Figure 1

HSI2 insertional mutants and overexpressing lines. (A) Diagram of the structure of the HSI2 gene (At2g30470) showing the position of T-DNA insertions (triangles). Open boxes indicate exons, while black boxes indicate untranslated regions. The transcriptional start site is indicated by the number 1. With the exception of T-DNA sizes, the diagram is drawn to scale. (B) Kinetic RT-PCR analysis of HSI2 mRNA abundance in the mutants and corresponding wild-types (hsi2-2/Col-0 and hsi2-5/Col-2). (C) Diagram of the structure of the HSI2 transgene. Open boxes indicate exons; 35S, Cauliflower mosaic virus 35S promoter; nosT, terminator region from the Agrobacterium tumefaciens nopaline synthase gene. (D) Kinetic RT-PCR analysis of HSI2 mRNA abundance in transgenic plants and untransformed Col-0. (E) Kinetic RT-PCR analysis of HSI2 mRNA abundance in 14 day old seedlings of hsi2-2 and Col-0, 4 h following treatment with 25 μM PBI425 or 20% PEG 8000. (F) Kinetic RT-PCR analysis of HSI2 mRNA abundance in 3-week-old leaves of hsi2-2 and Col-0 grown in soil saturated to field capacity or following watering withdrawal and development of visible wilting symptoms. For (F), amplification of the housekeeping gene encoding polypyrimidine tract-binding protein1 (PTB1, AT3G01150) was used as control to normalize expression data. All values represent the averages of three biological replicates, each analyzed three times (technical replicates) ± standard error.