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1.
Fontecha G Silva-Navas J Benito C Mestres MA Espino FJ Hernández-Riquer MV Gallego FJ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(2):249-260
Among cereal crops, rye is one of the most tolerant species to aluminum. A candidate gene approach was used to determine the
likely molecular identity of an Al tolerance locus (Alt4). Using PCR primers designed from a wheat aluminum tolerance gene encoding an aluminum-activated malate transporter (TaALMT1), a rye gene (ScALMT1) was amplified, cloned and sequenced. Subsequently, the ScALMT1 gene of rye was found to be located on 7RS by PCR amplification using the wheat–rye addition lines. SNP polymorphisms for this gene were detected among the parents
of three F2 populations that segregate for the Alt4 locus. A map of the rye chromosome 7R, including the Alt4 locus ScALMT1 and several molecular markers, was constructed showing a complete co-segregation between Alt4 and ScALMT1. Furthermore, expression experiments were carried out to clarify the function of this candidate gene. Briefly, the ScALMT1 gene was found to be primarily expressed in the root apex and upregulated when aluminum was present in the medium. Five-fold
differences in the expression were found between the Al tolerant and the Al non-tolerant genotypes. Additionally, much higher
expression was detected in the rye genotypes than the moderately tolerant “Chinese Spring” wheat cultivar. These results suggest
that the Alt4 locus encodes an aluminum-activated organic acid transporter gene that could be utilized to increase Al tolerance in Al sensitive
plant species. Finally, TaALMT1 homologous sequences were identified in different grasses and in the dicotyledonous plant Phaseolus vulgaris. Our data support the hypothesis of the existence of a common mechanism of Al tolerance encoded by a gene located in the
homoeologous group four of cereals.
G. Fontecha and J. Silva-Navas contributed equally to this work. 相似文献
2.
Genetic structure and diversity of European flint maize populations determined with SSR analyses of individuals and bulks 总被引:5,自引:0,他引:5
Miftahudin Chikmawati T Ross K Scoles GJ Gustafson JP 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(5):906-913
Characterization and manipulation of aluminum (Al) tolerance genes offers a solution to Al toxicity problems in crop cultivation on acid soil, which composes approximately 40% of all arable land. By exploiting the rice (Oryza sativa L.)/rye (Secale cereale L.) syntenic relationship, the potential for map-based cloning of genes controlling Al tolerance in rye (the most Al-tolerant cereal) was explored. An attempt to clone an Al tolerance gene (Alt3) from rye was initiated by using DNA markers flanking the rye Alt3 gene, from many cereals. Two rice-derived, PCR-based markers flanking the Alt3 gene, B1 and B4, were used to screen 1,123 plants of a rye F2 population segregating for Alt3. Fifteen recombinant plants were identified. Four additional RFLP markers developed from rice genes/putative genes, spanning 10 kb of a 160-kb rice BAC, were mapped to the Alt3 region. Two rice markers flanked the Alt3 locus at a distance of 0.05 cM, while two others co-segregated with it. The rice/rye micro-colinearity worked very well to delineate and map the Alt3 gene region in rye. A rye fragment suspected to be part of the Alt3 candidate gene was identified, but at this level, the rye/rice microsynteny relationship broke down. Because of sequence differences between rice and rye and the complexity of the rye sequence, we have been unable to clone a full-length candidate gene in rye. Further attempts to clone a full-length rye Alt3 candidate gene will necessitate the creation of a rye large-insert library. 相似文献
3.
AFLP markers tightly linked to the aluminum-tolerance gene Alt3 in rye (Secale cereale L.) 总被引:3,自引:0,他引:3
Miftahudin G. J. Scoles J. P. Gustafson 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(4):626-631
Rye (Secale cereale L.) is considered to be the most aluminum (Al)-tolerant species among the Triticeae. It has been suggested that aluminum
tolerance in rye is controlled by three major genes (Alt genes) located on rye chromosome arms 3RL, 4RL, and 6RS, respectively. Screening of an F6 rye recombinant inbred line (RIL) population derived from the cross between an Al-tolerant rye (M39A-1–6) and an Al-sensitive
rye (M77A-1) showed that a single gene controls aluminum tolerance in the population analyzed. In order to identify molecular
markers tightly linked to the gene, we used a combination of amplified fragment length polymorphism (AFLP) and bulked segregant
analysis techniques to evaluate the F6 rye RIL population. We analyzed approximately 22,500 selectively amplified DNA fragments using 204 primer combinations and
identified three AFLP markers tightly linked to the Alt gene. Two of these markers flanked the Alt locus at distance of 0.4 and 0.7 cM. Chromosomal localization using cloned AFLP and a restriction fragment length polymorphism
(RFLP) marker indicated that the gene was on the long arm of rye chromosome 4R. The RFLP marker (BCD1230) co-segregated with
the Alt gene. Since the gene is on chromosome 4R, the gene was designated as Alt3. These markers are being used as a starting point in the construction of a high resolution map of the Alt3 region in rye.
