Overexpression of BrSAC1 encoding a phosphoinositide phosphatase isolated from Chinese cabbage (Brassica rapa L) improved tolerance to cold, dehydration, and salt stresses in transgenic tobacco

  • Kyung Hee Han
  • Yu Jin Jung
  • Uuganchimeg Bayarsaikhan
  • In Hye Lee
  • Jang Sun Choi
  • Ill Sup Nou
  • Yong Gu Cho
  • Kwon Kyoo Kang

Abstract

This study demonstrates the isolation and characterization of cDNA encoding a phosphoinositide phosphatase (PIP) from a stem cell cDNA library of Chinese cabbage (Brassica rapa) seedling. The full length gene (BrSAC1; GenBank accession no., GU434275) contained 1999 base pairs (bp), with an open reading frame of 1785 bp, encoding a polypeptide of 594 amino acids with a predicted molecular weight of 65 kDa, including a putative N-terminal signal peptide (the signal peptide counted within the 594 residues). Other regions found within the sequence include a conserved KXKXX COPI-binding motif and a consensus Cx5R (T/S) catalytic motif. BrSAC1 protein shares 92% identity with AtSac1B, and 86% identity with AtRHD4 at the amino acid level. Gene expression analyses revealed that BrsSAC1 was constitutively expressed at high levels in the pistil, stamen and flower bud, whereas it was expressed at low levels in the leaf and stem. In addition to injury, BrSAC1 expression was also induced in response to different types of stress condition, namely cold, desiccation, salt, submergence, abscisic acid and heavy metals. Overexpression of BrSAC1 in transgenic tobacco conferred tolerance to cold, dehydration, and salt stress at the seed germination/seedling stage as reflected by the percentage of germination/green seedlings, the fresh weight of seedlings and their development pattern. Our data suggest that BrSAC1 is an important stress response determinant in plants.

Keywords: Abiotic stress, Brassica rapa, phosphoinositide phosphatase, transgenic plant

African Journal of Biotechnology Vol. 12(15), pp. 1782-1792

Author Biographies

Kyung Hee Han
Department of Horticulture, Hankyong National University, 67 Seokjeong-dong, Ansung 456-749, South Korea
Yu Jin Jung
Institute of Genetic Engineering, Hankyong National University, Ansung 456-749, Korea; Clone Company, 67 Seokjeong-dong, Ansung 456-749, South Korea
Uuganchimeg Bayarsaikhan
Department of Horticulture, Hankyong National University, 67 Seokjeong-dong, Ansung 456-749, South Korea
In Hye Lee
Department of Horticulture, Hankyong National University, 67 Seokjeong-dong, Ansung 456-749, South Korea
Jang Sun Choi
National Institute of Horticultural and Herbal Science, Suwon, 440-746, Korea.
Ill Sup Nou
Department of Horticulture, Sunchon National University, Suncheon 540-742, Korea.
Yong Gu Cho
National Institute of Horticultural and Herbal Science, Suwon, 440-746, Korea.
Kwon Kyoo Kang
Department of Horticulture, Hankyong National University, 67 Seokjeong-dong, Ansung 456-749, South Korea; Institute of Genetic Engineering, Hankyong National University, Ansung 456-749, Korea; Clone Company, 67 Seokjeong-dong, Ansung 456-749, South Korea
Published
2016-01-20
Section
Articles

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eISSN: 1684-5315