Controlling hyperhydricity in micropropagated plants of Lippia grata Schauer (Verbenaceae), a native species of a dry seasonal tropical forest with pharmacological potential

• Published in: Revista brasileira de botânica Vol. 41; no. 3; pp. 529 - 538
• Main Authors: Palhares Neto, Luiz, de Souza, Lindomar Maria, de Morais, Marciana Bizerra, de Albuquerque, Cynthia Cavalcanti, Camara, Terezinha Rangel, Ulisses, Claudia
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-09-2018; Springer Nature B.V
• Subjects: Activated carbon; Activated charcoal; Aluminum; Antioxidants; Biomedical and Life Sciences; Botany; Cell culture; Charcoal; Contamination; Cultivation; Cuttings; Endemic species; Explants; Flowers & plants; Gas exchange; Hydrogen peroxide; Indigenous species; Leaves; Life Sciences; Lipid peroxidation; Lippia; Malondialdehyde; Metal foils; Multiplication; Original Article; Oxidation; Peroxidation; Pharmacology; Plant Systematics/Taxonomy/Biogeography; Plant tissues; Polyethylene glycol; Polyvinylpyrrolidone; Propagation; Sealing; Tropical forests; Tubes; Antioxidative system; Gas exchange; Anatomy; Polyethylene glycol; Medicinal plant
• ISSN: 0100-8404; 1806-9959
• DOI: 10.1007/s40415-018-0476-6

The present study is to assess the morphophysiological development in vitro of
Lippia grata
Schauer, an endemic “Caatinga” species that shows pharmacological properties. Young cuttings containing nodal segments were divided into three explant types, namely E1 (apical bud), E2 (nodal segment below the apical bud) and E3 (nodal segment below E2); the explants were inoculated in MS medium supplemented with antioxidant compound (polyvinylpyrrolidone) or adsorbing agent (activated charcoal). The survival index, the occurrence of oxidation, contamination and the number of leaves and sprouts were assessed. The explants were cultivated in MS medium supplemented with polyethylene glycol 6000 (0, 0.5 and 1 g L
−1
) and closed with aluminum foil (total sealing) or with aluminum foil containing one hole (partial sealing), in the multiplication stage, due to hyperhydricity in vitro. Histological and biometric analyses were performed at the 45th cultivation day, as well as the analyses of antioxidative enzyme, and hydrogen peroxide and malondialdehyde levels. Normal leaves have presented greater organization and cellular development than hyperhydric leaves. The use of antioxidants was not efficient to control the oxidation of inoculated apical buds (E1), only. The lowest hyperhydricity rates in the multiplication stage were found in the partial sealing treatments; however, the total sealing of tubes, in combination with the PEG addition, has led to increased lipid peroxidation. In view of the results, it is concluded that the explant types, as well as the suitability of a functional gas exchange system in vitro, have favored the growth and development of cells and tissues, thus attenuating the hyperhydricity symptoms. In addition, this study demonstrates the suitability of the culture system through the facilitation of gas exchange allows the use of the protocol for in vitro propagation without compromising the leaf morphoanatomy.