A paper recently published in the journal Physiologia Plantarum by the group led by Dr. Pilar S. Testillano at the Margarita Salas Center for Biological Research (CSIC) presents a new biotechnological strategy to improve in vitro propagation of cork oak plants by modulating global genome methylation with small molecules.
Forest trees are essential to address the current challenges of global change, as they reduce greenhouse gas emissions and can store carbon in the long term among other benefits. Currently, many forest species, such as cork oak, are severely affected by diseases and have a low level of tolerance to changing environmental conditions.
In this context, it is urgent to develop solutions to restore forests with selected trees that are more resilient and better adapted. To this end, in vitro clonal regeneration by somatic embryogenesis is the best and fastest option for the propagation and conservation of selected tree genotypes. However, these techniques, based on somatic cell reprogramming, are very inefficient in many species of ecological and environmental interest, since the molecular mechanisms controlling cell reprogramming in these species are not yet well understood.
In this work, Carneros et al. analyze the DNA methylation-directed epigenetic regulation of the somatic embryogenesis process in cork oak, characterizing the global methylation patterns of the genome and the regulators involved. Using transient treatments with the small molecule azacytidine, an inhibitor of DNA methyltransferase activity, genome hypomethylation and an increase in the rate of reprogramming are induced, which after elimination of the compound leads to increased formation of somatic embryos and subsequently to seedlings.
The work has allowed the researchers to identify new elements of epigenetic regulation of somatic embryogenesis and to propose a new chemical strategy to improve the in vitro propagation of a forest tree, a species in which the knowledge of the process is still scarce.
Reference: DNA demethylation by transitory 5-azacytidine treatment improves somatic embryogenesis yield for regeneration and breeding of cork oak. Carneros E, Díaz-Luzza EM, Pérez-Pérez Y, Solís MT, Testillano PS (2024) Physiologia Plantarum, 176(1), e14143. doi: 10.1111/ppl.14143