*2.6. Expression Profiles of POD Genes After Drought Treatment*

To study the possible role of MePODs in the cassava response to drought stress, water was withheld from a wild subspecies (W14) and two cultivated varieties (Arg7 and SC124) for 12 days. The leaves and roots of these samples were then collected to perform RNA-Seq. Of the transcriptome data, the expression data were obtained for 71 out of the 91 cassava *POD* genes (Figure 6B; Table S4). After drought treatment, 6 (8%) and 5 (7%) *MePOD* genes in Arg7 were transcriptionally upregulated (log2-based fold change > 1), whereas 7 (10%) and 29 (41%) were down-regulated (log2 based fold change < −1) in the leaves and roots, respectively. After SC124 was subjected to drought stress, 9 (13%) and 4 (6%) *MePOD* genes were upregulated (log2-based fold change > 1) but 6 (8%) and 29 (41%) were downregulated (log2-based fold change <−1) in the leaves and roots, respectively. After the W14 subspecies was exposed to drought, 13 (18%) and 21 (30%) *MePOD* genes were induced (log2-based fold change > 1), whereas 11 (15%) and 9 (13%) were depressed (log2-based fold change < −1) in the leaves and roots, respectively. *MePOD13* (subgroup A) and *MePOD16* (subgroup B) were upregulated (log2-based fold change > 1) by drought stress in the leaves of all three genotypes. The above data reveal that more *MePOD* genes were upregulated in response to drought treatment in W14 than in Arg7 and SC124.
