E. coli cultures expressing a synthetic sequence of ptz gene (stz) promoted in vitro direct organogenesis in Nicotiana tabacum L

• Published in: Plant cell, tissue and organ culture Vol. 137; no. 1; pp. 87 - 100
• Main Authors: Camas-Reyes, Alberto, Laguna-Ramírez, Ricardo, Jofre-Garfias, Alba E., Cardoso-Martínez, Faviola, Hernández-Orihuela, Ana Lilia, Molina-Torres, Jorge, Martínez-Antonio, Agustino
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 15-04-2019; Springer Nature B.V
• Subjects: Bioassays; Biomedical and Life Sciences; Cell culture; Chemical synthesis; Cold shock; Culture media; Cytokinins; Deoxyribonucleic acid; DNA; E coli; Explants; Gene expression; Kinases; Life Sciences; Organic chemistry; Organogenesis; Original Article; Plant extracts; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant propagation; Plant Sciences; Plant species; Propagation; Rooting; Tobacco; In vitro organogenesis; Cytokinins; Tobacco; Synthetic biology
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-018-01554-7

In vitro plant organogenesis requires plant regulator cytokinins to be exogenously supplied to the culture media. Cytokinins are either obtained from natural sources, from purified commercial plant extracts or by chemical synthesis. Besides plants, several species of plant pathogenic bacteria also naturally produce cytokinins. For example,
Pseudomonas syringae
pv.
savastanoi
(
P. savastanoi
) produces cytokinins by virtue of its isopentenyl transferase (
ptz
) gene. Therefore, we asked whether cell cultures of an
Escherichia coli
(
E. coli
) strain transformed with a synthetic sequence of the
ptz
gene (
stz
) may induce a morphogenetic response in vitro. To address this question, the
stz
gene was inserted into the pColdI™ DNA cold shock expression vector, and this clone was used to genetically transform cells of the
E. coli
TOP10 strain. The same strain transformed with an empty expression vector was used as the experimental control. Our results showed that cell-free media and methanolic fractions of the cell-free media prepared from the
E. coli
TOP10 strain overexpressing the
stz
gene combined with MS basal medium were able to induce in vitro organogenesis in tobacco bioassays. These cell-free media promoted shoot and root formation in tobacco leaf explants. We propose that these types of cell-free extracts could be used not only for in vitro plant propagation, but also for promoting plant rooting.