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Soil phosphorus (P) deficiency is one of the main factors that diminish the yield of crops on the Loess Plateau. Fagopyrum tataricum is a dominant cereal plant on the Loess Plateau, whose responses to low-P stress are significantly different and dependent on its genotypes. Therefore, screening genotypes with efficient P utilization is an important approach to increase the yield of F. tataricum and promote the sustainable development of local agriculture. With fourteen F. tataricum genotypes, the agronomic traits, physiology and biochemical characters of F. tataricum at seedling stage under normal (2 mmol·L -1 ) and low-P treatment (0.2 mmol·L -1 ) were studied by using sand culture. By examining the characters of selected F. tataricum at seedling stage, the varieties of F. tataricum with low-P tolerance were screened out and their evaluation indices were assessed to provide theoretical basis for the breeding of F. tataricum with high P-efficiency and the infertile soil cultivation on the Loess Plateau. The results showed that under low-P stress, the shoots of all genotypes were more affected than roots, with the decline of shoot aboveground index, average root diameter, root surface area and root volume, whereas the length of main root was elongated. Root activity and soluble protein content were decreased. In contrast, other physiological and biochemical indicators were increased. Moreover, plant total phosphorus content and plant phosphorus accumulation reduced, but phosphorus use efficiency increased. The principal component analysis divided the 22 individual indicators into four mutually independent comprehensive indicators (cumulative contribution rate of 90.1%). Cluster analysis divided 14 kinds of F. tataricum into three categories: Low phosphorus tolerant, intermediate and phosphorus sensitive. In order to investigate the index of low-P tolerance of F. tataricum at seedling stage, the optimal regression equation was established with the comprehensive evaluation value of low-P tolerance (D value) as the dependent variable and the low-P tolerance index of each indicator as the independent variables. Seven indicators of root surface area, root length, plant height, aboveground dry mass, acid phosphatase, phosphorus accumulation and POD activity were examined, which could be used for the rapid identification of low-P tolerance of F. tataricum at seedling stage.

Olfactory adaptation is an important physiological function of animals, which can protect their own neurons from overstimulation, and be better to deal with all kinds of stimuli in the surrounding environment. In this article, we discuss the neuronal basis of olfactory adaptation in Caenorhabditis elegans . Up to now, several intracellular regulatory factors have been discovered to be associated with olfactory adaptation in Caenorhabditis elegans , including cyclic guanosine monophosphate (cGMP) signaling in the olfactory neurons AWC, OSM-9 in transient receptor potential vanilloid (TRPV) channel, arrestin ARR-1, diglyceride (DAG) pathway in G protein signaling pathways, etc. However, the neural circuits of the olfactory adaptation remains largely unknown. This paper reviews molecular and cell biological mechanism of olfactory adaptation in Caenorhabditis elegans , so as to provide reference for studies on olfactory sensation in advanced animals.

Post-translational modifications of histones, such as acetylation and methylation, have a pivotal role in regulating gene expression and cell growth. To elucidate the different roles and importance of H3K4 and H3K36 modifications in expression of inducible genes such as Cal1, SSA3, PHO5 and the growth of yeast cell, we constructed three different yeast mutant strains carrying mutations of lysine 4, 36, or both to leucine in the histone H3 tail. Real-time PCR and sensitive assay under the conditions of high temperature, NaCl, caffeine, 6-AU, or other conditions were carried out to characterize the effects of these mutations on cell growth and transcription levels of GAL1, SSA3 and PHO5. The results showed that three histone methylation mutants exhibited more severe growth defects and slower activation of GAL1, SSA3 and PHO5 than those of wild type; H3K4L/H3K36L double mutant strain D436 has the most severe phenotype. H3K4L mutants S4 exhibited more severe defects than those of H3K36L S36 mutants, especially at high temperature and high NaCl stresses. These results show that H3K4L and H3K36L are important for the growth and survival of yeast in unfavorable conditions, and that different mutations have different effects on the expression of single inducible gene, whereas the same mutation has different effects on the activation of different inducible genes in vivo. The post-translational modification of H3K4 is more important than H3K36 on the adaptation to harsh condition for yeast cell. The growth defects of histone mutant strains might arise from the slow activation of inducible gene essential for survival at harsh conditions.

The adaptive mutations exist widely in the evolution of cells, such as antibiotic resistance mutations of pathogenic bacteria, adaptive evolution of industrial strains, and cancerization of human somatic cells. However, how these adaptive mutations are generated is still controversial. Based on the mutational analysis models under the nonlethal selection conditions, stress-induced cellular adaptive mutagenesis is proposed as a new evolutionary viewpoint. The hypothetic pathway of stress-induced mutagenesis involves several intracellular physiological responses, including DNA damages caused by accumulation of intracellular toxic chemicals, limitation of DNA MMR (mismatch repair) activity, upregulation of general stress response and activation of SOS response. These responses directly affect the accuracy of DNA replication from a high-fidelity manner to an error-prone one. The state changes of cell physiology significantly increase intracellular mutation rate and recombination activity. In addition, gene transcription under stress condition increases the instability of genome in response to DNA damage, resulting in transcription-associated DNA mutagenesis. In this review, we summarize these two molecular mechanisms of stress-induced mutagenesis and transcription-associated DNA mutagenesis to help better understand the mechanisms of adaptive mutagenesis.

To investigate the association between SNPs located in 5'UTR and intron of prolyl hydroxylase 2 (EGLN1 or PHD2) and adaptation to high-altitude hypoxia, the SNPs (rs2066140, rs2808584, rs2491405, rs2486741, rs2486734 and rs21533646) of EGLN1 gene were genotyped using Sequenom MassArray genotyping system in 152 unrelated healthy Tibetan individuals (3 650 m altitude) and 192 Han (5 00 m altitude), and the haplotypes of these SNPs were constructed and analyzed. Our results showed all the homozygous genotypes of six SNPs loci were significantly different between the two groups (P<0.05). The frequencies of haplotypes G-G (rs2066140 and rs2808584) and G-C (rs2486741 and rs2486734) of high-altitude group were significantly different from low-altitude group (P<0.05). In addition, the frequencies of haplotypes C-A (rs2066140 and rs2808584) and C-T (rs2486741 and rs2486734) of high-altitude group were significantly lower than those in low-altitude group (P<0.05). Our results indicate that the polymorphism of homozygous genotype in six SNPs and their haplotypes were associated with adaptation to high-altitude hypoxia.

