Abstract
LEAFY COTYLEDON1 (LEC1) is a HAP3 subunit of CCAAT-binding transcription factor. The species in the genus Isoetes L. from China include I. hypsophila, I. yunguiensis, I. sinensis, I. orientalis, and I. taiwenensis. In this study, we initially gathered substantial samples from wide geographic ranges in China. Then we explored the evolutionary characteristics and expression profiles of LEC1 in Isoetes from China. We amplified 57 unique LEC1 nucleotide sequences from 94 individuals. The value of nucleotide diversity was 0.01693 for all samples, and neutrality tests indicated that LEC1 is under purifying negative selection in the evolutionary process. AMOVA analysis revealed that the genetic variation occurred mainly among populations within species. Moreover, the non-synonymous to synonymous substitution rates for 41 unique LEC1 protein sequences further demonstrated the presence of negative selection acting on the species from China to fix amino acid residues. Phylogenetic analyses of nucleotide and protein sequences showed consistently that the trees consisted of two well-supported main clades, and that the haplotypes from H42 to H57 in I. hypsophila were exclusive. In addition, expression profile analysis revealed that LEC1 transcripts accumulated primarily in reproductive organs. Looking at drought tolerance, LEC1 transcripts increased markedly at 24 h after drought treatment and reached a peak at 48 h. RNA accumulation reoccurred at relatively low levels and was slightly elevated at 48 h after rehydration. Altogether, our analyses provide insight into the evolutionary process of LEC1, and our results might promote further studies of functional genes in Isoetes.
Similar content being viewed by others
References
Arnold K, Bordoli L, Kopp J, Schwede T (2006) The SWISS-MODEL workspace: a web-based environment for protein structure homology modelling. Bioinformatics 22:195–201
Avise JC et al (1987) Intraspecific phylogeography: the mitochondrial DNA bridge between population genetics and systematics. Annu Rev Ecol Syst 18:489–522
Bandelt H-J, Forster P, Röhl A (1999) Median-joining networks for inferring intraspecific phylogenies. Mol Biol Evol 16:37–48
Brito PH, Edwards SV (2009) Multilocus phylogeography and phylogenetics using sequence-based markers. Genetica 135:439–455
Cagliari A, Turchetto-Zolet AC, Korbes AP, dos Santos MF, Margis R, Margis-Pinheiro M (2014) New insights on the evolution of Leafy cotyledon1 (LEC1) type genes in vascular plants. Genomics 103:380–387
Chevin L-M, Lande R, Mace GM (2010) Adaptation, plasticity, and extinction in a changing environment: towards a predictive theory. PLoS Biol 8:e1000357
Dellaporta SL, Wood J, Hicks JB (1983) A plant DNA minipreparation: version II. Plant Mol Biol Report 1:19–21
Dorn A, Bollekens J, Staub A, Benoist C, Mathis D (1987) A multiplicity of CCAAT box-binding proteins. Cell 50:863–872
Excoffier L, Laval G, Schneider S (2005) Arlequin (version 3.0): an integrated software package for population genetics data analysis. Evol Bioinformatics Online 1:47
Foster AS, Gifford EM (1959) Comparative morphology of vascular plants. Freeman, San Francisco
Fu Y-X, Li W-H (1993) Statistical tests of neutrality of mutations. Genetics 133:693–709
Ghalambor CK, Hoke KL, Ruell EW, Fischer EK, Reznick DN, Hughes KA (2015) Non-adaptive plasticity potentiates rapid adaptive evolution of gene expression in nature. Nature 525:372–375
Haldane JBS (1957) The cost of natural selection. J Genet 55:511–524
Harada JJ (2001) Role of Arabidopsis leafy cotyledon genes in seed development. J Plant Physiol 158:405–409
Hauser M-T, Harr B, Schlötterer C (2001) Trichome distribution in Arabidopsis thaliana and its close relative Arabidopsis lyrata: molecular analysis of the candidate gene GLABROUS1. Mol Biol Evol 18:1754–1763
