Lorena Palacio

Phenolic compound production in relation to differentiation in cell and tissue cultures of Larrea divaricata (Cav.)

The lignan nordihydroguaiaretic acid (NDGA) and its derivatives existing in Larrea divaricata species show a wide range of pharmacological activities which makes this genus an interesting target to consider the plant in vitro cultivation systems as a feasible alternative source for their production. These compounds are potentially useful in treating diseases related to heart condition, asthma, arteriosclerosis, viral and bacterial infections, inflammation and cancer. In the present study, calli, cell suspension cultures, and in vitro and wild plants of L. divaricata were investigated for their potential to synthesize phenolic compounds. Calli, both with and without organogenesis, produced NDGA and quercetin, as did plantlet and wild plants. NDGA was also produced by the cell suspension cultures, together with p-coumaric acid, ferulic acid and sinapyl alcohol. The capacity of undifferentiated tissues to form phenolic compounds is very limited, but when the calli underwent organogenesis, developing mainly adventitious shoots, the phenolic compound production increased significantly. Plantlets regenerated from adventitious shoots of L. divaricata calli did not show the same phenolic pattern as wild plants, with levels of NDGA and quercetin being 3.6- and 5.9-fold lower, respectively.

In Vitro Propagation of Muña-Muña (Clinopodium odorum (Griseb.) Harley)

A micropropagation protocol was developed which may assist in the safeguarding and augmentation of dwindling natural populations of Clinopodium odorum (Griseb.) Harley, a critically and endangered medicinal plant. Factors affecting culture initiation bud sprouting and growth, rooting, and acclimatization were studied, using nodal segments of in vitro germinated seedling as primary explants on six media supplemented with different concentrations and combinations of 6-benzylaminopurine (BAP) (0.5–1.5 and 2-Naphthalene acetic acid (NAA) (0.5–1.5). Best results for culture initiation with sustainable multiplication rates (100%) were obtained on WP medium without any growth regulator. WP with the addition of 0.5 : 1 or 0.5 : 1.5) of BAP and NAA promoted a higher elongation; however, the optimum number of nodes were obtained in plantlets grown on 1/2 MS with the addition of 1 : 1.5 of BAP and NAA. Culture of sectioned individual nodes transferred to the media with different rates of BAP and NAA 1/2 MS-9 (1.5 : 1.5), SH-8 (1.5 : 1.0), and 1/2 B5-4 (1.0 : 0.5) media resulted in no proliferated shoots. The in vitro plants were successfully acclimatized garden soil and sand (2 : 1) in the greenhouse, with over 90% survival rate. The in vitro-grown plants could be transferred to ex vitro conditions and the efficacy in supporting ex vitro growth was assessed, with a view to develope longer-term strategies for the transfer and reintroduction into natural habitats.