Exogenous proline modifies differential expression of superoxide dismutase genes in UV-B-irradiated Salvia officinalis plants

Exogenous proline modifies differential expression of superoxide dismutase genes in... Grown in water culture 6-week-old Salvia officinalis plants with 4–5 true leaves were exposed to irradiation with UV-B (10 min, 12.3 kJ/m2), subjected to 5 mM exogenous proline in the nutrient solution, and treated with a combination of both factors. The plants responded to short UV-B irradiation by the appearance of oxidative stress, which was manifested in elevated content of malondialdehyde in leaves. Exogenous proline added 24 h before the irradiation inhibited lipid peroxidation. The total activity of superoxide dismutase (SOD) was analyzed in plant leaves, and three SOD isoforms—Mn-SOD, Fe-SOD, and Cu/Zn-SOD—were identified. Activities of these isoforms were measured over time, and the expression of their respective genes was analyzed by reverse transcription polymerase chain reaction (RT-PCR). It is shown that the addition of proline, UV-B irradiation, or combination of both treatments regulated in a differential manner the activities of SOD isoforms localized in various cell compartments. The activity of the cytosolic Cu/Zn-SOD isoform was limited by the presence of its mRNA, the content of which was regulated by mRNA synthesis or decay rate. By contrast, the activity of plastidic Fe-SOD isoform was regulated on the substrate (allosteric) level, not on the level of FSD gene expression. The activity of mitochondrial Mn-SOD isoform was insensitive to UV-B irradiation, addition of proline, or combination of both treatments, even though the level of MSD gene transcripts increased significantly after UV-B irradiation. The results indicate that MSD gene transcripts induced by UV-B were not completely processed to produce mature mRNA or mature mRNA was not capable of translation. It cannot be excluded that the synthesized macromolecule, the Mn-SOD precursor did not undergo posttranslational maturation to produce biologically active enzyme molecules. It appears that proline is involved in the differentially regulated complex expression of various SOD isoforms. This regulation is largely based on various extents of oxidative stress in different cell compartments. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Russian Journal of Plant Physiology Springer Journals

Exogenous proline modifies differential expression of superoxide dismutase genes in UV-B-irradiated Salvia officinalis plants

Loading next page...
 
/lp/springer_journal/exogenous-proline-modifies-differential-expression-of-superoxide-YJG9vQrdst
Publisher
SP MAIK Nauka/Interperiodica
Copyright
Copyright © 2011 by Pleiades Publishing, Ltd.
Subject
Life Sciences; Plant Sciences ; Plant Physiology
ISSN
1021-4437
eISSN
1608-3407
D.O.I.
10.1134/S1021443711010122
Publisher site
See Article on Publisher Site

Abstract

Grown in water culture 6-week-old Salvia officinalis plants with 4–5 true leaves were exposed to irradiation with UV-B (10 min, 12.3 kJ/m2), subjected to 5 mM exogenous proline in the nutrient solution, and treated with a combination of both factors. The plants responded to short UV-B irradiation by the appearance of oxidative stress, which was manifested in elevated content of malondialdehyde in leaves. Exogenous proline added 24 h before the irradiation inhibited lipid peroxidation. The total activity of superoxide dismutase (SOD) was analyzed in plant leaves, and three SOD isoforms—Mn-SOD, Fe-SOD, and Cu/Zn-SOD—were identified. Activities of these isoforms were measured over time, and the expression of their respective genes was analyzed by reverse transcription polymerase chain reaction (RT-PCR). It is shown that the addition of proline, UV-B irradiation, or combination of both treatments regulated in a differential manner the activities of SOD isoforms localized in various cell compartments. The activity of the cytosolic Cu/Zn-SOD isoform was limited by the presence of its mRNA, the content of which was regulated by mRNA synthesis or decay rate. By contrast, the activity of plastidic Fe-SOD isoform was regulated on the substrate (allosteric) level, not on the level of FSD gene expression. The activity of mitochondrial Mn-SOD isoform was insensitive to UV-B irradiation, addition of proline, or combination of both treatments, even though the level of MSD gene transcripts increased significantly after UV-B irradiation. The results indicate that MSD gene transcripts induced by UV-B were not completely processed to produce mature mRNA or mature mRNA was not capable of translation. It cannot be excluded that the synthesized macromolecule, the Mn-SOD precursor did not undergo posttranslational maturation to produce biologically active enzyme molecules. It appears that proline is involved in the differentially regulated complex expression of various SOD isoforms. This regulation is largely based on various extents of oxidative stress in different cell compartments.

Journal

Russian Journal of Plant PhysiologySpringer Journals

Published: Jan 8, 2011

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off