicating a high potential for manipulation of alkaloid content through traditional breeding.  相似文献   

7.
Pepsin was assembled on the surface of prepared poly (ethylene terephthalate) (PET-NH3 +) substrates. The composition and structure of the pepsin/PET-NH3 + assembling films in different condition were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM).  相似文献   

8.
Zinc (Zn) is an essential micronutrient for humans, but Zn deficiency has become serious as equally as iron (Fe) and vitamin A deficiencies nowadays. Selection and breeding of high Zn-density crops is a suitable, cost-effective, and sustainable way to improve human health. However, the mechanism of high Zn density in rice grain is not fully understood, especially how Zn transports from soil to grains. Hydroponics experiments were carried out to compare Zn uptake and distribution in two different Zn-density rice genotypes using stable isotope technique. At seedling stage, IR68144 showed higher 68Zn uptake and transport rate to the shoot for the short-term, but no significant difference was observed in both genotypes for the long-term. Zn in xylem sap of IR68144 was consistently higher, and IR68144 exhibited higher Zn absorption ratio than IR64 at sufficient (2.0 μmol/L) or surplus (8.0 μmol/L) Zn supply level. IR64 and IR68144 showed similar patterns of 68Zn accumulation in new leaves at seedling stage and in developing grains at ripening stage, whereas 68Zn in new leaves and grains of IR68144 was consistently higher. These results suggested that a rapid root-to-shoot translocation and enhanced xylem loading capacity may be the crucial processes for high Zn density in rice grains.  相似文献   

9.
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10.
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11.
浅议植物组织培养技术在药用植物生产上的应用   总被引：2，自引：0，他引：2  
本文结合药用植物的生产状况,概述了植物组织培养技术在药用植物的种质资源保存、品种选育、快速繁殖与脱毒苗生产、次生代谢物生产等方面的应用。  相似文献   

12.
The genetic diversity and relationship among 40 elite barley varieties were analyzed based on simple sequence repeat (SSR) genotyping data. The amplified fragments from SSR primers were highly polymorphic in the barley accessions investigated. A total of 85 alleles were detected at 35 SSR loci, and allelic variations existed at 29 SSR loci. The allele number per locus ranged from 1 to 5 with an average of 2.4 alleles per locus detected from the 40 barley accessions. A cluster analysis based on the genetic similarity coefficients was conducted and the 40 varieties were classified into two groups. Seven malting barley varieties from China fell into the same subgroup. It was found that the genetic diversity within the Chinese malting barley varieties was narrower than that in other barley germplasm sources, suggesting the importance and feasibility of introducing elite genotypes from different origins for malting barley breeding in China.  相似文献   

13.
Drought,flood,salinity,or a combination of these limits rice production.Several rice varieties are well known for their tolerance to specific abiotic stresses.We determined genetic relationship among 12 rice varieties including 9 tolerant to drought,flood,or salinity using inter-simple sequence repeat (ISSR) markers.Based on all markers,the nine tolerant varieties formed one cluster distinct from the cluster of three control varieties.The salt-tolerant varieties were closest to two flood-tolerant varieties,and together they were distinct from the drought-tolerant varieties.(GA)8 YG was the most informative primer,showing the highest polymorphic information content (PIC) and resolving power (Rp).The drought-,flood-,and salt-tolerant varieties grouped in three distinct clusters within the group of tolerant varieties,when (GA)8 YG was used.Sabita was the only exception.The two aus varieties,Nagina22 and FR13A,were separated and grouped with the drought-and flood-tolerant varieties,respectively,but they were together in dendrograms based on other primers.The results show that ISSR markers associated with (GA)8 YG delineated the three groups of stress-tolerant varieties from each other and can be used to identify genes/new alleles associated with the three abiotic stresses in rice germplasm.  相似文献   

14.
Ammonium affects cell viability to inhibit root growth in Arabidopsis   总被引：1，自引：0，他引：1  
Ammonium (NH4 +) is an important form of nitrogen nutrient for most plants, yet is also a stressor for many of them. However, the primary events of NH4 + toxicity at the cellular level are still unclear. Here, we showed that NH4 + toxicity can induce the root cell death in a temporal pattern which primarily occurs in the cells of root maturation and elongation zones, and then spreads to the cells in the meristem and root cap. The results from the NH4 +-hypersensitive mutant hsn1 further confirmed our findings. Taken together, NH4 + toxicity inhibits primary root growth by inhibiting cell elongation and division and inducing root cell death.  相似文献   

15.
不同烤烟品种(系)苗期生长发育特性研究   总被引：1，自引：0，他引：1  
研究并比较了10个不同烤烟品种（系）苗期生长发育特性的差异．结果表明，10个（系）品种的出苗时间为10～13d，其中出苗时间最短的为DL04，云烟85与云烟87，而最长为DL01，红大与云97．不同烤烟品种苗期不同阶段的单株生物量及其累积速率明显不同，其中累积最快的发育阶段随品种而异，但累积最慢的时期大多为6至7叶期．从4叶期到13叶期，云97烟的生物量增长最多，而DL03增长最少；多数品种苗期根占全株的比重先是增加，然后下降，茎所占的比重随植株的发育而持续增加，而叶则持续下降．此外，不同烤烟品种叶片体内硝酸还原酶活性在苗期不同发育阶段存在差异，其中绝大多数品种烟苗的硝酸还原酶活性在后期达到最大，但DL02与云87烟却在前期达到最大。  相似文献   