The cadmium-resistant bacterium Pseudomonas aeruginosa strain ZGKD2 exhibiting tolerance to various heavy-metals was isolated from gangue pile of coal area in our laboratory. This bacterium could serve as an effective metal sequestering and growth-promoting bioinoculant for plants grown in metal-contaminated soil. However, the mechanism of heavy-metal tolerance is still unclear. When the beef extract-peptone medium was supplemented with 200-3 000 micromol x L(-1) Cd2+, Cu2+, Zn2+, Ni2+, Pb2+ or Mn2+, the maximum biomass of strain ZGKD2 decreased with the increase of heavy-metal concentrations, while different concentrations of heavy-metals had no significant effect on its alkaline production. Stationary-phase cells of strain ZGKD2 were exposed to 0, 200, 600 and 1 000 micromol x L(-1) of Cd2+ , Cu2+, Zn2+ and Ni2+ or 0, 1 000, 2 000 and 3 000 micromol x L(-1) of Pb2+ and Mn2+ for 2 h, respectively. The activity of SOD and CAT increased in a heavy-metal-concentration-dependent manner, especially in the Cd2+ and Cu2+ treatments. The siderophore production of strain ZGKD2 in modified sugar-aspartic acid medium was enhanced by 200- 1 000 micromol x L(-1) of various heavy-metals. Cd2+ and Zn2+ strongly induced the siderophore production of strain ZGKD2, Ni2+ and Mn2+ had little effect, whereas Cu2+ led to significant inhibition. The siderophore production of strain ZGKD2 was positively related with its metal tolerance. These results indicated that alkaline production, siderophore production, and the increase of antioxidant enzyme activities in strain ZGKD2 might be the main mechanisms of heavy-metal tolerance.

Taking thirty-seven hexaploid wheat (AABBDD) accessions with different drought resistance at seedling stage, three wheat species with A genome (AA), and three tetraploid wheat species (AABB) as test materials, and by direct sequencing the single nucleotide polymorphism (SNP) in TaCRT-A, this paper analyzed the relationships of the SNP with the drought resistance of wheat ( Triticum aestivum) at its seedling stage, and mapped the TaCRT-A on the chromosome of wheat. The full-length sequence of the TaCRT-A genomic DNA was 3887 bp. A total of 202 nucleotide variant loci were observed in the full length sequence of 167141 bp, among which, 165 SNP and 37 InDel with the frequencies of 1 SNP/1013 bp and 1 InDel/4517 bp were detected, respectively. The nucleotide diversity (pi) in coding region of TaCRT-A was lower than that in non-coding region, suggesting that the selection pressure in coding region was stronger than that in non-coding region. The 43 accessions could be classified as 14 haplotypes (H1-H14) by haploid analysis, among which, H1, H2, and H13 all contained one accession which was the donor species of A genome in common wheat, H16 and H7 had one high drought-resistant accession, H8 comprised tetraploid wheat, drought-resistant accessions, and drought-sensitive accessions, whereas H11 included the wheat accessions with drought-resistance and medium-drought resistance. Though the expression of TaCRT was induced by water stress, no significant relationship was identified between TaCRT-A polymorphism and drought resistance. Using a population of recombinant inbred lines derived from a cross of Opata 85 x W7984, the TaCRT-A was mapped between SSR markers Xmwg30 and Xmwg570 on chromosome 3A, and the genetic distances were 10.5 cM and 49.6 cM from the flanking markers, respectively.

A total of 120 recombinant inbred lines (RIL) derived from Chinese winter wheat cultivars Longjian 19xQ9086 and the two parents were taken as test materials to study the quantitative genetics characteristics of their plant height at different development stages, thousand-grain mass, as well as the correlations between the two traits under rainfed (drought stress) and well-watered conditions, and evaluate the genetic variation of the RIL. Under the two water conditions, the target traits of the RIL showed substantial transgressive segregation and great sensitivity to water condition. The drought stress coefficient of the plant height was higher at jointing stage, being up to 0.851. There was a significant positive correlation between the plant height at different development stages and the thousand-grain mass, and comparing with that at other growth stages, the plant height at jointing stage had a higher correlation coefficient with the thousand-grain mass (R2DS = 0.32, R2WW = 0.28). The plant height at both jointing and flowering stages had significant positive and direct effect but negative and indirect gross effect on the thousand-grain mass, while the plant height at heading and maturing stages was in adverse. The target traits showed a lower heritability ranged from 0.27 to 0.60. The numbers of the gene pairs controlling the thousand-grain mass were 10 under rainfed and 13 under well-watered conditions, while those of the gene pairs controlling the plant height at different development stages were 3-7 under rainfed and 4-14 under well-watered conditions, respectively. According to the clustering of the drought stress coefficient of plant height, the RIL could be classified into five subgroups, showing the abundant variation of the RIL in their phe- notypes and in the sensitivity to water condition. It was considered that the test RIL were appropriate for the study of the quantitative genetics of wheat drought resistance.

