PT  - JOURNAL ARTICLE
AU  - Cellier, Françoise
AU  - Conéjéro, Geneviève
AU  - Breitler, Jean-Christophe
AU  - Casse, Francine
TI  - Molecular and Physiological Responses to Water Deficit in Drought-Tolerant and Drought-Sensitive Lines of Sunflower
AID  - 10.1104/pp.116.1.319
DP  - 1998 Jan 01
TA  - Plant Physiology
PG  - 319--328
VI  - 116
IP  - 1
4099  - http://www.plantphysiol.org/content/116/1/319.short
4100  - http://www.plantphysiol.org/content/116/1/319.full
SO  - Plant Physiol.1998 Jan 01; 116
AB  - To investigate correlations between phenotypic adaptation to water limitation and drought-induced gene expression, we have studied a model system consisting of a drought-tolerant line (R1) and a drought-sensitive line (S1) of sunflowers (Helianthus annuus L.) subjected to progressive drought. R1 tolerance is characterized by the maintenance of shoot cellular turgor. Drought-induced genes (HaElip1, HaDhn1, andHaDhn2) were previously identified in the tolerant line. The accumulation of the corresponding transcripts was compared as a function of soil and leaf water status in R1 and S1 plants during progressive drought. In leaves of R1 plants the accumulation ofHaDhn1 and HaDhn2 transcripts, but notHaElip1 transcripts, was correlated with the drought-adaptive response. Drought-induced abscisic acid (ABA) concentration was not associated with the varietal difference in drought tolerance. Stomata of both lines displayed similar sensitivity to ABA. ABA-induced accumulation of HaDhn2 transcripts was higher in the tolerant than in the sensitive genotype.HaDhn1 transcripts were similarly accumulated in the tolerant and in the sensitive plants in response to ABA, suggesting that additional factors involved in drought regulation ofHaDhn1 expression might exist in tolerant plants.