Development of a high-density oligo microarray of cassava, an important tropical crop

We developed a 60-mer oligonucleotide Agilent microarray representing about 20,000 cassava genes and applied it to expression profiling under drought stress. We demonstrated that our microarray is an useful tool for analyzing the cassava transcriptome and that it can be applied to various cassava species. After cutting of shoots from the cassava plants, the shoots were grown in a glass bottle containing MS medium supplemented with 2% sucrose and 0.3% gelrite for 4 weeks (16 hours light / 8 hours dark). The plantlets were subjected to drought treatment by removing the plantlets from the gelrite plate, placing on a plastic plate and keeping them for 1 hour under 40-80 μmol photons m-2 sec-1 at 30ºC in 50% of relative humidity. Then total RNA was prepared from the shoots and used for the microarray hybridization. Three replicative hybridization experiments were carried out using the independent biological samples.