Developmental effects of additional ultraviolet a radiation, growth regulators and tyrosine in Alternanthera brasiliana (L.) Kuntze cultured in vitro

Abstract

ABSTRACT

Pigment production and growth of Alternanthera plants cultured in vitro in the presence of tyrosine

“…Thus, the addition of the substrate tyrosine might have facilitated the action of the enzyme and triggered reactions that increased the content of betacyanin. Similar to what happened in A. brasiliana cultured in MS medium containing tyrosine, Silva et al (2005) found that the accumulation of betacyanin was higher than in the control. Tyrosine was used in the present study because it was the precursor amino acid in betacyanin synthesis.…”

“…3D). These results corroborated those of Silva et al (2005), who tested other factors besides tyrosine in the in vitro culture of A. brasiliana. Regardless of the treatment used, these authors found that the presence of tyrosine in the culture medium led to the lowest values of dry matter.…”

“…In a study with lentil (Lens culinaris Medik), Sarker et al (2003) found that 20 µM tyrosine combined with other growth regulators showed successful regeneration and in vitro rooting. However, in the studies with A. brasiliana, Silva et al (2005) showed that the plants cultured in MS medium with 10 µM tyrosine under white light showed no difference in the root length compared to the control, with averages of 7.40 cm and 7.05 cm, respectively. In the present study, the treatment with 25 µM tyrosine led to a significant difference in the root formation of A. philoxeroides.…”

“…Berlin et al (1986) used 15 µM tyrosine in the culture of Chenopodium rubrum callus tissue and demonstrated an increase in the production of betalains of 50 to 100% after 28 days of culture. Silva et al (2005) found that the production of betalains increased compared to the control in the in vitro culture of A. brasiliana for 45 days in MS medium supplemented with 10 µM tyrosine. Other elicitors have also been used to increase the production of betalains in the plants.…”

“…Chemical synthesis of these molecules does not seem feasible due to a lack of clarification of several steps involved in this synthetic process (Pavokovi and Krsnik-Rasol 2011). Precursor amino acids, which are considered chemical elicitors, have been used successfully both in the cultured plant cells and in intact plants to improve the pigment production (Berlin et al 1986;Silva et al 2005). Given the medicinal importance of betacyanin and species of the genus Alternanthera, the aim of the present study was to evaluate the influence of tyrosine on the morphological characteristics of and betacyanin production in A. philoxeroides and A. tenella cultured in vitro.…”