caa a22 4500 397522711 CHVBK 20180308164637.0 cr unu---uuuuu 161202e199509 xx s 000 0 eng 10.1093/jxb/46.9.1147 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.9.1147 Drought effects on cellular and spatial parameters of leaf growth in tall fescue [Elektronische Daten] [Jean-Louis Durand, Bertrand Onillon, Hans Schnyder, Ingo Rademacher] The effect of drought and recovery on cellular and spatial parameters of the growth process in tall fescue leaves was studied in two experiments. In both experiments plants grown on vermiculite and maintained in a controlled environment were submitted to a 7 d drought period generated by withholding water. Drought was followed by a 3 d recovery period in experiment II. As leaf elongation rate (LER) decreased during developing drought both the growth zone length (initially 40 mm) and the maximum relative elemental growth rate (initially 0.09 mm mm−1 h−1 during the dark period of diurnal cycles) within the growth zone declined. But the growth zone still exhibited a length of approximately 15 mm when LER approached 0 under severe drought (−2.0 MPa predawn leaf water potential). The growth potential of the basal 15-mm-long portion of the leaf was conserved during the period when drought effected the complete arrest of leaf elongation. A (retrospective) analysis of the position-time relationships of epidermal cells identified on leaf replicas (experiment II) indicated that the cell flux out of the growth zone responded very sensitively to drought. Before drought the flux was maximum at approximately 3.2 cells (cell file h)−1 during the dark period. Flux decreased to 0 when leaf elongation stopped. Flux also varied diurnally both under well-watered and droughted conditions. In well-watered conditions it was about 30% less during the light than the dark period. Cell elongation was also sensitive to drought. Under well-watered conditions epidermal cell elongation stopped when cells attained a length of approximately 480 μm. During developing drought cells stopped elongating at progressively shorter lengths. When LER had decreased to almost nil, cells stopped elongating at a length of approximately 250 μn. When drought was relieved following a 2 d complete arrest of leaf elongation then cells shorter than 250 μm were able to resume expansion. Following rewatering cell flux out of the growth zone increased rapidly to and above the pre-drought level, but there was only a slow increase over time in the length at which cell elongation stopped. About 2 d elapsed until the leaf growth zone produced cells of similar length as before drought (i.e. approximately 480 μm). © Oxford University Press RESEARCH PAPERS nationallicence Epidermal cell length nationallicence cell flux nationallicence (leaf) growth zone nationallicence leaf elongation rate nationallicence relative elemental growth rate nationallicence position-time relationships (path line, growth trajectory) nationallicence drought nationallicence water deficit nationallicence Durand Jean-Louis Station d'Ecophysiologie des Plantes Fourragères INRA, F-86600 Lusignan, France aut Onillon Bertrand Station d'Ecophysiologie des Plantes Fourragères INRA, F-86600 Lusignan, France aut Schnyder Hans Lehrstuhl für Grünlandlehre an der TU München D-85350 Freising-Weihenstephan, Germany aut Rademacher Ingo Institut für Pflanzenbau Katzenburgweg 5, D-53115 Bonn, Germany aut Journal of Experimental Botany Oxford University Press 46/9(1995-09), 1147-1155 0022-0957 46:9<1147 1995 46 exbotj https://doi.org/10.1093/jxb/46.9.1147 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.9.1147 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Durand Jean-Louis Station d'Ecophysiologie des Plantes Fourragères INRA, F-86600 Lusignan, France aut NATIONALLICENCE 700 1- Onillon Bertrand Station d'Ecophysiologie des Plantes Fourragères INRA, F-86600 Lusignan, France aut NATIONALLICENCE 700 1- Schnyder Hans Lehrstuhl für Grünlandlehre an der TU München D-85350 Freising-Weihenstephan, Germany aut NATIONALLICENCE 700 1- Rademacher Ingo Institut für Pflanzenbau Katzenburgweg 5, D-53115 Bonn, Germany aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/9(1995-09), 1147-1155 0022-0957 46:9<1147 1995 46 exbotj Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford