Biology subjects

Knight, M. R.

Publications and source records attributed to Knight, M. R..

3 recordsLinked to original sources

bioRxiv2025

An elevated environmental temperature impairs accumulation of the pattern recognition receptor FLS2

Pattern-triggered immunity (PTI) is initiated when plants detect pathogen-associated molecular patterns (PAMPs) through pattern-recognition receptors (PRRs). How moderate increases in temperature affect this plant immune signalling remains unclear. We explored this by using flg22 and the leucine-rich repeat receptor kinase (LRR-RK) FLS2 as a model receptor-ligand system and Ca2+ signaling as a representative PTI output. A pre-treatment at 28 {degrees}C significantly impaired the flg22-induced [Ca2+]cyt influx, leading to a reduced expression of calcium-dependent defence genes, ICS1 and EDS1. This effect correlated with a temperature-dependent reduction in FLS2 abundance. A qualitatively similar inhibition of these responses was observed when membrane fluidity was artificially increased using benzyl alcohol. This suggests that the effect of elevated temperature might act through changes in membrane properties. Artificially restoring FLS2 protein levels rescued flg22-dependent Ca2+ signalling and ICS1 and EDS1 expression in seedlings pre-treated at 28{degrees}C or with benzyl alcohol. Together, these findings indicate that increased membrane fluidity reduces FLS2 protein levels, thereby compromising Ca2+ signalling, and probably other, flg22-indcued responses. This highlights a potential mechanistic link between temperature perception, membrane fluidity, and FLS2-dependent calcium signalling, providing insight into how an increase in global temperatures may compromise plant immune responses in the future.

plant biology↗

bioRxiv2024

Integration of multi-omics and deep phenotyping provides novel insights into multiple abiotic stress responses in potato

Potato is highly water and space efficient but susceptible to abiotic stresses such as heat, drought, or flooding, which are severely exacerbated by climate change. Understanding of crop acclimation to abiotic stress, however, remains limited. Here, we present a comprehensive molecular and physiological high-throughput profiling of potato (Solanum tuberosum, cv. Desiree) under heat, drought and waterlogging applied as single stresses or in combinations designed to mimic realistic future scenarios. Stress-responses were monitored via daily phenotyping and multi-omics analyses of leaf samples comprising transcriptomics, proteomics, metabolomics and hormonomics at several timepoints during and after stress treatments. Additionally, critical metabolites of tuber samples were analysed at the end of the stress period. Integrative analysis of multi-omics data was performed using a bioinformatic pipeline, which was established here, based on machine learning and knowledge networks. Overall, waterlogging had the most immediate and dramatic effects on potato plants, interestingly activating ABA-responses similar to drought stress. In addition, we observed distinct stress signatures at multiple molecular levels in response to heat or drought and to a combination of both. In response to all treatments, we found a downregulation of photosynthesis at different molecular levels, an accumulation of minor amino acids and diverse stress induced hormones. Our integrative multi-omics analysis provides global insights into plant stress responses, facilitating improved breeding strategies towards climate-adapted potato varieties. One Sentence SummaryIntegrated multi-omics analysis of high-throughput phenotyping in potato reveals distinct molecular signatures of acclimation to single and combined abiotic stresses related to climate change.

plant biology↗

bioRxiv2021

PIWI silencing mechanism involving the retrotransposon nimbus orchestrates resistance to infection with Schistosoma mansoni in the snail vector, Biomphalaria glabrata

BackgroundSchistosomiasis remains widespread in many regions despite efforts at its elimination. By examining changes in the transcriptome at the host-pathogen interface in the snail Biomphalaria glabrata and the blood fluke Schistosoma mansoni, we previously demonstrated that an early stress response in juvenile snails, manifested by induction of heat shock protein 70 (Hsp 70) and Hsp 90 and of the reverse transcriptase (RT) domain of the B. glabrata non-LTR-retrotransposon, nimbus, were critical for B. glabrata susceptibility to S. mansoni. Subsequently, juvenile B. glabrata BS90 snails, resistant to S. mansoni at 25{degrees}C become susceptible by the F2 generation when maintained at 32{degrees}C, indicating an epigenetic response. Methodology/Principal FindingsTo better understand this plasticity in susceptibility of the BS90 snail, mRNA sequences were examined from S. mansoni exposed juvenile BS90 snails cultured either at 25{degrees}C (permissive temperature) or 32{degrees}C (non-permissive). Comparative analysis of transcriptomes from snails cultured at the non-permissive and permissive temperatures revealed that whereas stress related transcripts dominated the transcriptome of susceptible BS90 juvenile snails at 32{degrees}C, transcripts encoding proteins with a role in epigenetics, such as PIWI (BgPiwi), chromobox protein homolog 1 (BgCBx1), histone acetyl transferase histone deacetylase (HDAC) and metallotransferase (MT) were highly expressed in those cultured at 25{degrees}C. To further determine a role for BgPiwi in B. glabrata susceptibility to S. mansoni, siRNA corresponding to the BgPiwi encoding transcript was utilized to suppress expression of BgPiwi, rendering the resistant BS90 juvenile snail susceptible to infection at 25{degrees}C. Given transposon silencing activity of PIWI as a facet of its role as guardian of the integrity of the genome, we examined the expression of the nimbus RT encoding transcript at 120 min after infection of resistant BS90 piwi-siRNA treated snails. We observed that nimbus RT was upregulated, indicating that modulation of the transcription of the nimbus RT was associated with susceptibility to S. mansoni in BgPiwi- siRNA treated BS90 snails. Furthermore, treatment of susceptible snails with the RT inhibitor lamivudine, before exposure to S. mansoni, blocked S. mansoni infection concurrent with downregulation of the nimbus RT transcript and upregulation of the BgPiwi encoding transcript in the lamivudine-treated, schistosome-exposed susceptible snails. Conclusions and SignificanceThese findings support a role for the interplay of BgPiwi and nimbus in the epigenetic modulation of plasticity of resistance/susceptibility in the snail-schistosome relationship.

molecular biology↗