Multiple isoforms of phosphoenolpyruvate carboxylase in the Orchidaceae (subtribe Oncidiinae): implications for the evolution of crassulacean acid metabolism
| Autor: | B. Leticia Rodriguez, Klaus Winter, John C. Cushman, Katia Silvera, Rebecca L. Albion |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
0106 biological sciences
Physiology Oncidiinae Oncidium sphacelatum Plant Science photosynthesis Trichocentrum 01 natural sciences Oncidium 03 medical and health sciences Botany Protein Isoforms Gene family Photosynthesis Orchidaceae Phylogeny Plant Proteins 030304 developmental biology 0303 health sciences biology gene duplication Plant Transpiration Carbon Dioxide biology.organism_classification Biological Evolution Phosphoenolpyruvate Carboxylase Plant Leaves Gomesa Crassulacean acid metabolism Phosphoenolpyruvate carboxylase Research Paper 010606 plant biology & botany |
| Zdroj: | Journal of Experimental Botany |
| ISSN: | 1460-2431 0022-0957 |
| DOI: | 10.1093/jxb/eru234 |
| Popis: | Summary Multiple isoforms of phosphoenolpyruvate carboxylase genes were sequenced from related orchid species with distinct photosynthesic types. Phylogenetic analysis indicated that CAM-associated isoforms originated from gene duplications and adaptive sequence divergence. Phosphoenolpyruvate carboxylase (PEPC) catalyses the initial fixation of atmospheric CO2 into oxaloacetate and subsequently malate. Nocturnal accumulation of malic acid within the vacuole of photosynthetic cells is a typical feature of plants that perform crassulacean acid metabolism (CAM). PEPC is a ubiquitous plant enzyme encoded by a small gene family, and each member encodes an isoform with specialized function. CAM-specific PEPC isoforms probably evolved from ancestral non-photosynthetic isoforms by gene duplication events and subsequent acquisition of transcriptional control elements that mediate increased leaf-specific or photosynthetic-tissue-specific mRNA expression. To understand the patterns of functional diversification related to the expression of CAM, ppc gene families and photosynthetic patterns were characterized in 11 closely related orchid species from the subtribe Oncidiinae with a range of photosynthetic pathways from C3 photosynthesis (Oncidium cheirophorum, Oncidium maduroi, Rossioglossum krameri, and Oncidium sotoanum) to weak CAM (Oncidium panamense, Oncidium sphacelatum, Gomesa flexuosa and Rossioglossum insleayi) and strong CAM (Rossioglossum ampliatum, Trichocentrum nanum, and Trichocentrum carthagenense). Phylogenetic analysis revealed the existence of two main ppc lineages in flowering plants, two main ppc lineages within the eudicots, and three ppc lineages within the Orchidaceae. Our results indicate that ppc gene family expansion within the Orchidaceae is likely to be the result of gene duplication events followed by adaptive sequence divergence. CAM-associated PEPC isoforms in the Orchidaceae probably evolved from several independent origins. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|