Received: 29 March 2000 / Accepted: 9 July 2001 相似文献
4.
B.-J. Shi J. P. Gustafson J. Button J. Miyazaki M. Pallotta N. Gustafson H. Zhou P. Langridge N. C. Collins 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(4):695-704
Rye is a diploid crop species with many outstanding qualities, and is important as a source of new traits for wheat and triticale
improvement. Rye is highly tolerant of aluminum (Al) toxicity, and possesses a complex structure at the Alt4 Al tolerance locus not found at the corresponding locus in wheat. Here we describe a BAC library of rye cv. Blanco, representing
a valuable resource for rye molecular genetic studies, and assess the library’s suitability for investigating Al tolerance
genes. The library provides 6 × genome coverage of the 8.1 Gb rye genome, has an average insert size of 131 kb, and contains
only ~2% of empty or organelle-derived clones. Genetic analysis attributed the Al tolerance of Blanco to the Alt4 locus on the short arm of chromosome 7R, and revealed the presence of multiple allelic variants (haplotypes) of the Alt4 locus in the BAC library. BAC clones containing ALMT1 gene clusters from several Alt4 haplotypes were identified, and will provide useful starting points for exploring the basis for the structural variability
and functional specialization of ALMT1 genes at this locus.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
A new aluminum tolerance gene located on rye chromosome arm 7RS 总被引:2,自引:0,他引:2
Matos M Camacho MV Pérez-Flores V Pernaute B Pinto-Carnide O Benito C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(2):360-369
Rye has one of the most efficient groups of genes for aluminum tolerance (Alt) among cultivated species of Triticeae. This tolerance is controlled by, at least, three independent and dominant loci (Alt1, Alt2, and Alt3) located on chromosome arms 6RS, 3RS, and 4RL, respectively. The segregation of Alt genes and several random amplified polymorphic DNA (RAPD), Secale cereale inter-microsatellite (SCIM), and Secale cereale microsatellite (SCM) markers in three F(2) between a tolerant cultivar (Ailés) and a non-tolerant inbred line (Riodeva) were studied. The segregation ratio obtained for aluminum tolerance in the three F(2) populations analyzed was 3:1 (tolerant:non-tolerant), indicating that tolerance is controlled by one dominant locus. SCIM811(1376) was linked to an Alt gene in the three F(2) populations studied, and three different SCIMs and one RAPD (SCIM811(1376), SCIM812(626), SCIM812(1138), and OPQ4(725)) were linked to the Alt gene in two F(2) populations. This result indicated that the same Alt gene was segregating in the three crosses. SCIM819(1434) and OPQ4(578) linked to the tolerance gene in one F(2) population were located using wheat-rye ditelosomic addition lines on the 7RS chromosome arm. The Alt locus is mapped between SCIM819(1434) and the OPQ4(578) markers. Two microsatellite loci (SCM-40 and SCM-86), previously located on chromosome 7R, were also linked to the Alt gene. Therefore, the Alt gene segregating in these F(2) populations is new and probably could be orthologous to the Alt genes located on wheat chromosome arm 4DL, on barley chromosome arm 4HL, on rye chromosome arm 4RL, and rice chromosome 3. This new Alt gene located on rye chromosome arm 7RS was named Alt4. A map of rye chromosome 7R with the Alt4 gene, 16 SCIM and RAPD, markers and two SCM markers was obtained. 相似文献
6.
7.
Aluminum (Al) toxicity is considered to be a major problem for crop growth and production on acid soils. The ability of crops to overcome Al toxicity varies among crop species and cultivars. Rye (Secale cereale L.) is the most Al-tolerant species among the Triticeae. Our previous study showed that Al tolerance in a rye F6 recombinant inbred line (RIL) population was controlled by a single gene designated as the aluminum tolerance (Alt3) gene on chromosome 4RL. Based on the DNA sequence of a rice (Oryza sativa L.) BAC clone suspected to be syntenic to the Alt3 gene region, we developed two PCR-based codominant markers flanking the gene. These two markers, a sequence-tagged site (STS) marker and a cleaved amplified polymorphic sequence (CAPS) marker, each flanked the Alt3 gene at an approximate distance of 0.4 cM and can be used to facilitate high-resolution mapping of the gene. The markers might also be used for marker-assisted selection in rye or wheat (Triticum aestivum L.) breeding programs to obtain Al-tolerant lines and (or) cultivars. 相似文献
8.
