Identification of genes expressed during aerenchyma formation in maize primary roots

Abstract

Oxygen supply to root tip is important for plants to grow under waterlogged conditions. It is known that aerenchyma, which is air spaces formed in cortex of roots or shoots, contributes to the oxygen transport. In maize, the aerenchyma formation is induced in response to low oxygen stress. Purpose of this study is to understand molecular mechanisms of the aerenchyma formation in maize primary roots.
Roots of 3-d-old maize seedlings were waterlogged for 6 h and then were fixed and embedded with paraffin. We isolated root cortex cells from the paraffin-embedded sections using Laser Microdissection (LM), extracted RNA and carried out a maize 15K cDNA microarray. Finally, we identified 36 genes that were expressed specifically in the root cortex during aerenchyma formation. Functional analyses of these candidate genes are under way.