Figure 2.

Root development of transgenic lines of potato ssp. andigena grown in vitro and in soil. A, For root fresh weight (fr wt) harvests, in vitro plantlets were grown for 4 weeks at 27°C under 16 h of light/8 h of dark. B, Roots from in vitro transgenic lines were generally longer and more robust than wild-type controls (WT). Soil plants were grown in pots in a growth chamber under long days (16 h of light/8 h of dark) at 24°C days and 18°C nights and harvested after 7 weeks. The se of several plants is shown in A. C to E, Accumulation of StGA2ox1 mRNA in leaves and lateral roots (C) and YUCCA1a (D) and IPT (E) mRNA in leaves and primary and lateral roots of wild-type andigena or the transgenic andigena line expressing full-length StBEL5 with a leaf-specific promoter, designated GAS. The transgenic leaf and root samples assayed in C to E are the same ones used in Figure 1B. RT-PCR was performed with gene-specific primers and standardized to yield product in the linear range, normalized using rRNA primers, and quantified by using ImageJ software (Abramoff et al., 2004). Values represent means ± se for three biological replicates. Asterisks indicate significant differences (*P < 0.05, **P < 0.01) using Student’s t test.