BACKGROUND: The wild relatives of crop species represent a potentially valuable source of novel genetic variation, particularly in the context of improving the crop's level of tolerance to abiotic stress. The mechanistic basis of these tolerances remains largely unexplored. Here, the focus was to characterize the transcriptomic response of the nodes (meristematic tissue) of couch grass (a relative of barley) to dehydration stress, and to compare it to that of the barley crown formed by both a drought tolerant and a drought sensitive barley cultivar. RESULTS: Many of the genes up-regulated in the nodes by the stress were homologs of genes known to be mediated by abscisic acid during the response to drought, or were linked to either development or lipid metabolism. Transporters also featured prominently, as did genes acting on root architecture. The resilience of the couch grass node arise from both their capacity to develop an altered, more effective root architecture, but also from their formation of a lipid barrier on their outer surface and their ability to modify both their lipid metabolism and transporter activity when challenged by dehydration stress. CONCLUSIONS: Our analysis revealed the nature of dehydration stress response in couch grass. We suggested the tolerance is associated with lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA. We also proved the applicability of barley microarray for couch grass stress-response analysis.

• Klíčová slova
• Barley, Couch grass, Crown, Dehydration stress, Drought, Microarray, Rhizome,
• MeSH
• elektrolyty metabolismus   MeSH
• fyziologický stres genetika   MeSH
• kyselina abscisová metabolismus   MeSH
• lipnicovité genetika   metabolismus   fyziologie   MeSH
• membránové transportní proteiny genetika   MeSH
• metabolismus lipidů genetika   MeSH
• období sucha * MeSH
• stanovení celkové genové exprese MeSH
• voda metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• elektrolyty MeSH
• kyselina abscisová MeSH
• membránové transportní proteiny MeSH
• voda MeSH

Drought is a serious threat for sustainable agriculture. Barley represents a species well adapted to environmental stresses including drought. To elucidate the adaptive mechanism of barley on transcriptional level we evaluated transcriptomic changes of two contrasting barley cultivars upon drought using the microarray technique on the level of leaves and crowns. Using bioinformatic tools, differentially expressed genes in treated vs. non-treated plants were identified. Both genotypes revealed tissue dehydration under drought conditions as shown at water saturation deficit and osmotic potential data; however, dehydration was more severe in Amulet than in drought-resistant Tadmor under the same ambient conditions. Performed analysis showed that Amulet enhanced expression of genes related to active plant growth and development, while Tadmor regarding the stimulated genes revealed conservative, water saving strategy. Common reactions of both genotypes and tissues included an induction of genes encoding several stress-responsive signaling proteins, transcription factors as well as effector genes encoding proteins directly involved in stress acclimation. In leaf, tolerant cultivar effectively stimulated mainly the expression of genes encoding proteins and enzymes involved in protein folding, sulfur metabolism, ROS detoxification or lipid biosynthesis and transport. The crown specific reaction of tolerant cultivar was an enhanced expression of genes encoding proteins and enzymes involved in cell wall lignification, ABRE-dependent abscisic acid (ABA) signaling, nucleosome remodeling, along with genes for numerous jasmonate induced proteins.

• Klíčová slova
• Amulet, Tadmor, barley, crown, drought, leaf, microarray,
• Publikační typ
• časopisecké články MeSH