Figure 3.

Histochemical localization of GUS activity under the control of the TRX m promoter. A to F, GUS expression in transgenic Arabidopsis plants carrying the PsTRXm1∷GUS fusion construct. A, GUS staining localized in the cotyledons of 7-d-old seedlings. B and C, Leaves and roots from a 15-d-old plantlet. C and D, GUS activity localized in root apical meristem and root hairs of 15-d-old plantlet. E, GUS staining localized in flowers of a 21-d-old plant. F, GUS expression in seeds in the silique. G to I, GUS expression under the deleted promoter PsTRXm2∷GUS. G, Additional staining in the hypocotyl of 7-d-old seedlings. H, GUS activity throughout the aerial part of a 15-d-old plant. I, Weaker GUS signals are visible in flowers, with the exception of strong staining in the stigma of a 21- to 30-d-old plant. J and K, Aerial part and root of a 15-d-old plant showing GUS expression under the deleted promoter PsTRXm3∷GUS. The pattern of expression is similar to that detected in PsTRXm2∷GUS transgenic plants. L and M, Aerial part and root of a 15-d-old plant, showing GUS activity under the deleted promoter PsTRXm4∷GUS. The signal in this transgenic line is similar to that found with the previous deleted construct. Assays with the PsTRXm5∷GUS fusion yielded no expression, as shown in N (10-d-old seedlings), O (root of a 15-d-old plant), and P (flowers of a 21- to 30-d-old plant). Q, Vector pBI101 in control transgenic plants.