Planta

, Volume 231, Issue 1, pp 93–107

Mitochondrial bioenergetics linked to the manifestation of programmed cell death during somatic embryogenesis of Abies alba

Authors

  • Elisa Petrussa
    • Section of Plant Biology, Department of Biology and Plant ProtectionUniversity of Udine
  • Alberto Bertolini
    • Section of Plant Biology, Department of Biology and Plant ProtectionUniversity of Udine
  • Valentino Casolo
    • Section of Plant Biology, Department of Biology and Plant ProtectionUniversity of Udine
  • Jana Krajňáková
    • National Forest CentreForest Research Institute
  • Francesco Macrì
    • Section of Plant Biology, Department of Biology and Plant ProtectionUniversity of Udine
    • Section of Plant Biology, Department of Biology and Plant ProtectionUniversity of Udine
Original Article

DOI: 10.1007/s00425-009-1028-x

Cite this article as:
Petrussa, E., Bertolini, A., Casolo, V. et al. Planta (2009) 231: 93. doi:10.1007/s00425-009-1028-x

Abstract

The present work reports changes in bioenergetic parameters and mitochondrial activities during the manifestation of two events of programmed cell death (PCD), linked to Abies alba somatic embryogenesis. PCD, evidenced by in situ nuclear DNA fragmentation (TUNEL assay), DNA laddering and cytochrome c release, was decreased in maturing embryogenic tissue with respect to the proliferation stage. In addition, the major cellular energetic metabolites (ATP, NAD(P)H and glucose-6-phosphate) were highered during maturation. The main mitochondrial activities changed during two developmental stages. Mitochondria, isolated from maturing, with respect to proliferating cell masses, showed an increased activity of the alternative oxidase, external NADH dehydrogenase and fatty-acid mediated uncoupling. Conversely, a significant decrease of the mitochondrial KATP+ channel activity was observed. These results suggest a correlation between mitochondrial activities and the manifestation of PCD during the development of somatic embryos. In particular, it is suggested that the KATP+ channel activity could induce an entry of K+ into the matrix, followed by swelling and a release of cytochrome c during proliferation, whereas the alternative pathways, acting as anti-apoptotic factors, may partially counteract PCD events occurring during maturation of somatic embryos.

Keywords

AbiesAlternative oxidaseKATP+ channelMitochondriaProgrammed cell deathSomatic embryogenesis

Abbreviations

ANT

Adenine nucleotide translocase

AOX

Cyanide-resistant alternative oxidase

DAPI

4′,6-Diamidino-2-phenylindole

∆F

Variations of fluorescence

DTE

Dithioerythritol

ΔΨ

Transmembrane electrical potential

ETC

Electron transport chain

FFA

Free fatty acids

Glu-6-P

Glucose-6-phosphate

IgG

Immunoglobulins

PCD

Programmed cell death

PEG

Polyethylene glycol

PEMs

Pro-embryogenic cell masses

PMSF

Phenylmethanesulphonyl fluoride

PTP

Permeability transition pore

PUMP

Plant uncoupling mitochondrial protein

PVPP

Polyvinylpolypyrrolidone

ROS

Reactive oxygen species

SE

Somatic embryogenesis

TMR

Tetramethyl-rhodamine

TUNEL

Terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end labelling

Copyright information

© Springer-Verlag 2009