F. J. Gallego C. Benito 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(3):393-399
Aluminium (Al) tolerance in roots of two cultivars (“Ailés” and “JNK”) and two inbred lines (“Riodeva” and “Pool”) of rye
was studied using intact roots immersed in a nutrient solution at a controlled pH and temperature. Both the cultivars and
the inbred lines analysed showed high Al tolerance, this character being under multigenic control. The inbred line “Riodeva”
was sensitive (non-telerant) at a concentration of 150 μM, whereas the “Ailes” cultivar showed the highest level of Al tolerance
at this concentration. The segregation of aluminium-tolerance genes and several isozyme loci in different F1s, F2s and backcrosses between plants of “Ailés” and “Riodeva” were also studied. The segregation ratios obtained for aluminium
tolerance in the F2s analysed were 3 : 1 and 15 : 1 (tolerant : non-tolerant) while in backcrosses they were 1 : 1 and 3 : 1. These results indicated
that Al tolerance is controlled by, at least, two major dominant and independent loci in rye (Alt1 and Alt3). Linkage analyses carried out between Al-tolerance genes and several isozyme loci revealed that the Alt1 locus was linked to the aconitase-1 (Aco1), nicotinamide adenine dinucleotide dehydrogenase-2 (Ndh2), esterase-6 (Est6) and esterase-8 (Est8) loci, located on chromosome arm 6RL. The order obtained was Alt1-Aco1-Ndh2-Est6-Est8. The Alt3 locus was not linked to the Lap1, Aco1 and Ndh2 loci, located on chromosome arms, 6RS, 6RL and 6RL respectively. Therefore, the Alt3 locus is probably on a different chromosome.
Received: 18 March 1997 / Accepted: 21 March 1997 相似文献
9.
E. Santos C. Benito J. Silva-Navas F. J. Gallego A. M. Figueiras O. Pinto-Carnide M. Matos 《Biologia Plantarum》2018,62(1):109-120
Aluminum (Al) is the main limiting factor for crop production in acidic soils. Efflux of organic acids is one of the mechanisms that determine Al-tolerance, and an Al-activated citrate transporter (multidrug and toxic compound extrusion) MATE1 gene is involved in different species. The contribution of the rye MATE1 gene (ScMATE1) depends on the rye (Secale cereale L.) cultivars and the crosses analyzed; there is no information about different rye species. The cDNA sequences, phylogenetic relationships, Al-tolerance, citrate exudation, and expression of the ScMATE1 gene were analyzed in several cultivars and wild species/subspecies of the Secale genus. Genotypes highly tolerant to Al were found within this genus. For the first time, sequences of the cDNA of the ScMATE1 gene were isolated and characterized in wild ryes. At least two copies of this gene were found likely to be related to Al-tolerance. The sequence comparison of 13 exons of ScMATE1 revealed variability between species, but also inter- and intra-cultivars. Variations were found in the Al-induced expression of ScMATE1 gene, as well as its contribution to Al-tolerance. The pattern of citrate exudation was inducible in most of the species/subspecies studied and constitutive in few. The phylogenetic analysis indicated that ScMATE1 is orthologue of two genes (HvMATE1 and TaMATE1) involved in the Al stress response in barley and wheat, respectively, but not orthologue of SbMATE, implicated in Al-tolerance in sorghum. ScMATE1 is involved in the response to Al stress in ryes, but its contribution to Al-tolerance is complex, and like in other species, there are tolerant and sensitive alleles in the different cultivars and species studied. 相似文献
10.
- Aluminium (Al) toxicity is the major constraint for crop productivity in acid soils. Wild rye species (Secale spp.) exhibit high Al tolerance, being a good source of genes related to this trait. The Alt1 locus located on the 6RS chromosome arm is one of the four main loci controlling Al tolerance in rye and is known to harbour major genes but, so far, none have been found.
- Through synteny among the short arm of the rye chromosome 6R and the main grass species, we found a candidate MATE gene for the Atl1 locus, later named ScMATE3, which was isolated and characterized in different Secale species.