16.
纳米银对黄瓜和小麦的毒性效应研究   总被引：1，自引：0，他引：1  
研究目的：研究纳米银对黄瓜和小麦的毒性及在植物中的转运和分布,探讨其毒性机制,为纳米银的环境风险评估提供科学依据。创新要点：1.选取单子叶和双子叶植物为对象,比较研究纳米银对其萌发阶段和生长阶段的毒性效应及其影响因素;2.多数研究中的纳米银均有表面修饰,本研究选择无表面修饰的纳米银材料,排除表面活性剂的干扰因素;3.以络合剂半胱氨酸掩蔽解离出的银离子,探讨纳米银颗粒对植物毒性的贡献。研究方法：通过植物根长（图2）和生物量（图3）分别评价萌发和生长阶段纳米银的植物毒性。利用电感耦合等离子体质谱（ICP-MS）测定植物组织银元素的含量（图7）。通过组织切片,利用透射电镜（TEM）观察植物根中银的微观分布（图6）。通过在暴露介质中添加半胱氨酸掩蔽银离子来评价纳米银颗粒对植物毒性的贡献（图3和5）。重要结论：在较高暴露浓度情况下,纳米银和银离子对小麦和黄瓜都具有明显的毒性。但当纳米银浓度低于200 mg/L,银离子浓度低于5 mg/L时,两者均能促进黄瓜根系的生长。两种植物在营养生长阶段比萌发阶段对纳米银的毒性更敏感。纳米银暴露后,银首先积聚于植物的根,然后被转移到地上部。为评价纳米银释放的银离子的作用,我们测定了暴露后介质中银离子的浓度。在种子萌发阶段,黄瓜和小麦的暴露液中约0.03%和0.01%的纳米银溶解,而在营养生长阶段,溶解的纳米银达到0.17%和0.06%。半胱氨酸作为银离子的强络合剂,能够彻底消除纳米银对黄瓜和小麦的作用,说明纳米银的植物效应可能来自于其释放的银离子。  相似文献   

17.
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18.
The Admitted Student Questionnaire Plus (ASQ+) is a standardised measure that provides an analysis of the student's college selection process. Among other things, the instrument inquires about the importance of 16 college characteristics, followed by quality ratings of specific colleges that the student considered on these same characteristics. This study investigated the utility of importance weights in the assessment of college choice, examining how much the importance rating would improve one's ability to predict the student's actual college choice over and above what is possible with just the quality ratings. Another purpose of the study was to determine if importance ratings and quality ratings were independent of each other or associated in some way. Two types of weights were studied: (1) standardised weights created by averaging the importance ratings of the entire sample; and (2) subjective weights unique to each respondent. The weights were combined with quality ratings by either: (1) multiplying the quality rating by the importance rating; or by (2) subtracting the quality rating from the importance rating (gap score). Standardised weights did not improve prediction at all, and subjective weights only improved the predictability of college choice by a very miniscule amount (about 1%). Importance and quality ratings were found to be associated, especially in the ratings of the college that the student decided to attend. Some correlations were linear in nature, but many were non-linear, such that characteristics rated high or low were perceived as more important than characteristics assigned mid-range quality ratings. It was concluded that importance weights do not enhance prediction of college choice, but they may be useful for administrators in prioritising interventions.  相似文献   

19.
Insect resistance and glyphosate tolerance have been two of the most important traits in the genetic improvement of various crops. In this study, two Bacillus thuringiensis (Bt) insecticidal genes, Cry1Ac and Cry1Ig, and a modified glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene (G10) were combined into a single transferred DNA (T-DNA) fragment and introduced into rice by Agrobacterium-mediated transformation. A transgenic line with single-copy T-DNA insertion named GAI-14 was found to be highly resistant to striped stem borer and rice leaf roller, and tolerant to glyphosate. Analysis of T-DNA border sequence suggested that the transgenes were inserted at the chromosome 3 and appeared to have not interrupted any known or putative genes. A field trial observed no significant difference in the basic agronomic traits between GAI-14 and the recipient rice.  相似文献   

20.
In the late phase of Bombyx mori nucleopolyhedrovirus (BmNPV) infection, a large amount of polyhedra appear in the infected cell nucleolus, these polyhedra being dense protein crystals protecting the incorporated virions from the harsh environment. To investigate whether the foreign protein could be immobilized into the polyhedra of BmNPV, two recombinant baculoviruses were generated by a novel BmNPV polyhedrin-plus (polh+) Bac-to-Bac system, designated as vBmBac(polh+)-enhanced green fluorescent protein (EGFP) and vBmBac(polh+)-LacZ, which can express the polyhedrin and foreign protein simultaneously. Light microscopy analysis showed that all viruses produced polyhedra of normal appearance. Green fluorescence can be apparently detected on the surface of the vBmBac(polh+)-EGFP polyhedra, but not the BmNPV polyhedra. Fluorescence analysis and anti-desiccation testing confirmed that EGFP was embedded in the polyhedra. As expected, the vBmBac(polh+)-LacZ polyhedra contained an amount of LacZ and had a higher β-galactosidase activity. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting were also performed to verify if the foreign proteins were immobilized into polyhedra. This study provides a new inspiration for efficient preservation of useful proteins and development of new pesticides with toxic proteins.  相似文献   

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