Biology subjects

Mantz, M.

Publications and source records attributed to Mantz, M..

3 recordsLinked to original sources

bioRxiv2023

Repression of pattern-triggered immune responses by hypoxia

Biotic and abiotic stresses frequently co-occur in nature, yet, relatively little is known about how plants co-ordinate the response to combined stresses. Previous research has shown that protein degradation by the ubiquitin/proteasome system is central to the regulation of multiple independent stress response pathways in plants. The Arg/N-degron pathway is a subset of the ubiquitin/proteasome system that targets proteins based on their N-termini and has been specifically implicated in the responses to biotic and abiotic stresses, including hypoxia via accumulation of ERF-VII transcription factors, which orchestrate the onset of the hypoxia response program. Here, we investigated the role of the Arg/N-degron pathway in mediating the crosstalk between coinciding abiotic and biotic stresses using hypoxia treatments and the flg22 elicitor of pattern-triggered immunity (PTI), respectively. We uncovered a link between the transcriptional responses of plants to hypoxia and flg22. Combined hypoxia/flg22 treatments showed that hypoxia represses the flg22 transcriptional program, as well as the expression of pattern recognition receptors, MAPK signalling and callose deposition during PTI, through mechanisms that are mostly independent from the ERF-VIIs. These findings aid understanding of the trade-offs between plant responses to combined abiotic/biotic stresses in the context of our efforts to increase crop resilience to global climate change. Our results also show that the well-known repressive effect of hypoxia on innate immunity in animals also applies to plants. Significance statementUnderstanding how plants regulate the crosstalk between stress response pathways is key to our efforts to increase crop resilience and mitigate yield losses caused by global climate change. Despite the urgency to do so, relatively little is known about how plants respond to combined stresses, which frequently occur in nature. Here, we show that the hypoxia response program and the basal layer of plant immunity (pattern-triggered immunity or PTI) share components. Our data also show that hypoxia represses several key aspects of PTI, a situation akin to that discovered in animals decades ago. These findings have implications for our ability to develop resilient crops by limiting the negative trade-offs that exist between hypoxia response and immunity.

plant biology↗

bioRxiv2022

Combination of transcriptomic, proteomic and degradomic profiling reveals common and distinct patterns of pathogen-induced cell death in maize

Regulated cell death (RCD) is crucial for plant development, as well as in decision-making in plant-microbe interactions. Previous studies revealed components of the molecular network controlling RCD, including different proteases. However, the identity, the proteolytic network as well as molecular components involved in the initiation and execution of distinct plant RCD processes, still remain largely elusive. In this study, we analyzed the transcriptome, proteome and N-terminome of Z. mays leaves treated with the Xanthomonas effector avrRxo1, the mycotoxin Fumonisin B1 (FB1), or the phytohormone salicylic acid (SA) to dissect plant cellular processes related to cell death and plant immunity. We found highly distinct and time-dependent biological processes being activated on transcriptional and proteome levels in response to avrRxo1, FB1 and SA. A correlation analysis of the transcriptome and proteome identified general, as well as trigger-specific markers for cell death in Z. mays. We found that proteases, particularly papain-like cysteine proteases, are specifically regulated during RCD. Collectivley, this study characterizes distinct RCD responses in Z. mays and provides a framework for the mechanistic exploration of components involved in the initiation and execution of cell death.

plant biology↗

bioRxiv2022

A phloem-localized Arabidopsis metacaspase (AtMC3) improves drought tolerance

Increasing drought phenomena pose a serious threat to agricultural productivity. Although plants have multiple ways to respond to the complexity of drought stress, the underlying mechanisms of stress sensing and signalling remain unclear. The role of the vasculature, in particular the phloem, in facilitating inter-organ communication is critical. Here, we investigated the role of AtMC3, a phloem-specific member of the metacaspase family, in osmotic stress responses in Arabidopsis thaliana. Overexpression of AtMC3 conferred drought tolerance by enhancing the differentiation of the metaphloem sieve elements and maintaining higher levels of vascular-mediated transportation, whilst plants lacking the protein showed an impaired response to drought and inability to respond effectively to the hormone abscisic acid. Analyses of the proteome in plants with altered AtMC3 levels revealed differential abundance of proteins related to osmotic stress. Overall, our data highlight the importance of AtMC3 and vascular plasticity in fine-tuning early drought responses at the whole plant level without affecting growth or yield.

plant biology↗