Investigation of cDNAs from R.etili inoculated bean root hairs

E. PELTZER AND O. M. AGUILAR

Salta, Argentina

Congreso; Phaseomics IV; 2005

Phaseomics

Analysis of cDNAs from R. etli-inoculated root hairs of the Mesoamerican bean cultivar Negro Xamapa cultivar Negro Xamapa R. etli-inoculated root hairs of the Mesoamerican bean cultivar Negro Xamapa Eitel Peltzer and O. Mario Aguilar Instituto de Bioquímica y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, (1900) La Plata, Argentina We have demonstrated the preferential nodulation of beans by geographically related R. etliR. etli lineages, which was independent of the nodulating environment. In addition, coinoculation of wild beans from each of the three BD centers with an equi-mixture of R. etli strains representative of the Mesoamerican and Southern Andean lineages revealed a host-related distinct competitiveness: beans from the Mesoamerican genetic pool were most efficiently nodulated by strains from their host region, whereas nodules of beans from the Southern Andes were largely occupied by the geographically-cognate R. etli lineages. These results suggest that coevolution processes have occurred between the two symbionts in the centers of host genetic diversity and domestication, leading to selectivity in the symbiotic association (Aguilar et al, 2004). In order to examine the expression pattern of common beans root hairs inoculated (24 hours) by the respective cognate strain, we constructed a subtractive cDNA library. About 300 cDNAs obtained by using the Mesoamerican cultivar Negro Xamapa inoculated with strain R. etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as suggest that coevolution processes have occurred between the two symbionts in the centers of host genetic diversity and domestication, leading to selectivity in the symbiotic association (Aguilar et al, 2004). In order to examine the expression pattern of common beans root hairs inoculated (24 hours) by the respective cognate strain, we constructed a subtractive cDNA library. About 300 cDNAs obtained by using the Mesoamerican cultivar Negro Xamapa inoculated with strain R. etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as representative of the Mesoamerican and Southern Andean lineages revealed a host-related distinct competitiveness: beans from the Mesoamerican genetic pool were most efficiently nodulated by strains from their host region, whereas nodules of beans from the Southern Andes were largely occupied by the geographically-cognate R. etli lineages. These results suggest that coevolution processes have occurred between the two symbionts in the centers of host genetic diversity and domestication, leading to selectivity in the symbiotic association (Aguilar et al, 2004). In order to examine the expression pattern of common beans root hairs inoculated (24 hours) by the respective cognate strain, we constructed a subtractive cDNA library. About 300 cDNAs obtained by using the Mesoamerican cultivar Negro Xamapa inoculated with strain R. etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as suggest that coevolution processes have occurred between the two symbionts in the centers of host genetic diversity and domestication, leading to selectivity in the symbiotic association (Aguilar et al, 2004). In order to examine the expression pattern of common beans root hairs inoculated (24 hours) by the respective cognate strain, we constructed a subtractive cDNA library. About 300 cDNAs obtained by using the Mesoamerican cultivar Negro Xamapa inoculated with strain R. etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as R. etli strains representative of the Mesoamerican and Southern Andean lineages revealed a host-related distinct competitiveness: beans from the Mesoamerican genetic pool were most efficiently nodulated by strains from their host region, whereas nodules of beans from the Southern Andes were largely occupied by the geographically-cognate R. etli lineages. These results suggest that coevolution processes have occurred between the two symbionts in the centers of host genetic diversity and domestication, leading to selectivity in the symbiotic association (Aguilar et al, 2004). In order to examine the expression pattern of common beans root hairs inoculated (24 hours) by the respective cognate strain, we constructed a subtractive cDNA library. About 300 cDNAs obtained by using the Mesoamerican cultivar Negro Xamapa inoculated with strain R. etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as suggest that coevolution processes have occurred between the two symbionts in the centers of host genetic diversity and domestication, leading to selectivity in the symbiotic association (Aguilar et al, 2004). In order to examine the expression pattern of common beans root hairs inoculated (24 hours) by the respective cognate strain, we constructed a subtractive cDNA library. About 300 cDNAs obtained by using the Mesoamerican cultivar Negro Xamapa inoculated with strain R. etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as R. etli lineages. These results suggest that coevolution processes have occurred between the two symbionts in the centers of host genetic diversity and domestication, leading to selectivity in the symbiotic association (Aguilar et al, 2004). In order to examine the expression pattern of common beans root hairs inoculated (24 hours) by the respective cognate strain, we constructed a subtractive cDNA library. About 300 cDNAs obtained by using the Mesoamerican cultivar Negro Xamapa inoculated with strain R. etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as R. etli SC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 asSC15 as tester and the same cultivar inoculated with the Southern Andean strain 55N1 as driver, were sequenced and analysed. Sequences showing homology to a diversity of genes were found. A few sequences showed no homology to the data base whereas other sequences such as those for the lipoxygenase gene and for the flavone synthase gene were also found by other authors to be expressed in common bean nodules and Lotus japonicum, respectively (Porta & Rocha-Sosa, 2000; Shimada et al., 2000). In addition, a putative signal element which shows homology to small GTP-binding proteins (GBP), present in from this cDNA, was identified and tested by PCR and Northern blot analyses of root hairs on a few hours time course after rhizobial infection. The small GBPs work as signalling switches controlling plant growth, development and plant responses to various environmental stimuli (Berken et al, 2005); it will be interesting to ascertain whether expression of GBP is another early response to rhizobial infection. (Porta & Rocha-Sosa, 2000; Shimada et al., 2000). In addition, a putative signal element which shows homology to small GTP-binding proteins (GBP), present in from this cDNA, was identified and tested by PCR and Northern blot analyses of root hairs on a few hours time course after rhizobial infection. The small GBPs work as signalling switches controlling plant growth, development and plant responses to various environmental stimuli (Berken et al, 2005); it will be interesting to ascertain whether expression of GBP is another early response to rhizobial infection. were found. A few sequences showed no homology to the data base whereas other sequences such as those for the lipoxygenase gene and for the flavone synthase gene were also found by other authors to be expressed in common bean nodules and Lotus japonicum, respectively (Porta & Rocha-Sosa, 2000; Shimada et al., 2000). In addition, a putative signal element which shows homology to small GTP-binding proteins (GBP), present in from this cDNA, was identified and tested by PCR and Northern blot analyses of root hairs on a few hours time course after rhizobial infection. The small GBPs work as signalling switches controlling plant growth, development and plant responses to various environmental stimuli (Berken et al, 2005); it will be interesting to ascertain whether expression of GBP is another early response to rhizobial infection. (Porta & Rocha-Sosa, 2000; Shimada et al., 2000). In addition, a putative signal element which shows homology to small GTP-binding proteins (GBP), present in from this cDNA, was identified and tested by PCR and Northern blot analyses of root hairs on a few hours time course after rhizobial infection. The small GBPs work as signalling switches controlling plant growth, development and plant responses to various environmental stimuli (Berken et al, 2005); it will be interesting to ascertain whether expression of GBP is another early response to rhizobial infection. , were sequenced and analysed. Sequences showing homology to a diversity of genes were found. A few sequences showed no homology to the data base whereas other sequences such as those for the lipoxygenase gene and for the flavone synthase gene were also found by other authors to be expressed in common bean nodules and Lotus japonicum, respectively (Porta & Rocha-Sosa,