Fig. S1 Structural features of ZmHK proteins. Transmembrane structure and putative motifs of ZmHK proteins were predicted by TMHMM Server v.2.0 software ( and SMART (Simple Modular Architecture Research Tool) database. Black rectangle, hydrophobic membrane-spanning domain; rectangle marked CHASE, input domain; HK, HK domain; RL, receiver-like domain; R, receiver domain (Muñiz et al. 2010).

Fig.S2 Promoter analysis of ZmHK genes. The PlantCARE database was used for the detection of different response elements.

Fig. S3 Expression pattern of ZmHK genes. Expression data were derived from genome-wide atlas of transcription during maize development (Sekhon et al. 2011), pictorial representations of expression of ZmHK1, ZmHK1a2, ZmHK1b1, ZmHK2, ZmHK2a2 and ZmHK3b can be found at In addition, the expression data of ZmHK1b2 gene was available at and electronic fluorescent pictograph of this gene was generated by using the eFP Browser software (Winter et al. 2007)

Fig. S4 Relative mRNA abundances of AHKs (AHK2, AHK3, AHK4) in wild type and ZmHK-OX transgenic plants. Relative mRNA abundances of AHKs in wild type were set to 1, and expression levels of three genes in transgenic lines were normalized to their respective wild type. * and ** refer to significance at p0.05 and p0.01, respectively.

Table S1.Specific primers used for amplification of the ZmHK cDNAs.

Gene / Forward primer (5′-3′) / Reverse primer (5′-3′)
ZmHK1 / ATGGGGGGCAAGTACCGC / TCAAACAGCCGAATCTGTCG
ZmHK1a2 / ATGGGGGGCAACAAGTAC / TTAAACAGTCGAATCTGTCG
ZmHK1b1 / GGGGTGGAGCCTGGGATGGG / AGGAGAATGGTGCCTCACTTGC
ZmHK1b2 / GGGGTGGAGCCTGGGATGGG / CCTCACCTCCAACGCATCACTTCGG
ZmHK2 / AGGAAAGGGAAAGGGGAATG / GCACAAACAACCAATACCTA
ZmHK2a2 / ATGGAGGAGAAGGGCGA / CTACTGAACTTGGTCTTG
ZmHK3b / ATGGTTCCGAACGGAGCA / TTATTCTATTTCATCAGTCTCTAA

Table S2. Specific primers used for quantitative real-time PCR

Gene / Forward primer (5′-3′) / Reverse primer (5′-3′)
ZmHK1 / TCGCTTCGATGCATGTTTTA / AACAGCCGAATCTGTCGTTC
ZmHK1a2 / CAGAATCGGCCATCATTTCT / TGAGCCTTCAATCAACACCA
ZmHK1b1 / CTCTCGCCAGCCTACAAGTT / CAGGGTCCAAGAACTTCTGC
ZmHK1b2 / GCCCTCCTACATGTCCCATA / GGGTCCAAGAACTTCTGCAA
ZmHK2 / ATGTGGCCTCCAGTTAGGTG / GACGATGCACAACAAAATGC
ZmHK3b / ACCGTAAAGTTGCAGCTGGT / ATCCATCCATTCCACACTGC
ZmHK2a2
ZmActin
AtPIN1
AtPIN3
AtPIN7
AHK2
AHK3
AHK4
ARR5 / TGCACTGCAGGAATGGAGTA
CAATGGCACTGGAATGGT
GAGATCTTCACATGTTTGTGTGG
CCCGAGAAAGAGTCAATTGTAGA
ACTCGGGCTATAAGCTCTTCAAT
CTTTAGGATGCAGCGAGTCC
ATCTTTGGCGATCCATTGAG
TGCATTGAATGGTGGAGTGT
TTGCGTCCCGAGATGTTAGAT / ATATTGGAGTTCGCCACTGC
ATCTTCAGGCGAAACACG
GCCAATACTTTGCTATCATCGTC
CATGTTTTGCTCCTCCTTATCTG
AGACAAGAAAAGGGTTTTTGGAT
ATAAGTCCGCGATGTGGAAC
TTTGCAACATCTGCTGCTTC
CGCAACTAAAGGGATTCCAA
GATCCTCAAATCCAACCGAACT
AtActin8 / TGCAGACCGTATGAGCAAAG / CCGTCATGGAAACGATGTCT

TableS3. Information of seven ZmHK genes.

Gene / Gene ID. / UniGene / Bin / BAC / No. of intron / No. of exon / MW(kDa) / Length of aa / Length of
CDS (bp)
ZmHK1 / GRMZM2G151223 / Zm.327 / 5.07 / AC195458 / 10 / 11 / 108.0743 / 974 / 2925
ZmHK1a2 / GRMZM2G125943 / Zm.37051 / 4.06 / AC185633 / 10 / 11 / 108.7804 / 975 / 2928
ZmHK1b1 / GRMZM2G155767 / Zm.82146 / 1.10 / AC190496 / 10 / 11 / 108.3848 / 995 / 2988
ZmHK1b2 / GRMZM2G039696 / Zm.21516 / 5.02 / AC193442 / 10 / 11 / 108.9818 / 996 / 2991
ZmHK2 / GRMZM2G471529 / Zm.16977 / 3.05 / AC205520 / 11 / 12 / 112.4112 / 1007 / 3023
ZmHK2a2 / GRMZM2G423456 / Zm.96567 / 8.06 / AC199726 / 8 / 9 / 115.5958 / 1031 / 3096
ZmHK3b / GRMZM2G158252 / Zm.697 / 5.03 / AC185417 / 8 / 9 / 116.1606 / 1049 / 3150

* Bin: The bin is an interval that includes all loci from the leftmost or top Core Marker to the next Core Marker. Bins are designated by a chromosome number followed by a two-digit decimal (e.g., 1.00, 1.01, 1.02, etc).Placement of a locus to a bin is dependent on the precision of mapping data, and increases in certainty as markers increase in number or populations increase in size.