Summary: 1Lesions in the mRNA cap-binding gene ABA
HYPERSENSITIVE 1 suppress FRIGIDA-mediated delayed
flowering in Arabidopsis
Isabel C. Bezerra
, Scott D. Michaels
, Fritz M. Schomburg and Richard M. Amasino*
Department of Biochemistry, University of Wisconsin, 433 Babcock Drive, Madison, WI 53706-1544, USA
Received 14 April 2004; revised 4 June 2004; accepted 5 July 2004.
For correspondence (fax 608 262 3453; e-mail firstname.lastname@example.org).3
Present address: EMBRAPA Hortalic¸as, Centro Nacional de Pesquisa de Hortalic¸as, CP 218 70359-970 Brasilia - DF - Brazil.
Present address: Department of Biology, Indiana University, 915 East Third Street, Bloomington, IN 47405, USA.
Recessive mutations that suppress the late-flowering phenotype conferred by FRIGIDA (FRI) and FLOWERING
LOCUS C (FLC) and which also result in serrated leaf morphology were identified in T-DNA and fast-neutron
mutant populations. Molecular analysis showed that the mutations are caused by lesions in the gene encoding
the large subunit of the nuclear mRNA cap-binding protein, ABH1 (ABA hypersensitive1). The suppression of
late flowering is caused by the inability of FRI to increase FLC mRNA levels in the abh1 mutant background. The