In order to investigate the role of the hypoxia inducible factor 1 alpha (HIF-1α) in the adaptation mechanism to high altitude hypoxia, the cloning of the HIF-1α gene cDNA of Tibetan antelope (Pantholops hodgsonii), using RT-PCR and RACE, was applied, and the comparative analysis of the tissue-specific expressions of HIF-1α among Tibetan antelope, Tibetan sheep and plain sheep was performed using real-time PCR and Western blot. The sequence analysis indicated that the cDNA sequences acquired by cloning from the HIF-1α gene of Tibetan antelope comprised a 2 471-bp open reading frame (ORF) and a 1 911-bp 3'UTR. The similarity between its coding sequence, predicted amino acid sequence and HIF-1α of other mammals exceeded 87%, in which the similarity with cow was up to more than 98%, which showed that this sequence was the cDNA of HIF-1α of Tibetan antelope. The results of real-time PCR and Western blot showed that expressions of HIF-1α mRNA and protein appeared in Tibetan antelope's lung, cardiac muscle and skeletal muscle, with the highest expression in lung. HIF-1α mRNA and protein had obvious differential expression in these tissues. Further research showed that Tibetan antelope and Tibetan sheep possessed higher expressions of HIF-1α protein in the three tissues above-mentioned compared with plain sheep, and the expressions of HIF-1α mRNA and protein in Tibetan antelope's lung, cardiac muscle and skeletal muscle were higher than those of Tibetan sheep. It illustrates that the hypoxic HIF-1α-specific expression is one of the molecular bases of high altitude hypoxia adaptation in Tibetan antelope.

Hypoxia-inducible factor (HIF) is an important transcription factor under hypoxic condition in many organisms, and plays a key role in the induction of hypoxia tolerance. It is necessary to establish a hypoxia model for HIF and to perform further hypoxia tolerance research. To investigate the value of Daphnia as a model organism in hypoxia precondition, we developed a preconditioning protocol with a model organism, Daphnia pulex. We found that two episodes of exposure to hypoxic solution resulted in enhanced hypoxia tolerance which is dependent on HIF. Comparative genomic analysis was also made to highlight the homology of HIF-related genes among Daphnia, fruitfly and human. We found that Daphnia is suitable for the study of human hypoxic injury as a model organism.

The horizontal transfer of mobile genetic elements (MGEs) in environmental microbial communities plays an important role in the evolution of bacterial genomes and the adaption of microbial populations to specific environmental stress. Inoculation of the bacterial strains with MGEs with pollutant-degrading gene and the subsequent horizontal transfer of the MGEs to one or various well-established and competitive indigenous bacterial populations in an ecosystem will allow the catabolic gene to be transferred and expressed in indigenous microbial populations, and hence, the survival of the introduced donor strains is no longer needed to be considered. The MGE-mediated bioremediation provides the feasibility for developing new bioremediation strategies. This paper summarized the diversity of MGEs with pollutant-degrading gene in the environment and the important roles of these MGEs in promoting pollutant degradation, introduced the methodological approaches for the isolation of the MGEs from environmental samples, and listed several studies that monitored the horizontal transfer of the MGEs in polluted soil, activated sludge, and other bioreactors.

The genetic adaptation of Plateau residents to hypoxia of low-pressure has been the hot spot for study. In terms of physiology, the adaptation involves the regulation responses of blood vessels, the changes in blood cells, antioxidant capacity and energy metabolism, as well as the hypoxia-induced changes in nuclear transcription. Physiological adaptation is heritable, so people who have already adapted themselves to high altitude are bound to be different, in regard to gene level, from the crowd who have not yet adapted themselves to high altitude environment. For this reason, researchers have studied a great deal of gene related-enzymes, the receptors, polypeptide, as well as transcription factors in body, and they found a number of the DNA polymorphism sites in the people who have adapted themsevles to high altitude being different from those in the people who do not get acclimatized. In this paper is reviewed the newest advance in research of these gene polymorphisms. The data could serve as references for further study of hypoxia genetic adaptation to high altitude.

Based on resistance selection, the life tables of abameetin-resistant (AbR), fenpropathrin-resistant (FeR), and susceptible (S) strains of Tetranychus cinnabarinus at 15 degrees C, 20 degrees C, 25 C, 28 degrees C, 31 degrees C, 34 degrees C, and 36 degrees C were constructed, and the development duration, fertility, and intrinsic rate of increase (r(m)) of the strains were compared, aimed to understand the relative fitness of T. cinnabarinus resistant strains at different temperatures. The results indicated that compared with S strain, AbR and FeR strains had longer development duration at 15 degrees C but lower fertility at 20 degrees C-28 degrees C, and their relative fitness (represented by r(m)) was smaller at 15 degrees C but similar at 20 degrees C - 31 degrees C. For AbR and FeR strains, the fitness cost was moderate at 15 degrees C but lower at 20 degrees C - 31 degrees C. However, at high temperatures ( > or =34 degrees C), FeR strain possessed remarkable fitness cost while AbR strain showed better fitness.

The growth characteristics and the decontamination of heavy metals in analogous heavy metals wastewater by transgenic Synechococcus sp. PCC 7002 with mouse metallothionein-I gene were studied. The results show that transgenic Synechococcus sp. PCC 7002 not only has a higher tolerance to heavy metals, but also has a higher growth rate than wild strain. The concentration of Cd2+, Pb2+ and Hg2+ decreases with the progress of cultivation, and its maximum decreasing extent occurs at 1 - 3 day. After three days of cultivation, the absorption of Cd2+, Pb2+ and Hg2+ by transgenic Synechococcus sp. PCC 7002 is 10.75, 58.89 and 112.61 mg g(-1) of dried cells respectively, which is 3.16, 2.18 and 100.45 times higher than wild cells. The mono-factor and overall model developed fit the experiment data well.

Based on the constructed promoter probe vectors that could replicate both in E. coli and in a cold-adapted bacterium, several candidate promoters were isolated and their activities were evaluated by RT-PCR. The transcription initiation sites and core sequence of promoters were determined by primer extension analysis. A low-temperature expression vector was constructed by using the strongest promoter and a thermolabile alpha-amylase gene was successfully overproduced under control of this promoter at low temperature (7 degrees C), while the secreted alpha-amylase amounted up to 35% of the total extracellular proteins. The expression system is expected to be useful for the production of thermolabile exogenous proteins at low temperatures.

