caa a22 4500 463236564 CHVBK 20180405153259.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1007/s11240-007-9275-7 doi (NATIONALLICENCE)springer-10.1007/s11240-007-9275-7 New insights into the in vitro organogenesis process: the case of Passiflora [Elektronische Daten] [Juliana Fernando, Maria Vieira, Silvia Machado, Beatriz Appezzato-da-Glória] We present evidences that ultrastructural electron microscope findings are valuable ways to understand the invitro regeneration process, in particular in the yellow passion fruit. Shoot-regeneration was induced in hypocotyl and leaf-derived explants using 4.44μM BAP, and the entire organogenic process was analyzed using conventional histology, scanning and transmission electronic microscopy. Both direct and indirect regeneration modes were observed in hypocotyl explants, but only direct regeneration occurred in leaf-derived cultures. In the direct pathway from both explant types, meristemoids developed into globular structures, here called protuberances. The peripheral meristematic layers of the protuberances displayed ultrastructural characteristics indicative of a high metabolic activity, and only these cells originated shoots and leaf primordia, the latter being frequent when leaf explants were used. Moreover, the peripheral cells of the protuberances derived from leaf explants lost adhesion during the culture, diminishing the regeneration rates. We recommend the use of hypocotyls as a source of explant to obtain shoots as well as a genetic transformation system for the yellow passion fruit. However, the direct pathway is preferred because a type of amitosis occurred in the peripheral cells of hypocotyl-derived calli, which has the potential to result in genetic instability of the regenerating plants/tissue. Springer Science+Business Media B.V., 2007 Amitosis nationallicence Electronic microscopy nationallicence Histology nationallicence Passion fruit nationallicence Protuberances nationallicence BAP N6 : 6-Benzylaminopurine nationallicence TDZ : Thidiazuron (N-phenyl-N′-1,2,3,-thiadiazol-5-ylurea) nationallicence SEM : Scanning electron microscopy nationallicence TEM : Transmission electron microscopy nationallicence Fernando Juliana Universidade Estadual de Campinas, Instituto de Biologia, Campinas, Brazil aut Vieira Maria Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz”, P.O. Box 9, 13418-900, Piracicaba, Brazil aut Machado Silvia Universidade Estadual Paulista, Instituto de Biociências, Botucatu, Brazil aut Appezzato-da-Glória Beatriz Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz”, P.O. Box 9, 13418-900, Piracicaba, Brazil aut Plant Cell, Tissue and Organ Culture Springer Netherlands 91/1(2007-10-01), 37-44 0167-6857 91:1<37 2007 91 11240 https://doi.org/10.1007/s11240-007-9275-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11240-007-9275-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fernando Juliana Universidade Estadual de Campinas, Instituto de Biologia, Campinas, Brazil aut NATIONALLICENCE 700 1- Vieira Maria Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz”, P.O. Box 9, 13418-900, Piracicaba, Brazil aut NATIONALLICENCE 700 1- Machado Silvia Universidade Estadual Paulista, Instituto de Biociências, Botucatu, Brazil aut NATIONALLICENCE 700 1- Appezzato-da-Glória Beatriz Universidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz”, P.O. Box 9, 13418-900, Piracicaba, Brazil aut NATIONALLICENCE 773 0- Plant Cell, Tissue and Organ Culture Springer Netherlands 91/1(2007-10-01), 37-44 0167-6857 91:1<37 2007 91 11240 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer