Generation and characterization of soybean and marker-free tobacco plastid transformants over-expressing a bacterial 4-hydroxyphenylpyruvate dioxygenase which provides strong herbicide tolerance.
Plant 4-hydroxyphenylpyruvate dioxygenase (HPPD) is part of the biosynthetic pathway leading to plastoquinone and vitamin E. This enzyme is also the molecular target of various new bleaching herbicides for which genetically engineered tolerant crops are being developed. We have expressed a sensitive bacterial hppd gene from Pseudomonas fluorescens in plastid transformants of tobacco and soybean and characterized in detail the recombinant lines. HPPD accumulates to approximately 5% of total soluble protein in transgenic chloroplasts of both species. As a result, the soybean and tobacco plastid transformants acquire a strong herbicide tolerance, performing better than nuclear transformants. In contrast, the over-expression of HPPD has no significant impact on the vitamin E content of leaves or seeds, quantitatively or qualitatively. A new strategy is presented and exemplified in tobacco which allows the rapid generation of antibiotic marker-free plastid transformants containing the herbicide tolerance gene only. This work reports, for the first time, the plastome engineering for herbicide tolerance in a major agronomic crop, and a technology leading to marker-free lines for this trait.
Dufourmantel
Nathalie
N
Bayer BioScience, 14-20 rue Pierre Baizet, BP9163, 69263 Lyon Cedex 09, France.
Dubald
Manuel
M
Matringe
Michel
M
Canard
Hélène
H
Garcon
Frédéric
F
Job
Claudette
C
Kay
Elisabeth
E
Wisniewski
Jean-Pierre
JP
Ferullo
Jean-Marc
JM
Pelissier
Bernard
B
Sailland
Alain
A
Tissot
Ghislaine
G
D015111:4-Hydroxyphenylpyruvate Dioxygenase / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004361:Drug Tolerance / Q000235:genetics; D006540:Herbicides / Q000633:toxicity*; D018087:Plastids / Q000235:genetics*; D011551:Pseudomonas fluorescens / Q000201:enzymology / Q000235:genetics*; D011994:Recombinant Proteins / Q000378:metabolism; D013025:Glycine max / Q000235:genetics*; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics*
D001426:Bacterial Proteins; D006540:Herbicides; D011994:Recombinant Proteins; D015111:4-Hydroxyphenylpyruvate Dioxygenase