Hewitt GM (1999) Post-glacial re-colonization of European biota. Biol J Linn Soc 68:87–112
Hoot SB, Taylor WC (2001) The utility of nuclear ITS, a LEAFY homolog intron, and chloroplast atpB-rbcL spacer region data in phylogenetic analyses and species delimitation in Isoëtes. Am Fern J 91:166–177
Jones DT, Taylor WR, Thornton JM (1992) The rapid generation of mutation data matrices from protein sequences. Comput Appl Biosci: CABIOS 8:275–282
Junker A, Bäumlein H (2012) Multifunctionality of the LEC1 transcription factor during plant development. Plant Signal Behav 7:1718–1720
Kenrick P, Crane PR (1997) The origin and early evolution of plants on land. Nature 389:33–39
Kirkbride RC, Fischer RL, Harada JJ (2013) LEAFY COTYLEDON1, a key regulator of seed development, is expressed in vegetative and sexual propagules of Selaginella moellendorffii. PLoS ONE 8(6):e67971. doi:10.1371/journal.pone.0067971
Kotlík P, Marková S, Vojtek L, Stratil A, Šlechta V, Hyršl P, Searle JB (2014) Adaptive phylogeography: functional divergence between haemoglobins derived from different glacial refugia in the bank vole. Proc R Soc Lond B Biol Sci 281:20140021
Kwong RW, Bui AQ, Lee H, Kwong LW, Fischer RL, Goldberg RB, Harada JJ (2003) LEAFY COTYLEDON1-LIKE defines a class of regulators essential for embryo development. Plant Cell 15:5–18
Larkin MA et al (2007) Clustal W and Clustal X version 2.0. Bioinformatics 23:2947–2948
Lee H, Fischer RL, Goldberg RB, Harada JJ (2003) Arabidopsis LEAFY COTYLEDON1 represents a functionally specialized subunit of the CCAAT binding transcription factor. Proc Natl Acad Sci USA 100:2152–2156
Librado P, Rozas J (2009) DnaSP v5: a software for comprehensive analysis of DNA polymorphism data. Bioinformatics 25:1451–1452
Liu X, Gituru WR, Wang QF (2004) Distribution of basic diploid and polyploid species of Isoetes in East Asia. J Biogeogr 31:1239–1250
Livak KJ, Schmittgen TD (2001) Analysis of relative gene expression data using real-time quantitative PCR and the 2− ΔΔCT method. Methods 25:402–408
Lotan T et al (1998) Arabidopsis LEAFY COTYLEDON1 is sufficient to induce embryo development in vegetative cells. Cell 93:1195–1205
Lu G, Moriyama EN (2004) Vector NTI, a balanced all-in-one sequence analysis suite. Brief Bioinform 5:378–388
Maity SN, de Crombrugghe B (1998) Role of the CCAAT-binding protein CBF/NF-Y in transcription. Trends Biochem Sci 23:174–178
Mantovani R (1999) The molecular biology of the CCAAT-binding factor NF-Y. Gene 239:15–27
Meinke DW (1992) A homoeotic mutant of Arabidopsis thaliana with leafy cotyledons. Science 258:1647–1650
Meinke DW, Franzmann LH, Nickle TC, Yeung EC (1994) Leafy cotyledon mutants of Arabidopsis. Plant Cell 6:1049–1064
Mu J et al (2008) LEAFY COTYLEDON1 is a key regulator of fatty acid biosynthesis in Arabidopsis. Plant Physiol 148:1042–1054
Nelson DE et al (2007) Plant nuclear factor Y (NF-Y) B subunits confer drought tolerance and lead to improved corn yields on water-limited acres. Proc Natl Acad Sci USA 104:16450–16455
Piccinali R, Aguadé M, Hasson E (2004) Comparative molecular population genetics of the Xdh locus in the cactophilic sibling species Drosophila buzzatii and D. koepferae. Mol Biol Evol 21:141–152
Pigg KB (1992) Evolution of isoetalean lycopsids. Ann Mo Bot Gard 79:589–612
Pigg KB (2001) Isoetalean lycopsid evolution: from the Devonian to the present. Am Fern J 91:99–114
Pond SLK, Frost SD (2005a) Datamonkey: rapid detection of selective pressure on individual sites of codon alignments. Bioinformatics 21:2531–2533
Pond SLK, Frost SD (2005b) Not so different after all: a comparison of methods for detecting amino acid sites under selection. Mol Biol Evol 22:1208–1222
