*4.4. Gene Isolation and Sequence Analysis*

The full length of the *ZmWRKY106* gene was amplified by PCR with specific primers from maize cDNA. The primers of *ZmWRKY106*-F and *ZmWRKY106*-R are listed in Supplementary Table S1. The PCR products were cloned into pLB vector (Tiangen, China) and sequenced. The homologs of *ZmWRKY106* in different species were searched for in the NCBI database. Sequence alignments of *ZmWRKY106* orthologs were performed by ClustalX software. The phylogenetic tree was constructed using the neighbor-joining method by the MEGA 5.0 program with bootstrap analysis of 1000 replicates [51].
