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Selenium is essential for many organisms, but is toxic at higher levels. To investigate the genetic basis of selenate tolerance in Arabidopsis thaliana, quantitative trait loci (QTL) associated with selenate tolerance in accessions Landsberg erecta and Columbia were mapped using recombinant inbred lines (RILs). The selenate tolerance index (TI(D10) = root growth + 30 microm selenate/root growth control x 100%) was fourfold higher for parental line Col-4 (59%) than for parent Ler-0 (15%). Among the 96 F8 RILs, TI(D10) ranged from 11 to 75% (mean 37%). Using composite interval mapping, three QTL were found on chromosomes 1, 3 and 5, which together explained 24% of variation in TI(D10) and 32% of the phenotypic variation for the difference in root length +/- Se (RL(D10)). Highly significant epistatic interactions between the QTL and markers on chromosome 2 explained additional variation for both traits. Potential candidate genes for Se tolerance in each of the QTL regions are discussed. These results offer insight into the genetic basis of selenate tolerance, and may be useful for identification of selenate-tolerance genes. 相似文献
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SANDEEP SHARMA WENDAR LIN JOJI GRACE VILLAMOR PAUL E. VERSLUES 《Plant, cell & environment》2013,36(5):994-1008
The Arabidopsis thaliana accession Shahdara (Sha) differs from Landsberg erecta (Ler) and other accessions in its responses to drought and low water potential including lower levels of proline accumulation. However, Sha maintained greater seedling root elongation at low water potential and a higher NADP/NADPH ratio than Ler. Profiling of major amino acids and organic acids found that Sha had reduced levels of all glutamate family amino acids metabolically related to proline, but increased levels of aspartate‐derived amino acids (particularly isoleucine), leucine and valine at low water potential. Although Sha is known for its different abiotic stress response, RNA sequencing and co‐expression clustering found that Sha differed most from Ler in defence/immune response and reactive oxygen‐related gene expression. HVA22B and Osmotin34 were two of the relatively few abiotic stress‐associated genes differentially expressed between Ler and Sha. Insensitivity to exogenous glutamine and a different expression profile of glutamate receptors were further factors that may underlie the differing metabolism and low water potential phenotypes of Sha. These data define the unique environmental adaptation and differing metabolism of Sha including differences in defence gene expression, and will facilitate further analysis of Sha natural variation to understand metabolic regulation and abiotic/biotic stress interaction. 相似文献
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Louai Rishmawi Jonas Bühler Benjamin Jaegle Martin Hülskamp Maarten Koornneef 《Plant, cell & environment》2017,40(8):1429-1441
Leaf veins provide the mechanical support and are responsible for the transport of nutrients and water to the plant. High vein density is a prerequisite for plants to have C4 photosynthesis. We investigated the genetic variation and genetic architecture of leaf venation traits within the species Arabidopsis thaliana using natural variation. Leaf venation traits, including leaf vein density (LVD) were analysed in 66 worldwide accessions and 399 lines of the multi‐parent advanced generation intercross population. It was shown that there is no correlation between LVD and photosynthesis parameters within A. thaliana. Association mapping was performed for LVD and identified 16 and 17 putative quantitative trait loci (QTLs) in the multi‐parent advanced generation intercross and worldwide sets, respectively. There was no overlap between the identified QTLs suggesting that many genes can affect the traits. In addition, linkage mapping was performed using two biparental recombinant inbred line populations. Combining linkage and association mapping revealed seven candidate genes. For one of the candidate genes, RCI2c, we demonstrated its function in leaf venation patterning. 相似文献
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Quantitative trait loci controlling light and hormone response in two accessions of Arabidopsis thaliana 总被引:11,自引:0,他引:11
Borevitz JO Maloof JN Lutes J Dabi T Redfern JL Trainer GT Werner JD Asami T Berry CC Weigel D Chory J 《Genetics》2002,160(2):683-696
