The role of plasticity in the acclimation of desert plants to their environment

To date, very little is known about the molecular mechanisms underlying the acclimation of plants to their habitat. This knowledge is crucial because in nature, unlike the controlled conditions used in the laboratory, a large number of different parameters may affect the plant simultaneously. To study the response of plants to changes in environmental conditions within their ecosystem we study the evergreen C3 desert legume Retama raetam. We use plants that grow naturally within an arid dune ecosystem (located along the Israeli-Egyptian border in Nizzana; see,, and we correlate all of our findings to environmental parameters recorded at the research site by data loggers. Our analysis includes physiological measurements of plants in the field and molecular analysis of samples collected from the field in the lab. Our studies revealed that the R. raetam uses an acclimation strategy of partial plant dormancy to acclimate to its ecosystem. We cloned different genes associated with dormancy in this plant, and we are in the process of studying whether the plasticity observed in the cycles of dormancy and growth in this plant are crucial for its survival within the harsh desert habitat.

Mittler, R., Merquiol, E., Hallak-Herr, E., Kaplan, A., and Cohen, M. (2001) Living under a "dormant" canopy: a molecular acclimation mechanism of the desert plant Retama raetam. Plant J. 25, 407-416.

Pnueli, L., Hallak-Herr, E., Rozenberg, M., Cohen, M., Goloubinoff, P., Kaplan, A. and Mittler, R. (2002) Molecular and biochemical mechanisms associated with dormancy and drought tolerance in the desert legume Retama raetam. Plant J. 31, 319-330.

Mittler, R., Merquiol, E., Hallak-Herr, E., Kaplan, A., and Cohen, M. (2002) Seasonal and diurnal variations in gene expression in the desert legume Retama raetam. Plant Cell & Environment. 25, 1627-1638.