Biology subjects

Gould, P. D.

Publications and source records attributed to Gould, P. D..

4 recordsLinked to original sources

bioRxiv2025

Two cowpea Rubisco activase isoforms for crop thermotolerance

O_LIA vital crop for sub-Saharan Africa, cowpea productivity is threatened by climate change, including increased heatwave intensity, duration, and frequency. Rubisco activase (Rca) is a key molecular chaperone that maintains Rubisco activity and due to its thermal sensitivity is a key target for improving crop climate resilience. C_LIO_LIWe identified and characterised four Rca isoforms in Vigna unguiculata (L.) Walp. cv. IT97K-499-35 in vitro: Rca1{beta}, Rca8, Rca10 and Rca10{beta}. Cowpea leaf and plant growth traits were also investigated during a 5-day +10 {degrees}C heatwave that included assessment of Rubisco and Rca activity in leaf extracts, and relative changes in the abundance of the four Rca isoforms. C_LIO_LICowpea Rca10 and Rca10{beta} had higher thermal maxima, broader thermal optima and higher rates of ATP hydrolysis and Rubisco reactivation in vitro. In the absence of water deficit, the heatwave caused only mild effects, including increases in leaf temperature and expression of Rca10, small decreases in Rubisco activity and activation state, and unaltered temperature response of Rubisco activation by Rca. C_LIO_LIThe superior Rca10 and Rca10{beta} isoforms offer the prospect of enhancing the thermotolerance of cowpea and other crops in anticipation of more extreme future heatwaves. C_LI

plant biology↗

bioRxiv2019

Nanopore direct RNA sequencing maps an Arabidopsis N6 methyladenosine epitranscriptome

Understanding genome organization and gene regulation requires insight into RNA transcription, processing and modification. We adapted nanopore direct RNA sequencing to examine RNA from a wild-type accession of the model plant Arabidopsis thaliana and a mutant defective in mRNA methylation (m6A). Here we show that m6A can be mapped in full-length mRNAs transcriptome-wide and reveal the combinatorial diversity of cap-associated transcription start sites, splicing events, poly(A) site choice and poly(A) tail length. Loss of m6A from 3 untranslated regions is associated with decreased relative transcript abundance and defective RNA 3' end formation. A functional consequence of disrupted m6A is a lengthening of the circadian period. We conclude that nanopore direct RNA sequencing can reveal the complexity of mRNA processing and modification in full-length single molecule reads. These findings can refine Arabidopsis genome annotation. Further, applying this approach to less well-studied species could transform our understanding of what their genomes encode.

molecular biology↗

bioRxiv2019

Coordinated circadian timing through the integration of local inputs in Arabidopsis thaliana

Every plant cell has a genetic circuit, the circadian clock, that times key processes to the day-night cycle. These clocks are aligned to the day-night cycle by multiple environmental signals that vary across the plant. How does the plant integrate clock rhythms, both within and between organs, to ensure coordinated timing? To address this question, we examined the clock at the sub-tissue level across Arabidopsis thaliana seedlings under multiple environmental conditions and genetic backgrounds. Our results show that the clock runs at different speeds (periods) in each organ, which causes the clock to peak at different times across the plant in both constant environmental conditions and light-dark cycles. Closer examination reveals that spatial waves of clock gene expression propagate both within and between organs. Using a combination of modeling and experiment, we reveal that these spatial waves are the result of the period differences between organs and local coupling, rather than long distance signaling. With further experiments we show that the endogenous period differences, and thus the spatial waves, are caused by the organ specificity of inputs into the clock. We demonstrate this by modulating periods using light and metabolic signals, as well as with genetic perturbations. Our results reveal that plant clocks are set locally by organ specific inputs, but coordinated globally via spatial waves of clock gene expression.

plant biology↗

bioRxiv2017

Coordination of robust single cell rhythms in the Arabidopsis circadian clock via spatial waves of gene expression

The Arabidopsis circadian clock orchestrates gene regulation across the day/night cycle. Although a multiple feedback loop circuit has been shown to generate the 24h rhythm, it remains unclear how robust the clock is in individual cells, or how clock timing is coordinated across the plant. Here we examine clock activity at the single cell level across Arabidopsis seedlings over several days. Our data reveal robust single cell oscillations, albeit desynchronised. In particular, we observe two waves of clock activity; one going down, and one up the root. We also find evidence of cell-to-cell coupling of the clock, especially in the root tip. A simple model shows that cell-to-cell coupling and our measured period differences between cells can generate the observed waves. Our results reveal the spatial structure of the plant circadian clock and suggest that unlike the centralised mammalian clock, the clock has multiple points of coordination in Arabidopsis.

systems biology↗