The maize lilliputian mutation is responsible for disrupted morphogenesis and minute stature

A recessive maize mutant disrupted in seedling development was isolated fol lowing transpositional mutagenesis with Mutator. This mutant, lilliputian ( lil1), exhibits a phenotype consisting of a large primary root, extremely r educed stature, crinkly leaves and has been mapped by TB-A translocations o n the short arm of chromosome 2. Comparative histological analyses revealed an increase in cell number in the mutant root and leaves, as well as an ir regularity in cell shapes, suggesting that the altered morphology of lil1 r oots and leaves is related to an uncoordinated increase in cell divisions a nd to a defect in division plane alignment. On the other hand, the reduced stature of the mutant plant may be ascribed to a defect in cell elongation. In situ hybridization of primary root tissues reveals higher levels of a-t ubulin transcripts in the pericycle and in cells surrounding vascular eleme nts in mutant rather than in wild-type tissues. These features suggest a ro le of the Lil1 gene in the correct functioning of microtubules. Moreover, t he fact that the mutation is recognizable even in the dormant embryo and th at mutant seedlings are obtained from immature (12 DAP) lil1 embryos indica tes that the defect in cell division pattern accounting for the disrupted s eedling morphology manifests itself even during embryo development.