Plant Reproduction

, Volume 26, Issue 3, pp 245–254

PsPMEP, a pollen-specific pectin methylesterase of pea (Pisum sativum L.)

Authors

  • María Dolores Gómez
    • Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV)
  • Begoña Renau-Morata
    • Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV)
  • Edelín Roque
    • Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV)
  • Julio Polaina
    • Instituto de Agroquímica y Tecnología de Alimentos (CSIC)
  • José Pío Beltrán
    • Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV)
    • Instituto de Biología Molecular y Celular de Plantas (CSIC-UPV)
Original Article

DOI: 10.1007/s00497-013-0220-0

Cite this article as:
Gómez, M.D., Renau-Morata, B., Roque, E. et al. Plant Reprod (2013) 26: 245. doi:10.1007/s00497-013-0220-0

Abstract

Pectin methylesterases (PMEs) are a family of enzymes involved in plant reproductive processes such as pollen development and pollen tube growth. We have isolated and characterized PsPMEP, a pea (Pisum sativum L.) pollen-specific gene that encodes a protein with homology to PMEs. Sequence analysis showed that PsPMEP belongs to group 2 PMEs, which are characterized by the presence of a processable amino-terminal PME inhibitor domain followed by the catalytic PME domain. Moreover, PsPMEP contains several motifs highly conserved among PMEs with the essential amino acid residues involved in enzyme substrate binding and catalysis. Northern blot and in situ hybridization analyses showed that PsPMEP is expressed in pollen grains from 4 days before anthesis till anther dehiscence and in pollinated carpels. In the PsPMEP promoter region, we have identified several conserved cis-regulatory elements that have been associated with gene pollen-specific expression. Expression analysis of PsPMEP promoter fused to the uidA reporter gene in Arabidopsis thaliana plants showed a similar expression pattern when compared with pea, indicating that this promoter is also functional in a non-leguminous plant. GUS expression was detected in mature pollen grains, during pollen germination, during pollen tube elongation along the transmitting tract, and when the pollen tube reaches the embryo sac in the ovule.

Keywords

Pectin methylesterase Pea (Pisum sativum L.) Pollen-specific PMEI Gene promoter Pollen tube growth Arabidopsis

Supplementary material

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Figure S1. Neighbor-Joining Tree of selected pollen-specific PMEs. The numbers next to the nodes refer to bootstrap values from 1000 pseudo-replicates. Accession numbers for the PME proteins used in this N-J tree are: O80722 (AT2G47040), Q9FJ21 (AT5G49180), AEE35001(AT1G69940) and ABI97858.1 (AT5G55590.1) Arabidopsis thaliana; P41510 Brassica napus; Q42608 Brassica rapa; Q43043 Petunia integrifolia subsp. inflata; AAX13972 Nicotiana tabacum; Q9MBB6 Salix gilgiana; Q24596 Zea mays; Q9SC89, Q9SC90 Medicago truncatula; Q42920 Medicago sativa and KC964536 (PsPMEP) Pisum sativum. We inferred the phylogeny based on the alignment of mature enzyme sequences of 14 representative PMEs from pollen, which are clustered into four clades (A to D). Branch lengths are proportional to sequence divergence
497_2013_220_MOESM2_ESM.docx (12 kb)
Table S1. Primers used to sequence the PsPMEP genomic clone
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Table S2. Putative pollen-specific motifs identified in the PsPMEP promoter region (-1 to -2133)

Copyright information

© Springer-Verlag Berlin Heidelberg 2013