- The sequence comparisons revealed both intraspecific and interspecific variability, with high sequence conservation in the Secale genus. SNP with replacement substitution that changed the structure of the protein and can be involved in the Al tolerance trait were found in ScMATE3 gene. The predicted subcellular localization of ScMATE3 is the vacuolar membrane which, together with the phylogenetic relationships performed with other MATE genes of the Poaceae related to Al detoxification, suggest involvement of ScMATE3 in an internal tolerance mechanism. Moreover, expression studies of this gene in rye corroborate its contribution in some Al resistance mechanisms.
- The ScMATE3 gene is located on the 6RS chromosome arm between the same markers in which the Alt1 locus is involved in Al resistance mechanisms in rye, thus being a good candidate gene for this function.
11.
M. Matos V. Pérez-Flores M. V. Camacho B. Pernaute O. Pinto-Carnide C. Benito 《Molecular breeding : new strategies in plant improvement》2007,20(2):103-115
Aluminium toxicity is a major problem for crop production on acid soils. Rye (Secale cereale L.) has one of the most efficient group of genes for aluminium tolerance, at least, four independent and dominant loci, Alt1, Alt2, Alt3 and Alt4, located on chromosome arms 6RS, 3RS, 4RL and 7RS, have been described. The increasing availability of expressed sequence
tags in rye and related cereals provides a valuable resource of non-anonymous DNA molecular markers. In order to obtain simple
sequence repeat (SSR) markers related with Al tolerance more than 1,199 public accessible rye cDNA sequences from Al-stressed
roots were exploited as a resource for SSR markers development. From a total of 21 S. cereale microsatellite (SCM) loci analysed, 12 were located on chromosomes 1R, 2R, 3R, 4R and 5R, using wheat–rye addition lines
or mapped using a F2 population segregating for Al tolerance. Seven SCM loci were included in a rye map with other SCIM and RAPD markers. Moreover,
14 SCM loci could be associated to proteins with known or unknown function. The possible implications of these sequences in
aluminium tolerance mechanisms are discussed. 相似文献
12.
J. Silva-Navas C. Benito B. Téllez-Robledo D. Abd El-Moneim F. J. Gallego 《Molecular breeding : new strategies in plant improvement》2012,30(2):845-856
Soluble aluminum (Al3+) is a major constraint to plant growth in highly acidic soils, which comprise up to 50% of the world??s arable land. The primary mechanism of Al resistance described in plants is the chelation of Al3+ cations by release of organic acids into the rhizosphere. Candidate aluminum tolerance genes encoding organic acid transporter of the ALMT (aluminum-activated malate transporter) and MATE (multi-drug and toxic compound extrusion) families have been characterized in several plant species. In this study, we have isolated in five different cultivars the rye ScAACT1 gene, homolog to barley aluminum activated citrate transporter HvAACT1. This gene mapped to the 7RS chromosome arm, 25?cM away from the ScALMT1 aluminum tolerance gene. The gene consisted of 13 exons and 12 introns and encodes a predicted membrane protein that contains the MatE domain and at least seven putative transmembrane regions. Expression of the ScAACT1 gene is Al-induced, but there were differences in the levels of expression among the cultivars analyzed. A new quantitative trait locus for Al tolerance in rye that co-localizes with the ScAACT1 gene was detected in the 7RS chromosome arm. These results suggest that the ScAACT1 gene is a candidate gene for increased Al tolerance in rye. The phylogenetic relationships between different MATE proteins are discussed. 相似文献
13.
Physiological basis of reduced Al tolerance in ditelosomic lines of Chinese Spring wheat 总被引:13,自引:0,他引:13
Aluminum tolerance was assessed in the moderately Al-tolerant wheat (Triticum aestivum L.) cultivar Chinese Spring and a set of ditelosomic lines derived from Chinese Spring. Three ditelosomic lines lacking chromosome
arms 4DL, 5AS and 7AS, respectively, exhibited decreased Al tolerance relative to the euploid parent Chinese Spring based
on reduced root growth in Al-containing solutions. The physiological basis of the reduced Al tolerance was investigated. Measurements
by inductively coupled argon plasma mass spectroscopy of root apical Al accumulation demonstrated that two of these three
lines had a decreased ability to exclude Al from the root apex, the site of Al phytotoxicity. As Al-induced malate exudation
has been suggested to be an important physiological mechanism of Al tolerance in wheat, this parameter was quantified and
malate exudation was shown to be smaller in all three deletion lines compared with Chinese Spring. These results suggest that
the decreased Al tolerance in at least two of the three ditelosomic lines is due to the loss of different genes independently
influencing a single Al-tolerance mechanism, rather than to the loss of genes encoding alternative Al-tolerance mechanisms.
