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[Arabidopsis] Re: GV3101::pMP90 -- '::' indicates integration in bacterial chromosome?

Steen Hoyer via arab-gen%40net.bio.net (by j.s.hoyer from wustl.edu)
Wed Jan 13 11:23:07 EST 2016

Dear Dr. Concz,      thank you for your very thorough and prompt reply! 
I feel much better now that I know the correct strain designation and 
what it means.

Thanks again,

On 2016-01-13 7:02 AM, koncz wrote:
> Dear Steen,
> GV3101 means historically:
> GV = Genetische Virologie (the old name of the Ghent University 
> department of Jeff Schell and Marc Van Montagu)
> 3101 = strain number in the original collection, made by Marcel 
> Holster by curing the pTiC58 Ti plasmid from a Rifampicin resistant 
> C58 strain.
> So, GV3101 is a TiC58 free cured Rif resistant  Agrobacterium 
> tumefaciens strain, which is thus avirulent and thus designated 
> alternatively C58C1 RifR (where C1 stands for cured 1).
> pMP90 = plasmid Max-Planck 90 made by me by precisely deleting the 
> T-region of pTiC58 TraC nocC (transfer and nopaline catabolism 
> constitutive) and labelling the deletion with a gentamycin resistance 
> gene. pMP90 is a T-DNA/T-region free helper plasmid, which is used in 
> combination with binary vectors, which are capable for autonomous 
> replication in Agrobacterium, for plant transformation.
> The only correct designation of this strain is GV3101 (pMP90) or C58C1 
> RifR (pMP90). If you write GV3101 alone it means that you use a Ti 
> plasmid cured Agrobacterium strain, which has no helper plasmid, so 
> avirulent. Therefore, the GV3101 citation of the GV3101 (pMP90) strain 
> is absolutely incorrect.
> pMP90 is completely stable, replicates like pTiC58 but has no 
> transferred DNA. It is NOT integrated into the chromosome, yet 
> completely stable.
> Consequently, we do not use Gm or Rif selection to grow the strain for 
> plant transformation.
> However, proper selection for the antibiotic resistance marker of the 
> binary vector, which you use for plant transformation in GV3101 (pMP90) is
> absolutely necessary since none of the binary vectors used in our work 
> have proper partitioning functions, thus segregate randomly and tend 
> to be lost
> if no selection is applied to secure their presence in each cell.
> You find an alternative description of this system in
> Koncz C, Martini N, Szabados L, Hrouda M, Bachmair A, and Schell J 
> (1994) Specialized vectors for gene tagging and expression studies. 
> In: Plant Molecular Biology Manual, Gelvin S and Schilperoort B 
> (eds.), Kluwer Academic, Dordrect, B2, 1-22. and also in wider terms 
> of Agrobacterium biology/genetics: Koncz C, Schell J, and Rédei GP 
> (1992) T-DNA transformation and insertion mutagenesis. In Methods in 
> Arabidopsis Research, Koncz C, Chua N-H, and Schell J (eds.), World 
> Scientific, Singapore, pp. 224-273.
> Check it online: http://www.mpipz.mpg.de/koncz/publications
> greetings: Csaba
> On 13/01/2016 01:50, Steen Hoyer wrote:
>> Agrobacterium notation question: what does '::', in the name of a 
>> strain such as 'GV3101::pMP90' indicate? Does it indicate that a 
>> cassette was integrated into an Agrobacterium chromosome?
>> I am particularly interested in pMP90. A review by Hellens et al. 
>> (reference 1 below) implies that the relevant parts of the plasmid 
>> were integrated, but I cannot tell if that is the case from the 
>> original reference (Koncz and Schell 1986; ref 2).
>> Many authors state that they used GV3101 without specifying which 
>> helper plasmid (if any) they used with it. Sometimes they indicate 
>> the helper function in parentheses, implying (I think) the function 
>> is present as a plasmid. If integrated into a chromosome, it would 
>> not be strictly necessary to maintain antibiotic selection, and so 
>> users might not think about whether the helper function was present.
>> Dr. Koncz,  I hope you do not mind my sending this question to a 
>> mailing list---this is a difficult-to-google question, so I thought 
>> it would be useful to query in a public forum. Thanks for developing 
>> such useful strains and plasmids!
>> Thanks and best wishes,
>>       Steen
>> 1. Hellens et al. http://doi.org/10.1016/S1360-1385(00)01740-4
>> 2. Koncz and Schell http://doi.org/10.1007/BF00331014
> -- 
> Csaba Koncz
> Max-Planck Institut für
> Züchtungsforschung
> Carl-von-Linné-Weg 10.
> D-50829 Köln
> Germany
> Tel: +49-221-5062-230
> Fax: +49-221-5052-213
> E-mail:koncz from mpipz.mpg.de
> Institute of Plant Biology
> Biological Research Center of
> Hungarian Academy of Sciences
> H-6724 Szeged
> Temesvári krt. 62/64.
> Hungary
> E-mail:koncz.csaba from brc.mta.hu

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