Sugarcane genes differentially expressed during water deficit

To identify genes that are up and down-regulated by water deficit in sugarcane we used the macroarray methodology and the expression level of 3 575 independent sugarcane cDNAs was measured by hybridization with RNA extracted from plants submitted to mild, moderate and severe water deficit. We identified approximately 1 670 differentially expressed genes from which 62 % were up-regulated by different stress-conditions, whereas many repressed genes were exclusive for each time-point. Analysis of similarity showed that approximately 24 % of the differentially expressed genes shared homology with proteins involved in different processes such as signal transduction, hormone metabolism, photosynthesis, transcription and stress response. Transcripts with no known function accounted for approximately 39 % and those without similarity represented 36 % of the sequences. Five genes analyzed by RT-PCR confirmed the macroarray results.