Functional & Integrative Genomics

, Volume 13, Issue 2, pp 167–177

A root-specific wall-associated kinase gene, HvWAK1, regulates root growth and is highly divergent in barley and other cereals

Original Paper


Wall-associated receptor-like kinases (WAKs) are important candidates for directly linking the extracellular matrix with intracellular compartments and are involved in developmental processes and stress response. WAK gene family has been identified in plants such as Arabidopsis and rice. Here, we present a detailed analysis of the WAK1 gene from barley cv. Golden Promise, mapped to chromosome 5H. Three BAC clones corresponding to the WAK fragment were sequenced and the full-length WAK1 gene was characterized. The gene has three exons and two short introns with a coding region of 2,178 bp encoding a protein of 725 amino acids. A regulatory region was analyzed in −1,000 bp sequence upstream to start codon. Using conserved domains database and SMART, various conserved domains such as GUB WAK Bind, epidermal growth factor CA, and protein kinase C as well as other regions like signal peptides, active sites, and transmembrane domains were identified. The gene organization of HvWAK1 was compared with wheat (TaWAK1) and Arabidopsis (AtWAK1), suggesting that the WAK1 gene organization has remained highly conserved. Nonetheless, WAK1 was found to be highly divergent when compared with sequences available from barley cv. Haruna Nijo (50 %), rice (46 %), wheat (21 %), Arabidopsis (25 %), and maize (19 %). This divergence may have facilitated a better adaptation to surrounding environments due to its role in communication between the extracellular matrix, cell, and outer environment. Semiquantitative RT-PCR-based expression analysis indicates HvWAK1 expression is specific to roots. Significant differences in root growth between GP wild type and GP-Ds mutant seedlings were observed under control and salt stress conditions.


WAKs Barley Abiotic stress Bioinformatics Ac/Ds 

Supplementary material

10142_2013_310_MOESM1_ESM.ppt (71 kb)
Fig. S1Insertion position of Ds in the exon 1 of HvWAK1 gene. The Ds was inserted at 70 bp in exon 1 (PPT 71 kb)
10142_2013_310_MOESM2_ESM.ppt (921 kb)
Fig. S2Comparative colinearity map of barley 5H chromosome with rice generated using HarvEST database, showing synteny of 5H with chromosome 3, 9, and 12 of rice. Five marker and loci, RZ404, Xa21like, raw1, HVDHN009, and MWG914, are located in region of 110 and 120 cM (GrainGenes 2.0 database). Three QTLs, QHd.HaTR-5H, QLr.HaTR-5H and QNb.HaTR-5H are also located in this region (PPT 921 kb)
10142_2013_310_MOESM3_ESM.ppt (94 kb)
Fig. S3Root length of wild type and Ds mutant plants under water and 300 mM NaCl treatment (PPT 93 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Plant Science DepartmentMcGill UniversitySte Anne de BellevueCanada

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