Biology subjects

Ingle, R. A.

Publications and source records attributed to Ingle, R. A..

3 recordsLinked to original sources

bioRxiv2026

Transcriptional regulation of the response to water availability in the resurrection plant Xerophyta elegans

Vegetative desiccation tolerance (VDT) has evolved independently across vascular plants, but its genetic basis remains poorly understood. Although VDT is associated with expansion of the ELIP gene family, the contribution of other lineage-specific expansions is unclear. We assembled genomes for Xerophyta elegans and Xerophyta humilis, identifying expanded gene families largely involved in chlorophyll metabolism and abscisic acid-mediated stress responses. Using a dense dehydration-rehydration transcriptome series in X. elegans seedlings, we reconstructed the regulatory network underlying VDT. Transcription factors from the ABF, ZAT and HSFC families were associated with early responses to desiccation. Key regulators of the seed maturation programme, including NAC transcription factors (ATAF1 and ANAC032), DOG genes and the trihelix factor ASIL1, were also implicated. These findings indicate that VDT arises through integration of abiotic stress signalling with rewiring of the seed maturation network, enabling desiccation tolerance in vegetative tissues.

plant biology↗

bioRxiv2025

Supergene control of chiral development in mirror-image flowers

How genes determine the left-versus right-handed development of chiral structures is a fascinating question. The reciprocal placement of female and male organs on opposite sides of the midline in mirror-image flowers limits selfing and promotes efficient cross-pollination. Here we identify the molecular and developmental basis of floral handedness in butterfly lilies. Female and male organs deflect by a combination of genetically controlled chirality and gravitropism, orienting left and right with respect to an external rather than internal reference axis. Coordinated organ placement is controlled by a hemizygous supergene containing two causal loci, MIR156-R and YUCCA-R, responsible for opposite female and male organ orientation, respectively. This genomic architecture results in differential placement of the supergene alleles on the pollinators and maintenance of the reproductive polymorphism.

plant biology↗

bioRxiv2024

Style deflection is determined by the handedness of phyllotaxis and differential cell elongation in a species with mirror-image flowers

Many animals and plants show left-right (LR) asymmetry. In some animal systems, handedness has a simple genetic basis, which has allowed identifying how handedness is determined at the molecular level, even if its functional relevance often remains unclear. Mirror-image flowers represent an example of LR asymmetry of clear functional significance, with the reciprocal placement of male and female organs in left- versus right-handed flowers promoting cross-pollination. Here, we use the South African geophyte Cyanella alba to study how handedness of its mirror-image flowers is determined and elaborated during development. Inflorescences of C. alba produce flowers with a largely consistent handedness. However, we find that this handedness has no simple genetic basis, and individual plants can switch their predominant handedness between years. Rather, it is the direction of the phyllotactic spiral that determines floral handedness. Cellular analysis combined with biophysical modelling demonstrates that style deflection is driven by increased cell expansion in the adaxial carpel facing the next oldest flower compared to the other adaxial carpel. The more expanding carpel shows transcriptional signatures of increased auxin signaling compared to the less expanding one, and auxin application to the latter can reverse the orientation of style deflection. We propose that a recently described inherent LR auxin asymmetry in the initiating organs of spiral phyllotaxis determines handedness in C. alba, representing a conserved non-genetic mechanism for creating a stable floral polymorphism. This mechanism links chirality across different levels of plant development and exploits a developmental constraint in a core patterning process to produce morphological variation of ecological relevance.

plant biology↗