Biology subjects

Marzec, M.

Publications and source records attributed to Marzec, M..

3 recordsLinked to original sources

bioRxiv2026

Benzyl Cyanide Triggers A Regeneration Program in Arabidopsis

Phenylacetic acid (PAA) is a naturally occurring auxin whose biosynthesis and function during plant regeneration remain poorly understood. PAA may be synthesized from phenylalanine via the CYP79A2-dependent phenylacetaldoxime pathway, in which benzyl cyanide/phenylacetonitrile (BnCN/PAN) is a potential intermediate and substrate for NITRILASE (NIT) enzymes. Here, we investigated whether BnCN/PAN promotes somatic embryogenesis (SE) through NIT-dependent PAA biosynthesis. Low concentrations of BnCN/PAN stimulated somatic embryo formation in Arabidopsis thaliana, whereas exogenous PAA also promoted embryogenic induction. Transcriptome profiling revealed that BnCN/PAN upregulated genes associated with SE, including key embryogenic regulators and EMBRYO DEFECTIVE genes. RNA-seq data further indicated enhanced auxin signalling, which was independently confirmed using the pDR5::GUS reporter line. Inhibition of NIT activity by heatin reduced the embryogenic competence of BnCN/PAN-treated explants, supporting the involvement of NIT enzymes in this response. Collectively, our findings provide the first evidence that BnCN/PAN promotes embryogenic transition and suggest that NIT functions in SE extend beyond their proposed role in indole-3-acetic acid biosynthesis. Summary statementThis study uncovers a previously unrecognized pathway regulating plant regeneration, providing new insights into how naturally occurring metabolites influence embryo formation.

plant biology↗

bioRxiv2026

Generation and characterization of a barley strigolactone mutant collection: from plant architecture to drought stress response

Strigolactones (SLs) are known to regulate shoot architecture and to be involved in plant responses to environmental stress, whereas their specific contributions to drought adaptation in barley remain incompletely defined. In this study, we analysed transcriptional, hormonal, and physiological responses to water deficit in barley SL mutants affected in early biosynthesis (Hvd10 and Hvd17), late biosynthesis (Hvmax1a), or signalling (Hvd14). The Hvd10, Hvd17, and Hvd14 mutants exhibited the typical high-tillering phenotype of SL deficiency, whereas Hvmax1a displayed characteristics similar to the wild type (WT), indicating functional differences within the SL biosynthetic pathway. Transcriptome analysis showed a clear overlap in gene expression among the high-tillering SL mutants under both control and drought conditions. We also used computational methods to identify potential transcription factors that might regulate SL-dependent gene expression. A drought experiment showed that SL mutants exhibited reduced biomass, relative water content, and photosynthetic efficiency, with the most pronounced effects observed in the high-tillering lines. Drought also activated the abscisic acid (ABA) pathway in all genotypes, with particularly high accumulation of ABA metabolites in the high-tillering SL mutants. Notably, Hvmax1a resembled the mutant-like metabolic profile, despite maintaining a wild-type-like architecture. Taken together, these results provide new insights into the roles of SL pathway components in drought responses and highlight functional differences among individual genes influencing both plant architecture and stress-related transcriptional programmes. Furthermore, the mutants generated in this study using Cas9-mediated genome editing represent a valuable genetic collection for future research into SL-mediated development and stress responses in barley.

plant biology↗

bioRxiv2020

Diverse roles of MAX1 homologues in rice

Cytochrome P450 enzymes encoded by MORE AXILLARY GROWTH1 (MAX1)-like genes produce most of the structural diversity of strigolactones during the final steps of strigolactone biosynthesis. The diverse copies of MAX1 in Oryza sativa provide a resource to investigate why plants produce such a wide range of strigolactones. Here we performed in silico analyses of transcription factors and microRNAs that may regulate each rice MAX1, and compared the results with available data about MAX1 expression profiles and genes co-expressed with MAX1 genes. Data suggest that distinct mechanisms regulate the expression of each MAX1. Moreover, there may be novel functions for MAX1 homologues, such as the regulation of flower development or responses to heavy metals. In addition, individual MAX1s could be involved in specific functions, such as the regulation of seed development or wax synthesis in rice. Our analysis reveals potential new avenues of strigolactone research that may otherwise not be obvious.

plant biology↗