Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 May 6:14:122.
doi: 10.1186/1471-2229-14-122.

Genome variations account for different response to three mineral elements between Medicago truncatula ecotypes Jemalong A17 and R108

Tian-Zuo Wang, Qiu-Ying Tian, Bao-Lan Wang, Min-Gui Zhao, Wen-Hao Zhang  1
Affiliations

Genome variations account for different response to three mineral elements between Medicago truncatula ecotypes Jemalong A17 and R108

Tian-Zuo Wang et al. BMC Plant Biol. .

Abstract

Background: Resequencing can be used to identify genome variations underpinning many morphological and physiological phenotypes. Legume model plant Medicago truncatula ecotypes Jemalong A17 (J. A17) and R108 differ in their responses to mineral toxicity of aluminum and sodium, and mineral deficiency of iron in growth medium. The difference may result from their genome variations, but no experimental evidence supports this hypothesis.

Results: A total of 12,750 structure variations, 135,045 short insertions/deletions and 764,154 single nucleotide polymorphisms were identified by resequencing the genome of R108. The suppressed expression of MtAACT that encodes a putative aluminum-induced citrate efflux transporter by deletion of partial sequence of the second intron may account for the less aluminum-induced citrate exudation and greater accumulation of aluminum in roots of R108 than in roots of J. A17, thus rendering R108 more sensitive to aluminum toxicity. The higher expression-level of MtZpt2-1 encoding a TFIIIA-related transcription factor in J. A17 than R108 under conditions of salt stress can be explained by the greater number of stress-responsive elements in its promoter sequence, thus conferring J. A17 more tolerant to salt stress than R108 plants by activating the expression of downstream stress-responsive genes. YSLs (Yellow Stripe-Likes) are involved in long-distance transport of iron in plants. We found that an YSL gene was deleted in the genome of R108 plants, thus rendering R108 less tolerance to iron deficiency than J. A17 plants.

Conclusions: The deletion or change in several genes may account for the different responses of M. truncatula ecotypes J. A17 and R108 to mineral toxicity of aluminum and sodium as well as iron deficiency. Uncovering genome variations by resequencing is an effective method to identify different traits between species/ecotypes that are genetically related. These findings demonstrate that analyses of genome variations by resequencing can shed important light on differences in responses of M. truncatula ecotypes to abiotic stress in general and mineral stress in particular.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Effect of Al3+ on root elongation, citrate exudation and Al content in roots of J. A17 and R108 plants. The relative root elongation was determined by exposing 3-d-old seedlings of J. 17 and R108 to 5 μM AlCl3 (pH 4.5) for 2 days (a). Data are mean ± s.e. with n = 10. Al contents in roots of J. A17 and R108 plants before and after exposure to 5 μM AlCl3 (pH 4.5) for 2 days (b). Data are mean ± s.e. with n = 4. Citrate exudation rate from roots of J. A17 and R108 plants treated with 5 μM AlCl3 (pH 4.5) for 24 h (c). Data are mean ± s.e. with n = 5. * and ** indicate significant difference between genotypes within a given growth condition (−Al or + Al) at P ≤ 0.05 and P ≤ 0.01, respectively.
Figure 2
Figure 2
Effects of salt stress and iron deficiency on Na+ and K+ concentrations, Na+/K+ ratio, and Fe concentrations in shoots of J. A17 and R108 plants. Concentrations of Na and K and Na+/K+ ratio in shoots treated with and without 100 mM NaCl for 5 days were shown in panel (a), (b) and (c), respectively. Data are mean ± s.e. with n = 4. Fe concentration in shoots of 5-d-old seedlings of J. A17 and R108 plants exposed to control, Fe-sufficient medium (100 μM Fe-EDTA, +Fe) and Fe-deficient medium (1 μM Fe-EDTA) for 5 days (d). * and ** indicate significant difference between genotypes within a given growth condition at P ≤ 0.05 and P ≤ 0.01, respectively.
Figure 3
Figure 3
The sequencing coverage of 8 chromosomes in the genome of R108 against to the reference of J. A17 genome. One hundred kb was defined as one window.
Figure 4
Figure 4
Similarity of MtAACT protein to other known AACT proteins and effect of Al3+ on expression of MtAACT in J. A17 and R108 plants. Phylogenetic tree of known and putative Al-activated citrate transporters was constructed by MEGA 5 in panel (a). The accession numbers of SbMATE, HvAACT1, AtMATE, ZmMATE1, MtMATE, At4g38380 and At2g38330 in GenBank are ABS89149.1, BAF75822.1, NP_974000.1, ACM47311.1, XP_003627698.1, NP_195551.5 and NP_181367.2, respectively. The expression of MtAACT in roots of J. A17 and R108 plants under the conditions of with or without 5 μM A1Cl3 (pH 4.5) in medium for 1 days (b). Data are mean ± s.e. with three biological replicates. * and ** indicate significant difference between genotypes within a given growth condition (−Al or + Al) at P ≤ 0.05 and P ≤ 0.01, respectively.
Figure 5
Figure 5
Analysis of MtZpt2-1 promoter sequence of J. A17 and R108. The arrows above line represent cis-elements of J. A17, and that of below the line indicate elements of R108.
Figure 6
Figure 6
Sequence analysis of YSL protein family. Phylogenetic tree of these proteins was constructed by MEGA 5. The corresponding IDs were shown in the figure.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Graham PH, Vance CP. Legumes: Importance and constraints to greater use. Plant Physiol. 2003;131(3):872–877. doi: 10.1104/pp.017004. - DOI - PMC - PubMed
    1. Cook DR. Medicago truncatula - a model in the making! Commentary. Curr Opin Plant Biol. 1999;2(4):301–304. doi: 10.1016/S1369-5266(99)80053-3. - DOI - PubMed
    1. Ma JF, Ryan PR, Delhaize E. Aluminium tolerance in plants and the complexing role of organic acids. Trends Plant Sci. 2001;6(6):273–278. doi: 10.1016/S1360-1385(01)01961-6. - DOI - PubMed
    1. Thimm O, Essigmann B, Kloska S, Altmann T, Buckhout TJ. Response of arabidopsis to iron deficiency stress as revealed by microarray analysis. Plant Physiol. 2001;127(3):1030–1043. doi: 10.1104/pp.010191. - DOI - PMC - PubMed
    1. Munns R, Tester M. Mechanisms of salinity tolerance. Annu Rev Plant Biol. 2008;59:651–681. doi: 10.1146/annurev.arplant.59.032607.092911. - DOI - PubMed

Publication types

MeSH terms

  NODES
twitter 2