The INIA1 and the IVIA2 from Spain have a granted United States patent directed to a method for transforming adult citrus plants with A. tumefacienshaving a gene of interest.

The invention discloses in vitro micrografting of transformed shoots onto stocks, at least twice, in order to generate complete adult plants. The second in vitro micrografting can be skipped by planting the first micrografted plants directly into soil.

The related European application EP 870 838 A3, which is not presented here, does not refer to a transformation method in particular, and instead inoculation of a vector carrying a gene of interest into a citrus plant can be performed by any method, including Agrobacterium as disclosed in dependent Claim 2. Furthermore, independent Claim 1 covers any woody species, therefore this application is mentioned in the section ‘Woody Tree Species’.

1 Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), Spain

2 Instituto Valenciano de Investigaciones Agrarias (IVIA), Spain

Specific Patent Information

Patent Number Title, Independent Claims and Summary of Claims Assignee
US 6103955

  • Earliest priority – 5 March 1997
  • Filed – 5 March 1998
  • Granted – 15 August 2000
  • Expected expiry – 4 March 2018
Title – Procedure for the genetic transformation of adult plants of woody species

Claim 1
A procedure for the genetic transformation of citrus adult plants consisting of:

(a) co-culturing explants of adult tissue from citrus plant species, from the first flushes of the grafts of buds of citrus adult plants onto stocks, with a non-oncogenic strain of Agrobacterium tumefaciens, optionally modified to further contain genes which encode the characteristics of interest to be inserted into the citrus plant, in feeder plates, and subsequently, in a culture medium which favors the induction of transgenic shoots and permits the selection thereof;
(b) in vitro micrografting said transgenic shoots, their buds or apices, onto stocks cultivated in vitro; and
(c) grafting the resulting in vitro micrografted plants, their buds and apices, onto other stocks which give vigor and allowing the successful grafts to grow to generate complete adult plants, or directly transplanting the in vitro micrografted plants into the soil to generate complete adult plants.

Method for transforming explants of adult citrus plants with a non-oncogenic A. tumefaciens having a gene of interest. The transformed shoots are micrografted onto other stocks to allow regeneration of complete adult plants.

  1. Related application in Europe (EP 870838) is pending.
  2. Related patent granted in Spain (ES 2151338), however, claim 1 recites a procedure for the genetic transformation of adult plants of woody species, and is not limited to those of citrus species.

Note: Patent information on this page was last updated on 14 March 2006.