Recent findings have shown that photosynthesis in the skin of the seed of Posidonia oceanica enhances seedling growth. The seagrass genus Posidonia is found only in two distant parts of the world, the Mediterranean Sea and southern Australia. This fact led us to question whether the acquisition of this novel mechanism in the evolution of this seagrass was a pre-adaptation prior to geological isolation of the Mediterranean from Tethys Sea in the Eocene. Photosynthetic activity in seeds of Australian species of Posidonia is still unknown. This study shows oxygen production and respiration rates, and maximum PSII photochemical efficiency (Fv : Fm) in seeds of two Australian Posidonia species (P. australis and P. sinuosa), and compares these with previous results for P. oceanica. Results showed relatively high oxygen production and respiratory rates in all three species but with significant differences among them, suggesting the existence of an adaptive mechanism to compensate for the relatively high oxygen demands of the seeds. In all cases maximal photochemical efficiency of photosystem II rates reached similar values. The existence of photosynthetic activity in the seeds of all three species implicates that it was an ability probably acquired from a common ancestor during the Late Eocene, when this adaptive strategy could have helped Posidonia species to survive in nutrient-poor temperate seas. This study sheds new light on some aspects of the evolution of marine plants and represents an important contribution to global knowledge of the paleogeographic patterns of seagrass distribution.
Unidad Académica de Sistemas Arrecifales (Puerto Morelos), Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Apto Postal 1152, CP: 77500, Cancún, Quintana Roo, Mexico;Marine Biological Laboratory, The Ecosystems Center, Woods Hole, MA, United States of America;School of Veterinary and Life Sciences, Environmental and Conservation Sciences, Murdoch University, Murdoch, WA, 6150, Australia;School of Veterinary and Life Sciences, Environmental and Conservation Sciences, Murdoch University, Murdoch, WA, 6150, Australia;Departamento de Ecología e Hidrología, Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
Recommended Citation:
David Celdran,Javier Lloret,Jennifer Verduin,et al. Linking Seed Photosynthesis and Evolution of the Australian and Mediterranean Seagrass Genus Posidonia[J]. PLOS ONE,2015-01-01,10(6)