Monitoring large-scale changes in transcript abundance in drought- and salt-stressed barley.
Responses to drought and salinity in barley (Hordeum vulgare L. cv. Tokak) were monitored by microarray hybridization of 1463 DNA elements derived from cDNA libraries of 6 and 10 h drought-stressed plants. Functional identities indicated that many cDNAs in these libraries were associated with drought stress. About 38% of the transcripts were novel and functionally unknown. Hybridization experiments were analyzed for drought- and salinity-regulated sequences, with significant changes defined as a deviation from the control exceeding 2.5-fold. Responses of transcripts showed stress-dependent expression patterns and time courses. Nearly 15% of all transcripts were either up- or down-regulated under drought stress, while NaCl led to a change in 5% of the transcripts (24 h, 150 mM NaCl). Transcripts that showed significant up-regulation under drought stress are exemplified by jasmonate-responsive, metallothionein-like, late-embryogenesis-abundant (LEA) and ABA-responsive proteins. Most drastic down-regulation in a category was observed for photosynthesis-related functions. Up-regulation under both drought and salt stress was restricted to ESTs for metallothionein-like and LEA proteins, while increases in ubiquitin-related transcripts characterized salt stress. A number of functionally unknown transcripts from cDNA libraries of drought-stressed plants showed up-regulation by drought but down-regulation by salt stress, documenting how precisely transcript profiles report different growth conditions and environments.
Oztur
Z Neslihan
ZN
Department of Biochemistry and Molecular Biophysics, University of Arizona, Biosciences West, Tucson 85721-0088, USA.
Talamé
Valentina
V
Deyholos
Michael
M
Michalowski
Christine B
CB
Galbraith
David W
DW
Gozukirmizi
Nermin
N
Tuberosa
Roberto
R
Bohnert
Hans J
HJ
D004190:Disasters; D015536:Down-Regulation / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D015723:Gene Library; D017343:Genes, Plant / Q000235:genetics; D001467:Hordeum / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D014158:Transcription, Genetic; D015854:Up-Regulation / Q000187:drug effects; D014867:Water / Q000494:pharmacology*
D018749:RNA, Plant; D014867:Water; D012965:Sodium Chloride