Fig. 6. A. thaliana plants overexpressing NtKIS1a and AtCycD3;1 display a wildtype phenotype. (A) The interaction between NtKIS1a and AtCycD3;1 using the two-hybrid system is presented. BD-NtKIS1a corresponds to the DNA binding domain of GAL4 fused to NtKIS1a and AD-AtCycD3;1 corresponds to the activation domain of GAL4 fused to AtCycD3;1. AD and BD correspond respectively to the activation and DNA binding domains of GAL4. (B) RT-PCR analysis was performed as described in Materials and Methods. Lanes WT, AtCycD3;1, NtKIS1a, AtCycD3;1xNtKIS1a and AtCycD3;1+NtKIS1a are RT-PCR products obtained from RNA samples of the corresponding plants. AtCycD3;1xNtKIS1a correspond to the F1 plants of the cross between the AtCycD3;1 and NtKIS1a-overexpressing lines. AtCycD3;1+NtKIS1a correspond to T1 plants issued from the transformation of the AtCycD3;1-overexpressing line by the NtKIS1a-containing transgene. Three independent plants were tested for AtCycD3;1xNtKIS1a. PCR was performed with specific primers from NtKIS1a (first row), AtCycD3;1 (second row) and Actin2 (third row; used as control), respectively. (C) Top row: view of a 6-week-old plantlet from the AtCycD3;1-overexpressing line (AtCycD3;1), and view of 4-week-old plantlets from 35S::NtKIS1a (NtKIS1a) and AtCycD3;1xNtKIS1a lines. Bottom row: view of 3-week-old plantlets from AtCycD3;1-overexpressing line (AtCycD3;1), AtCycD3;1+NtKIS1a and WT. (D) From several scanning electron microscopy images of the lines described in C, bottom row, cell areas were measured using the Optimas 6.0 software. The averages of cell areas were reported in three categories, as described in the legend of Fig. 4. The measurement presented here for WT is an independent measurement of the WT measurement shown in Fig. 4.