Proteomics 2014, 14, 153–154
153
DOI 10.1002/pmic.201300552
Proteomic mapping for legume nodule organogenesis Nagib Ahsan and Severin E. Stevenson Department of Biochemistry and Interdisciplinary Plant Group, Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
While genetic screens have identified mutants of the model legume Lotus japonicus that can nodulate in the absence of rhizobia, the lack of a proteome map is a major hindrance to understanding the functional protein networks associated with this nodulation process. In this issue of Proteomics, Dam et al. (Proteomics 2014, 14, 230–240) developed 2D gel-based reference maps of nodules and roots of Lotus and a spontaneous nodule formation mutant (snf1). Comparative proteomic analysis of roots and two developmental stages of nodules provide useful insights into tissue-specific mechanisms underlying nodule organogenesis. Additionally, a comparison of interspecies nodule proteomes displays that overlapping and individual mechanisms are associated with legume nodulation.
Received: December 13, 2013 Accepted: December 16, 2013
Keywords: Comparative proteomics / Legumes / Lotus japonicus / Nodule
Nodule formation is one of the key characteristics of most legumes. It is a complex organogenesis process involving signal exchanges between the host plant roots and their rhizobial symbionts. In the functioning nodules, atmospheric nitrogen is fixed by the bacteria, made available as ammonium for the host plants in exchange for carbon derived from photosynthesis by the plant. Although some of the key genes involved in the nodulation process have been discovered for some legume species including Lotus japonicus [1–5], the cellular processes are also regulated by protein–protein interactions, posttranslational modifications, and enzymatic activities, which cannot be identified solely by gene expression studies. Proteomics provides powerful tools that enable the interrogation of many aspects of the nodulation process from a biochemical and physiological perspective. Such approaches are increasingly being utilized in many models and/or economically important legume species, such as Medicago, soybean, and pea [6–9]. However, limited information is available from the nodule
Correspondence: Dr. Nagib Ahsan, Department of Biochemistry and Interdisciplinary Plant Group, 204 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA E-mail: [email protected]; [email protected]
C 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
proteome of Lotus [10, 11]. It has been reported that nodulation processes in legume families have evolved quite independently among and even within individual families indicating that nitrogen-fixing legumes likely did not share a common ancestor [12]. In the current issue of Proteomics, Dam et al. [13] investigated the proteomes of roots and the plant cytosolic fraction of two different developmental stages (white and red) of nodules from Lotus. In addition, they also characterized the snf1 mutant root and nodule proteome. The proteome reference maps of Lotus roots and nodules led to the identification of 790 and 780 proteins, respectively, revealing
153
DOI 10.1002/pmic.201300552
Proteomic mapping for legume nodule organogenesis Nagib Ahsan and Severin E. Stevenson Department of Biochemistry and Interdisciplinary Plant Group, Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
While genetic screens have identified mutants of the model legume Lotus japonicus that can nodulate in the absence of rhizobia, the lack of a proteome map is a major hindrance to understanding the functional protein networks associated with this nodulation process. In this issue of Proteomics, Dam et al. (Proteomics 2014, 14, 230–240) developed 2D gel-based reference maps of nodules and roots of Lotus and a spontaneous nodule formation mutant (snf1). Comparative proteomic analysis of roots and two developmental stages of nodules provide useful insights into tissue-specific mechanisms underlying nodule organogenesis. Additionally, a comparison of interspecies nodule proteomes displays that overlapping and individual mechanisms are associated with legume nodulation.
Received: December 13, 2013 Accepted: December 16, 2013
Keywords: Comparative proteomics / Legumes / Lotus japonicus / Nodule
Nodule formation is one of the key characteristics of most legumes. It is a complex organogenesis process involving signal exchanges between the host plant roots and their rhizobial symbionts. In the functioning nodules, atmospheric nitrogen is fixed by the bacteria, made available as ammonium for the host plants in exchange for carbon derived from photosynthesis by the plant. Although some of the key genes involved in the nodulation process have been discovered for some legume species including Lotus japonicus [1–5], the cellular processes are also regulated by protein–protein interactions, posttranslational modifications, and enzymatic activities, which cannot be identified solely by gene expression studies. Proteomics provides powerful tools that enable the interrogation of many aspects of the nodulation process from a biochemical and physiological perspective. Such approaches are increasingly being utilized in many models and/or economically important legume species, such as Medicago, soybean, and pea [6–9]. However, limited information is available from the nodule
Correspondence: Dr. Nagib Ahsan, Department of Biochemistry and Interdisciplinary Plant Group, 204 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA E-mail: [email protected]; [email protected]
C 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
proteome of Lotus [10, 11]. It has been reported that nodulation processes in legume families have evolved quite independently among and even within individual families indicating that nitrogen-fixing legumes likely did not share a common ancestor [12]. In the current issue of Proteomics, Dam et al. [13] investigated the proteomes of roots and the plant cytosolic fraction of two different developmental stages (white and red) of nodules from Lotus. In addition, they also characterized the snf1 mutant root and nodule proteome. The proteome reference maps of Lotus roots and nodules led to the identification of 790 and 780 proteins, respectively, revealing