With cDNA from Phellodendron amurense seedlings treated with drought stress as tester and cDNA from this plant in normal growth as driver, we construct cDNA subtracted library using suppression subtractive hybridization (SSH). In the library, the rate of recombination was 95%, the size of inserts was 300-800 bp. Two hundred and sixty-five new genes were obtained by DNA sequencing 816 positive clones picked randomly, and partitioned to 16 classes after nucleotide Blast and BlastX homological analysis against NT, NR, SWISSPROT, KEGG database. Forty-four drought stress associated genes, such as heat shock protein cognate 70, dehydration responsive protein 22, universal stress protein, metallothionein II, late embryogenesis abundant protein, were obtained, which made 16.6% of the overall genes. These genes included osmotic regulator, signal component regulatory protein and antioxidant enzyme. The research had established a basis for cloning stress resistance genes and further studying genes expression in P. amurense seedlings under drought stress.

OsMAPK4 gene was obtained by RT-PCR using gene special primer from Liaoyan241 leaf treated with low temperature. Plant expression vector pBME12 was constructed in which OsMAPK4 gene was regulated by E12 promoter. OsMAPK4 gene was transferred into tobacco via Agrobacterium-mediated method and 25 transgenic plants obtained. The results of drought resistance experiments showed that overexpression of OsMAPK4 gene conferred enhanced drought resistance of T1 transgenic plants. Kanamycin-resistance segregation in T1 transgenic plants showed that the most transgenic lines were in single gene inheritance.

The TFA-type zinc finger protein belongs to C2H2-type zinc finger protein family with the finger structure of CX2-4CX3FX5LX2HX3-5H. Recent studies have shown that TFA zinc finger protein family also play important roles in stress responses. It is being believed that TFA zinc finger protein genes will become another target for engineering the biotech crops with enhanced tolerance to abiotic stress.

Drought and heavy metals contamination greatly affect plant growth, while the cloning and function analysis of stress-inducible genes provide an effective approach to improve the stress tolerance and yield of crops by genetic engineering. The expression of LEA (late embryogenesis abundant protein) gene could be induced by various stresses such as drought, high salinity, cold, and heavy metals. The study on transgenic plants showed that LEA could increase plant tolerance to water stress, had ion-binding activity, and acted as an antioxidant under abiotic stresses. Aquaporins largely presented in plasma membrane and vacuolar membrane, and played a key role in root water uptake and transportation both at cellular and at whole plant level. The expression of aquaporins was up-regulated in response to drought and salinity, and conferred the water stress tolerance in plant. Cation-efflux transport proteins were involved in the absorption, transportation, and accumulation of heavy metals in plants. All of the proteins mentioned above could have potential applied profits on improving the biological water-saving, drought resistance, and heavy metals tolerance of lawny grass.

Objective: To identify differentially expressed genes in human embryo lung fibroblasts MRC-5 with adaptive response induced by low concentration of hydrogen peroxide (H(2)O(2)) using fluorescent differential display-RT-PCR (FDDRT-PCR)., Methods: The dose-effect pattern of H2O2 toxicity was determined using MTT assay, and the dose of 0.088, 0.88, 8.8, 88 micro;mol/L was defined as the low concentration, and 1100 micromol/L as the high concentration. Adaptive response model was established in MRC-5 cells verified using LDH release and cell apoptosis analyses. Differentially expressed genes in the cells with exposure to different doses of H(2)O(2) were detected by FDDRT-PCR, and some of the differentially displayed genes were determined using real-time quantitative PCR., Results: Cells challenged with high-concentration H(2)O(2) for 1 h after H(2)O(2) pretreatment at low concentrations for 24 h resulted in lessened toxic effect in comparison with direct high-concentration H(2)O(2) exposure. The adaptive response of the cells was most obvious with H(2)O(2) pretreatment at 0.88 micromol/L. Altogether 60 differentially expressed genes were detected with FDDRT-PCR in different treatment groups, and 5 of them were identified and verified, including 1 unknown gene and 4 known genes (bcl-2, EIF3S5, NDUFS4 and RPS10)., Conclusion: According to the results of FDDRT-PCR, the genes bcl-2, EIF3S5, NDUFS4 and RPS10 can be involved in H(2)O(2)-induced adaptive response of the MRC-5 cells.

In this study the blood sample was collected from eighty-six athletes in Tibetan mountaining team and Tibetan mountaining sports school and ninety healthy Han nationality people in Guangdong province, and genomic DNA was extracted from peripheral leukocyte. The allele frequency distribution and the genotypes combination distribution of hypoxia-inducible factor-la gene (HIF-1alpha)exonl2 C1772T and G1790A were examined by restriction fragment length polymorphism PCR (PCR-RFLP) in order to evaluate the association of single nucleotide polymorphisms (SNPs) of HIF-1alpha C1772T and G1790A with hypoxic acclimation in high altitude in Tibetans. The results indicated that the genotype frequency of HIF-1alpha C1772T in Tibetan and in Han nationality was 13.95% versus 16.67% in genotype CC, 38.37% versus 41.11% in genotype CT and 47.68% versus 42.22% in genotype TT. No significant difference in CC, CT and TT genotype frequency of HIF-1alphaC1772T was shown between Tibetans and Han nationality respectively, while GA genotype frequency of HIF-la G1790A in Tibetans was higher than that in Han nationality. The GA genotype of HIF-1alpha G1790A may be involved in the hypoxic acclimation of high altitude , and it is worth of deep-going investigation.

This investigation was conducted to explore the relationship between the polymorphism of gene of glucose transport 1(GLUT1) and the human body adaptation to high altitude hypoxia environment. The data on glucose transport 1 gene polymorphism in Tibetan mountaineers (high altitude group) were analyzed and compared with the data from the level-land Guangdong Hans (control group). The genotype of 86 Tibetan mountaineers and 90 level-land Hans as controls were tested with polymerase chain reaction followed by restriction fragment length polymorphism analysis for GLUT1 gene. The results showed that, in the high altitude mountaineer group, the frequencies of +22999 locus genotypes GG, GT and TT were 44.2%, 46.5% and 9.3% respectively, and such frequencies in the control group were 66.7%, 31.1% and 2.2% respectively. The frequencies of + 22999 polymorphic genotypes and alleles showed statistically significant difference between the high altitude group and the control group (P<0.05). Genetic single nucleotide polymorphism in GLUT1 G+22999T may be associated with the adaptation to high altitude hypoxia.

