Histochemical localization of LRX
expression in LRX promoter::uidA
transgenic plants. A and B, pPEX3::uidA
expression. C, pLRX6::uidA expression.
D through F, pLRX5::uidA expression. G
through I, pLRX4::uidA expression. A,
Open flower. Mature pollen grains show a strong expression of
pPEX3::uidA. B, Pollen germinating on a
stigma. C, Emerging lateral roots, showing strong expression of
pLRX6::uidA in the lateral root
meristem, as well as in the vascular tissue of the mature primary root.
D, Root of a 7-d-old seedling; GUS activity is restricted to the
emerging lateral roots. E, Fourteen-day-old seedlings;
pLRX5::uidA is expressed in the leaf
primordia and stipules (inset image) at the basis of the rosette
leaves. A moderate activity persisted during further expansion of the
leaves, preferentially in petioles. F, Opened flowers and flower buds.
GUS activity is detected in the carpels and faintly in the pedicels.
Carpel expression seems higher in the style directly under the stigma
and at the base of the organ and the junction with the receptacle
(abscission zone). G, Primary mature roots; the vascular bundle is
strongly stained. H, Fourteen-day-old seedlings; the inset picture
shows a leaf stained for a shorter time to reveal the stronger
expression in vascular tissue. I, Open flower; GUS activity is detected
in sepals, mostly in the veins. Bars = 1 mm (A, F, and I), 50 μm
(B–D), 2 mm (E and H), 350 μm (E, inset image), and 200 μm
(G).