Somatic Embryogenesis: A Model for Early Development in Higher Plants

Recurrent Somatic Embryogenesis and Plantlet Regeneration in Psidium guajava L.

“…During this unique developmental process, cells have to dedifferentiate, activate cell division, and reprogram their physiology, metabolism, and gene expression patterns (Yang and Zhang, 2010). Thus, SE is an ideal demonstration of plant totipotency, which represents how a somatic cells contain the essential genetic draft for complete plant development without fertilization (Zimmerman, 1993 Kamle et al, 2013). Numerous problems encountered during the optimization of a high-efficiency protocol for induction of somatic embryogenesis from zygotic embryo explants of various cultivars of guava.…”

“…Somatic embryogenesis (SE) is a perfect confrontational system in which every somatic cells under special circumstances build up into embryos and passing through various developmental stages ultimately give rise to a complete plantlet formation (Arnold et al, 2002). SE is one form of asexual reproduction by which somatic cells, under suitable induction conditions, undergo a complete genome shift and embark into a new developmental pathway ending in the formation of asexual embryos morphologically identical to their zygotic counterparts (Zimmerman, 1993;Schmidt et al, 1997;Arnold et al, 2002;Feher et al, 2003). During this unique developmental process, cells have to dedifferentiate, activate cell division, and reprogram their physiology, metabolism, and gene expression patterns (Yang and Zhang, 2010).…”

High Frequency in vitro Propagation Through Somatic Embryogenesis of Iphigenia indica Kunth et Benth, an Endangered Medicinal and Colchicines Yielding Herb of Commercial Interest

“…It is generally believed that continuous presence of auxin leads to a differential changes in gene expression probably by increasing demethylation of DNA (Lo Schiavo et al 1989, Litz andGray 1995) proembryonic mass or callus tissue in this stage contains many other mRNAs and proteins whose continued presence generally inhibit the continuation of the embryonic program, the removal of auxin from the medium is needed to inactivate a number of genes for continuation of embryogenesis process. The new gene products needed for the transition of the globular embryos to the heart shaped stage can be synthesized only when exogenous auxin is removed (Zimmermann 1993). It is also assumed that removal of exogenous auxin from the medium helps to establish a bilateral symmetry in polar auxin transport, an essential phenomenon for embryogenesis (Zimenez 2001).…”

Controle da calogênese do pau-brasil in vitro

“…No entanto, o procedimento mais comumente utilizado é o da exclusão ou diminuição da concentração de auxina. Segundo Zimmerman (1993), a retirada da auxina do meio de cultura provoca a inativação de uma série de genes e permite que o programa da embriogênese dê continuidade. A aquisição de polaridade em embriões é tida com frequência como o primeiro passo no processo da embriogênese (WARREN e WARREN, 1993), e a divisão assimétrica não resulta diretamente em embrião e, sim, em MPEs, nas quais apenas algumas irão se desenvolver em embriões (NUTI RONCHI e GIORGETTI, 1995).…”