Abstract
The Arabidopsis acaulis1 (acl1) mutants, originally isolated in a screening for the mutants with reduced stem lengths, have curly leaves, compact rosettes and few flowers. The defect in the stem elongation in acl1 mutants is due to reduced cell size. Vascular cells and guard cells are not fully differentiated in a severe allele. Moreover, callose is accumulated ectopically in the stems of acl1 mutants. The acl1 phenotype is not rescued by phytohormones such as auxin, gibberellin or brassinosteriod. However, when grown at higher temperature, the mature acl1 mutants are indistinguishable from wild-type plants. Also, by adding NH4NO3 into the growth medium, the acl1 phenotype was partially rescued. Both acl1-1 (severe allele) and acl1-3 (weak allele) are recessive mutations. Genetic mapping revealed acl1 is located on chromosome 4.
