Phenotypes exhibited by T1 plants carrying a GST hpRNA transgene targeting the indicated endogenous gene. (A) At5g17420 codes for CesA7, a subunit of cellulose synthase. (Top) Five-week-old control wild-type Arabidopsis plants. (Bottom) Eight-week-old T1 plants. The transformed plants grow more slowly than the wild type and have the weak, floppy stems seen in knockout mutants of this gene (scale bar, 6 cm). (B) At1g20260 codes for the vacuolar-type H+-ATPase subunit B3. Figure and insets show a representative range of phenotypes in T1 plants 7 wk after germination. In particular, the insets document severe dwarfing, particularly in rosette tissue, whereas flower size and development are not similarly affected (scale bars, 1 cm). (C) At1g20300 codes for a pentatricopeptide repeat protein predicted to be localized in mitochondria. Individual T1 plants (at 7 wk) and duplicate siliques from six independent T1 lines (at 8 wk) illustrate varying degrees of infertility that correlates with phenotype severity (scale bars, 1 cm). Identical symbols indicate the correspondence between a silique pair and its source plant when both are depicted in the panel.
