Articles
The effect of ethylene on Solanum betaceum Cav. in vitro regeneration: from meristem propagation to somatic embryogenesis
Article number
1439_32
Pages
243 – 252
Language
English
Abstract
Despite of its importance in micropropagation, the effect of ethylene on the regeneration of woody species has not yet been thoroughly investigated.
Here, we induced several regeneration processes in the presence of ethylene modulators such as AgNO3 (action inhibitor) and Ethephon (ETH, chemical precursor) in the woody species Solanum betaceum Cav. (tamarillo). Preliminary results showed that ethylene is essential for axillary shoot proliferation since the inhibition of its action by AgNO3 significantly reduced the explant response capacity (%). It was also demonstrated that ethylene plays a positive role in de novo shoot organogenesis, via upregulation of regeneration-related genes, such as STM, WUS and PIN1 during the pluripotent callus phase and promeristem initiation.
In somatic embryogenesis, a decrease in ethylene biosynthesis and its perception reduced both the embryogenic competence acquisition and callus development.
The opposite effect was found in the presence of ETH, in which we observed an increase in embryogenic callus induction.
However, further somatic embryo development was disrupted with the enhancing of ethylene availability by ETH. Moreover, AgNO3 promoted an increase in the number of somatic embryos.
Our results suggest that ethylene acts synergistically with auxins during the different stages of cell dedifferentiation and differentiation.
Overall, our study provides new insights into how ethylene influences tamarillo micropropagation, with possible applications in the overcoming of regeneration bottlenecks of other woody species.
Here, we induced several regeneration processes in the presence of ethylene modulators such as AgNO3 (action inhibitor) and Ethephon (ETH, chemical precursor) in the woody species Solanum betaceum Cav. (tamarillo). Preliminary results showed that ethylene is essential for axillary shoot proliferation since the inhibition of its action by AgNO3 significantly reduced the explant response capacity (%). It was also demonstrated that ethylene plays a positive role in de novo shoot organogenesis, via upregulation of regeneration-related genes, such as STM, WUS and PIN1 during the pluripotent callus phase and promeristem initiation.
In somatic embryogenesis, a decrease in ethylene biosynthesis and its perception reduced both the embryogenic competence acquisition and callus development.
The opposite effect was found in the presence of ETH, in which we observed an increase in embryogenic callus induction.
However, further somatic embryo development was disrupted with the enhancing of ethylene availability by ETH. Moreover, AgNO3 promoted an increase in the number of somatic embryos.
Our results suggest that ethylene acts synergistically with auxins during the different stages of cell dedifferentiation and differentiation.
Overall, our study provides new insights into how ethylene influences tamarillo micropropagation, with possible applications in the overcoming of regeneration bottlenecks of other woody species.
Authors
M. Neves, S. Correia, J.M. Canhoto
Keywords
ACC, meristem, micropropagation, silver nitrate, Solanaceae, woody species
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