We have mapped quantitative trait loci (QTL) responsible for natural variation in light and hormone response between the Cape Verde Islands (Cvi) and Landsberg erecta (Ler) accessions of Arabidopsis thaliana using recombinant inbred lines (RILs). Hypocotyl length was measured in four light environments: white, blue, red, and far-red light and in the dark. In addition, white light plus gibberellin (GA) and dark plus the brassinosteroid biosynthesis inhibitor brassinazole (BRZ) were used to detect hormone effects. Twelve QTL were identified that map to loci not previously known to affect light response, as well as loci where candidate genes have been identified from known mutations. Some QTL act in all environments while others show genotype-by-environment interaction. A global threshold was established to identify a significant epistatic interaction between two loci that have few main effects of their own. LIGHT1, a major QTL, has been confirmed in a near isogenic line (NIL) and maps to a new locus with effects in all light environments. The erecta mutation can explain the effect of the HYP2 QTL in the blue, BRZ, and dark environments, but not in far-red. LIGHT2, also confirmed in an NIL, has effects in white and red light and shows interaction with GA. The phenotype and map position of LIGHT2 suggest the photoreceptor PHYB as a candidate gene. Natural variation in light and hormone response thus defines both new genes and known genes that control light response in wild accessions. 相似文献
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Towards the genetic architecture of seed lipid biosynthesis and accumulation in Arabidopsis thaliana
O'Neill CM Morgan C Hattori C Brennan M Rosas U Tschoep H Deng PX Baker D Wells R Bancroft I 《Heredity》2012,108(2):115-123
We report the quantitative genetic analysis of seed oil quality and quantity in six Arabidopsis thaliana recombinant inbred populations, in which the parent accessions were from diverse geographical origins, and were selected on the basis of variation for seed oil content and lipid composition. Although most of the biochemical steps involved in lipid biosynthesis are known and the key genes have been identified, the regulation of the processes that results in the final oil composition and total amount is not understood. By using physically anchored markers it was possible to compare results across populations. A total of 219 quantitative trait loci (QTLs) were identified, of which 81 were significant at P<0.001. Some of these colocalise with QTLs identified previously, but many novel QTLs were also identified. The results highlight the importance of studying traits in multiple populations, which will lead to a better understanding of the contribution that natural variation makes to the genetic architecture of a phenotype. 相似文献
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QTL architecture of resistance and tolerance traits in Arabidopsis thaliana in natural environments 总被引:4,自引:0,他引:4
Quantitative-genetic approaches have offered significant insights into phenotypic evolution. However, quantitative-genetic analyses fail to provide information about the evolutionary relevance of specific loci. One complex and ecologically relevant trait for plants is their resistance to herbivory because natural enemies can impose significant damage. To illustrate the insights of combined molecular and ecological research, we present the results of a field study mapping quantitative trait loci (QTL) for resistance and tolerance to natural rabbit herbivory in the genetic model, Arabidopsis thaliana. Replicates of the Ler x Col recombinant inbred lines were planted into field sites simulating natural autumn and spring seasonal germination cohorts. Shortly after flowering, herbivores removed the main flowering inflorescence (apical meristem). We found several main-effect QTL for resistance within each seasonal cohort and significant QTL-season interactions, demonstrating that the loci underlying resistance to a single herbivore differ across seasonal environments. The presence of QTL x environment also shows that variation at specific loci is only available to selection in some environments. Despite significant among-line variance components, no QTL for tolerance were detected. The combined results of the quantitative-genetic and QTL analyses demonstrate that many loci of small effect underlie tolerance to damage by rabbits, and counter the hypothesis of locus-specific tradeoffs between resistance and tolerance. The results also provide insights as to the locus-specific nature of evolutionary constraints, i.e. some loci influence flowering time and resistance in both seasonal cohorts. Our results show how linking molecular-genetic tools with field studies in ecologically relevant settings can clarify the role of specific loci in the evolution of quantitative traits. 相似文献
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Hausmann NJ Juenger TE Sen S Stowe KA Dawson TE Simms EL 《Evolution; international journal of organic evolution》2005,59(1):81-96
