Amino Acids

, Volume 42, Issue 2, pp 1025–1035

Polyamines and transglutaminase activity are involved in compatible and self-incompatible pollination of Citrus grandis

  • Alessandra Gentile
  • Fabiana Antognoni
  • Rosa Anna Iorio
  • Gaetano Distefano
  • Giuseppina Las Casas
  • Stefano La Malfa
  • Donatella Serafini-Fracassini
  • Stefano Del Duca
Original Article

DOI: 10.1007/s00726-011-1017-9

Cite this article as:
Gentile, A., Antognoni, F., Iorio, R.A. et al. Amino Acids (2012) 42: 1025. doi:10.1007/s00726-011-1017-9

Abstract

Pollination of pummelo (Citrus grandis L. Osbeck) pistils has been studied in planta by adding compatible and self-incompatible (SI) pollen to the stigma surface. The pollen germination has been monitored inside the pistil by fluorescent microscopy showing SI altered morphologies with irregular depositions of callose in the tube walls, and heavy callose depositions in enlarged tips. The polyamine (PA) content as free, perchloric acid (PCA)-soluble and -insoluble fractions and transglutaminase (TGase) activity have been analyzed in order to deepen their possible involvement in the progamic phase of plant reproduction. The conjugated PAs in PCA-soluble fraction were definitely higher than the free and the PCA-insoluble forms, in both compatible and SI pollinated pistils. In pistils, pollination caused an early decrease of free PAs and increase of the bound forms. The SI pollination, showed highest values of PCA-soluble and -insoluble PAs with a maximum in concomitance with the pollen tube arrest. As TGase mediates some of the effects of PAs by covalently binding them to proteins, its activity, never checked before in Citrus, was examined with two different assays. In addition, the presence of glutamyl-PAs confirmed the enzyme assay data and excluded the possibility of a misinterpretation. The SI pollination caused an increase in TGase activity, whereas the compatible pollination caused its decrease. Similarly to bound PAs, the glutamyl-PAs and the enzyme activity peaked in the SI pollinated pistils in concomitance with the observed block of the pollen tube growth, suggesting an involvement of TGase in SI response.

Keywords

CitrusPollenPolyaminesReproductionSelf-incompatibilityTransglutaminase

Abbreviations

BCA

Bicinchoninic acid

BSA

Bovine serum albumin

DMC

N′,N′-dimethyl casein

DTT

Dithiothreitol

EDTA

Ethylene diamine tetraacetic acid

EGTA

Ethylene glycol tetraacetic acid

GSI

Gametophytic self-incompatible

HPLC

High-performance liquid chromatography

PAs

Polyamines

PBS

Phosphate-buffered saline

PMSF

Phenyl methyl sulfonyl fluoride

PCA

Perchloric acid

PCD

Programmed cell death

PU

Putrescine

SI

Self-incompatible

SD

Spermidine

SM

Spermine

SSI

Sporophytic self-incompatible

TCA

Trichloroacetic acid

TGase

Transglutaminase

tTGase

Tissue transglutaminase

UP

Unpollinated

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Alessandra Gentile
    • 1
  • Fabiana Antognoni
    • 2
  • Rosa Anna Iorio
    • 2
  • Gaetano Distefano
    • 1
  • Giuseppina Las Casas
    • 1
  • Stefano La Malfa
    • 1
  • Donatella Serafini-Fracassini
    • 2
  • Stefano Del Duca
    • 2
  1. 1.Dipartimento di Scienze delle Produzioni Agrarie e AlimentariUniversità di CataniaCataniaItaly
  2. 2.Dipartimento di Biologia e.s.Università degli Studi di BolognaBolognaItaly