Biology subjects

Verbruggen, N.

Publications and source records attributed to Verbruggen, N..

5 recordsLinked to original sources

bioRxiv2025

Zinc deficiency induces spatially distinct responses in roots and impacts ZIP12-dependent zinc homeostasis in Arabidopsis

How zinc (Zn) deficiency shapes root development remains unclear, with conflicting reports on its effect on primary root growth in Arabidopsis thaliana (Arabidopsis). The impact of Zn shortage on the root apical meristem (RAM) in particular has not been systematically explored. Using an integrative approach combining cell biology, transcriptomics, and ionomics, we dissected how Zn deficiency alters root zonation and function. We showed that Zn deficiency triggers a striking reorganization of the root tip (RT): the RAM size is reduced, yet meristematic activity and local Zn levels are preserved. This is accompanied by promoted cell elongation and differentiation. Transcriptome profiling revealed a distinct Zn deficiency response in the RAM-enriched RT compared to mature root tissues, with ZIP12 emerging as the most strongly induced gene in the RT. Functional analysis of zip12 mutants uncovered major defects in root growth, RAM structure, expression of Zn-responsive genes, and metal partitioning. Our work unveiled a new layer of root developmental plasticity under Zn deficiency and identified ZIP12 as a central player in maintaining Zn homeostasis and root meristem function in Arabidopsis. These findings provide a framework to better understand how plants adapt root growth to fluctuating micronutrient availability.

plant biology↗

bioRxiv2024

Specific redox and iron homeostasis responses in the root tip of Arabidopsis upon zinc excess

O_LIZinc (Zn) excess negatively impacts primary root growth in Arabidopsis. Yet, the effects of Zn excess on specific growth processes in the root tip remain largely unexplored. C_LIO_LITranscriptomics, ionomics and metabolomics were used to examine the specific impact of Zn excess on the root tip (RT) compared to the remaining root (RR). C_LIO_LIZn excess exposure resulted in shortened root apical meristem and elongation zone, with differentiation initiating closer to the tip of the root. Zn accumulated at a lower concentration in the RT than in RR. This pattern was associated with lower expression of Zn homeostasis and Fe deficiency response genes. C_LIO_LIA distinct distribution of Zn and Fe in RT and RR was highlighted by Laser Ablation ICP-MS analysis. C_LIO_LISpecialized Trp-derived metabolism genes, typically associated with redox and biotic stress responses, were specifically up-regulated in the RT upon Zn excess, among those Phytoalexin Deficient 3 (PAD3) encoding the last enzyme of camalexin synthesis. In roots of wild-type seedlings, camalexin concentration increased by 6-fold upon Zn excess and a pad3 mutant displayed increased Zn sensitivity and an altered ionome. C_LIO_LIOur results indicate that distinct redox and iron homeostasis mechanisms are key elements of the response to Zn excess in the RT. C_LI

plant biology↗

bioRxiv2024

A multi-omics analysis of Arabidopsis thaliana root tips under Cd exposure: A role of HY5 in limiting accumulation

O_LICadmium (Cd) is a major environmental pollutant with high toxicity potential. Even though a reduction of growth, including the primary root, is a clear consequence of Cd exposure, a profound understanding of the impact of Cd on the root apical meristem (RAM) and the elongation/differentiation zone (EDZ) is still lacking. C_LIO_LIIn this study, Arabidopsis thaliana roots were subjected to Cd and divided into root tips (RT) and remaining roots (RR) to separately assess the effect of Cd using transcriptomics, ionomics and metabolomics. C_LIO_LIElemental profiling revealed lower Cd accumulation in RT and differences in mineral contents between RT and RR. Transcriptomic analysis demonstrated distinct gene expression patterns in RT and RR, with Cd having less impact in RT. Functional enrichment analysis revealed genes associated with iron and sulfur homeostasis as well as the response to light in both RR and RT. RT-specific responses to Cd included several genes regulated by the transcription factor ELONGATED HYPOCOTYL 5 (HY5) and notably, the hy5 mutant showed increased Cd sensitivity and accumulation compared to the wild type. C_LIO_LIThis study provides comprehensive insights into the inhibitory effects of Cd on primary root growth, elucidating molecular mechanisms involved, particularly highlighting the role of HY5 in Cd accumulation. C_LI

plant biology↗

bioRxiv2020

Magnesium maintains length of circadian period in Arabidopsis thaliana

The circadian clock coordinates the physiological response of a biological system to day and night rhythms through complex loops of transcriptional/ translational regulation. It can respond to external stimuli and adjust generated circadian oscillations accordingly to keep an endogenous period close to 24 h. To date, the interaction between nutritional status and circadian rhythms in plants is poorly understood. Magnesium (Mg) is essential for numerous biological processes in plants and its homeostasis is crucial to maintain optimal development and growth. Magnesium deficiency in young Arabidopsis thaliana seedlings increased the circadian period of pCCA1:LUC oscillations and dampened its amplitude in constant light in a dose-dependent manner. Although circadian period increase by Mg deficiency was light dependent, it did not depend on active photosynthesis. Mathematical modelling of the Mg input to the circadian clock reproduced the experimental increase of the circadian period and suggested that Mg is likely to affect global transcription/translation levels rather than a single component of the circadian oscillator. The model prediction was supported by a synergistic interaction between Mg deficiency and cyclohexamide, an inhibitor of translation. These findings suggest that proper Mg supply is required to support proper timekeeping in plants. One sentence summaryMagnesium maintains the circadian period in Arabidopsis seedlings and interferes with the circadian oscillator most likely through translational mechanisms.

molecular biology↗

bioRxiv2019

Evidence for the involvement of protein lysine methylation in the response of sensitive and tolerant Arabidopsis species to cadmium stress

The mechanisms underlying the response and adaptation of plants to excess of trace elements are not fully described. Here, we analyzed the importance of protein lysine methylation for plants to cope with cadmium. We analyzed the effect of cadmium on lysine-methylated proteins and protein lysine methyltransferases (KMTs) in two cadmium-sensitive species, Arabidopsis thaliana and A. lyrata, and in three populations of A. halleri with contrasting cadmium accumulation and tolerance traits. We showed that some proteins are differentially methylated at lysine residues in response to Cd and that a few genes coding KMTs is regulated by cadmium. Also, we showed that nine out of 23 A. thaliana mutants interrupted in KMT genes have a tolerance to cadmium that is significantly different from that of wild-type seedlings. We further characterized two of these mutants, one was knocked-out in the calmodulin lysine methyltransferase gene and displayed increased tolerance to cadmium, the other was interrupted in a KMT gene of unknown function and showed a decreased capacity to cope with cadmium. Together, our results showed that lysine methylation of non-histone proteins is impacted by cadmium and that several methylation events are important for modulating the response of Arabidopsis plants to cadmium stress.

plant biology↗