Low water availability is the major environmental factor limiting crop productivity. Transcriptome analysis was used to study terminal drought response in wild emmer wheat, Triticum dicoccoides, genotypes contrasting in their productivity and yield stability under drought stress. A total of 5,892 differentially regulated transcripts were identified between drought and well-watered control and/or between drought resistant (R) and drought susceptible (S) genotypes. Functional enrichment analyses revealed that multilevel regulatory and signalling processes were significantly enriched among the drought-induced transcripts, in particular in the R genotype. Therefore, further analyses were focused on selected 221 uniquely expressed or highly abundant transcripts in the R genotype, as potential candidates for drought resistance genes. Annotation of the 221 genes revealed that 26% of them are involved in multilevel regulation, including: transcriptional regulation, RNA binding, kinase activity and calcium and abscisic acid signalling implicated in stomatal closure. Differential expression patterns were also identified in genes known to be involved in drought adaptation pathways, such as: cell wall adjustment, cuticular wax deposition, lignification, osmoregulation, redox homeostasis, dehydration protection and drought-induced senescence. These results demonstrate the potential of wild emmer wheat as a source for candidate genes for improving drought resistance.
Bibliographical noteFunding Information:
Acknowledgment This project was supported by the Programme for Sustainable Agriculture funded by the Israel Ministry of Science (# 01-21-00048), the French Ministry for Foreign Affairs and the French Ministry for Education and Research; we also acknowledge The Israel Science Foundation grant #1089/04 and equipment grants #048/99 and 1478/04. Z. Peleg is indebted to the Israel Council for the Higher Education postdoctoral fellowships award. The authors thank A. Fahum, M. Goldshmit, S. Chalifa and Y. Jun for their excellent technical assistance.
- Abiotic stress
- Drought resistance
- Gene discovery