caa a22 4500 397522347 CHVBK 20180308164636.0 cr unu---uuuuu 161202e199510 xx s 000 0 eng 10.1093/jxb/46.10.1543 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.10.1543 Influence of mycorrhizae and Rhizobium on cytokinin content in drought-stressed alfalfa [Elektronische Daten] [N. Goicoechea, K. Dolézal, M.C. Antoĺin, M. Strnad, M. S´nchez-Dĺaz] The objective of this research was to study the growth response to drought of arbuscular mycorrhizal and non-mycorrhizal alfalfa (Medicago sativacv. Aragón) in relation to leaf cytokinin levels. In the experiment, four treatments were used: (a) plants inoculated with Clomus fasciculatum (Taxter sensu Gerd.) Gerdemann and Trappe and Rhizobium meliloti 102 F51 strain, (MR); (b) plants inoculated with only Rhizobium (RP); (c) plants inoculated with only mycorrhizae (MN); and (d) plants non-inoculated (NP). Non-mycorrhizal plants were supplemented with phosphorus and nonnodulated ones with nitrogen to achieve similar size in all treatments. Plants were subjected to drought by withholding irrigation in a cyclic way. The effects of drought on growth, number of stems, degree of senescence, and leaf cytokinin levels were measured. Results of identification of cytokinins showed that dihydrozeatin riboside (dHZR) and ortno-topolin riboside (oTR) were predominant in alfalfa leaves. Nonsymbiotic plants (NP) showed higher total cytokinin concentrations (dHZR and oTR). Under drought, NP plants showed the largest percentage drop in cytokinins and lower number of stems as well as increased degree of senescent leaf tissue relative to control values. By contrast, stressed symbiotic plants (RP, MN and MR) showed higher green leaf weight than nonsymbiotic ones (NP) due to delay of leaf senescence and maintenance (RP) or increase (MN, MR) of stem leaf cytokinin levels during drought. The relationships between growth and the different cytokinins are discussed, suggesting an important role of mycorrhizal symbiosis in maintaining cytokinin levels under drought. © Oxford University Press Research Papers nationallicence Alfalfa nationallicence arbuscular mycorrhizae nationallicence cytokinins nationallicence drought nationallicence leaf senescence nationallicence Goicoechea N. Departamento de Fisiologia Vegetal, Universidad de Navarra c/lrunlarrea s/n, E-31008 Pamplona, Spain aut Dolézal K. Department of Plant Biotechnology, Institute of Experimental Botany 77200 Olomouc, Czech Republic aut Antoĺin M.C. Departamento de Fisiologia Vegetal, Universidad de Navarra c/lrunlarrea s/n, E-31008 Pamplona, Spain aut Strnad M. Department of Plant Biotechnology, Institute of Experimental Botany 77200 Olomouc, Czech Republic aut S´nchez-Dĺaz M. Departamento de Fisiologia Vegetal, Universidad de Navarra c/lrunlarrea s/n, E-31008 Pamplona, Spain aut Journal of Experimental Botany Oxford University Press 46/10(1995-10), 1543-1549 0022-0957 46:10<1543 1995 46 exbotj https://doi.org/10.1093/jxb/46.10.1543 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.10.1543 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Goicoechea N. Departamento de Fisiologia Vegetal, Universidad de Navarra c/lrunlarrea s/n, E-31008 Pamplona, Spain aut NATIONALLICENCE 700 1- Dolézal K. Department of Plant Biotechnology, Institute of Experimental Botany 77200 Olomouc, Czech Republic aut NATIONALLICENCE 700 1- Antoĺin M.C. Departamento de Fisiologia Vegetal, Universidad de Navarra c/lrunlarrea s/n, E-31008 Pamplona, Spain aut NATIONALLICENCE 700 1- Strnad M. Department of Plant Biotechnology, Institute of Experimental Botany 77200 Olomouc, Czech Republic aut NATIONALLICENCE 700 1- S´nchez-Dĺaz M. Departamento de Fisiologia Vegetal, Universidad de Navarra c/lrunlarrea s/n, E-31008 Pamplona, Spain aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/10(1995-10), 1543-1549 0022-0957 46:10<1543 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