Phenotypic plasticity is an important response mechanism of plants to environmental heterogeneity. Here, we explored the genetic basis of plastic responses of Arabidopsis thaliana to water deficit by experimentally mapping quantitative trait loci (QTL) in two recombinant inbred populations (Cvi x Ler and Ler x Col). We detected genetic variation and significant genotype-by-environment interactions for many traits related to water use. We also mapped 26 QTL, including six for carbon isotope composition (delta13C). Negative genetic correlations between fruit length and fruit production as well as between flowering time and branch production were corroborated by QTL colocalization, suggesting these correlations are due to pleiotropy or physical linkage. Water-limited plants were more apically dominant with greater root:shoot ratios and higher delta13C (higher water-use efficiency) when compared to well-watered plants. Many of the QTL effects for these traits interacted significantly with the irrigation treatment, suggesting that the observed phenotypic plasticity is genetically based. We specifically searched for epistatic (QTL-QTL) interactions using a two-dimensional genome scan, which allowed us to detect epistasis regardless of additive genetic effects. We found several significant QTL-QTL interactions including three that exhibited environmental dependence. These results provide preliminary evidence for proposed genetic mechanisms underlying phenotypic plasticity. 相似文献
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The tolerances of Columbia Arabidopsis thaliana (L.) Heynh. to NaCl, L-asparagine (L-Asn) and D-asparagine (D-Asn) during seedling establishment on sterile agar medium were determined. Germination and the establishment of upright seedlings with expanded green cotyledons were increasingly inhibited by NaCl concentrations from 20 to 180 m M and radicle growth was prevented at 225 m M NaCl. Tolerance of established seedlings to NaCl was similar at these concentrations. Seedling establishment was prevented at 20 m M L-Asn and 60 m M D-Asn, but L-Asn was not toxic to established seedlings. At lower concentrations, exogenous L- and D-Asn enhanced NaCl tolerance during germination and seedling establishment. Inhibition of seedling establishment by NaCl concentrations below 225 m M was reduced by the addition of L- and D-Asn to the medium. Maximal reduction of NaCl inhibition occurred between 2 and 4 m M for both L- and D-Asn. Higher concentrations of NaCl prevented establishment whether exogenous Asn was present or not. Reduction of NaCl inhibition occurred to the same extent whether L-Asn was presented simultaneously with the NaCl or preloaded for up to 24 h. The total seedling content of Na+ increased about 4-fold to 55 μg (mg dry weight)−1 as the medium concentration of NaCl was increased from 9 μ M to 150 m M NaCl. Total K+ content declined about 80% from about 34 μg (mg dry weight)−1 over the same range of NaCl concentrations. The Na+ uptake and K+ efflux by whole seedlings were similar whether or not NaCl tolerance was increased by exogenous Asn. 相似文献
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MIKAEL BROSCHÉ EBE MERILO FLORIAN MAYER PRIIT PECHTER IRINA PUZÕRJOVA GÜNTER BRADER JAAKKO KANGASJÄRVI HANNES KOLLIST 《Plant, cell & environment》2010,33(6):914-925
Genetic variation between naturally occurring populations provides a unique source to unravel the complex mechanisms of stress tolerance. Here, we have analysed O3 sensitivity of 93 natural Arabidopsis thaliana accessions together with five O3‐sensitive mutants to acute O3 exposure. The variation in O3 sensitivity among the natural accessions was much higher than among the O3‐sensitive mutants and corresponding wild types. A subset of nine accessions with major variation in their O3 responses was studied in more detail. Among the traits assayed, stomatal conductance (gst) was an important factor determining O3 sensitivity of the selected accessions. The most O3‐sensitive accession, Cvi‐0, had constitutively high gst, leading to high initial O3 uptake rate and dose received during the first 30 min of exposure. Analyzing O3‐induced changes in stress hormone concentrations indicated that jasmonate (JA) concentration was also positively correlated with leaf damage. Quantitative trait loci (QTL) mapping in a Col‐0 × Cvi‐0 recombinant inbred line (RIL) population identified three QTLs for O3 sensitivity, and one for high water loss of Cvi‐0. The major O3 QTL mapped to the same position as the water loss QTL further supporting the role of stomata in regulating O3 entry and damage. 相似文献
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Effects of preconditioning and temperature during germination of 73 natural accessions of Arabidopsis thaliana 总被引:1,自引:0,他引:1