Objective: To investigate the association of single nucleotide polymorphisms (SNPs) of 1772 (C-->T) and 1790 (G-->A) in exon 12 of hypoxia-inducible factor 1, alpha subunit gene (HIF1A) with hypoxia adaptation in high altitude in Sherpas., Methods: The blood samples were chosen from 148 Sherpas in Tibet high altitude and 90 Han nationality healthy people in Guangdong province, and from which genomic DNA was extracted. The single nucleotide polymorphisms of 1772(C-->T) and 1790(G-->A) in exon 12 of HIF1A gene were examined by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR)., Results: The genotype frequency of HIF1A gene 1790 (G-->A) in Sherpas and Han nationality was 57.43% versus 75.56% in GG genotype, 37.84% versus 21.11% in GA genotype and 4.73% versus 3.33% in AA genotype. GG genotype frequency in Sherpas was lower than that in Han nationality (P<0.01), while GA genotype frequency in Sherpas was higher than that in Han nationality (P<0.01). No significant difference in CC, CT and TT genotype frequency of 1772(C-->T) was shown between two groups respectively. The total frequency of CC + GA, CT + AA, TT + GA and TT + AA in Sherpas was higher than that in Han nationality., Conclusion: Polymorphisms of HIF1A gene 1790 (G-->A) are associated with hypoxia adaptation in high altitude in Sherpas. GA and AA genotype may be benefit to hypoxia adaptation, and it is worthy of deep-going investigation.

Environmental stresses and the continuing deterioration of arable land, along with an explosive increase in world population, pose serious threats to global agricultural production and food security. Improving the tolerance of the major crop plants to abiotic stresses has been a main goal in agriculture for a long time. As rice is considered one of the major crops, the development of new cultivars with enhanced abiotic stress-tolerance will undoubtedly have an important effect on global food production. The transgenic approach offers an attractive alternative to conventional techniques for the genetic improvement of rice cultivars. In recent years, an array of stress-related genes has already been transferred to rice to improve its resistance against abiotic stresses. Many transgenic rice plants with enhanced abiotic stress-tolerance have been obtained. This article focuses on the progress in the study of abiotic stress tolerance in transgenic rice breeding.

The Arabidopsis thaliana tonoplast Na+ /H+ antiporter gene, AtNHX1, was transferred into buckwheat by Agrobacterium-mediated method. Transgenic buckwheat plants were regenerated and selected on MS basal medium supplemented with 2.0mg/L 6-BA, 1.0mg/L KT, 0.lmg/L IAA, 50mg/L kanamycin and 500mg/L carbenicillin. 426 seedlings from 36 resistant calli originated from 864 explants (transformed about at 4.17 percentage) exhibited resistance to kanamycin. The transformants were confirmed by PCR, Southern blotting, RT-PCR and Northern blotting analysis. After stress treatment for 6 weeks with 200mmol/L NaCl, transgenic plants survived, while wild-type plants did not. After 3 days of stress treatment through different concentrations of NaCl, transgenic plants accumulated higher concentration of Na+ and proline than the control plants. However, the K+ concentration of transgenic plants declined in comparison with the control plants. Moreover, the rutin content of the roots, stems and leaves of transgenic buckwheat increased than those of the control plants. These results showed that it could be possible to improve the salt-tolerance of crops with genetic technology.

Hypoxia inducible factor-1 (HIF-1) is a transcriptional factor first discovered in cancer cells under hypoxic conditions, and was demonstrated to play a key role in the organism's adaptation to changing oxygen tensions. The Tibetan chicken, a breed indigenous to the Tibetan plateau is particularly adaptable to the low oxygen tension and low temperature conditions in the high altitude environment. By comparison, the White Leghorn and ShouGuang chicken are low-altitude chicken breeds. The eggs of these three chicken breeds were incubated in a fitted hatcher that simulated hypoxic condition. The results demonstrated that the hatching rate for Tibetan chicken was significantly higher than the two low altitude breeds, and Tibetan chicken displayed higher endurance in the hypoxia environment. To a certain degree, the hypoxic condition proved fatal to hatching for the low-altitude chickens. Gene expression of HIF-1alpha was detected in brain and skeletal muscle tissues for three chicken varieties using the TaqMan probe FQRT-PCR method. The results showed that HIF-1alpha mRNA displayed tissue specific differential expression, with the highest in the brain. In addition, the expression of HIF-1alpha mRNA in the brain of Tibetan chicken embryos was similar to that of the low-altitude chickens when they were hatched under normal oxygen tensions.

To investigate the role of ZmPIP1-1 and ZmPIP1-2 in water uptake of roots and drought resistance of crops, semi-quantitative PCR was used to examine the expression of ZmPIP1-1 and ZmPIP1-2 in root systems of different maize genotypes under water deficit. These genotypes showed different resistance to water shortage under field conditions. The reference gene to target genes was tubulin. Maize seedlings were grown by hydroponics in a growth chamber. Water deficit was imposed on the seedlings with PEG-6000. The result showed that ZmPIP1-1 was up-regulated under water deficit in root systems of plants of the filial generation 'Hudan 4' and the mother line 'Tiansi', which were resistant to water shortage, but there was no noticeable up-regulation of ZmPIP1-1 in the root systems of the father line '803', which was sensitive to water deprivation. The result also showed that the extent of up-regulation was positively correlated with drought resistance of maize (Fig.3). On the other hand, the expression of ZmPIP1-1 showed different degrees of tendency after different duration of water stress in the root systems of the maize seedlings of different genotypes. The result showed that ZmPIP1-2 was identically expressed in three different species of maize and under different water conditions. The results support the theory that the intercellular water transport contributes to increased water uptake in root systems under water deficit by up-regulating the number of some kinds of aquaporins. The increases amount of transcripts of aquaporins is positively correlated to drought resistance of plant varieties. But not all kinds of number of aquaporins is up-regulated during water shortage, some kinds of aquaporins are identically expressed under water deficit conditions and well watered conditions.

