Functional & Integrative Genomics

, Volume 10, Issue 2, pp 191–205

Drought response in the spikes of barley: gene expression in the lemma, palea, awn, and seed


    • Department of BiologyUniversity of Northern Iowa
  • Kalpalatha Melmaiee
    • Department of BiologyUniversity of Northern Iowa
    • PMGG Lab, Department of Agricultural and Natural ResourcesDelaware State University
  • Virginia Berg
    • Department of BiologyUniversity of Northern Iowa
  • Roger P. Wise
    • Corn Insects and Crop Genetics Research, USDA/ARS and Department of Plant PathologyIowa State University
Original Paper

DOI: 10.1007/s10142-009-0149-4

Cite this article as:
Abebe, T., Melmaiee, K., Berg, V. et al. Funct Integr Genomics (2010) 10: 191. doi:10.1007/s10142-009-0149-4


The photosynthetic organs of the barley spike (lemma, palea, and awn) are considered resistant to drought. However, there is little information about gene expression in the spike organs under drought conditions. We compared response of the transcriptome of the lemma, palea, awn, and seed to drought stress using the Barley1 Genome Array. Barley plants were exposed to drought treatment for 4 days at the grain-filling stage by withholding water. At the end of the stress, relative water content of the lemma, palea, and awn dropped from 85% to 60%. Nevertheless, the water content of the seed only decreased from 89% to 81%. Transcript abundance followed the water status of the spike organs; the awn had more drought-regulated genes followed by lemma and palea, and the seed showed very little change in gene expression. Despite expressing more drought-associated genes, many genes for amino acid, amino acid derivative, and carbohydrate metabolism, as well as for photosynthesis, respiration, and stress response, were down-regulated in the awn compared with the lemma, palea, and seed. This suggests that the lemma and the palea are more resistant to drought stress compared with the awn.


Awn Drought Lemma Palea Seed Transcriptome

Supplementary material

10142_2009_149_MOESM1_ESM.doc (74 kb)
Supplementary Figure S1 Organ-specific expression of drought-regulated genes in the spike (DOC 74 kb)
10142_2009_149_MOESM2_ESM.doc (76 kb)
Supplementary Table S1 Primer sequences for real-time PCR (DOC 76 kb)
10142_2009_149_MOESM3_ESM.doc (73 kb)
Supplementary Table S2 RWC of drought-stressed lemma, palea, awn, and seed of barley (DOC 73 kb)
10142_2009_149_MOESM4_ESM.xls (205 kb)
Supplementary Table S3 Expression profile of genes associated with major GO biological process categories in drought-stressed organs of the barley spike (XLS 205 kb)
10142_2009_149_MOESM5_ESM.doc (75 kb)
Supplementary Table S4 Comparison of gene expression in the spike organs using the Barley1 GeneChip and real-time PCR (DOC 75 kb)

Copyright information

© Springer-Verlag 2009