cDNA microarray analysis of early response to submerging stress in Zea mays roots

The complete expression profile of maize has not yet been published, especially at the early submerging treatment. These early-response genes play key roles in regulating the expressions of late-response genes leading to morphological and metabolic adaptations. In this study, a cDNA microarray platform has been developed to investigate the early submerging stress responses. Transcriptional level of many genes was markedly altered after 2-h long submerging treatment. The expressions of 32 cDNA clones, which represent 24 non-redundant genes, were more than threefold upregulated or downregulated under submerging stress as compared to their expression under nonsubmerged control conditions. Early-responsive to submergence genes are involved in signal transduction, glycolysis, photosynthesis, transcription and translation, and lipid and energy metabolic pathways. A full-length cDNA coined ZmZF (AY515607) was cloned from maize. Sequence analysis showed that ZmZF shares high homology with zinc finger-like proteins. In addition, expression of SKP1/ASK1-like protein and 20S proteasome subunit alpha-3 increased significantly after 2-h low-oxygen stress. Based on their expression pattern and function, we hypothesize that regulatory mechanisms at the translation level also play a crucial role in low-oxygen response at early submergence.