Plant Cell Reports

, Volume 24, Issue 10, pp 612–618 | Cite as

Expression analysis of a cold responsive transcript from trifoliate orange by real-time PCR and RT-PCR

Genetics and Genomics

Abstract

CLTa and CLTb are two transcripts produced by the citrus CLT gene. CLTb is constitutively expressed, while CLTa is a low temperature responsive transcript expressed in temperatures below 10°C during the acclimation process of some species of citrus. Real-time PCR was used to study CLTa expression pattern in trifoliate orange during acclimation, gradual deacclimation and abrupt deacclimation. A standard curve of nine dilution series from 10×106 to 10×10−3 fg was constructed, using part of the CLTa transcript, which enabled us to determine the concentration of the transcript at different temperatures and conditions. It was found that during acclimation, CLTa expression is first detected at 10°C, reaching a maximum after 24 h of exposure at −1°C. During gradual deacclimation, the transcript accumulated at 5°C and after this point it degrades, reaching a low level at 10°C. When the plants were abruptly transferred to room temperature after being acclimated to −1°C, the transcript reduced from 11,303 fg to levels below the threshold 3 h later, indicating a rapid degradation and how the expression of CLTa is dependent on low temperature. Exposure of trifoliate plants to abscisic acid (ABA) and salts indicated that CLTa is not induced by these treatments at the concentrations used. CLTa expression was also verified in other citrus species and was not detected in the acclimated cold-sensitive species “Mexican lime” (Citrus aurantifolia Swing.) and in the cold hardy “Satsuma mandarin (C. unchiu Marc.).

Keywords

Low temperature responsive genes Cold acclimation Deacclimation Citrus 

Abbreviations

ABAs

Abscisic acid

CLTs

Citrus low temperature

ORFs

Open reading frame

PCRs

Polymerase chain reaction

UTRs

Untranslated region

References

  1. Cai Q, Moore GA, Guy CL (1995)An unusual group of 2 LEA gene family in citrus responsive to low temperature.Plant Mol Biol 29:11–23CrossRefPubMedGoogle Scholar
  2. Capel J, Jarillo JA, Salinas J Martinez-Zapater JM (1997) Two homologous low-temperature-inducible genes from Arabidopsis encode highly hydrophobic proteins. Plant Physiol 115:569–576CrossRefPubMedGoogle Scholar
  3. Goddard NJ, Dunn MA, Zhang L, White AJ, Jack PL, Hughes MA (1993) Molecular analysis and spatial expression pattern of a low-temperature specific barley gene, blt 101. Plant Mol Biol 23:871–879CrossRefPubMedGoogle Scholar
  4. Guy CL (1990) Cold acclimation and freezing stress tolerance: role of protein metabolism. Annu Rev Plant Physiol Plant Mol Biol 41:187–223Google Scholar
  5. Hughes MA Dunn MA (1996) The molecular biology of plant acclimation to low temperature. J Exp Bot 47:291–305CrossRefGoogle Scholar
  6. Jia Y, del Rio HS, Robbins AL, Louzada ES (2004) Cloning and sequence analysis of a low temperature-induced gene from trifoliate orange with unusual pre-mRNA processing. Plant Cell Rep 23:159–166CrossRefPubMedGoogle Scholar
  7. Knight H, Veale EL, Warren GJ Knight MR (1999) The sfr6 mutation in Arabidopsis suppress low-temperature induction of genes dependent on the CRT/DRE sequence motif. Plant Cell 11:875–886CrossRefPubMedGoogle Scholar
  8. Liu Q, Kasuga M, Sakuna Y, Abe H, Miura S, Yamaguchi-Shinozaki K Shinozaki K (1998) Two transcription factors, DREB1 and DREB2, with an EREBP/AP2 DNA binding domain separate two cellular signal transduction pathways in drought- and low-temperature-responsive gene expression, respectively, in Arabidopsis. Plant Cell 10:1391–1406CrossRefPubMedGoogle Scholar
  9. Medina J, Catalá R Salinas J (2001) Developmental and stress regulation of RCI2A and RCI2B, two cold-induced genes of Arabidopsis encoding highly conserved hydrophobic protein. Plant Physiol 125:1655–1666CrossRefPubMedGoogle Scholar
  10. Peynado A Cooper WC (1963) A comparison of three major Texas freezes and tissue temperatures of citrus tree parts during the January 9 to 12 freeze. Proc Rio Grande Valley Hort Soc 17:15–23Google Scholar
  11. Rouse RE (1985) Review of citrus rootstock for Texas following the 1983 freeze. J Rio Grande Valley Hort Soc 38:19–26Google Scholar
  12. Tignor ME, Davies FS Sherman WB (1997) Rapid freeze acclimation of Poncirus trifoliata seedlings exposed to 10°C and long days. Hortscience 32:854–857Google Scholar
  13. Thomashow MF (1990) Molecular genetics of cold acclimation in higher plants. Adv Genet 28:99–131CrossRefGoogle Scholar
  14. Thomashow MF (1994) Arabidopsis thaliana as a model for studying mechanisms of plant cold tolerance. In: Meyerowitz E, Somerville C (eds) Arabidopsis. Cold Spring Harbor Laboratory Press, New York, pp 807–834Google Scholar
  15. Thomashow MF (1999) Plant cold acclimation: Freezing tolerance genes and regulatory mechanisms. Annu Rev Plant Physiol 50:571–599CrossRefGoogle Scholar
  16. Weiser CJ (1970) Cold resistance and injury in woody plants. Science 169:1269–1278PubMedCrossRefGoogle Scholar
  17. Yelenosky G, Hearn CJ Cooper WC (1968) Relative growth of trifoliate orange selections. Proc Fla State Hort Soc 93:205–209Google Scholar
  18. Yelenosky G (1996) An overview of Florida citrus freeze survival. Proc Fla State Hort Soc 109:118–123Google Scholar

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Texas A&M University-KingsvilleCitrus CenterWeslacoUSA

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