Received: 3 July 2000 / Accepted: 9 August 2000 相似文献
14.
Narasimhamoorthy B Bouton JH Olsen KM Sledge MK 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(5):901-913
Aluminum (Al) toxicity in acid soils is a major limitation to the production of alfalfa (Medicago sativa subsp. sativa L.) in the USA. Developing Al-tolerant alfalfa cultivars is one approach to overcome this constraint. Accessions of wild
diploid alfalfa (M. sativa subsp. coerulea) have been found to be a source of useful genes for Al tolerance. Previously, two genomic regions associated with Al tolerance
were identified in this diploid species using restriction fragment length polymorphism (RFLP) markers and single marker analysis.
This study was conducted to identify additional Al-tolerance quantitative trait loci (QTLs); to identify simple sequence repeat
(SSR) markers that flank the previously identified QTLs; to map candidate genes associated with Al tolerance from other plant
species; and to test for co-localization with mapped QTLs. A genetic linkage map was constructed using EST-SSR markers in
a population of 130 BC1F1 plants derived from the cross between Al-sensitive and Al-tolerant genotypes. Three putative QTLs on linkage groups LG I,
LG II and LG III, explaining 38, 16 and 27% of the phenotypic variation, respectively, were identified. Six candidate gene
markers designed from Medicago truncatula ESTs that showed homology to known Al-tolerance genes identified in other plant species were placed on the QTL map. A marker
designed from a candidate gene involved in malic acid release mapped near a marginally significant QTL (LOD 2.83) on LG I.
The SSR markers flanking these QTLs will be useful for transferring them to cultivated alfalfa via marker-assisted selection
and for pyramiding Al tolerance QTLs. 相似文献
15.
A rapid hydroponic screening for aluminium tolerance in barley 总被引:9,自引:0,他引:9
Jian Feng Ma Shao Jian Zheng Xiao Feng Li Kazuyoshi Takeda Hideaki Matsumoto 《Plant and Soil》1997,191(1):133-137
Selection and breeding of crops for aluminium (Al) tolerance is a useful approach to increase production on acid soils. This requires a rapid and reliable system to discriminate between Al-tolerant and Al-sensitive genotypes. A hydroponic system was developed to screen for Al tolerance in barley (t Hordeum vulgare L.) to overcome several problems encountered in previous screening methods. Four levels of Al (5, 10, 20, and 40 t M) in 1 mt M CaCl2 solution at pH 4.5 were used to rank lines for Al-tolerance. Each line was cultured in a different compartment to eliminate chemical and pH interactions among lines. To avoid changes in Al tolerance due to other factors such as the calcium (Ca) concentration of the solution, Al-tolerant (Atlas 66) and Al-sensitive (Scout 66) cultivars of wheat (t Triticum aestivum L.) were used as reference cultivars. Five ranks of Al tolerance from highly tolerant to highly sensitive were established by comparison with each reference. Eriochrome cyanine R staining was used for the rapid evaluation of Al tolerance. This screening system allowed classification of about 50 barley lines into five different Al tolerance groups within one week. Using this system, screening of ca. 600 barley lines from various regions of the world was conducted. Most lines were sensitive to Al, but ninety lines showed intermediate Al-tolerance. Thirty nine lines were highly sensitive to Al in solution. 相似文献
16.
Aluminum Tolerance in Wheat (Triticum aestivum L.) (II. Aluminum-Stimulated Excretion of Malic Acid from Root Apices) 总被引:19,自引:13,他引:6 下载免费PDF全文
We investigated the role of organic acids in conferring Al tolerance in near-isogenic wheat (Triticum aestivum L.) lines differing in Al tolerance at the Al tolerance locus (Alt1). Addition of Al to nutrient solutions stimulated excretion of malic and succinic acids from roots of wheat seedlings, and Al-tolerant genotypes excreted 5- to 10-fold more malic acid than Al-sensitive genotypes. Malic acid excretion was detectable after 15 min of exposure to 200 [mu]M Al, and the amount excreted increased linearly over 24 h. The amount of malic acid excreted was dependent on the external Al concentration, and excretion was stimulated by as little as 10 [mu]M Al. Malic acid added to nutrient solutions was able to protect Al-sensitive seedlings from normally phytotoxic Al concentrations. Root apices (terminal 3-5 mm of root) were the primary source of the malic acid excreted. Root apices of Al-tolerant and Al-sensitive seedlings contained similar amounts of malic acid before and after a 2-h exposure to 200 [mu]M Al. During this treatment, Al-tolerant seedlings excreted about four times the total amount of malic acid initially present within root apices, indicating that continual synthesis of malic acid was occurring. Malic acid excretion was specifically stimulated by Al, and neither La, Fe, nor the absence of Pi was able to elicit this response. There was a consistent correlation of Al tolerance with high rates of malic acid excretion stimulated by Al in a population of seedlings segregating for Al tolerance. These data are consistent with the hypothesis that the Alt1 locus in wheat encodes an Al tolerance mechanism based on Al-stimulated excretion of malic acid. 相似文献
17.
