Figure 1

Experimental Design. Unrelated genotypes 1-4 represent four different clones developed from full-sib crosses of elite commercial genotypes as described in Materials and Methods. Rooted cuttings (propagules) were exposed to drought stress 10 months post planting. Mean predawn needle water potentials were determined each day and roots were harvested at indicated time points. RNA for each genotype was isolated from three individuals from different treatment blocks and pooled. Target cDNAs were synthesized and labeled with Cy3 on three separate occasions, and each was hybridized to PtGen2 twice along with Cy5 labeled reference RNA for a total of 72 hybridizations. The origin of the reference RNA is described in Materials and Methods.