Morphometric and Biochemical Changes in Agave americana L. Plantlets Induced By Ethyl Methanesulfonate

Abstract

A. americana L. is a crop with very little genetic variability. In order to evaluate the effect of ethyl methanesulfonate (EMS) to induce variability in in vitro plantlets of A. americana, different explants (meristems, leaves and roots) were evaluated for the production of callus. MS medium supplemented with ANA (2.68 μM) and BAP (2.68 μM) was used. Callus obtained from apical meristem were treated with 15 mM EMS for two hours after which shoot formation was induced using 2,4-D (0.11 μM) and BAP (44 μM). The EMS induced variations in the morphometric and morphological parameters of the plantlets obtained, with 60% of the plantlets presenting differences such as dwarfism and different leaf forms, without the presence of spines, as well as an increase in fructan content of 30% with respect to the control plantlets. PAL was increased and this activity is related with higher anthocyanins concentration in A. americana L. plantlets.

Ethyl Methanesulfonate as Inductor of Somaclonal Variants in Different Crops

“…Various research works mention that the EMS mutagen increases the activity of the enzyme phenylalanine ammonium lyase (PAL), which is important in wound recovery and as a defence mechanism against infection by pathogens, this finding was corroborated when treating calluses of Agave americana with EMS, the researchers demonstrated that PAL activity increased by 80% [11], results similar to those found by Soleht et al [49], where they observed that the PAL enzyme increased its activity in the rice cultivars Pari Ireng (72%) and Melik (66%) after infection by Xanthomonas oryzae pv. Oryzae.…”

“…Regarding the use of EMS to generate plants resistant to phytopathogens, Sánchez-Martín et al [24] used mutants originated by the action of EMS to identify genes for resistance to various phytopathogens. In addition, Reyes-Zambrano et al [11] evaluated Agave americana L and identified that EMS caused phenotypic modifications in the morphological and morphometric parameters, in addition to an increase in the activity of the enzyme (PAL), which is related to resistance to biotic stress. The use of EMS has been also documented to generate plants resistant to abiotic stress.…”

“…The effect of EMS has been also documented on the production of secondary metabolites of interest. Reyes-Zambrano et al [11] found that the calli of A. americana L. treated with EMS showed a higher concentration of fructans and anthocyanins, compared to the untreated ones. Asif et al [7] quantified the content of thymoquinone in the mutant line VLY3 of N. sativa.…”

“…Another research work determined the LD50 on calli of A. americana L. at a concentration of 15 mM with a contact time of two hours, since it allowed the highest content of fructans [11].…”

“…EMS is used to generate resistant and tolerant plants to biotic and abiotic stress, for this purpose, Shi et al [10] found a mutant with a greater number of expressed genes that allowed it to generate mechanisms to tolerate low temperatures (down to -3°C). Other investigations have identified defence mechanisms against pathogens in different crops, including an increase in the activity of phenylalanine ammonium lyase (PAL) [11] and an increase in the content of secondary metabolites, mainly flavonoids [12] and proline [13].…”