Genetic and molecular analysis of INCURVATA2, a negative regulator of floral homeotic genes in the leaves of Arabidopsis thaliana

One of the largest available collections of plant morphological mutants is the Arabidopsis Information Service (AIS) Form Mutants collection. We studi ed 152 AIS lines already known to display abnormally shaped leaves, finding 22 that exhibited involute, upwardly curled, vegetative leaves, a phenotyp e that we named Incurvata (Icu). Here we present advances in a positional a ttempt to clone the INCURVATA2 gene, whose recessive allele icu2 is carried by the AIS line N329, and which was mapped near the lower telomere of chro mosome 5. The icu2 mutation causes early flowering and Apetala flowers, tog ether with involute leaves, a phenotypic trait associated to ectopic derepr ession in the leaves of the AGAMOUS and APETALA3 floral organ identity gene s.