Regulation of Agrobacterium tumefaciens T- cyt gene expression in leaves of transgenic potato ( Solanum tuberosum L. cv. Désirée) is strongly influenced by plant culture conditions.

Autor: Dymock, Dave, Risiott, Ruth, Pater, Sylvia, Lancaster, Jane, Tillson, Penny, Ooms, Gert
Zdroj: Plant Molecular Biology; Oct1991, Vol. 17 Issue 4, p711-725, 15p
Abstrakt: The promoter region of the Agrobacterium tumefaciens T- cyt gene was linked in a translational fusion to the coding DNA of the reporter gene uidA (for β-glucuronidase or GUS protein; EC 3.2.1.31) and to nos 3′ flanking DNA. The chimaeric gene was introduced by Agrobacterium transformation into potato ( Solanum tuberosum L. cv. Désirée). In nine transgenic lines, the average GUS levels were highest in extracts from stems and roots of in vitro grown plants ( ca. 11 000 GUS activity units per pmol MU per mg protein per min) but lower in leaves of the in vitro grown plants ( ca. 7000 units). GUS activity was intermediate in stems and roots of plants grown in soil as well as in in vitro crown galls ( ca. 3000 units). Activity was low in tubers, irrespective of whether these developed in vitro or in soil (both ca. 100 units), and lowest of all in leaves of soil-grown plants ( ca. 10-15 units). However, in shoot cultures reestablished from soil-grown plants, GUS activity in the leaves increased to that determined in the original shoot cultures. Hence, plant culture conditions strongly influenced the expression of the T- cyt-uidA-nos gene. In particular, it was silenced in leaves of soil-grown plants. The results are compared with previous analyses of the promoter region of the wild-type T- cyt gene and with the growth properties of a large number of crown gall cell lines and crown-gall-derived plants, including over forty S. tuberosum cv. Désirée cell lines isolated in the present study that were transformed with the wild-type T- cyt gene and six promoter-mutated derivatives. A number of implications are discussed for crown gall formation and for control of expression of plant genes which contain Activator or G-box type 5′ expression control sequences. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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