Biology subjects

Martignago, D.

Publications and source records attributed to Martignago, D..

3 recordsLinked to original sources

bioRxiv2026

CRISPR-Cas9 Induced Knockout of BEL5 in Tetraploid Potato: Optimized Methodology via Repeated de novo Regeneration and Impact on Tuberization

CRISPR-Cas9 has emerged as a powerful tool for targeted genome editing in plants; however, its application in tetraploid potato (Solanum tuberosum ssp. tuberosum) remains challenging due to its vegetative propagation and complex highly heterozygous genome. Availability of whole-genome sequence data for the specific genotype is crucial to ensure complete knockout of all alleles of target genes while minimizing off-target mutations. In this study, using the tetraploid potato cultivar Desiree, we report, a complete CRISPR-Cas9-mediated knockout of the BEL5 gene, encoding a transcription factor, known as one of the key regulators driving tuber formation. We employed Agrobacterium-mediated transformation and demonstrated that repeated de novo regeneration could improve editing efficiency by promoting emergence of new mutations. BEL5 knockout plants exhibited a delayed onset of tuberization under inductive short-day conditions in hydroponics; however, their overall tuber yields were comparable to wild type plants. Based on our results, we propose a regulatory role of BEL5 in the timing of tuber onset but, unexpectedly, its dispensability for tuber development in modern cultivated potato. Besides providing functional insight into the BEL5 role in potato, this study includes a methodological approach for efficient CRISPR-Cas9 gene editing in this vegetatively propagated polyploid crop, along with strategies for detecting mutations in genes that lack clear phenotypic manifestation.

plant biology↗

bioRxiv2024

Abscisic acid and GIGANTEA signalling converge to regulate the recruitment of CONSTANS to the FT promoter and activate floral transition

Plants align flowering with optimal seasonal conditions to increase reproductive success. This process depends on modulating signalling pathways that respond to diverse environmental and hormonal inputs, thereby regulating the transition to flowering at the shoot apical meristem. In Arabidopsis, long-day photoperiods (LDs) stimulate the transcription of FLOWERING LOCUS T (FT), encoding the main florigenic signal. FT activation is mediated by the transcriptional regulator CONSTANS (CO), which binds to the CO responsive elements (COREs) located in the proximal FT promoter region. The phytohormone abscisic acid also (ABA) contributes to FT activation together with GIGANTEA (GI) to regulate drought escape (DE). Whether CO is a target of ABA and GI actions for the regulation of FT is, however, unknown. Here, we report that ABA and its signalling components promote CO recruitment to the CORE1/2, without causing reductions in the diel pattern of CO protein accumulation. ChIPseq analyses show that ABA broadly shapes the CO DNA binding landscape, which is enriched at the promoters of genes involved in the response to abiotic stress. We also found that GI promotes CO recruitment to the CORE1/2 region, and that CO recruitment is required for the accumulation of RNAPol II at the transcription start site of FT. Finally, we show that GI and ABA signalling pathways are largely epistatic in the control of flowering time, suggesting their involvement in the same molecular process. Taken together, these observations suggest that varying water deficit conditions modulate CO recruitment and FT expression, thus dictating DE strategies in Arabidopsis. HighlightABA and GIGANTEA signalling promote FLOWERING LOCUS T (FT) transcriptional activation by regulating the binding of the transcription factor CONSTANS to the proximal FT promoter.

plant biology↗

bioRxiv2024

Molecular and physiological characterization of brassinosteroid receptor BRI1 mutants in Sorghum bicolor

SUMMARYO_LIThe high sequence and structural similarities between BRI1 brassinosteroid receptors of Arabidopsis (AtBRI1) and sorghum (SbBRI1) prompted us to study the functionally conserved roles of BRI in both organisms. C_LIO_LIIntroducing sorghum SbBRI1 in Arabidopsis bri1 mutants restores defective growth and developmental phenotypes to WT levels. C_LIO_LISorghum mutants for SbBRI1 receptors show defective BR sensitivity and impaired growth and development throughout the entire sorghum life cycle. Embryonic analysis of sorghum primary roots permit to trace back root growth and development to early stages, revealing the functionally conserved roles of SbBRI1 receptor in BR perception during meristem development. RNA-seq analysis uncovers the downstream regulation of the SbBRI1 pathway in cell wall biogenesis during cell growth. C_LIO_LITogether, these results uncover that sorghum SbBRI1 receptor protein play functionally conserved roles in plant growth and development, while encourage the study of BR pathways in sorghum and its implications for improving resilience in cereal crops. C_LI

plant biology↗