title: Transcriptome analysis reveals the role of the root hairs as environmental sensors to maintain plant functions under water-deficiency conditions.
abstract: An important part of the root system is the root hairs, which play a role in mineral and water uptake. Here, we present an analysis of the transcriptomic response to water deficiency of the wild-type (WT) barley cultivar 'Karat' and its root-hairless mutant rhl1.a. A comparison of the transcriptional changes induced by water stress resulted in the identification of genes whose expression was specifically affected in each genotype. At the onset of water stress, more genes were modulated by water shortage in the roots of the WT plants than in the roots of rhl1.a. The roots of the WT plants, but not of rhl1.a, specifically responded with the induction of genes that are related to the abscisic acid biosynthesis, stomatal closure, and cell wall biogenesis, thus indicating the specific activation of processes that are related to water-stress signalling and protection. On the other hand, the processes involved in the further response to abiotic stimuli, including hydrogen peroxide, heat, and high light intensity, were specifically up-regulated in the leaves of rhl1.a. An extended period of severe stress caused more drastic transcriptome changes in the roots and leaves of the rhl1.a mutant than in those of the WT. These results are in agreement with the much stronger damage to photosystem II in the rhl1.a mutant than in its parent cultivar after 10 d of water stress. Taking into account the putative stress sensing and signalling features of the root hair transcriptome, we discuss the role of root hairs as sensors of environmental conditions.
authors.affiliation: Department of Genetics, University of Silesia in Katowice, 40-032 Katowice, Poland miroslaw.kwasniewski@us.edu.pl.
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Kwasniewski
authors.affiliation: Department of Genetics, University of Silesia in Katowice, 40-032 Katowice, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Daszkowska-Golec
authors.affiliation: Department of Genetics, University of Silesia in Katowice, 40-032 Katowice, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Janiak
authors.affiliation: Department of Genetics, University of Silesia in Katowice, 40-032 Katowice, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Chwialkowska
authors.affiliation: Department of Genetics, University of Silesia in Katowice, 40-032 Katowice, Poland.
authors.forename: Urszula
authors.initials: U
authors.lastname: Nowakowska
authors.affiliation: Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Ultimo, NSW 2007, Australia.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Sablok
authors.affiliation: Department of Genetics, University of Silesia in Katowice, 40-032 Katowice, Poland.
authors.forename: Iwona
authors.initials: I
authors.lastname: Szarejko
mesh_terms: D018744:DNA, Plant / Q000235:genetics* / Q000378:metabolism; D055864:Droughts; D020869:Gene Expression Profiling; D001467:Hordeum / Q000235:genetics / Q000502:physiology*; D018517:Plant Roots / Q000502:physiology*; D017422:Sequence Analysis, DNA; D059467:Transcriptome
chemical_list: D018744:DNA, Plant
keywords: Barley; drought; environmental sensor; gene expression; root hair; water stress.