Biology subjects

Kanstrup, C.

Publications and source records attributed to Kanstrup, C..

3 recordsLinked to original sources

bioRxiv2026

Water stress adaptive responses in plants require movement of ABA and AB-aldehyde from vascular to target tissues

Vascular plants rapidly coordinate root and shoot responses to water stress. Abscisic acid (ABA) mediates these adaptations; however, it remains unclear which cells produce ABA, whether ABA synthesis shifts during stress, and whether ABA movement is required for its adaptive functions. Here, we map ABA biosynthesis at cellular resolution in Arabidopsis and report that water-stress adaptive responses in roots and shoots require movement of ABA and its precursor AB-aldehyde from vascular tissues to target cells. We suggest that ABA accumulation arises from two parallel routes: (i) ABA synthesized in the vasculature via ABA2 and AAO3, then moving to guard cells, and (ii) phloem-derived AB-aldehyde being converted to ABA in the epidermis or bundle sheath by AAO1 and AAO2. Finally, we predict that tightly packed cells beneath leaf veins facilitate efficient ABA delivery to guard cells, an anatomical arrangement that has enabled angiosperms to evolve the use of ABA to rapidly close stomata.

plant biology↗

bioRxiv2023

Altered defense patterns upon retrotransposition highlights the potential for rapid adaptation by transposable elements

Transposable elements can be activated in response to environmental changes and lead to changes in DNA sequence. Their target sites of insertions have previously been thought to be random, but this theory has lately been contradicted. For instance, mobilization is favored towards genes involved in regulatory processes. This makes them interesting as potential players in rapid responses required under stressful environmental conditions. In this paper, we report the in-depth characterization of an Arabidopsis thaliana Col-0-based line whose altered DNA methylation pattern made it vulnerable for transposable element movement. We identified a transposable element retrotransposition into a transporter of glucosinolate defense compounds. As a consequence of this transposable element movement, the plants showed tissue-specific changes in glucosinolate profiles and levels accompanied by rewiring of glucosinolate- and defense-related transcriptional changes. As this single transposable element had strong impact on the plants resistance to insect herbivory, our findings highlight the potential for transposable elements to play a role in plant adaptation.

plant biology↗

bioRxiv2023

Mechanistic insight into substrate specificity of plant glucosinolate transporters

Plants depend on transport processes for correct allocation of specialized metabolites. This is important for optimal defense, avoidance of autotoxicity, connecting compartmented biosynthetic modules and more. Transport of a wide variety of specialized metabolites is mediated by transporters from the Nitrate and Peptide transporter Family (NPF), which belongs to the Major Facilitator Superfamily (MFS). However, the mechanism by which NPF members recognize and transport specialized metabolites remains unknown. Here we mutate eight residues to reciprocally swap the substrate-preference of two closely related glucosinolate transporters (GTRs). Seven of these residues assemble in a ring-like structure in all conformations of the transporters. We labeled the ring-like structure a selectivity filter and based on docking studies, we propose that the interaction between the selectivity filter and the glucosinolate side chain determines whether a given glucosinolate is recognized as a substrate. Besides partly explaining the distinct substrate preference of GTR1 (NPF2.10) and GTR3 (NPF2.9), this study proposes fundamental principles of substrate recognition in the NPF and establishes the GTR subclade as a novel model system for studying structure function relationships in the NPF.

molecular biology↗