Fig. 1. Fruit tissue structure and the HECATE genes of Arabidopsis. (A,B) Colorized longitudinal (A) and transverse (B) sections showing internal fruit tissues of wild-type Arabidopsis. Stigma (Sg), yellow; style (Sy), turquoise; septum (S), pink; transmitting tract (TT), blue; ovules (O), brown; ovule funiculus (F), green. (C) Diagrams of HEC1 (At5g67060), HEC2 (At3g50330) and HEC3 (At5g09750) showing the location of the bHLH domain. Positions of the T-DNA (not shown to scale) insertions in HEC1 and HEC3 are represented by triangles. The region of HEC2 used for creating the HEC2-RNAi construct is bracketed. (D) Alignment of the bHLH domains (underlined) of the HEC, INDEHISCENT (IND) (Liljegren et al., 2004) and the distantly related SPATULA (SPT) (Heisler et al., 2001) proteins. The alignment includes a region upstream of the bHLH domain, where the HECs and IND also show conservation. The asterisk marks an alanine that replaces the conserved glutamate carried by most other Arabidopsis bHLH proteins.