Anais da Academia Brasileira de Ciências ISSN: 0001-3765 [email protected] Academia Brasileira de Ciências Brasil Martins, Shirley; Alves, Marccus; Scatena, Vera L. Occurrence and evolutionary inferences about Kranz anatomy in Cyperaceae (Poales) Anais da Academia Brasileira de Ciências, vol. 87, núm. 4, octubre-diciembre, 2015, pp. 2177-2188 Academia Brasileira de Ciências Rio de Janeiro, Brasil Available in: http://www.redalyc.org/articulo.oa?id=32743236023 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Anais da Academia Brasileira de Ciências (2015) 87(4): 2177-2188 (Annals of the Brazilian Academy of Sciences) Printed version ISSN 0001-3765 / Online version ISSN 1678-2690 http://dx.doi.org/10.1590/0001-3765201520150175 www.scielo.br/aabc Occurrence and evolutionary inferences about Kranz anatomy in Cyperaceae (Poales) SHIRLEY Martins1, MARCCUS Alves2 and VERA L. Scatena3 1Centro de Ciências Biológicas e da Saúde, Laboratório de Botânica, Universidade Estadual do Oeste do Paraná, UNIOESTE, Rua Universitária, 2069, Jardim Universitário, 85819-110 Cascavel, PR, Brasil 2Centro de Ciências Biológicas, Departamento de Botânica, Laboratório de Morfotaxonomia Vegetal, Universidade Federal de Pernambuco, UFPE, Rua Prof. Moraes Rego, s/n, Cidade Universitária, 50670-901 Recife, PE, Brasil 3Instituto de Biociências, Departamento de Botânica, Laboratório de Anatomia Vegetal, Universidade Estadual Paulista, UNESP, Avenida 24A, 1515, Bela Vista, 13506-900 Rio Claro, SP, Brasil Manuscript received on March 5, 2015; accepted for publication on May 13, 2015 ABSTRACT Cyperaceae is an angiosperm family with the greatest diversity of species with Kranz anatomy. Four different types of Kranz anatomy (chlorocyperoid, eleocharoid, fimbristyloid and rhynchosporoid) have been described for this angiosperm family, and the occurrence and structural characteristics of these types are important to trace evolutionary hypotheses. The purpose of this study was to examine the available data on Cyperaceae Kranz anatomy, emphasizing taxonomy, geographic distribution, habitat and anatomy, to infer the potential origin of the Kranz anatomy in this family. The results showed that the four types of Kranz anatomy (associated with C4 photosynthesis) in Cyperaceae emerged numerous times in unrelated phylogenetic groups. However, the convergence of these anatomical types, except rhynchosporoid, was observed in certain groups. Thus, the diverse origin of these species might result from different environmental pressures that promote photorespiration. Greater variation in occurrence of Kranz anatomy and anatomical types was observed in Eleocharis, whose emergence of the C4 pathway was recent compared with other genera in the family, and the species of this genus are located in aquatic environments. Key words: anatomy, ultrastructure, taxonomy, phylogeny, Cyperaceae. INTRODUCTION increased levels of O2 (Sage 2004, Lundgren et al. 2014). Several factors, such as water stress, high The Kranz anatomy represents a structural temperature and lightness, and the salinity and high modification of photosynthetic tissues, generally density of plants, influence the reduction of CO two distinct concentric layers of chlorenchyma 2 (Sage et al. 2012). cells, associated with C metabolism, the main 4 The structural modification (Kranz anatomy) function in plants with suppressed photorespiration, was initially reported in Cyperaceae species induced through decreased levels of CO and 2 (Haberlandt 1914). Since then, several studies using Correspondence to: Shirley Martins different approaches have examined the Kranz E-mail: [email protected] structure and the C4 pathway in this family (e.g. An Acad Bras Cienc (2015) 87 (4) 2178 SHIRLEY MARTINS, MARCCUS ALVES and VERA L. SCATENA Carolin et al. 1977, Takeda et al. 1985, Bruhl et al. The variations of Kranz anatomy observed in 1987, Ueno and Samejina 1989, Bruhl 1995, Bruhl this family have generated important taxonomic, and Perry 1995, Soros and Dengler 2001, Martins ecological and evolutive interpretations. Therefore, and Alves 2009, Martins and Scatena 2011). The the aim of the present study was to review Kranz structure varies in the Cyperaceae family, taxonomic, ecological, structural and phylogenetic and four anatomical types have been described: data associated with the structural analyses chlorocyperoid, eleocharoid, fimbristyloid and performed with Cyperaceae species of the four rhynchosporoid. These types anatomically differ Kranz types (Martins and Scatena 2011, Martins in the number and continuity of the vascular and Scatena 2015, Martins et al. 2015) to develop bundle sheath and in the