Genetics and evolution of leaf development

Comparative Genetics

 

The LEAFY gene does not have the same role in the tomato leaf as it does in the pea leaf. The tomato leafy mutant retains compound pinnate leaves (Molinero-Rosales et al., 1999, Plant Journal 20: 685-693), whereas the pea leafy mutant develops simplified, unifoliolate leaves (Hofer et al., 1997, Current Biology 7: 581-587). In tomato leaf architecture, class 1 homeobox (KNOX) and PHANTASTICA genes are implicated instead (Hareven et al., 1996, Cell 84: 735-744; Kim et al., 2003, Nature 424:438-442).

 

We studied class 1 KNOX gene expression in pea and saw that PSKN1 was excluded from developing leaf primordia, suggesting it does not play a role (Hofer et al., 2001, Plant Molecular Biology 45: 387-398).  These results suggest that pea and tomato evolved mechanisms for pinnate leaf architectures independently.

 

Further, we studied a phantastica mutant in pea, known as the crispa mutant. Downregulation of the PHANTASTICA gene in transgenic tomato results in simplifed leaves (Kim et al., 2003, Nature 424:438-442), but the pea crispa mutant, which lacks a functional PHANTASTICA gene, retains compound pinnate leaves (Tattersall et al., 2005, Plant Cell 17: 1046-1060).  These new results corroborate our earlier conclusions: that compound leaf architectures evolved independently in pea and tomato.

 

Papers from our lab are highlighted in yellow.

 

 

 

 

 

 

 

 

Norwich Research Park, Colney, Norwich NR4 7UH, UK