Salt Tolerance Enhanced by Transformation of a P5CS Gene in Carrot

  • Han Kyu-Hyun (School of Bioresource Sciences, Dankook University) ;
  • Hwang Cheol-Ho (School of Bioresource Sciences, Dankook University)
  • Published : 2003.09.01


Proline is known as an osmoprotectant accumulating in response to salt and dehydration stresses. An increased level of proline is achieved by either an induced synthesis or a reduced degradation of proline. In an attempt to increase salt tolerance in carrot, a P5CS gene from mothbean was introduced via an Agrobacterium-mediated transformation. The resulting carrot cells and the regenerated plants containing the transgene showed increased levels of proline compared to nontransgenics. The transgenic cell line, Pj2 showed about 6 times increased degree of tolerance determined by relative growth after a treatment in 250 mM NaCl. In facts, due to the retarded growth shown in non-saline condition, Pj2 cells grow only about 1.2 times better than nontransgenic control under salt stress condition. Taken together, it appears that a P5CS is a key enzyme in proline biosynthesis and the increased accumulation of proline by overexpression of the enzyme is enough to enhance tolerance to salt stress in carrot.


  1. Plant Physiol v.120 Proline accumulation in development grapevine fruit occurs independently of change in levels of △¹-pyrroline-5-carboxylate synthetase mRNA or protein Anna,P.S.;Dean,J.N.;Peter,B.H.J.;Robyn,van,H.
  2. Cellular energy metabolism and its regulation Atkinson,D.E.
  3. Plant and Soil v.39 Rapid determination of free proline for water stress studies Bates,L.S.;Walden,R.P.;Tear,I.D
  4. Plant J v.4 Proline biosynthesis and osmoregulation in plants Delauney,A.J.;Verma,D.P.S.
  5. Anne Rev Plant Physiol v.33 Metabolic response of mesophytic plants to water deficits Hanson,A.D.;Hitz,W.D.
  6. Plant Growth Regul v.21 Metabolic implications of stress-induced proline accumulation in plants Hare,P.D.;Cress,W.A.
  7. Plant Physiol v.122 Removal of feedback inhibition of △¹-pyrroline-5-carboxylate synthetase results in increased proline accumulation and protection of plants from osmotic stress hong,Z.;Lakkineni,K.;Zhang,Z.;Verma,D.P.S.
  8. Proc Natl Acad Sci USA v.89 A bifunctional enzyme(△¹-pyrroline-5-carboxylate synthetase) catalyzes the first two steps in proline biosynthesis in plants Hu,C.A.;Delauney,A.J.;Verma,D.P.S.
  9. Plant Physiol v.108 Overexpression of △¹-pyrroline-5-carboxylate synthetase increases proline production and confers osmotolerance in transgenic plants Klshor,P.B.;Hong,K.Z.;Miao,G.H.;Hu,C.A.;Verma,D.P.S.
  10. Korean J Corp Sci v.48 Proline accumulation and P5CS(△¹-pyrroline-5-carboxylate synthetase)gene expression in response to salt stress in Zoysiagrasses Lee,D.J.;Hwang,C.H.
  11. FEBS Lett v.461 Antisense suppression of proline degradation improves tolerance to freezing and salinity in Arobidopsis thaliana Nanjo,T.;Kobayashi,M.;Yoshiba,Y.;Kakubari,Y.;Yamaguchi-Shinozaki,K.;Shinozaki,K.
  12. Mol Gen Genet v.253 Reciprocal regulation of △¹-pyrroline-5-carboxylate synthetase and proline dehydrogenase genes controls proline levels during and after osmotic stress in plants Peng,Z.;Lu,Q.;Verma,D.P.S.
  13. Plant Physiol v.91 Oxidation of proline and glutamate by mitochondria of the inflorescence of voodoo lily(Sauromatum guttatum) Skubatz,H.;Meeuse,B.J.D.;Bendich,A.J.
  14. pHYTOCHEMISITRY v.28 Hydroxyl radical scavenging activity of compatible solutes Smirnoff,N.;Cumbes,Q.J.
  15. Plant Physiol v.120 Proline accumulation in developing grapevine fruit occurs independently of changes in the levels of △¹-pyrroline-5-carboxylate synthetase mRNA or protein Stines,A.D.;Naylor,D.J.;Hoj,P.B.;van Heeswijck,R.
  16. Science v.259 Stress protection of transgenic tobacco by production of the osmolyte mannitol Tarczynski,M.C.;Jensen,R.G.;Bohnert,H.J.
  17. Plant Physiol v.118 Comparative analysis of regulation of expression and structure of two evolutionarily divergent genes for △¹-pyrroline-5-carboxylate synthetase from tomato Tomomichi,F.;Maggio,A.;Mario,G.R.;Bressan,R.A.;Csonka,L.N.
  18. Proc Natl Acad Sci USA v.93 Environmental and developmental signals modulate proline homeostasis:Evidence for a negative transcriptional regulaotor Verbruggen,N.;Hua,X.J.;May,M.;Van Montagu,M.
  19. Biochem Genet v.26 Betaine aldehyde dehydrogenase polymorphism in spinach:Genetic and biochemical characterization Weretilnyk,E.A.;Hanson,A.D.
  20. Plant Cell Cell singnaling during cold, drought, and salt stress Xiong,L.;Schumaker,K.S.;Zhu,J.K.
  21. Plant J v.7 Correlation between the induction of gene for △¹-pyrroline-5-carboxylate synthetase and accumulation of proline in Arabidopsis thaliana under osmotic stress Yoshiba,Y.;Kiyosue,T.;Katagirl,T.;Ueda,H.;Mizoguchi,T.;Yamaguchi-Shinozaki,K.;Wada,K.;Harada,Y.;Shinozaki,K.
  22. Planta v.154 Proline synthesis in germinating pollen of petunia:Role of proline Zang,H.Q.;Crose,A.F.;Linskens,H.F.
  23. Proc Natl Acad Sci USA v.95 Eskimo1 mutants of Arabidopsis are constitutively freezing-tolerant Zhanguo,X.;Browse,J.
  24. Plant Sci v.139 Overexpression of a △¹-pyrroline-5-carboxylate synthetase gene and analysis of tolerance to water-and salt-stress in transgenic rice Zhu,B.;Su,J.;Chang,M.;Verma,D.P.S.;Fan,Y.L.;Wu,R.