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

Karidas, Premananda and Challa, Krishna Reddy and Nath, Utpal (2015) The tarani mutation alters surface curvature in Arabidopsis leaves by perturbing the patterns of surface expansion and cell division. In: JOURNAL OF EXPERIMENTAL BOTANY, 66 (7). pp. 2107-2122.

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Abstract

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 leaf flatness, primarily because only a few mutants with altered surface curvature have been isolated and studied. Characterization of mutants of the CINCINNATA-like TCP genes in Antirrhinum and Arabidopsis have revealed that their products help maintain flatness 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 Arabidopsis due to excess division of dispersed meristemoid cells. Here, we report the isolation and characterization of an Arabidopsis 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 gibberellic acid levels rescued the tni phenotype. Genetic interactions demonstrated that TNI maintains leaf flatness independent of TCPs and PEAPODs.

Item Type:	Journal Article
Publication:	JOURNAL OF EXPERIMENTAL BOTANY
Publisher:	OXFORD UNIV PRESS
Additional Information:	Copy right for this article belongs to the OXFORD UNIV PRESS, GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND
Keywords:	Arabidopsis thaliana; cell proliferation; gibberellic acid (GA); leaf shape; surface curvature; TARANI
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	15 Jun 2015 07:25
Last Modified:	15 Jun 2015 07:25
URI:	http://eprints.iisc.ac.in/id/eprint/51657

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