Saha J, Gupta K, Gupta B (2013) In silico characterization and evolutionary analyses of CCAAT binding proteins in the lycophyte plant Selaginella moellendorffii genome: a growing comparative genomics resource. Comput Biol Chem 47:81–88
Schneider H, Pryer KM, Cranfill R, Smith AR, Wolf PG (2002) Evolution of vascular plant body plans: a phylogenetic perspective. Syst Assoc Spec Vol 65:330–364
Sinha S, Kim I-S, Sohn K-Y, De Crombrugghe B, Maity SN (1996) Three classes of mutations in the A subunit of the CCAAT-binding factor CBF delineate functional domains involved in the three-step assembly of the CBF-DNA complex. Mol Cell Biol 16:328–337
Tajima F (1989) Statistical method for testing the neutral mutation hypothesis by DNA polymorphism. Genetics 123:585–595
Tamura K, Stecher G, Peterson D, Filipski A, Kumar S (2013) MEGA6: molecular evolutionary genetics analysis version 6.0. Mol Biol Evol 30:2725–2729
Tan H et al (2011) Enhanced seed oil production in canola by conditional expression of Brassica napus LEAFY COTYLEDON1 and LEC1-LIKE in developing seeds. Plant Physiol 156:1577–1588
Verdier J, Thompson RD (2008) Transcriptional regulation of storage protein synthesis during dicotyledon seed filling. Plant Cell Physiol 49:1263–1271
Warpeha KM et al (2007) The GCR1, GPA1, PRN1, NF-Y signal chain mediates both blue light and abscisic acid responses in Arabidopsis. Plant Physiol 143:1590–1600
West MA, Yee KM, Danao J, Zimmerman JL, Fischer RL, Goldberg RB, Harada JJ (1994) LEAFY COTYLEDON1 is an essential regulator of late embryogenesis and cotyledon identity in Arabidopsis. Plant Cell 6:1731–1745
Xie Z, Li X, Glover BJ, Bai S, Rao G-Y, Luo J, Yang J (2008) Duplication and functional diversification of HAP3 genes leading to the origin of the seed-developmental regulatory gene, LEAFY COTYLEDON1 (LEC1), in nonseed plant genomes. Mol Biol Evol 25:1581–1592
Yang Z (2006) Computational molecular evolution vol 21. Oxford University Press, Oxford
Yang Z (2007) PAML 4: phylogenetic analysis by maximum likelihood. Mol Biol Evol 24:1586–1591
Yang T, Liu X (2015) Comparative transcriptome analysis of isoetes sinensis under terrestrial and submerged conditions. Plant Mol Biol Report 33:1–10
Acknowledgments
The authors would like to thank Junneng Wang for presenting the samples from Taiwan and Guangqian Ge for the samples from Nayong, Guizhou. The research was supported by “National Natural Science Foundation of China” (30870168 and 31170203) and “the Fundamental Research Funds for the Central Universities” (2014204020206).
Contributions
T.Y. cultured the plant tissue and isolated RNA, performed the experiments, analyzed the data, and drafted the manuscript. W.Z., M.D. and F.T. performed the experiments and analyzed the data. X.D. analyzed partial data. X.L. and Y.G. revised the manuscript. All authors reviewed the final manuscript.
Author information
Authors and Affiliations
Corresponding authors
Electronic supplementary material
Below is the link to the electronic supplementary material.
Fig. S1
Median joining network for all 57 haplotypes. The pie charts are proportional in size to the contained haplotypes and the colors in the pie charts are according to species. (GIF 186 kb)
Fig. S2
Alignment of 41 LEC1 amino acid sequences obtained in this study. (GIF 307 kb)
Fig. S3
Three-dimensional structures of LEC1 proteins for a I. hypsophila, b I. yunguiensis, c I. sinensis, d I. orientalis, and e I. taiwanensis. (GIF 178 kb)
Table S1
Accession numbers for all obtained LEC1 sequences in this study (DOCX 20 kb)
Rights and permissions
About this article
Cite this article
Yang, T., Zan, Ww., Du, Mf. et al. Evolutionary and Functional Analysis of LEAFY COTYLEDON1 in Isoetes L. from China. Plant Mol Biol Rep 35, 154–165 (2017). https://doi.org/10.1007/s11105-016-1009-8
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11105-016-1009-8