Multiple sequence alignments were conducted using ClustalW (version 1.8.1) and presented using BOXSHADE (version 3.21; http://www.ch.embnet.org/software/BOX_form.html). Identical amino acid residues are boxed, and similar residues are shaded in gray. Dashes indicate gaps in the sequences to allow maximum alignment. The subdomains of catalytic domain are marked by a solid line. Arabidopsis Genome Initiative identification numbers of the Arabidopsis SnRK2 members are as follows: SnRK2.1 (At5g08590), SnRK2.2 (At3g50500), SnRK2.3 (At5g66880), SnRK2.4 (At1g10940), SnRK2.5 (At5g63650), SnRK2.6/OST1/SRK2E (At4g33950), SnRK2.7 (At4g40010), SnRK2.8 (At1g78290), SnRK2.9 (At2g23030), and SnRK2.10 (At1g60940). OST1/SRK2E is synonymous to SnRK2.6. Nomenclature of the soybean SnRK2 members followed that of the Phytozome v5.0: Glycine max database (http://www.phytozome.net/soybean) and the GenBank accession numbers of the sequences from soybean are as follows: SPK-1(AAA33979), SPK-2(AAA34017), SPK-3(AAB68961) and SPK-4(AAB68962).