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Hancock, R. D.

Publications and source records attributed to Hancock, R. D..

2 recordsLinked to original sources
bioRxiv2024

GERMIN3 plays a role in plasmodesmatal gating to regulate meristem activation related to tuberisation, tuber dormancy release and stem branching in potato

O_LIGERMIN3 has previously been identified as a target of the tuberigen activation complex suggesting a function in potato tuberisation but its role is presently unknown. C_LIO_LITo understand the role of GERMIN3 we analysed morphological, agronomic and molecular phenotypes in transgenic lines. C_LIO_LIGERMIN3 over-expressing lines of Solanum tuberosum ssp. andigena exhibited increased tuber yields under permissive conditions and enhanced tuber numbers. Post-harvest tuber sprouting exhibited reduced apical dominance with increased numbers of sprouts. Apical dominance was reduced in aerial tissues of mature plants where stem growth from axillary buds was activated. Similar results were observed in the commercial cultivar Desiree. Over-expression of GERMIN3 had no impact on the expression of SP6A, a positive regulator of tuberisation or TFL1B, a negative regulator. The GERMIN3 protein localised to the endoplasmic reticulum and transient expression in N. benthamiana leaves resulted in plasmodesmatal gating allowing intercellular transport of GFP-tagged sporamin independent of GERMIN3 oxalate oxidase activity. C_LIO_LIGERMIN3 affects tuberisation and other developmental processes by facilitating meristem activation. This identifies GERMIN3 as a novel protein associated with control of plasmodesmatal transport and supports the importance of plasmodesmatal gating in the regulation of key potato developmental processes. C_LI

plant biology↗
bioRxiv2024

Silencing of a raspberry homologue of VRN1 is associated with disruption of dormancy induction and misregulation of subsets of dormancy-associated genes.

Winter dormancy is a key process in the phenology of temperate perennials. The changing climate is severely impacting its course leading to economic losses in agriculture. A better understanding of the underlying mechanisms, as well as the genetic basis of the different responses, are necessary for the development of climate-resilient cultivars. This study aims to provide an insight into winter dormancy in red raspberry (Rubus idaeus L). We report the transcriptomic profiles during dormancy in two raspberry cultivars with contrasting responses. The cultivar Glen Ample showed a typical perennial phenology, whereas Glen Dee registered consistent dormancy dysregulation, exhibiting active growth and flowering out of season. RNA-seq combined with weighted gene co-expression network analysis (WGCNA) highlighted gene clusters in both genotypes that exhibited time-dependent expression profiles, Functional analysis of Glen Ample gene clusters highlighted the significance of the cell and structural development prior to dormancy entry as well the role of genetic and epigenetic processes such as RNAi and DNA methylation in regulating gene expression. On the contrary, dormancy release in Glen Ample was associated with upregulation of transcripts associated with the resumption of metabolism, nucleic acid biogenesis and processing signal response pathways. Many of the processes occurring in Glen Ample were dysregulated in Glen Dee and twenty-eight transcripts exhibiting time-dependent expression in Ample that also had an Arabidopsis homologue were not found in all samples from Glen Dee. These included a gene with homology to Arabidopsis VRN1 (RiVRN1.1) that exhibited a sharp decline in expression following dormancy induction in Glen Ample. Characterisation of the gene region in the Glen Dee genome revealed two large insertions upstream of the ATG start codon. We propose that non-expression of a specific VRN1 homologue in Glen Dee causes dormancy misregulation as a result of inappropriate expression of a subset of genes that are directly or indirectly regulated by RiVRN1.1. HIGHLIGHTThe raspberry cultivar Glen Dee exhibits aberrant winter dormancy status associated with insertions in the upstream promoter region of a VRN1 (RiVRN1.1) homologue that silence expression, allowing the identification of dormancy-associated genetic modules that are regulated by RiVRN1.1.

plant biology↗