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Biology subjects

Persson, D. P.

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

3 recordsLinked to original sources

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↗

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↗

Endodermal suberin deposition restricts potassium leakage from roots

O_LIThe endodermis is a checkpoint for ions and water escaping or entering the root. It has been hypothesized that suberin acts as a physical barrier preventing potassium (K) leakage from the stele during translocation, but attempts to support this idea has yielded contradictory results. C_LIO_LIWe developed a Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) based element bioimaging method to study K leakage from roots with different suberin deposition, where we show that cesium (Cs) is an excellent tracer for K. C_LIO_LIElement bioimaging of roots and total shoot concentrations from various Arabidopsis thaliana mutants all showed a positive relationship between suberin deposition and K translocation efficiency. In addition, images from the fully suberized barley (Hordeum vulgare) seminal roots revealed a strongly reduced K leakage compared to less suberized root zones. C_LIO_LINodal roots form a scattered deposition of suberin towards the phloem in the mature root zone. This incomplete suberin deposition also restrict K leakage efficiently. C_LIO_LICollectively, our findings provide experimental evidence that suberin act as a barrier for K leakage upon root-to-shoot translocation by restricting K movement over the endodermis from the stele to cortex. C_LI

plant biology↗