Plant Molecular Biology

, Volume 53, Issue 5, pp 655–667

Members of the aquaporin family in the developing pea seed coat include representatives of the PIP, TIP, and NIP subfamilies


  • Jolanda A.M.J. Schuurmans
    • Transport PhysiologyUtrecht University, Sorbonnelaan 16
    • Molecular Plant PhysiologyUtrecht University, Padualaan 8
  • Joost T. van Dongen
    • Transport PhysiologyUtrecht University, Sorbonnelaan 16
    • Max Planck Institute of Molecular Plant Physiology, Am Mü:hlenberg 1
  • Bas P.W. Rutjens
    • Transport PhysiologyUtrecht University, Sorbonnelaan 16
    • Molecular Plant PhysiologyUtrecht University, Padualaan 8
  • Alex Boonman
    • Transport PhysiologyUtrecht University, Sorbonnelaan 16
    • Plant Ecophysiology GroupUtrecht University, Sorbonnelaan 16
  • Corné M.J. Pieterse
    • Section of PhytopathologyUtrecht University, Sorbonnelaan 16
    • Transport PhysiologyUtrecht University, Sorbonnelaan 16

DOI: 10.1023/B:PLAN.0000019070.60954.77

Cite this article as:
Schuurmans, J.A., van Dongen, J.T., Rutjens, B.P. et al. Plant Mol Biol (2003) 53: 655. doi:10.1023/B:PLAN.0000019070.60954.77


Water and nutrients required by developing seeds are mainly supplied by the phloem and have to be released from a maternal parenchyma tissue before being utilized by the filial tissues of embryo and endosperm. To identify aquaporins that could be involved in this process four full-length cDNAs were cloned and sequenced from a cDNA library of developing seed coats of pea (Pisum sativum L.). The cDNA of PsPIP1-1 appeared to be identical to that of clone 7a/TRG-31, a turgor-responsive gene cloned previously from pea roots. PsPIP1-1, PsPIP2-1, and PsTIP1-1, or their possible close homologues, were also expressed in cotyledons of developing and germinating seeds, and in roots and shoots of seedlings, but transcripts of PsNIP-1 were only detected in the seed coat. In mature dry seeds, high hybridization signals were observed with the probe for PsPIP1-1, but transcripts of PsPIP2-1, PsTIP1-1, and PsNIP-1 were not detected. Functional characterization after heterologous expression in Xenopus oocytes showed that PsPIP2-1 and PsTIP1-1 are aquaporins whereas PsNIP-1 is an aquaglyceroporin. PsNIP-1, like several other NIPs, contains a tryptophan residue corresponding with Trp-48 in GlpF (the glycerol facilitator of Escherichia coli) that borders the selectivity filter in the permeation channel. It is suggested that PsPIP1-1 and/or its possible close homologues could play a role in water absorption during seed imbibition, and that PsPIP2-1, possibly together with PsPIP1-1, could be involved in the release of phloem water from the seed coat symplast, which is intimately connected with the release of nutrients for the embryo. Abbreviations: MIPs, major intrinsic proteins; NIPs, nodulin 26-like intrinsic proteins; PIPs, plasma membrane intrinsic proteins; SIPs, small, basic intrinsic proteins; TIPs, tonoplast intrinsic proteins

aquaglyceroporinsaquaporinsMIPsseed coatseed developmentseed germination

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© Kluwer Academic Publishers 2003