Tissue specificity and expression level of gusA under rolD, mannopine synthase and translation elongation factor 1 subunit alpha promoters in transgenic Gladiolus plants
K. Kamo et A. Blowers, Tissue specificity and expression level of gusA under rolD, mannopine synthase and translation elongation factor 1 subunit alpha promoters in transgenic Gladiolus plants, PL CELL REP, 18(10), 1999, pp. 809-815
Transgenic plants of Gladiolus cv. Jenny Lee were developed that contain th
e bargusA fusion gene under either the mannopine synthase 2 (mas2), transla
tion elongation factor 1 subunit alpha (EF-1 alpha), rolD, or the cauliflow
er mosaic virus 35S (CaMV 35S) promoters. The relative level of gusA expres
sion in leaves of five to ten independently transformed, in-vitro-grown pla
nts representing each promoter was similar for transgenic plants containing
the rolD and CaMV 35S promoter and 2.0-fold and 3.3-fold higher than the l
evel for the mas2 and EF-1 alpha promoters , respectively. The maximum leve
l of gusA specific activity by leaves was 135-173 nmol 4-methylumbelliferon
e (4-MU)/h per milligram protein for plants containing either CaMV 35S or r
olD as compared to only 27-38 nmol 4-MU/h per milligram protein for plants
with either mas2 or EF-1 alpha. Histochemical staining confirmed the relati
vely high level of gusA expression throughout the length of the older, 6-cm
-long leaves of plants that contained bargusA under rolD, whereas gusA expr
ession was infrequently observed throughout the older leaves of plants cont
aining either the mas2 or EF-1 alpha promoters. In contrast to the older le
aves, staining showed that strong gusA expression was frequently observed t
hroughout young leaves of plants with either the mas2, EF-1 alpha, or rolD
promoters. Roots of plants with the rolD and EF-1 alpha promoters showed st
rong gusA expression specifically in 93% and 68%, respectively, of the root
tips. Roots of the plants with the mas2 promoter showed strong gusA expres
sion throughout the entire length of the root.