Exogenous application of benzyl cyanide, also designated as phenylacetonitrile, promotes somatic embryo formation in the model plant species Arabidopsis thaliana, according to new research published in BMC Plant Biology. Investigating regenerative processes in plant cell and tissue culture, the research team evaluated whether this chemical compound could activate the developmental reprogramming required for embryo production. Their experimental observations confirmed that low concentrations of exogenous benzyl cyanide effectively stimulated somatic embryo formation in cultured explants. In accompanying experimental tests, the exogenous administration of phenylacetic acid likewise promoted embryogenic induction, establishing that both molecules are capable of facilitating this developmental transition in plant tissues.

The study centered on phenylacetic acid, an endogenous and naturally occurring auxin whose metabolic biosynthetic routes and biological functions during plant regeneration remain poorly understood. Biochemical evidence indicates that phenylacetic acid may be synthesized from the amino acid phenylalanine via the CYP79A2-dependent phenylacetaldoxime pathway. In this metabolic sequence, benzyl cyanide represents a potential reaction intermediate and a direct enzymatic substrate for nitrilase enzymes. These biochemical relationships led the investigators to test the hypothesis that exogenous benzyl cyanide promotes somatic embryogenesis specifically by serving as a substrate for nitrilase-dependent phenylacetic acid biosynthesis in Arabidopsis explants.

To characterize the underlying molecular changes accompanying this chemical treatment, the researchers carried out transcriptome profiling via RNA sequencing on the treated explant tissues. The RNA-seq profiling data revealed that benzyl cyanide application significantly upregulated an array of genes associated with the somatic embryogenesis program. Specifically, this upregulation encompassed key embryogenic regulators as well as several EMBRYO DEFECTIVE genes critical to embryogenesis. Furthermore, the transcriptome dataset demonstrated widespread enhancement of auxin signaling activity, a molecular signature that the investigators independently confirmed in plant tissues using the pDR5::GUS reporter line.

To test whether nitrilase enzyme activity is functionally required for this developmental response, the research team deployed the chemical inhibitor heatin to suppress nitrilase function during culture. When explants exposed to benzyl cyanide were treated with heatin to inhibit nitrilase activity, their overall embryogenic competence was noticeably reduced. This observed reduction demonstrates that blocking nitrilase enzymatic activity impairs the explants’ embryogenic response, providing experimental evidence that nitrilase enzymes participate in mediating the pro-embryogenic effects of benzyl cyanide.

Collectively, the study provides the first experimental evidence demonstrating that exogenous benzyl cyanide can activate the somatic embryogenesis program and promote embryogenic transition in Arabidopsis thaliana explants.

Subject of Research: Nitrilase-dependent somatic embryogenesis induced by benzyl cyanide in Arabidopsis

Article Title: Exogenous benzyl cyanide activates the somatic embryogenesis program in Arabidopsis

Article References: Falińska, J., Wójcikowska, B., & Marzec, M. (2026). Exogenous benzyl cyanide activates the somatic embryogenesis program in Arabidopsis. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10296-0

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10296-0

Keywords: Arabidopsis thaliana, benzyl cyanide, phenylacetonitrile, somatic embryogenesis, phenylacetic acid, auxin biosynthesis, nitrilase enzymes, CYP79A2, phenylacetaldoxime pathway, EMBRYO DEFECTIVE genes, pDR5::GUS, RNA-seq, transcriptome profiling, heatin, embryogenic induction, plant regeneration