Evolutionary, Genetic, Environmental And Hormonal-induced Plasticity In The Fate Of Organs Arising From Axillary Meristems In Passiflora Spp.

Tendrils can be found in different plant species. In legumes such as pea, tendrils are modified leaves produced by the vegetative meristem but in the grape vine, a same meristem is used to either form a tendril or an inflorescence. Passiflora species originated in ecosystems in which there is dense vegetation and competition for light. Thus climbing on other plants in order to reach regions with higher light using tendrils is an adaptive advantage. In Passiflora species, after a juvenile phase, every leaf has a subtending vegetative meristem, and a separate meristem that forms both flowers and a tendril. Thus, flowers are formed once a tendril is formed yet whether or not this flower will reach bloom depends on the environment. For example, in Passiflora edulis flowers do not develop under shaded conditions, so that tendrils are needed to bring the plant to positions were flowers can develop. This separate meristem generally forms a single tendril in different Passiflora species yet the number and position of flowers formed from the same meristem diverges among species. Here we display the variation among species as well as variation within a single species, P. edulis. We also show that the number of flowers within a specific genotype can be modulated by applying Cytokinins. Finally, this separate meristem is capable of transforming into a leaf-producing meristem under specific environmental conditions. Thus, behind what appears to be a species-specific rigid program regarding the fate of this meristem, our study helps to reveal a plasticity normally restrained by genetic, hormonal and environmental constraints. © 2012 Elsevier Ireland Ltd.13016169Aizza, L.C., Dornelas, M.C., A genomic approach to study anthocyanin synthesis and flower pigmentation in passionflowers (2011) J. Nucleic Acids, 2011, p. 371517Akamine, E.K., Girolami, G., Pollination and fruit set in the yellow passion fruit (1959) Hawaii Agr. Expt. Sta. Bul., 39, pp. 1-44Barton, M.K., Twenty years on: the inner workings of the shoot apical meristem, a developmental dynamo (2010) Dev Biol., 341, pp. 95-113Benlloch, R., Berbel, A., Serrano-Mislata, A., Madueño, F., Floral initiation and inflorescence architecture: a comparative view (2007) Ann. Bot., 100, pp. 659-676Calonje, M., Cubas, P., Martínez-Zapater, J.M., Carmona, M.J., Floral meristem identity genes are expressed during tendril development in grapevine (2004) Plant Physiol., 135, pp. 1491-1501Cervi, A.C., Rodrigues, W.A., Nomenclatural and taxonomic review of Passifloraceae species illustrated and described by Vellozo in Flora Fluminensis (2010) Acta Bot. Bras., 24, pp. 1109-1111Cusset, G., Les vrilles des Passifloracées (1968) Bull. Soc. Bot. France, 115, pp. 45-61Gourlay, C.W., Hofer, J.M., Ellis, T.H., Pea compound leaf architecture is regulated by interactions among the genes UNIFOLIATA, cochleata, afila, and tendril-less (2000) Plant Cell, 12, pp. 1279-1294Hansen, A.K., Gilbert, L.E., Simpson, B.B., Downie, S.R., Cervi, A.C., Jansen, R.K., Phylogenetic relationships and chromosome number evolution in Passiflora (2006) Syst. Bot., 31, pp. 138-150Krosnick, S.E., Freudenstein, J.V., Monophyly and floral character homology of Old World Passiflora (subgenus Decaloba: Supersection Disemma) (2005) Syst. Bot., 30, pp. 139-152Mader, G., Zamberlan, P.M., FAgundes, N.J., Magnus, T., Salzano, F.M., Bonatto, S.L., Freitas, L.B., (2010), pp. 99-108. , The use and limits of ITS data in the analysis of intraspecific variation in Passiflora L. (Passifloraceae). Gen. Mol. Biol. 33Menzel, C.M., Simpson, D.R., (1994), 2, pp. 225-242. , Passionfruit. In Schaffer, B., Andersen, P.C. (Eds.), Handbook of Environmental Physiology of Fruit Crops vol. , CRC Press, Boca Raton, ppMoncur, M.W., (1988), Floral Development of Tropical and Subtropical Fruit and Nut Species. An Atlas of Scanning Electron Micrographs. CSIRO, CanberraMuschner, V.C., Lorenz, A.P., Cervi, A.C., Bonatto, S.L., Souza-Chies, T.T., Salzano, F.M., Freitas, L.B., A first molecular phylogenetic analysis of Passiflora (Passifloraceae) (2003) Am. J. Bot., 90, pp. 1229-1238Nave, N., Katz, E., Chayut, N., Gazit, S., Samach, A., Flower development in the passion fruit Passiflora edulis requires a photoperiod-induced systemic graft-transmissible signal (2010) Plant Cell. Environ., 33, pp. 2065-2083Okada, K., Ueda, J., Komaki, M.K., Bell, C.J., Shimura, Y., Requirement of the auxin polar transport system in early stages of Arabidopsis floral bud formation (1991) Plant Cell, 3, pp. 677-684Pope, W.T., The edible passionfruit in Hawaii (1935) Hawaii Agr. Expt. Sta. Bul., 74, pp. 1-22São-José, A.R., (1991), A cultura do maracujá no Brasil, UNESP-FUNEP, JaboticabalUlmer, T., MacDougal, J.M., (2004) Passiflora: Passionflowers of the World, , Timber Press, PortlandWang, Y., Li, J., Molecular basis of plant architecture (2008) Ann. Rev. Plant Biol., 59, pp. 253-279Whipple, C.J., Hall, D.H., DeBlasio, S., Taguchi-Shiobara, F., Schmidt, R.J., Jackson, D.P., A conserved mechanism of bract suppression in the grass family (2010) Plant Cell, 22, pp. 565-578Yotoko, K.S., Dornelas, M.C., Togni, P.D., Fonseca, T.C., Salzano, F.M., Bonatto, S.L., Freitas, L.B., Does variation in genome sizes reflect adaptive or neutral processes? New clues from Passiflora (2011) PLoS One, 6, pp. e1821