Figure 4

Transcript levels of poplar leaf apoplast proteins and their transcriptional regulation by stress. (A) Year-round transcript levels of P. deltoides leaf apoplast proteins using poplar microarrays, and hierarchical clustering of the transcripts corresponding to 139 proteins. Transcript abundance over time is represented as the log2 fold-change of each time point to the baseline time point (September). Vertical bars with a color represent a module. Functional classification of each module is shown on the right with the number (n) of genes. (B) Heat map showing response of genes corresponding to apoplast proteins at the transcript level to water stress in P. deltoides that was subjected to moderate (-0.49 MPa) to severe (-1.26 MPa) cyclical water stress. Expression less than 1.0 is down-regulated compared to control, whereas expression greater than 1.0 is up-regulated. (C-E) Transcript response of genes corresponding to apoplast proteins in leaves when poplar NM6 (P. nigra X P. maximowiczii) was challenged with the isolates of M. medusae f. sp. deltoidae (Mmd) and M. laricipopulina (Mlp). Control (ctrl) tissues were also analyzed. Error bars show standard deviation about the mean.