Characterization of abiotic stress-responsive Arabidopsis thaliana RD29A and RD29B genes and evaluation of transgenes

Joseph Msanne, Jiusheng Lin, Julie M. Stone, Tala Awada

Research output: Contribution to journalArticle

128 Scopus citations

Abstract

Abiotic stresses have adverse effects on plant growth and productivity. The homologous RD29A and RD29B genes are exquisitely sensitive to various abiotic stressors. Therefore, RD29A and RD29B gene sequences have potential to confer abiotic stress resistance in crop species grown in arid and semi-arid regions. To our knowledge, no information on the physiological roles of the proteins encoded by RD29A and RD29B are available in the literature. To understand how these proteins function, we used reverse genetic approaches, including identifying rd29a and rd29b T-DNA knockout mutants, and examining the effects of complementing transgenes with the genes under control of their native promoters and chimeric genes with the native promoters swapped. Four binary vectors with the RD29A and RD29B promoters upstream of the cognate RD29A and RD29B cDNAs and as chimeric genes with noncognate promoters were used to transform rd29a and rd29b plants. Cold, drought, and salt induced both genes; the promoter of RD29A was found to be more responsive to drought and cold stresses, whereas the promoter of RD29B was highly responsive to salt stress. Morphological and physiological responses of rd29a and rd29b plants to salt stress were further investigated. Root growth, and photosynthetic properties declined significantly, while solute concentration (Ψπ), water use efficiency (WUE) and δ13C ratio increased under salt stress. Unexpectedly, the rd29a and rd29b knockout mutant lines maintained greater root growth, photosynthesis, and WUE under salt stress relative to control. We conclude that the RD29A and RD29B proteins are unlikely to serve directly as protective molecules.

Original languageEnglish (US)
Pages (from-to)97-107
Number of pages11
JournalPlanta
Volume234
Issue number1
DOIs
StatePublished - Jul 1 2011

Keywords

  • Abiotic stress
  • Carbon isotope ratio
  • Gas exchange
  • Photosynthesis
  • RD29
  • Water use efficiency

ASJC Scopus subject areas

  • Genetics
  • Plant Science

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