This paper studied the effects of weak light on the photosynthetic characteristics, assimilates allocation, yield formation, and seedling growth of different ecotype capsicum (hot pepper and sweet pepper). The results showed that under weak light, the net photosynthetic rate (Pn) , dark respiration rate (Rd ) , night respiration rate (Rn) , transpiration rate (Tr) , water use efficiency (WUE) , light compensation point (LCP) , CO2 compensation point (CCP) and carboxylation efficiency ( CE) of test capsicums decreased, while their apparent quantum yield (AQY) increased. The decrease of Pn was considered as a result of non-stomata restriction. Weak light increased plant height/stem diameter ratio and specific leaf area, but decreased root/shoot ratio, total dry mass, and seedling' s healthy index. Under the effect of weak light, the formation of biological and economic yields was inhibited significantly, and the allocation of assimilates to stem and leaf was increased while that to fruit decreased. Hot pepper under weak light had lower light compensation point, higher relative healthy index, higher relative yield per plant, and higher relative setting rate, showing a stronger capability of weak light tolerance than sweet pepper.

The regulation networks of gene expression mediated by transcription factors play important roles in plant responses to a range of environmental stresses. Transcription factors and their families identified to be involved in plant stress responses include APETALA2/EREBP, bZIP, WRKY, MYB, etc., which can constitute regulation networks to regulate the temporal-spatial expression of each kind of related genes in plant stress responses. The genetic modifications of transcription factors and their regulation networks are increasingly becoming the effective approaches for understanding stress biology at system level, and a new way for enhancing the stress tolerance and resistance of plants.

Two strains, Cu/Zn SOD and APX gene transferred sweet potato (TS) and non-transgenic sweet potato (Ipomoea batatas L.) (NT), were used as experimental materials to study the drought tolerance under three different degrees of water stress: 0, -0.44 MPa, -0.78 MPa. The results showed that activities of Cu/Zn SOD and APX increased under -0.44 MPa and decreased under -0.78 MPa (Fig. 2), P(n), G(s) and leaf water content decreased, C(i) increased, then decreased under water stress (Fig. 6), but under the same PEG concentration all these indexes in the TS were higher than those in NT. The accumulation of H(2)O(2) and O(-*)(2) (Fig. 1) increased the degree of lipid peroxidation of the plasma membrane (Fig. 4), prompted the accumulation of MDA (Fig. 3), and the accumulation of TS always lower than the NT at the same PEG concentration. All the results showed that the transgenic sweet potato has a stronger ability to clean up active oxygen than the non-transgenic one, and it can keep a higher leaf water content and P(n) under water stress, so it has a stronger tolerance to drought.

The heat shock protein ClpB is a member of the Clp family and functions as molecular chaperones. ClpB is related to the acquired thermotolerance in organisms. A cDNA of 3144 bp was screened out of a tomato cDNA library. The polypeptide deduced from the longest ORF contains 980 amino acid residues, and was classified into HSP100/ClpB family based on the result of molecular phylogenesis analysis. Thus it was named as LeHSP110/ClpB according to its calculated molecular weight. LeHSP110/ClpB was characteristic of heat-inducibility but no constitutive expression, and was demonstrated to locate in chloroplastic stroma. An antisense cDNA fragment of LeHsp110/ClpB under the control of CaMV 35S promoter was introduced into tomato by Agrobacterium tumefactions-mediated method. At high temperature, the mRNA levels of LeHsp110/ClpB in antisense transgenic plants were lower than those in control plants. The PS II of transgenic plants is more sensitive to high temperature than that of control plants according to data of Fv/Fm. These results clearly showed that HSP110/ClpB plays an important role in thermotolerance of high plants.

To investigate gene expression profile in response to aluminum stress and to cloning the key genes related to aluminum tolerance, are crucial to genetic improvement of plant aluminum tolerance. In this study, suppression subtractive hybridization method was adopted to construct SSH-cDNA libraries at seedling stage of two maize inbred lines (Fig. 1), of which Mo17 is sensitive to aluminum toxicity and TL94B is tolerant. As a result, a forward SSH-cDNA library including 762 clones and a reverse SSH-cDNA library including 382 clones were constructed for Mo17. In the same way, a forward SSH-cDNA library including 760 clones and a reverse SSH-cDNA library including 380 clones were constructed for TL94B. Identification of these SSH-cDNA libraries shows that the length of inserted fragments ranges from 250 bp to 1.0 kb (Fig. 2), of which nearly 18% are positive clones. Through differential hybridization screening (Fig. 3), 124 and 47 positive clones were screened from forward and reverse SSH-cDNA libraries of Mo17 respectively; 103 and 64 positive clones from forward and reverse SSH-cDNA libraries of TL94B respectively. Total 338 positive clones from four SSH-cDNA libraries were sequenced, and all of the sequences of inserted fragments were analyzed using bioinformatical methods. A total of 232 kinds of EST sequences were obtained. Among these ESTs, 70.2% had significant homology with known genes, and the remaining 29.8% were function-unknown including 21 kinds of newly found ESTs (Table 1). An aluminum tolerant gene, GDP dissociation inhibitor gene, was detected its expression character by Northern hybridization (Fig. 4). These results indicate that the responses of maize to aluminum stress involve the interactions among different signal/metabolism pathways, such as signal transduction of stress-related factors, transcription and regulation of responsive genes, synthesis and transport of substances, changes in cell structures and functions.

Horizontal gene transfer, unlike vertical gene transfer, is a means of genetic communication in bacteria. In the special polluted environment, horizontal transfer of polluted-degrading gene has significant functions. Study on horizontal transfer of degrading gene in polluted environment may deepen our understanding of the mechanism of bacterial adaptation to the organic-polluted environment. In the practical application in bioremediation, horizontal transfer of degrading gene can be regulated to promote degrading ability of microorganisms. In this article, we will review the advances in the study on mechanisms of genetic interactions among bacteria, the effect of degrading gene transfer in contaminated environment on microorganisms'adaptation to contaminated environment and the degradation of the pollutants.

