Draft genome sequence of pigeonpea (Cajanus cajan), an orphan legume crop of resource-poor farmers

Journal name:
Nature Biotechnology
Volume:
30,
Pages:
83–89
Year published:
DOI:
doi:10.1038/nbt.2022
Received
Accepted
Published online

Abstract

Pigeonpea is an important legume food crop grown primarily by smallholder farmers in many semi-arid tropical regions of the world. We used the Illumina next-generation sequencing platform to generate 237.2 Gb of sequence, which along with Sanger-based bacterial artificial chromosome end sequences and a genetic map, we assembled into scaffolds representing 72.7% (605.78 Mb) of the 833.07 Mb pigeonpea genome. Genome analysis predicted 48,680 genes for pigeonpea and also showed the potential role that certain gene families, for example, drought tolerance–related genes, have played throughout the domestication of pigeonpea and the evolution of its ancestors. Although we found a few segmental duplication events, we did not observe the recent genome-wide duplication events observed in soybean. This reference genome sequence will facilitate the identification of the genetic basis of agronomically important traits, and accelerate the development of improved pigeonpea varieties that could improve food security in many developing countries.

At a glance

Figures

  1. Extensive synteny between the pigeonpea and soybean genomes.
    Figure 1: Extensive synteny between the pigeonpea and soybean genomes.

    Soybean pseudomolecules, labeled as Gm, are represented as green boxes. Numbers along each chromosome box are sequence length in megabases. Pigeonpea pseudomolecules, labeled as CcLG, are shown with each chromosome as a different color. Syntenic blocks were identified through reciprocal best matches between gene models and block identification using i-ADHoRe. Each line radiating from a pigeonpea pseudomolecule represents a gene match found in a block between soybean and pigeonpea.

  2. Microsynteny analysis between pigeonpea and soybean genomes.
    Figure 2: Microsynteny analysis between pigeonpea and soybean genomes.

    One chromosome arm of soybean chromosome 01S (south arm) and pigeonpea CcLG06 (indicated as a green circle in the whole-genome dot-plot in Supplementary Fig. 6) is shown here as a representation of microsynteny. Mapping of the pigeonpea transcriptome assembly contigs (TACs) of the pigeonpea transcriptome assembly (CcTA v2) onto both genomes (indicated by green lines) was used as a measure of conserved gene order. (a) The first part shows local rearrangements. (b) The later part indicates very good collinearity among genes in the two genomes.

  3. Distribution of gene families among five eudicot genomes (M. truncatula, soybean, L. japonicus, pigeonpea and grapevine).
    Figure 3: Distribution of gene families among five eudicot genomes (M. truncatula, soybean, L. japonicus, pigeonpea and grapevine).

    Homologous genes in pigeonpea, soybean, M. truncatula, L. japonicus and grapevine were clustered to gene families. The numbers of gene families are indicated for each species and species intersection.

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Author information

Affiliations

  1. International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India.

    • Rajeev K Varshney,
    • Rachit K Saxena,
    • Sarwar Azam,
    • Reetu Tuteja,
    • Hari D Upadhyaya,
    • Trushar Shah &
    • K B Saxena
  2. CGIAR Generation Challenge Programme (GCP), c/o CIMMYT, Mexico DF, Mexico.

    • Rajeev K Varshney
  3. Beijing Genomics Institute (BGI)-Shenzhen, Shenzhen, China.

    • Wenbin Chen,
    • Guangyi Fan,
    • Bicheng Yang,
    • Gengyun Zhang,
    • Huanming Yang,
    • Jun Wang &
    • Xun Xu
  4. University of Georgia, Athens, Georgia, USA.

    • Yupeng Li,
    • Aiko Iwata &
    • Scott A Jackson
  5. National Center for Genome Resources (NCGR), Santa Fe, New Mexico, USA.

    • Arvind K Bharti,
    • Andrew D Farmer &
    • Gregory D May
  6. University of North Carolina, Charlotte, North Carolina, USA.

    • Jessica A Schlueter,
    • Adam M Whaley &
    • Jaime Sheridan
  7. National University of Ireland Galway (NUIG), Botany and Plant Science, Galway, Ireland.

    • Mark T A Donoghue,
    • Reetu Tuteja &
    • Charles Spillane
  8. University of California, Davis, California, USA.

    • R Varma Penmetsa &
    • Douglas R Cook
  9. Monsanto Company, Creve Coeur, Missouri, USA.

    • Wei Wu,
    • Shiaw-Pyng Yang &
    • Todd Michael
  10. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA.

    • W Richard McCombie
  11. Department of Biology, University of Copenhagen, Denmark.

    • Jun Wang
  12. BGI-Americas, Cambridge, Massachusetts, USA.

    • Xun Xu

Contributions

R.K.V., W.C., R.K.S., G.F., R.V.P., H.D.U., K.B.S., W.R.McC., B.Y., G.Z., D.R.C., G.D.M., X.X., contributed to generation of genome sequence, transcriptome sequence and genetic mapping data; W.C., G.F., R.T., W.W., S.-P.Y., T.M., W.R.McC., G.Z., H.Y., J.W., X.X., worked on genome assembly; W.C., Y.L., A.K.B., R.K.S., S.A., A.D.F., H.Y., J.W., X.X., contributed to genome annotation and gene function; R.K.V., W.C., Y.L., A.K.B., R.K.S., J.A.S., J.S., A.I., M.T.A.D., A.M.W., A.D.F., J.S., R.T., T.S., C.S., D.R.C., G.D.M., X.X., S.A.J., worked on genome analysis and comparative genomics and R.K.V., together with S.A.J., D.R.C., C.S., W.C., A.K.B., R.K.S., S.A., J.A.S., wrote and finalized the manuscript. R.K.V. conceived and directed the project.

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The authors declare no competing financial interests.

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Supplementary information

PDF files

  1. Supplementary Text and Figures (2 MB)

    Supplementary Tables 1–14,16,18,19 and Supplementary Figures 1–12

Excel files

  1. Supplementary Table 15 (2 MB)

    Primer sequences for the SSR markers

  2. Supplementary Table 17 (2 MB)

    SNP information across 12 pigeonpea genotypes

Additional data