BACKGROUND AND AIMS: Germination and establishment of seeds are complex traits affected by a wide range of internal and external influences. The effects of parental temperature preconditioning and temperature during germination on germination and establishment of Arabidopsis thaliana were examined. METHODS: Seeds from parental plants grown at 14 and at 22 degrees C were screened for germination (protrusion of radicle) and establishment (greening of cotyledons) at three different temperatures (10, 18 and 26 degrees C). Seventy-three accessions from across the entire distribution range of A. thaliana were included. KEY RESULTS: Multifactorial analyses of variances revealed significant differences in the effects of genotypes, preconditioning, temperature treatment, and their interactions on duration of germination and establishment. Reaction norms showed an enormous range of plasticity among the preconditioning and different germination temperatures. Correlations of percentage total germination and establishment after 38 d with the geographical origin of accessions were only significant for 14 degrees C preconditioning but not for 22 degrees C preconditioning. Correlations with temperature and precipitation on the origin of the accessions were mainly found at the lower germination temperatures (10 and 18 degrees C) and were absent at higher germination temperatures (26 degrees C). CONCLUSIONS: Overall, the data show huge variation of germination and establishment among natural accessions of A. thaliana and might serve as a valuable source for further germination and plasticity studies. 相似文献
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Cold tolerance in plants is an ecologically important trait that has been under intensive study for basic and applied reasons. Determining the fitness benefits and costs of cold tolerance has previously been difficult because cold tolerance is normally an induced trait that is not expressed in warm environments. The recent creation of transgenic plants constitutively expressing cold tolerance genes enables the investigation of the fitness consequences of cold tolerance in multiple temperature environments. We studied three genes from the CBF (C-repeat/dehydration responsive element binding factor) cold tolerance pathway, CBF1, 2 and 3, in Arabidopsis thaliana to test for benefits and costs of constitutive cold tolerance. We used multiple insertion lines for each transgene and grew the lines in cold and control conditions. Costs of cold tolerance, as determined by fruit number, varied by individual transgene. CBF2 and 3 overexpressers showed costs of cold tolerance, and no fitness benefits, in both environments. CBF1 overexpressing plants showed no fitness cost of cold tolerance in the control environment and showed a marginal fitness benefit in the cold environment. These results suggest that constitutive expression of traits that are normally induced in response to environmental stress will not always lead to costs in the absence of that stress, and that the ecological risks of CBF transgene escape should be assessed prior to their use in commercial agriculture. 相似文献
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Heterosis is broadly defined as the increased vigour of hybrids in comparison to their parents. In the model plant Arabidopsis thaliana, a significant heterosis effect on leaf-freezing tolerance was observed in the F(1) generation of a cross between the accessions Columbia-0 (Col) and C24. Parental Col plants were significantly more freezing-tolerant than C24 plants in both the acclimated and non-acclimated (NA) states. Mid-parent heterosis was observed in the F(1) plants, both in the basic tolerance of non-adapted plants and in freezing tolerance after cold acclimation. Best-parent heterosis, on the other hand, was only found after cold acclimation. The heterosis effect was reduced in the F(2) populations such that only mid-parent heterosis was evident. The leaf content of soluble sugars (fructose (Fru), glucose (Glc), sucrose (Suc) and raffinose (Raf)) increased dramatically in the F(1) plants after cold acclimation as compared to the parental lines. The content of proline (Pro), however, was only moderately increased in the F(1) plants under the same conditions. Correlation analyses showed that only Raf content was consistently related to leaf-freezing tolerance in both the acclimated and NA states. A quantification of mRNA levels in leaves of parental and F(1) lines using quantitative real-time RT-PCR showed no clear indication for an involvement of the investigated genes (CBF (C-repeat binding factor)1, CBF2, (cold-regulated protein (COR) 6.6, COR15a, COR15b, COR47 and COR78) in the heterosis effect. 相似文献
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E. Schiantarelli A. De la Peña M. Candela 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(2-3):335-341
The Landsberg erecta× Columbia recombinant inbred lines (RILs) of Arabidopsis have been used in order to identify and localize chromosome regions involved in the genetic control of the in vitro regeneration
ability. Callus morphology (CM) and shoot regeneration (SR) traits have been considered for both leaf and root explants. The
MAPMAKER analysis of leaf culture data has revealed at least one chromosome region involved with CM and several with SR, the
29–30 region of chromosome 1 being common for the two traits. Root explants did not segregate for CM but several QTLs have
been detected for SR. The chromosome regions involved with leaf culture regeneration seem to be different from those of root
cultures, although the regeneration of abnormal shoots in leaf explants share two chromosome regions with the regeneration
of normal shoots in root cultures.