Fifty nine accessions of soybean (Glycine max (L.) Merr.) selected from 301 ones in Huang-Huai-Hai and Middle-Lower Changjiang Valleys were tested in two years for their tolerance to drought by using the mean membership index value averaged over those of plant height,leave number,dry root weight and dry stem and leaf weight. Four most tolerant accessions (Rank 1) and two most sensitive ones (Rank 5) were identified. There existed very significant correlations between drought tolerance and relative values of dry root weight,total root length, and root volume (per plant dry weight basis), respectively,which could be used as root indicators of drought tolerance. The RIL population derived from Kefeng 1 x Nannong 1138-2 was used to analyze the inheritance of the three related root traits by using the segregation analysis of quantitative traits under the major gene plus polygene mixed inheritance model. The results showed that between the two parents (Rank 1 x Rank 4), the relative values of dry root weight,total root length and root volume were respectively controlled by two major genes (linked together for the latter two traits, recombination value being 4.30% and 1.93%, respectively) plus polygenes with their major gene heritability values of 62.26%-91.81% and polygene heritability values 2.99%-24.75%, indicating that the major genes,especially the one with larger effect,accounted for a major part of the genetic variation between the two parents. It was identified that five, three, and five QTLs located on N6-C2, N8-D1b + W, N11-E, and N18-K linkage groups for relative dry root weight, total root length and root volume, respectively. Each of the traits appeared to have one locus (Dw1, R/1, and Rv1) with relatively large effect in comparison with their other loci, and those major ones were located near the same site of the same linkage group N6-C2. The results of segregation analysis and QTL mapping appeared pretty consistent with each other, which could be used as a demonstration of each other.

Transgenic tobacco plants expressing a stress responsive gene BoRS1, isolated from Brassica oleracea var. acephala, under the control of the 35S promoter of the Cauliflower mosaic virus were produced. Some plants were further used to test the effect of high level BoRS1 expression on drought stress resistance. The presence of transgene in putative transgenic plants was confirmed by PCR analysis. Thirty-six among 130 transformants showed amplification of predicted fragment of BoRS1 while no amplification was observed in the control. Some transgenic lines confirmed by PCR analysis were analyzed through semi-quantitative one-step RT-PCR for the expression of BoRS1 gene. Amplification of 1.4 kb cDNA product revealed transcription of BoRS1 gene. Meanwhile, differential intensity of the cDNA band indicated variable expression levels of the transgene among different transformed lines. The water loss of detached leaves from the transgenic plants was slower than that of the control. Transgenic tobaccos and the non-transgenic controls were used for further drought stress experiments by using different concentration of mannitol. The transformants showed higher tolerance to drought stress than non-transgenic plants and different transgenic lines exhibited different tolerance during drought stress. These results showed that the BoRS1 gene probably play role in enhancing the ability to drought stress.

The evolution of plant disease resistance genes has shaped in some kinds of common forms. The duplication of plant progenitor disease resistance gene creates disease resistance gene loci. The intragenic and extragenic recombination results in variation. Recombination also is involved in generation novel resistance specificities. In addition, the leucine-rich repeats (LRRs) involved in recognitional specificity are subject to adaptive selection. Insertion of transposable elements into several resistance gene loci result in further evolution of resistance genes. With the evolution of plant disease resistance genes, the R genes (resistance genes)-mediated response shows diversification which represents different stages in the oscillating evolution between plants and their pathogens.

Aluminium toxicity is the major factor limiting crop growth on acid soils, which greatly affects the crop productivity on about 40% cultivated soils of the world and 21% of China. In the past decades, a lot of researches on aluminium toxicity and resistant mechanisms have been doing, and great progress was achieved. This paper dealt with the genetic differences in aluminium tolerance among plants, screening and selecting methods and technologies for identifying aluminium resistance in plants, and physiological and molecular mechanism resistance to aluminium toxicity. Some aspects needed to be further studied were also briefly discussed.

Objective: To construct subtracted cDNA library in hypothalamus of the seasickness adaptive rats for providing theoretical basis for effective adaptive training against seasickness., Methods: Suppression subtract hybridization technique was used, and forward and reverse hybridization was performed on the hypothalamus of seasickness adaptive rats and that of normal rats so that to construct subtracted cDNA library. Dot blot was used for differential screening the subtracted library., Results: 23 fragments of differentially expressed genes was obtained including 10 up-regulating and 13 down-regulating fragments., Conclusion: Many played role in adaptability formation to seasickness such as SAM, vasopressin, and heme oxygenase.

Objective: To demonstrate the tissue specific expression of five rat genes related to centrifuge training and the relationship between expression change and duration of training., Method: mRNA was extracted from hearts, brains, kidneys, lungs and intestines of rats after different durations of training. Five genes obtained by SSH from centrifuge-trained rats were labeled by Dig-11-dUTP as probes. The expression levels were measured by thin-line hybridization. Optical density (OD) values were obtained by scanning and treated with statistics., Result: As compared with control group, the new gene CH157 expression decreased in hearts and brains of rats trained for 6 d (P<0.05), but returned to control levels after 12 d training; the new gene CH244 expression depressed in rat hearts, brains, and intestines after 6 d or 12 d training, but it was not statistically significant owing to large individual differences; gene expression of protein inhibitor of neuronal nitric oxide syntheses (PIN) increased gradually and significantly in rat hearts (P<0.01 after 12 d training) and kidneys (P<0.05 after 12 d training); Cyt b gene expression in rat hearts and brains increased increasingly (P<0.01 after 12 d training), however, it increased obviously (P<0.05) in kidneys, lungs and intestines of rats trained for 6 d, while it returned back a little in rats trained for 12 d; enlongation factor 1-alpha expression levels in intestines of rats trained for 6 d increased significantly (P<0.05), but it became no significant in rats trained for 12 d, while the expression in brains increased gradually (P<0.01)., Conclusion: It suggested that the change in gene expression in several tissues of rats caused by centrifuge training contribute in enhancing +Gz tolerance.

