Gene family identification was done by comparing the first exon of EF1A gene from cassava (AF041463) using blastn to the EF1A gene family available on Manihot esculenta genome database (Phytozome) [45] . A set of primers then was designed from that blastn result in order to clone the promoters from EF1A gene family. Genomic DNA was isolated from cassava leaves using CTAB method [46] . The promoter regions from each gene family were amplified using specific primers (Table 1 ). PCR amplification was performed using Kapa 2G Polymerase™ (Kapa Biosystem) in Veriti 96 well Thermal cycler (Applied Biosystems).
Each of PCR products from single PCR reaction were purified using Geneaid™ PCR purification kit (Geneaid) following the manufacturer’s protocol and cloned into pJET1.2/blunt vector (Fermentas). Then the vectors are introduced into Escherichia coli strain DH5α with heat shock method [47] . The plasmid vector was extracted by Geneaid™ plasmid isolation kit (Geneaid) and both strands were sequenced using pJET 1.2 forward and pJET 1.2 reverse primers at Macrogen Inc, South Korea.
Each of PCR products from single PCR reaction were purified using Geneaid™ PCR purification kit (Geneaid) following the manufacturer’s protocol and cloned into pJET1.2/blunt vector (Fermentas). Then the vectors are introduced into Escherichia coli strain DH5α with heat shock method [47] . The plasmid vector was extracted by Geneaid™ plasmid isolation kit (Geneaid) and both strands were sequenced using pJET 1.2 forward and pJET 1.2 reverse primers at Macrogen Inc, South Korea.