Received: 19 April 2000 / Accepted: 12 May 2000 相似文献
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To investigate the genetic mechanism of AI-tolerance in soybean,a recombinant inbred line population (RIL) with 184 F2:7:11 lines derived from the cross of Kefeng No.1 x Nannong 1138-2 (AI-tolerant x AI-sensitive) were tested in pot experimentwith sand culture medium in net room in Nanjing.Four traits,i.e.plant height,number of leaves,shoot dry weight and root dry weight at seedling stage,were evaluated and used to calculate the average membership index (FAi) as the indicator of AI-tolerance.The composite interval mapping (ClM) under WinQTL Cartographer v.2.5 detected five QTLs (i.e.qFAiol,qFAi-2,qFAi-3,qFAi-4 and qFAi-5),explaining 5.20%-9.07% of the total phenotypic variation individually.While with the multiple interval mapping (MIM) of the same software,five QTLs (qFAi-1,qFAi-5,qFAi-6,qFAi-7,and qFAi-8) explaining 5.7%-24.60% of the total phenotypic variation individually were mapped.Here qFAi-1 and qFAi-5 were detected by both CIM and MIM with the locations in a same flanking marker region,GMKF046-GMKF080 on B1 and satt278-sat_95 on L,respectively.While qFAi-2 under CIM and qFAi-6 under MIM both on D1b2 were located in neighboring regions with their confidence intervals overlapped and might be the same locus.Segregation analysis under major gene plus polygene inheritance model showed that Al-tolerance was controlled by two major genes (h2mg =33.05%) plus polygenes (h2pg=52.73%).Both QTL mapping and segregation analysis confirmed two QTLs responsible for Al-tolerance with relatively low heritability,and there might be a third QTL,confounded with the polygenes in segregation analysis. 相似文献
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Gupta Rajeev Webster Carl I. Walker Amanda R. Gray John C. 《Plant molecular biology》1997,34(3):529-536
A cDNA encoding the HMG-I/Y protein from Arabidopsis thaliana has been isolated and characterised by nucleotide sequencing. The 903 bp cDNA contains a 612 bp open reading frame encoding a protein of 204 amino acid residues showing homology to HMG-I/Y proteins from other plant species. The protein contains four copies of the AT-hook motif which is involved in binding A/T-rich DNA. Southern blotting showed that the HMG-I/Y gene was present in a single copy in the Arabidopsis genome. The gene was localised to the top of chromosome 1 by RFLP analysis of F8 recombinant inbred lines. Northern blotting showed that the gene was expressed in all organs examined, with the highest expression in flowers and developing siliques. 相似文献
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Evolutionary genetics of resistance and tolerance to natural herbivory in Arabidopsis thaliana 总被引:5,自引:0,他引:5
Weinig C Stinchcombe JR Schmitt J 《Evolution; international journal of organic evolution》2003,57(6):1270-1280
Resistance and tolerance are widely viewed as two alternative adaptive responses to herbivory. However, the traits underlying resistance and tolerance remain largely unknown, as does the genetic architecture of herbivory responses and the prevalence of genetic trade-offs. To address these issues, we measured resistance and tolerance to natural apical meristem damage (AMD) by rabbits in a large field experiment with recombinant inbred lines (RILs) of Arabidopsis thaliana (developed from a cross between the Columbia x Landsberg erecta ecotypes). We also measured phenological and morphological traits hypothesized to underlie resistance and tolerance to AMD. Recombinant inbred lines differed significantly in resistance (the proportion of replicates within an RIL that resisted herbivory), and early flowering plants with tall apical inflorescences were more likely to experience damage. Tolerance (the difference in fitness between the damaged and undamaged states), also differed significantly among RILs, with some lines overcompensating for damage and producing more fruit in the damaged than undamaged state. Plastic increases in basal branch number, basal branch height, and senescence date in response to damage were all associated with greater tolerance. There was no evidence for a genetic trade-off between resistance and tolerance, an observation consistent with the underlying differences in associated morphological and phenological characters. Selection gradient analysis detected no evidence for direct selection on either resistance or tolerance in this experiment. However, a statistical model indicates that the pattern of selection on resistance depends strongly on the mean level of tolerance, and selection on tolerance depends strongly on the mean level of resistance. These observations are consistent with the hypothesis that selection may act to maintain resistance and tolerance at intermediate levels in spatially or temporally varying environments or those with varying herbivore populations. 相似文献