Objective: To explore the effects of acute hypoxia and intermittent hypoxic acclimatization on gene expression of erythropoietin (EPO) and hypoxia-inducible factor-1alpha (HIF-1alpha) in rat hepatic and renal tissues., Methods: Twenty-four rats (weight was 180 to 220 g) were divided into three groups: normal control group (NC), intermittent hypoxic acclimatization (IH) and acute hypoxia groups (AH). Gene expression of EPO and HIF-1alpha were examined with Northern dot blot method., Results: As compared with NC group, the levels of EPO gene expression in rat hepatic and renal tissues in AH group were both significantly elevated (P<0.05 or P<0.01). In IH group, the contents of EPO mRNA in hepatic and renal tissues were apparently decreased versus AH group (P<0.01), whilst were not differently elevated in comparison with group NC (P>0.05). In hepatic tissue from AH group, the content of HIF-1alpha mRNA were more than those in NC group and IH group, while the levels of gene expression of HIF-1alpha were no substantial change in renal tissues from different groups (all P>0.05)., Conclusion: Hypoxic acclimatization can inhibit the increment of EPO gene expression induced by acute hypoxia in rat hepatic and renal tissues, in which HIF-1alpha may play important roles.

In order to transfer the genes for salt tolerance and disease resistance from Thinopyrum bessarabicum into wheat, the hybrid progenies between T. aestivum cv. Chinese Spring and T. aestivum cv. Chinese Spring-amphiploid Th. bessarabicum were screened. A set of T. aestivum-Th. bessarabicum disomic addition lines was developed with the assistance of mitotic chromosome C-banding and genomic in situ hybridization (GISH), as well as GISH on meiotic M I chromosome preparations. The results indicated that all the wheat chromosomes in the lines remained unchanged karyotypically, while the added Th. bessarabicum chromosomes paired regularly in meiosis. The developed disomic addition lines were designated temporarily as DAJ1, DAJ2, DAJ3, DAJ4, DAJ5, DAJ6 and DAJ7 respectively. Determination of the homoelogous groups of the added Th. bessarabicum chromosomes and localization of the genes for salt tolerance and disease resistance are undergoing.

To provide necessary information for further understanding of molecular mechanism of hypoxia acclimatization, the differentially expressed genes of HepG2 cells exposed to normoxia, acute hypoxia-treated cells which were exposed to 1% oxygen for 48 h, and hypoxia-acclimatized HepG2 cells which were cultured for 6 circles of alternate low oxygen (1% oxygen for 24 h) and normal oxygen (21% oxygen for 24 h), were identified respectively by combining the suppression subtractive hybridization (SSH) and cDNA microarray. Thirty-seven genes were expressed differentially in cells exposed to 1% oxygen for 48 h compared with those in cells exposed to normoxia. The expression of all these 37 genes was down-regulated, including the genes participating in cell cycle, cell response to stimulus, and cell signal transduction, and cell cytoskeleton formation, the genes associated with transcription and cell metabolism, 4 expressed sequence tags (ESTs), and 12 genes of which the functions are not known. There is a novel gene sequence, which has not been found in existing databases. There were only 6 genes differentially expressed in the hypoxia-acclimatized cells compared with cells exposed to normoxia, including two mitochondrion genes, metalloprotease-1 gene, ferritin gene, thymosin beta-4 and TPT1 genes. The expressions of mitochondrion ND4, ferritin, thymosin beta-4 and TPT1 were up-regulated, while the expressions of mitochondrion ND1 gene and metalloproease-1 gene were down-regulated. Cell tolerance to hypoxia increased after the cells were hypoxia-acclimatized. The different gene expression patterns of the acute hypoxia-treated cells and the hypoxia-acclimatized cells may be related to the increased tolerance of the cells to hypoxia.

The genotypic differences in P uptake efficiency of three rice varieties (IR74, IR71331 and IR71379) were studied under the P-deficiency condition with hydroponics, and their adaptability to low phosphorus stress about physio-biochemical mechanisms was further studied. The results showed that rice genotypes tolerated low P stress resulted from the co-ordination of P uptake efficiency, internal utilization efficiency and its translocation efficiency. The higher P-efficiency type IR74 and the middle type IR71331 had a higher P uptake efficiency. The rice genotype with higher P-efficiency was characterized by higher activity and desirable kinetic parameters of H2 PO4- uptake, showing lower Km and Cmin, but higher Imax values and relative APase activity, small amount of Km and Cmin. Moreover, under low P stress, the activity of RNase was about ten to fifteen times as high as that of the control (CK), but it had little genotypic differences.

Poplar(Pupulus x Xiao zhannica, cv. "balizhuang-yang") transferred with mtl-D gene was used as an experimental material. Through tissue culture, aquaculture and pot culture transgenic poplars are tested with variant Nacl salt gradient. In it transgenic poplar raises its initial days for differentiation, differentiation rate, bud intensity, bud height and growth potential than control plant. At the same time, the transgenic poplar has higher rooting rate and more top roots, side roots and higher root length than control under the same salt stress. The result shows that the transgenic poplar has better tolerance ability than control plant in the salt 4@1000 contensity mediums.

The morphological differences, chlorophyll contents, fluorescence and diurnal course of leaf gas exchange between terrestrial banyan and amphibious banyan were compared with pot culture. The amphibious banyan possesses well developed aerial and hydro-adventitious roots, and wider leaf with inclination of evolution toward mesophytic traits. The chlorophyll content of terrestrial banyan was higher than that of amphibious banyan. The diurnal course of leaf gas exchange indicated that net photosynthetic rate of terrestrial banyan was slightly higher than that of amphibious banyan grown in water, but much higher than that grown in soil. The amphibious banyan grown in water had the highest transpiration rate, the terrestrial banyan had a lower one, and the amphibious banyan grown in soil had the lowest. Linear regression analysis showed a positive correlation between net photosynthetic rate and stomatal conductance, implying that the stomatal conductance was dominant factor controlling the gas exchange. In this study, the term of intrinsic water use efficiency (net photosynthetic rate/stomatal conductance ratio, Intrinsic WUE) was applied to describe the photosynthesis and water properties, and the result showed that it was a more suitable measure compared to the usual WUE(net photosynthetic rate/transpiration rate). Among the three banyan plants examined, the amphibious banyan had the highest intrinsic WUE.