presence of chloroplasts potential hypotheses concerning the origins of in the bundle sheath (Carolin et al. 1977, Soros and these plants. Dengler 2001, Martins and Scatena 2011). MATERIALS AND METHODS Representatives of the Cyperaceae family with Kranz anatomy are restricted to four of The species used to illustrate anatomical and the 13 tribes of the Cyperoideae subfamily: ultrastructural features are listed in Table I. The Abildgaardieae, Cypereae, Eleocharideae and voucher materials were deposited at the Herbarium Rhynchosporeae (Goetghebeur 1998). Among of the Department of Botany, Universidade these, only Abildgaardieae and Eleocharideae Estadual Paulista (HRCB). The data collected here are closely related in phylogenetic studies added to the literature are given in Table II. (Ghamkhar et al. 2007, Muasya et al. 2008). To anatomically illustrate the different Kranz The Kranz Cypereae species present a Kranz types, portions of at least three fully expanded leaf anatomy of the chlorocyperoid type, while the blade or scapes were ixed in FAA 50 and stored Abildgaardieae species present a Kranz anatomy in 70% ethanol (Johansen 1940) and subsequently of the imbristyloid type (Bruhl and Wilson 2007). dehydrated in an ethyl alcohol series and embedded Chlorocyperoid, eleocharoid and fimbristyloid in Historesin (Leica Historesin Embedding Kit, types have been described in the Eleocharideae tribe Nussloch, Germany) (Feder and O’Brien 1968). (Murphy et al. 2007, Martins and Scatena 2015), Transverse sections of the mid-region were and chlorocyperoid and rhynchosporoid types have obtained using a microtome, and the sections been reported in Rhynchosporeae (Martins and were stained with periodic acid-Schiff’s reagent Scatena 2011, Ueno 2013). and toluidine blue (Feder and O’Brien 1968) and Therefore, it has been suggested that the mounted in Entellan (Merck Darmstadt, Germany). origin of Kranz anatomy emerged four times in The images were obtained using Leica DFC 290 Cyperaceae, one type in each tribe (Soros and digital camera on a Leica DM LB microscope Bruhl 2000). In subsequent studies using molecular using IM50 software. markers, five potential appearances of Kranz To illustrate the ultrastructural features of the anatomy were reported: two types in Eleocharideae four Kranz types, samples from the mid-region of and one type in each of the remaining Kranz at least three fully expanded leaf blades or scapes tribes (Besnard et al. 2009). Phylogenetic studies were fixed in 2.5% glutaraldehyde solution in of Abildgaardieae (Ghamkhar et al. 2007) and 0.1 M phosphate buffer, pH 7.3, for 24 h at 5ºC, Eleocharideae (Roalson et al. 2010) indicated post-ixed with 1% osmium tetroxide in the same multiple origins of C4 photosynthesis. buffer for 1 h at 25ºC, dehydrated with an acetone An Acad Bras Cienc (2015) 87 (4) EVOLUTIONARY INFERENCES ABOUT KRANZ ANATOMY IN CYPERACEAE 2179 series and embedded in Araldite resin (Machado Abildgaardia hygrophila and Fimbristylis and Rodrigues 2004). Ultrathin transverse sections variegata. This tribe is non-monophyletic, and were obtained using a Diatome diamond knife, representatives of the non-Kranz Arthrostylideae and the sections were subsequently stained with tribe emerge as the sister group of the clade uranyl acetate and lead citrate (Reynolds 1963). Fimbristylis-Abildgaardia-Crosslandia (Fig. The samples were examined using a Philips EM 1e). The Kranz taxa of Abildgaardieae possess 301 transmission electron microscope (MET). the imbristyloid type, characterized by vascular To illustrate the occurrence of the Kranz bundles surrounded by three sheaths, an outer anatomical types in Cyperaceae, these data sheath (Os), a continuous middle sheath (Ms), were plotted onto cladograms from previously and a discontinuous inner sheath (Is) in the published phylogenetic analyses for each tribe: major bundles, interrupted by only one or two Abildgaardieae (Ghamkhar et al. 2007), Cypereae metaxylem vessels (Fig. 1a-b). The outer bundle (Muasya et al. 2009), Eleocharideae (Roalson et al. sheath originates from the ground meristem, while 2010) and Rhynchosporeae (Thomas et al. 2008). the middle and inner sheaths develop from the procambium. The chloroplasts in the outer-sheath RESULTS cells present well-developed grana, similar to the Abildgaardieae tribe – This tribe has six genera mesophyll cells. The middle-sheath cells do not with Kranz anatomy, Abildgaardia, Bulbostylis, show chloroplasts, and the inner-sheath cells show Crosslandia, Fimbristylis, Nelmesia and Nemum centrifugal chloroplasts without grana (Fig. 1c) and (Tab. II), and two non-Kranz (C3) species, with convoluted and