DAÑO OCASIONADO POR BOMBARDEO DE PARTÍCULAS EN CULTIVOS CELULARES DE CEMPAXÚCHIL (Tagetes erecta L.)

Abstract

Marigold (Tagetes erecta L.) is an ornamental plant which accumulate carotenoids has yellow or orange inflorescences, even there are white varieties. These metabolites have nutraceutical properties and are used for the prevention of some diseases. In this research assessed the damage caused to the wall and cell membrane by gold particles bombardment in undifferentiated cells of T. erecta of marigold French Vanilla variety (FV). Callus growth kinetic characterization was performed in dry weight (DW) daily for 14 days. Points were selected on the kinetics of cell growth (0, 4, 6, 11, 13 and 14 days) in order to bombard gold microparticles with plasmid pBI426, by biolistic technique, at distance of 11.5 cm and a pressure of 60 psi, evaluating transient expression of uidA gene. On the other hand, use of two different fluorochromes: fluorescein diacetate (DAF) and propidium iodide (PI) allowed quantify viability of bombarded calluses. DAF was detected with living cells and dead cells were identified IP. Finally, were evaluated changes in cell morphology of bombarded calli of the four treatments were evaluated, bombarded with osmotic medium (B/OS), bombarded without osmotic medium (B/sinOS) not bombarded with osmotic medium (sinB/OS), and not bombarded without osmotic medium (sinB/sinOS). Obtained images were processed using digital image treatment (TDI), plasmolysis was observed in bombarded cells, pretreated with osmotic medium of 0.2 M D-mannitol. Results showed that day 4 is the best moment to bombard because uidA gene expression showed a mean of 44.6 foci and viability of 49.7%, above the two remaining treatments B/sinOS and sinB/OS, which showed no uidA gene expression. From the captured and processed images analysis of treatments B/OS, B/sinOS, sinB/OS and sinB/sinOS, were observed changes in the shape descriptors such as area, perimeter, circularity and maximum length, observing area increased after day 4 and, circularity of calli was losing their balance or spherical morphology over time and not recovered after 14 days, suggesting evident morphostructural changes in which the values of circularity, ranging from 0.71 to a more irregular or elongated value of 0.65 in cell wall and, values around 0.53 in the cell membrane with osmotic treatments medium indicating that it is happening a change by treatment effect.