Pre-procambial cells are niches for pluripotent and totipotent stem-like cells for organogenesis and somatic embryogenesis in the peach palm: a histological study

Autor(es)

de Almeida, Marcilio ^[1] ; de Almeida, Cristina Vieira ^[2] ; Graner, Erika Mendes ^[3] ; Brondani, Gilvano Ebling ^[4] ; de Abreu-Tarazi, Monita Fiori ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, Dept Ciencias Biol, PPG Fisiol Bioquim Plantas & PPG Recursos Florest, BR-13418900 Sao Paulo - Brazil

^[2] InVitroPalm Consultoria Estudo & Desenvolvimento, BR-1343256 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, Dept Ciencias Biol, PPG Fisiol & Bioquim Plantas, BR-13418900 Sao Paulo - Brazil

^[4] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, Dept Ciencias Florestais, PPG Recursos Florestais, BR-13418900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Plant Cell Reports; v. 31, n. 8, p. 1495-1515, AUG 2012.
• Citações Web of Science: 28

Resumo

The direct induction of adventitious buds and somatic embryos from explants is a morphogenetic process that is under the influence of exogenous plant growth regulators and its interactions with endogenous phytohormones. We performed an in vitro histological analysis in peach palm (Bactris gasipaes Kunth) shoot apexes and determined that the positioning of competent cells and their interaction with neighboring cells, under the influence of combinations of exogenously applied growth regulators (NAA/BAP and NAA/TDZ), allows the pre-procambial cells (PPCs) to act in different morphogenic pathways to establish niche competent cells. It is likely that there has been a habituation phenomenon during the regeneration and development of the microplants. This includes promoting the tillering of primary or secondary buds due to culturing in the absence of NAA/BAP or NAA/TDZ after a period in the presence of these growth regulators. Histological analyses determined that the adventitious roots were derived from the dedifferentiation of the parenchymal cells located in the basal region of the adventitious buds, with the establishment of rooting pole, due to an auxin gradient. Furthermore, histological and histochemical analyses allowed us to characterize how the PPCs provide niches for multipotent, pluripotent and totipotent stem-like cells for vascular differentiation, organogenesis and somatic embryogenesis in the peach palm. The histological and histochemical analyses also allowed us to detect the unicellular or multicellular origin of somatic embryogenesis. Therefore, our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to potential niche establishment, depending on the positioning of the competent cells and their interaction with neighboring cells. Key message Our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to potential niche establishment, depending on the positioning of the competent cells and their interaction with neighboring cells. (AU)