Transcriptional profiling implicates novel interactions between abiotic stress and hormonal responses in Thellungiella, a close relative of Arabidopsis.
Thellungiella, an Arabidopsis (Arabidopsis thaliana)-related halophyte, is an emerging model species for studies designed to elucidate molecular mechanisms of abiotic stress tolerance. Using a cDNA microarray containing 3,628 unique sequences derived from previously described libraries of stress-induced cDNAs of the Yukon ecotype of Thellungiella salsuginea, we obtained transcript profiles of its response to cold, salinity, simulated drought, and rewatering after simulated drought. A total of 154 transcripts were differentially regulated under the conditions studied. Only six of these genes responded to all three stresses of drought, cold, and salinity, indicating a divergence among the end responses triggered by each of these stresses. Unlike in Arabidopsis, there were relatively few transcript changes in response to high salinity in this halophyte. Furthermore, the gene products represented among drought-responsive transcripts in Thellungiella associate a down-regulation of defense-related transcripts with exposure to water deficits. This antagonistic interaction between drought and biotic stress response may demonstrate Thellungiella's ability to respond precisely to environmental stresses, thereby conserving energy and resources and maximizing its survival potential. Intriguingly, changes of transcript abundance in response to cold implicate the involvement of jasmonic acid. While transcripts associated with photosynthetic processes were repressed by cold, physiological responses in plants developed at low temperature suggest a novel mechanism for photosynthetic acclimation. Taken together, our results provide useful starting points for more in-depth analyses of Thellungiella's extreme stress tolerance.
Wong
Chui E
CE
Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Li
Yong
Y
Labbe
Aurelie
A
Guevara
David
D
Nuin
Paulo
P
Whitty
Brett
B
Diaz
Claudia
C
Golding
G Brian
GB
Gray
Gordon R
GR
Weretilnyk
Elizabeth A
EA
Griffith
Marilyn
M
Moffatt
Barbara A
BA
D017360:Arabidopsis / Q000235:genetics; D019607:Brassicaceae / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D016000:Cluster Analysis; D003080:Cold Temperature; D003517:Cyclopentanes / Q000378:metabolism; D015536:Down-Regulation; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins; D010788:Photosynthesis / Q000502:physiology; D010937:Plant Growth Regulators / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D014867:Water / Q000378:metabolism
D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D012333:RNA, Messenger; D014867:Water; D012965:Sodium Chloride; C011006:jasmonic acid