Ecological-genetic feedback in DNA repair in wild barley, Hordeum spontaneum

Achsa Lupu, Eviatar Nevo, Irina Zamorzaeva, Abraham Korol

Research output: Contribution to journalArticlepeer-review

Abstract

Regulation of genetic variation in natural populations is a problem of primary importance to evolutionary biology. In the reported study, the repair efficiency of double strand DNA breaks was compared in six wild barley accessions from Israeli natural populations of H. spontaneum: three from mesic populations (one from Maalot and two from Mount Meron, Upper Galilee) and three from xeric populations (one from Wadi Quilt in the Judean Desert and two from Sede Boqer, in the northern Negev Desert). Pulsed field gel electrophoresis was used to score double-strand breaks of DNA (DSBs) caused by methyl methanesulphonate (MMS) treatment. All six accessions were also tested for heat tolerance: four of these, three xeric and one mesic (from Maalot population), were scored as heat tolerant whereas both accessions from Mount Meron population displayed heat sensitivity. MMS caused a significant increase in the level of DSBs relative to the control in all accessions. The major questions were whether and how the efficiency of DNA repair after mutagenic treatment is affected by the environmental conditions and accession's adaptation to these conditions. Differences were found among the accessions in the repair pattern. Plants of two out of the four heat tolerant accessions did not manage to repair DNA neither at 25°C nor at 37°C. The remaining two heat tolerant accessions significantly repaired the breaks at 37°C, but not at 25°C. By contrast, plants of the two heat susceptible accessions significantly lowered the level of DSBs at 25°C but not at 37°C. Therefore, the accessions that proved capable to repair the induced damages in DNA at one of the two temperatures displayed a pattern that may imply the existence of a negative feedback mechanism in regulation of genetic variation. Such a dependence of DNA integrity on environment and genotype may serve an important factor for maintaining relatively high level of mutability without increasing the genetic load.

Original languageEnglish
Pages (from-to)121-132
Number of pages12
JournalGenetica
Volume127
Issue number1-3
DOIs
StatePublished - May 2006

Bibliographical note

Funding Information:
This work was supported by the Graduate School of the University of Haifa, Israel, and the German–Israeli Project Cooperation (DIP project, funded by the BMBF, and supported by BMBF’s International Bureau and the DLR).

Keywords

  • Adaptation
  • DNA repair
  • Double-strand breaks
  • Heat stress
  • Hordeum spontaneum

ASJC Scopus subject areas

  • Insect Science
  • Genetics
  • Animal Science and Zoology
  • Plant Science

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