Plant Cell Reports

, Volume 26, Issue 10, pp 1839–1859

Transgenic tobacco plants overexpressing the heterologous lea gene Rab16A from rice during high salt and water deficit display enhanced tolerance to salinity stress

Authors

  • Aryadeep RoyChoudhury
    • Department of BotanyBose Institute
    • Department of BotanyUniversity of Calcutta
  • Chaitali Roy
    • Department of BotanyBose Institute
    • Department of BotanyBose Institute
Physiology and Biochemistry

DOI: 10.1007/s00299-007-0371-2

Cite this article as:
RoyChoudhury, A., Roy, C. & Sengupta, D.N. Plant Cell Rep (2007) 26: 1839. doi:10.1007/s00299-007-0371-2

Abstract

The full length Rab16A, from the indica rice Pokkali, was introduced into tobacco by Agrobacterium-mediated transformation. The transgene was stably integrated into the genome and they originated from different lines of integration. Expression of Rab16A transcript driven by its own promoter (stress inducible) in T2 progenies, only when triggered by salinity/ABA/PEG (Polyethylene glycol)-mediated dehydration, but not at the constitutive level, led to the stress-induced accumulation of RAB16A protein in the leaves of transgenic plants. The selected independent transgenic lines showed normal growth, morphology and seed production as the WT plants without any yield penalty under stress conditions. They exhibited significantly increased tolerance to salinity, sustained growth rates under stress conditions; with concomitant increased osmolyte production like reducing sugars, proline and higher polyamines. They also showed delayed development of damage symptoms with better antioxidative machinery and more favorable mineral balance, as reflected by reduced H2O2 levels and lipid peroxidation, lesser chlorophyll loss as well as lesser accumulation of Na+ and greater accumulation of K+ in 200 mM NaCl. These findings establish the potential role of Rab16A gene in conferring salt tolerance without affecting growth and yield, as well as pointing to the fact that the upstream region of Rab16A behaves as an efficient stress-inducible promoter. Our result also suggests the considerable potential of Group 2 lea genes as molecular tools for genetic engineering of plants towards stress tolerance.

Keywords

Agrobacterium-mediated transformationAntioxidantsDehydrinLeaLipid peroxidationRice Rab16A geneSalt stressSalt tolerantTransgenic tobacco

Abbreviations

ABA

Abscisic acid

EMSA

Electrophoretic mobility shift assay

LEA

Late embryogenesis abundant

LOX

Lipoxygenase

MDA

Malondialdehyde

ORF

Open reading frame

PEG

Polyethylene glycol

Rab

Responsive to abscisic acid

RWC

Relative water content

WT

Wild type

Copyright information

© Springer-Verlag 2007