To enrich differentially expressed sequence tags (ESTs) for aluminum (Al) tolerance, cDNA subtraction libraries were generated from Al-stressed roots of two wheat (Triticum aestivum L.) nearisogenic lines (NILs) contrasting in Al-tolerance gene(s) from the Al-tolerant cultivar Atlas 66, using suppression subtractive hybridization (SSH). Expression patterns of the ESTs were investigated with nylon filter arrays containing 614 cDNA clones from the subtraction library. Gene expression profiles from macroarray analysis indicated that 25 ESTs were upregulated in the tolerant NIL in response to Al stress. The result from Northern analysis of selected upregulated ESTs was similar to that from macroarray analysis. These highly expressed ESTs showed high homology with genes involved in signal transduction, oxidative stress alleviation, membrane structure, Mg2 transportation, and other functions. Under Al stress, the Al-tolerant NIL may possess altered structure or function of the cell wall, plasma membrane, and mitochondrion. The wheat response to Al stress may involve complicated defense-related signaling and metabolic pathways.The present experiment did not detect any induced or activated genes involved in the synthesis of malate and other organic acids in wheat under Al-stress. 相似文献
18.
19.
Nylon Filter Arrays Reveal Differential Expression of Expressed Sequence Tags in Wheat Roots Under Aluminum Stress 总被引:6,自引:0,他引:6
KaiXIAO Gui-HuaBAI BrettFCARVER 《植物学报(英文版)》2005,47(7):839-848
To enrich differentially expressed sequence tags (ESTs) for aluminum (A1) tolerance, cDNA subtraction libraries were generated from Al-stressed roots of two wheat (Triticum aestivum L.) nearisogenic lines (NILs) contrasting in Al-tolerance gene(s) from the Al-tolerant cultivar Atlas 66, using suppression subtractive hybridization (SSH). Expression patterns of the ESTs were investigated with nylon filter arrays containing 614 cDNA clones from the subtraction library. Gene expression profiles from macroarray analysis indicated that 25 ESTs were upregulated in the tolerant NIL in response to A1 stress. The result from Northern analysis of selected upregulated ESTs was similar to that from macroarray analysis. These highly expressed ESTs showed high homology with genes involved in signal transduction, oxidative stress alleviation, membrane structure, Mg^2 transportation, and other functions. Under A1 stress, the Al-tolerant NIL may possess altered structure or function of the cell wall, plasma membrane, and mitochondrion. The wheat response to A1 stress may involve complicated defense-related signaling and metabolic pathways. The present experiment did not detect any induced or activated genes involved in the synthesis of malate and other organic acids in wheat under Al-stress. 相似文献
20.
Involvement of multiple aluminium exclusion mechanisms in aluminium tolerance in wheat 总被引:5,自引:0,他引:5
Pellet D.M. Papernik L.A. Jones D.L. Darrah P.R. Grunes D.L. Kochian L.V. 《Plant and Soil》1997,192(1):63-68
The goal of this study was to determine if Al-chelators other than malate are released from root apices and are involved in Al-tolerance in different wheat (Triticum aestivum L.) genotypes. Also we wanted to establish if root exudates contribute to increases in rhizosphere pH around the root tip. In seedlings of Al-tolerant Atlas, we have documented a constitutive phosphate exudation from the root apex. Because phosphate can complex Al and bind protons, it could play an important role in Al tolerance, both via complexation of Al3+ and by contributing to the alkalinization of rhizosphere pH observed at the apex of Atlas. This study suggests that in wheat, Al-tolerance can be mediated by multiple exclusion mechanisms controlled by different genes. 相似文献