Leaf polarity establishment and the two sets of regulators

Abstract

Proper leaf morphogenesis is evolutionarily important for higher plants in enabling them the maximum photosynthesis capacity. This complex developmental process comprises of several stages. The establishment of leaf polarity along the adaxial (doral)-abaxial (ventral) axis occurs in young leaf primordia and is critically required for subsequent leaf blade expansion. This polar patterning results in distinct anatomical and morphological structures between the upper and the lower sides of the leaf. The first recognition of leaf polarity began with a classical microsurgical study on potato shoot tips over 50 years ago. Subsequently, important leaf polarity regulators have been identified through genetic and molecular studies. This review is mainly focused on characterization of Arabidopsis key determinants that regulate leaf polarity establishment at various levels including transcription, post-transcription, translation and post-translation. Recent development in leaf polarity study is also provided.