Plant Molecular Biology

, Volume 67, Issue 1, pp 169–181

Characterization of transcription factor gene SNAC2 conferring cold and salt tolerance in rice

  • Honghong Hu
  • Jun You
  • Yujie Fang
  • Xiaoyi Zhu
  • Zhuyun Qi
  • Lizhong Xiong
Article

DOI: 10.1007/s11103-008-9309-5

Cite this article as:
Hu, H., You, J., Fang, Y. et al. Plant Mol Biol (2008) 67: 169. doi:10.1007/s11103-008-9309-5

Abstract

Plants respond to adverse environment by initiating a series of signaling processes including activation of transcription factors that can regulate expression of arrays of genes for stress response and adaptation. NAC (NAM, ATAF, and CUC) is a plant specific transcription factor family with diverse roles in development and stress regulation. In this report, a stress-responsive NAC gene (SNAC2) isolated from upland rice IRA109 (Oryza sativa L. ssp japonica) was characterized for its role in stress tolerance. SNAC2 was proven to have transactivation and DNA-binding activities in yeast and the SNAC2-GFP fusion protein was localized in the rice nuclei. Northern blot and SNAC2 promoter activity analyses suggest that SNAC2 gene was induced by drought, salinity, cold, wounding, and abscisic acid (ABA) treatment. The SNAC2 gene was over-expressed in japonica rice Zhonghua 11 to test the effect on improving stress tolerance. More than 50% of the transgenic plants remained vigorous when all WT plants died after severe cold stress (4–8°C for 5 days). The transgenic plants had higher cell membrane stability than wild type during the cold stress. The transgenic rice had significantly higher germination and growth rate than WT under high salinity conditions. Over-expression of SNAC2 can also improve the tolerance to PEG treatment. In addition, the SNAC2-overexpressing plants showed significantly increased sensitivity to ABA. DNA chip profiling analysis of transgenic plants revealed many up-regulated genes related to stress response and adaptation such as peroxidase, ornithine aminotransferase, heavy metal-associated protein, sodium/hydrogen exchanger, heat shock protein, GDSL-like lipase, and phenylalanine ammonia lyase. Interestingly, none of the up-regulated genes in the SNAC2-overexpressing plants matched the genes up-regulated in the transgenic plants over-expressing other stress responsive NAC genes reported previously. These data suggest SNAC2 is a novel stress responsive NAC transcription factor that possesses potential utility in improving stress tolerance of rice.

Keywords

OryzaTranscription factorNACAbiotic stressExpression regulation

Abbreviations

ABA

Abscisic acid

CUC

Cup-shaped cotyledon

GFP

Green fluorescence protein

NAM

No apical meristem

SNAC

Stress-responsive NAC

PCR

Polymerase chain reaction

RT

Reverse transcription

RWC

Relative water content

NAC

NAM, ATAF, and CUC

NACRS

NAC recognition site

Supplementary material

11103_2008_9309_MOESM1_ESM.doc (194 kb)
(DOC 193 kb)Nucleotide and amino acid sequences of SNAC2. Predicted nuclear localization sequence is indicated in red. Boxed region is NAM DNA-binding domain
11103_2008_9309_MOESM2_ESM.doc (120 kb)
(DOC 120 kb)GUS assay of PSNAC2:GUS transgenic rice. A, GUS staining of different organs or tissues. a: Root; b: stem and internodes; c: Leaf segment; d: sheath and ligule; e: spikelet; f: callus. B, Activity of SNAC2 promoter induced by dehydration stress (transgenic seedlings were exposed to air with out water supply)
11103_2008_9309_MOESM3_ESM.doc (77 kb)
(DOC 77 kb)Northern (A) and Southern (B) analysis of SNAC2-overexpression transgenic plants. WT: wild type Zhonghua 11. T050U and T050H are two over-expression constructs under the maize ubiquitin1 promoter and an inducible promoter respectively
11103_2008_9309_MOESM4_ESM.doc (165 kb)
(DOC 165 kb)Comparison of the sequences flanking the core DNA-binding site (CACG) of NAC in the putative target genes of SNAC1 (A) and SNAC2 (B)

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Honghong Hu
    • 1
  • Jun You
    • 1
  • Yujie Fang
    • 1
  • Xiaoyi Zhu
    • 1
  • Zhuyun Qi
    • 1
  • Lizhong Xiong
    • 1
  1. 1.National Center of Plant Gene Research (Wuhan), National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanChina