Revealing diversity in structural and biochemical forms of C4 photosynthesis and a C3-C4 intermediate in genus Portulaca L. (Portulacaceae)

Abstract

Portulacaceae is one of 19 families of terrestrial plants in which species having C4 photosynthesis have been found. Representative species from major clades of the genus Portulaca were studied to characterize the forms of photosynthesis structurally and biochemically. The species P. amilis, P. grandiflora, P. molokiniensis, P. oleracea, P. pilosa, and P. umbraticola belong to the subgenus Portulaca and are C4 plants based on leaf carbon isotope values, Kranz anatomy, and expression of key C4 enzymes. Portulaca umbraticola, clade Umbraticola, is NADP-malic enzyme (NADP-ME)-type C4 species, while P. oleracea and P. molokiniensis in clade Oleracea are NAD-ME-type C4 species, all having different forms of Atriplicoid-type leaf anatomy. In clade Pilosa, P. amilis, P. grandiflora, and P. pilosa are NADP-ME-type C4 species. They have Pilosoid-type anatomy in which Kranz tissues enclose peripheral vascular bundles with water storage in the centre of the leaf. Portulaca cf. bicolor, which belongs to subgenus Portulacella, is an NADP-ME C4 species with Portulacelloid-type anatomy; it has well-developed Kranz chlorenchyma surrounding lateral veins distributed in one plane under the adaxial epidermis with water storage cells underneath. Portulaca cryptopetala (clade Oleracea), an endemic species from central South America, was identified as a C3–C4 based on its intermediate CO2 compensation point and selective localization of glycine decarboxylase of the photorespiratory pathway in mitochondria of bundle sheath cells. The C4 Portulaca species which were examined also have cotyledons with Kranz-type anatomy, while the stems of all species have C3-type photosynthetic cells. The results indicate that multiple structural and biochemical forms of C4 photosynthesis evolved in genus Portulaca.

Phylogeny of Sesuvioideae (Aizoaceae) – Biogeography, leaf anatomy and the evolution of C4 photosynthesis

“…The salsoloid leaf type is common in the speciose Chenopodiaceae subf. Salsoloideae (Kadereit et al, 2003), the portulacelloid leaf type is only known from Portulaca section Portulacella (Portulacaceae; Ocampo et al, 2013;Voznesenskaya et al, 2010), while the pilosoid-leaf type is also found in Portulaca (Pilosa clade, Portulacaceae; Edwards and Voznesenskaya, 2011;Ocampo et al, 2013). Mapping the leaf types onto the phylogeny illustrates that they do not consistently correspond to the distinct subclades of Sesuvioideae, but occur in several lineages indicating that leaf anatomy can be altered with relative ease in Sesuvioideae (Fig.…”

“…The only anatomical type documented in the Sesuvoideae is the atriplicoid-type, but only a few species have been studied (Carolin et al, 1978;Muhaidat et al, 2007). Multiple C 4 anatomical types have been identified in numerous families of hot, arid and/or saline habitats, most notable in the Chenopodiaceae (Jacobs, 2001;Freitag and Kadereit, 2013;Kadereit et al, 2003;Schütze et al, 2003) and Portulacaceae (Voznesenskaya et al, 2010) in which succulence is common in sister lineages to C 4 clades (Kadereit et al, 2012;Ocampo et al, 2013). Together, these observations indicate that the Sesuvioideae may be a hotspot for C 4 evolution, potentially evolving multiple lineages with diverse types of C 4 metabolism and anatomy.…”

Initial Events during the Evolution of C4 Photosynthesis in C3 Species of Flaveria

“…While G estimates from C 2 species are abundant in the literature (Monson and Rawsthorne, 2000;Vogan et al, 2007;Voznesenskaya et al, 2007), C* estimates are rare (Voznesenskaya et al, 2010). As an indicator of photorespiratory CO 2 refixation, C* has advantages over the commonly used parameter G. Rubisco carboxylation capacity, R d , CO 2 refixation, and the oxygenationto-carboxylation ratio of Rubisco influence G (Tholen et al, 2012;Busch et al, 2013), whereas C* is largely a function of the refixation of (photo)respired CO 2 and the oxygenation-to-carboxylation ratio of Rubisco (von Caemmerer, 2000;Busch et al, 2013).…”

Fitotoxicidad De Aceites Esenciales Y Extractos Acuosos De Plantas Mediterráneas Para El Control De Arvenses

“…El género Portulaca incluye más de 100 especies (Poellnitz, 1934;Legrand, 1958) distribuidas en los trópicos y subtrópicos, con centros de diversidad en Sudamérica y África (Voznesenskaya et al, 2010).…”

“…(Pignatti, 1982a;Flora iberica, 1990;Walters, 1993;Riccieri y Arrigoni, 2000). P. oleracea es una especie anual, con tallos suculentos, carnosos y fotosíntesis tipo C4 (Guralnick et al, 2008;Voznesenskaya et al, 2010). Se desarrolla en campos de cultivo, jardines, terrenos baldíos, bordes de caminos, y laderas erosionadas.…”