Functional Analysis of Leaf Pattern Formation

Iowa State University, Ames IA

Investigators

Abstract

Michael G. Muszynski IOS-1022452 Functional Analysis of Leaf Pattern Formation Multicellular organisms must control the spatial organization of cells and tissues during development in order to attain their proper forms. The nature of the signals that control how spatially organized patterns are formed during growth is poorly understood. This project aims to increase our understanding of how patterns are formed in plants by studying maize leaf growth. The maize leaf is an excellent system in which to study pattern formation since it is organized into four distinct tissues. The leaf sheath is the most proximal tissue located closest to the stem, while the blade is the most distal tissue located furthest from the stem. Separating the sheath and blade are the auricle and the ligule. This proximal-to-distal pattern of growth is established early in developing leaf primordia and is essential for normal leaf shape. Molecular genetic studies revealed that mutations in a protein that initiates signaling of the perception of the plant hormone cytokinin (CK), the maize cytokinin receptor, disrupted the proximal-distal pattern of leaf growth. This result suggests a direct link between CK signaling and leaf pattern formation which is a new function for this critical plant hormone. This project will investigate the role CK signaling plays in establishing proper leaf growth patterns using a combination of molecular, genetic, genomic and cell biological approaches. The results of this project are expected to reveal how the components of CK signaling participate in guiding leaf growth patterns and to identify additional molecular players controlling pattern formation in leaves. The project will involve cross-disciplinary training of a post-doctoral scientist and several undergraduate students. Furthermore, a detailed understanding of the molecular control of leaf development is essential to improve crop production in the face of a changing climate and increased global demand.