The tarani mutation alters surface curvature in XXXX leaves by perturbing the patterns of surface expansion and cell division.

@entity958 @entity9635 @entity33949 @entity12318
UNASSIGNED: The leaf surface usually stays flat, maintained by coordinated growth. Growth perturbation can introduce overall surface curvature, which can be negative, giving a saddle-shaped leaf, or positive, giving a cup-like leaf. Little is known about the molecular mechanisms that underlie @entity12318 , primarily because only a few mutants with altered surface curvature have been isolated and studied. Characterization of mutants of the CINCINNATA-like @entity33949 genes in Antirrhinum and @entity958 have revealed that their products help maintain @entity12318 by balancing the pattern of cell proliferation and surface expansion between the margin and the central zone during leaf morphogenesis. On the other hand, deletion of two homologous PEAPOD genes causes cup-shaped leaves in @entity958 due to excess division of dispersed meristemoid cells. Here, we report the isolation and characterization of an @entity958 mutant, tarani (tni), with enlarged, cup-shaped leaves. Morphometric analyses showed that the positive curvature of the tni leaf is linked to excess growth at the centre compared to the margin. By monitoring the dynamic pattern of CYCLIN D3;2 expression, we show that the shape of the primary arrest front is strongly convex in growing tni leaves, leading to excess mitotic expansion synchronized with excess cell proliferation at the centre. Reduction of cell proliferation and of endogenous @entity9635 levels rescued the tni phenotype. Genetic interactions demonstrated that TNI maintains @entity12318 independent of TCPs and PEAPODs.
