Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
2009
Volume 12
Issue 4
Topic:
Biology
ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Urbańska A. 2009. OCCURRENCE AND SOURCE OF HYDROGEN PEROXIDE IN APHIDS, EJPAU 12(4), #27.
Available Online: http://www.ejpau.media.pl/volume12/issue4/abs-27.html

OCCURRENCE AND SOURCE OF HYDROGEN PEROXIDE IN APHIDS

Anna Urbańska
Department of Biochemistry and Molecular Biology, University of Natural Sciences and Humanities in Siedlce, Poland

 

ABSTRACT


This paper concerns with the production of the hydrogen
peroxide (H2O2), representative of the reactive oxygen
species (ROS), in aphids Rhopalosiphum padi L. and Sitobion avenae F.
Three aspects of the subject have been investigated: (I) 'centre' of H2O2 occurrence;
(II) variability of H2O2 production in aphids, in response
to dietary chemicals; (III) 'molecular source' of H2O2,
amongst free radiacals and oxidases. It is known that the H2O2 production
focuses in the midgut and in the salivary secretions. Compounds among o-dihydroxyphenolics
e.g. caffeic acid, (+) – catechin, L-dihydoxyphenylalanine, increase rate of
H2O2 production. Whereas, monophenolics e.g. p-coumaric
acid, p-hydroxybenzolic acid, ferulic acid are rather non-prooxidant.
Presence of superoxide anion (O2·–) in the midgut – major
'compartment' of H2O2 generation – evidences that O2·– participates
in 'chemical route' of H2O2 generation. Polyphenol oxidase
(EC 1.10.3.1), primary biocatalyst of Aphididae for the oxidative metabolism
of the phenolic allelochemicals, seems to provide O2·–,
precursor of H2O2. The aphid H2O2 generated
in the midgut and additionally also in the saliva appears as toxic by-product
of the oxidation of the o-dihydroxyphenolic allelochemicals. Visualization
of H2O2 is accomplished via the ferricyanide-ferrichloride
staining method. 'Amount' of H2O2 is determined via UV-spectrophotometry,
A240. O2·– is examined with the conventional
Nitro blue tetrazolium (NBT) microscopic assay. The results indicate that each
amongst used assay is simple, sensitive and specific for determined molecule
and that all they can be used to visualize/measure of H2O2 and
O2·– in animal and plant cells and tissues. I recommend
these methods for education in biochemistry.

Key words: hydrogen peroxide, H2O2, superoxide anion, O2·– aphid, Rhopalosiphum padi, Sitobion avenae, phenolic compound, polyphenol oxidase, aphid – plant interaction.


Anna Urbańska
Department of Biochemistry and Molecular Biology,
University of Natural Sciences and Humanities in Siedlce, Poland
B. Prusa 12, 08-110 Siedlce, Poland
phone: +48 25 643 12 22,
fax: +48 25 644 59 59
email: annau@uph.edu.pl

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.