Positive selection system based on polyol carrier

Centre National de la Recherche Scientifique (Paris Cedex, FR) holds a patent in the United States that is related to the use of a DNA sequence coding for a polyol carrier for screening genetically modified plants.  Related patent applications are also pending in Europe, Australia, Canada and Japan.

Technology overview

The plants are capable of synthesizing, via photosynthesis, primary compounds such as glucides by using light energy.  Only certain organs of the plant, mainly the adult leaves, are capable of manufacturing and exporting the glucides towards the storage organs, such as the tubers, the seeds and the fruits.  In the majority of plants, the main glucide transported is saccharose.  However in a large number of plants, other compounds, such as polyols, are also transported. Polyols (or sugar alcohols) are, like saccharose, primary products of photosynthesis which include mannitol, sorbitol, dulcitol, galactitol, inositol, myo-inositol, ribitol, xylitol and more.

As an example, mannitol is present in more than 100 species of higher plants.  It is produced in the mesophyll cells (cells containing chlorophyll).  To circulate, it must re-enter the sieve tubes (veins).  However, there is no continuity between the mesophyll cells and the sieve tubes, and a mannitol carrier is therefore needed.  In this way, the mannitol leaves the mesophyll cells and uses the carrier to enter the sieve tubes.

By transforming plant cells with a DNA sequence coding for a polyol carrier, the transformed cells willl have an advantage in growth over their non-transformed cells when selection is carried out on a medium containing the polyol.

Specific patent information

Patent/Application Number

Title, Independent Claims and Summary

Applicant
US 2005/015832 A1

  • Earliest priority – 11 Jul 2000 (FR)
  • Filed – 30 Aug 2004
  • Granted – Pending
  • Expected expiry – N/A
Title – DNA sequences coding for a polyol carrier and use thereof, in particular for preparing transgenic plants

Claim 1
Use of a DNA sequence coding for a linear polyol carrier, in plants and fungi, such as polyols having main chain containing 5 to 8 carbon atoms, in particular 5 to 7 carbon atoms, in particular 6 carbon atoms, these polyols being advantageously chosen from mannitol, sorbitol, dulcitol, galactitol, inositol, myo-inositol, ribitol and xylitol, and being in particular mannitol, for the preparation of transgenic plants.
Claim 3
Protein characterized in that it comprises or is constituted by: sequence SEQ ID NO: 2, or any sequence derived from SEQ ID NO: 2, in particular by substitution, suppression or addition of one or more amino acids, having the property of transporting linear polyols in plants and fungi, such as polyols having a main chain containing 5 to 8 carbon atoms, in particular 5 to 7 carbon atoms, in particular 6 carbon atoms, these polyols being advantageously chosen from mannitol, sorbitol, dulcitol, galactitol, inositol, ribitol and xylitol, and being in particular mannitol, any homologous sequence of SEQ ID NO: 2, preferably having a homology of at least approximately 50% with sequence SEQ ID NO: 2 and possessing the property of transporting, in plants and fungi, polyols as defined above, or any fragment of one of the sequences defined above, on the condition that it possesses the property of transporting, in plants and fungi, polyols as defined above, in particular any fragment being constituted by at least approximately 10 amino acids adjacent in the sequence SEQ ID NO: 2.
Claim 5
DNA sequence which comprises or is constituted by: nucleotide sequence SEQ ID NO: 1, or any nucleotide sequence derived, by degeneration of the genetic code, from the sequence SEQ ID NO: 1 coding for a protein represented by SEQ ID NO: 2, or any nucleotide sequence derived, in particular by substitution, suppression or addition of one or more nucleotides, from the sequence SEQ ID NO: 1 coding for a protein derived from SEQ ID NO: 2, as defined in claim 3, or any homologous nucleotide sequence of SEQ ID NO: 1, preferably having a homology of at least approximately 35% with the sequence SEQ ID NO: 1 coding for a homologous protein of SEQ ID NO: 2, as defined in claim 3, or any fragment of the nucleotide sequence SEQ ID NO: 1 or of the nucleotide sequences defined above, said fragment being preferably constituted of at least approximately 30 nucleotides adjacent in said sequence, or any complementary nucleotide sequence of the above-mentioned sequences or fragments, or any nucleotide sequence capable of hybridizing in stringent conditions with the complementary sequence of one of the abovementioned sequences fragments.

Centre National De La Recherche Scientifique

US 7098313

  • Earliest priority – 11 Jul 2000 (FR)
  • Filed – 30 Aug 2004
  • Granted – 29 Aug 2006
  • Expected expiry – 30 Aug 2024
Title – DNA sequences coding for a polyol carrier and their use, in particular for the preparation of transgenic plants

Claim 1
A protein, comprising: sequence SEQ ID NO: 2.

This is the granted patent of the US application US 2005/015832 A1.  The total claims were reduced from sixteen to two.

EP 1299554 A1

  • Earliest priority – 11 Jul 2000 (FR)
  • Filed – 22 Jun 2001
  • Granted – Pending
  • Expected expiry – N/A
Title – DNA sequences coding for a polyol carrier and use thereof, in particular for preparing transgenic plants

The claims of this European application are the same as the United States application

US 2005/015832 A1

Remarks

A patent was already granted in France (FR 2811679 B1).  Related patent applications were also filed in Australia (AU 200169241 A1), Canada (CA 2416203) and Japan (JP 2004502461).  The PCT application is WO 2002/04647 A1.

Search strategy

Search details
Date of search 09/06/2006
Database searched Patent Lens
Type of search Expert, stemming off
Collections searched AU-B, US-A, US-B, EP-B, WO
Search terms (growth near/5 advantage) AND (plant near/5 growth) AND ((transformed near/2 cell) in claims)
Results 38 hits
Comments The following new docs are relevant to positive selection:

US 2003/167526

: Compositions and methods for identifying transformed cells; by PIONEER HI-BRED
US 6284947: Methods of using viral replicase polynucleotides and polypeptides; by PIONEER HI-BRED
US 2005/15832: Dna sequences coding for a polyol carrier and use thereof, in particular for preparing transgenic plants; by CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE