Biology subjects

Burow, M.

Publications and source records attributed to Burow, M..

9 recordsLinked to original sources

bioRxiv2026

Transport-driven spatial patterning of glucosinolates structures root microbiome assembly

Plant roots actively assemble distinct microbial communities, yet how host chemical traits are organized to structure them remains poorly understood. Glucosinolates are hallmark defense metabolites of Brassicaceae, but their axial distribution in roots and ecological relevance belowground remain largely unknown. Here, we combine spatial metabolite profiling and microbiome analysis in Arabidopsis thaliana and the oilseed crop Camelina sativa using mutants lacking the glucosinolate transporters GTR1 and GTR2. We find that both species exhibit a conserved, transporter-dependent enrichment of long-chained aliphatic glucosinolates at the root tip, revealing active axial organization of chemical defenses in roots. Using 16S rRNA amplicon-based sequencing, we show that plant species identity is the primary determinant of bacterial community composition. However, disruption of axial glucosinolate distribution significantly alters spatial patterns of microbiome assembly along the root in a species-dependent manner. In Arabidopsis, this assembly effect is most pronounced in the rhizosphere, whereas in Camelina, root-associated communities were also affected. Together, our findings demonstrate that glucosinolate transport establishes chemical landscapes along the root axis, thereby shaping spatial patterns of microbiome assembly. This identifies spatially structured specialized metabolite allocation as an important mechanism by which plants shape their belowground microbial environment.

plant biology↗

bioRxiv2025

Antagonistic and Synergistic Roles of Tomato AFP3 Isoforms in Hormonal Regulation and Development

The ABA INSENSITIVE5 BINDING PROTEIN (AFP) family plays a critical role in abscisic acid (ABA) signaling through interaction with the transcription factor ABI5, impacting seed germination and stress responses. Here, we characterize tomato AFP3, which produces two isoforms: a full-length protein and a shorter microProtein (sAFP3) containing only the C-terminal domain. Functional analyses reveal contrasting roles of these isoforms in development; while AFP3 overexpression accelerates shoot growth but impairs seed germination, both afp3 loss-of-function and sAFP3-expressing mutants (afp3-D) exhibit stunted growth and developmental defects. Transcriptome profiling highlights that AFP3 and sAFP3 differentially regulate hormone-related pathways, including salicylic acid, gibberellic acid, and jasmonic acid metabolism. Proteomic interaction studies demonstrate that AFP3 and sAFP3 physically interact, sharing partners involved in hormone signaling. Hormone quantification confirms that AFP3 modulates multiple phytohormones, with elevated ABA in afp3-D mutants and increased gibberellic acid, jasmonic acid, and salicylic acid in both afp3 and afp3-D mutant backgrounds. Moreover, AFP3 controls flower and fruit development, influencing yield and ripening. Together, these findings identify AFP3 as a key integrator of hormonal crosstalk that coordinates growth, development, and stress responses in tomato. The production of dual AFP3 isoforms through alternative transcription, combined with microProtein-mediated dominant-negative regulation, reveals a sophisticated mechanism for dynamically fine-tuning transcriptional networks. This versatile strategy underscores how plants--and potentially other organisms--achieve precise control over complex signaling pathways.

plant biology↗

bioRxiv2025

FMO and CYP monooxygenase families determine the metabolic flux of hydroxylated tryptamine derivatives in barley (Hordum vulgare) following pathogen infection

To counteract pathogenic microorganisms, plants execute a complex resistance response that includes major metabolic reprogramming and production of bioactive defensive compounds. Barley (Hordeum vulgare) is a major cereal crop, but suffers significant yield losses due to pathogen attack every year. Here we use an untargeted metabolomic approach to assess the diversity and shifts in key barley metabolites produced in response to Pyrenophora teres f. teres infection, a hemibiotrophic fungal pathogen and causal agent of net blotch disease. Tryptophan-derived compounds, including tryptamine, serotonin, and a novel indole alkaloid - 2-oxo-tryptamine (2OT) - were among the most significantly induced and abundant compounds, with mass spectrometry imaging revealing that these metabolites accumulate at the site of infection. A transcriptomic approach identified a flavin-containing monooxygenase (FMO), which was functionally characterized as a 2-oxo-tryptamine synthase (2OTS). In addition, a cytochrome P450 (CYP71P10) was characterized as a tryptamine-5-hydroxylase, responsible for serotonin biosynthesis. These characterized genes are tightly co-expressed with genes involved in tryptophan biosynthesis and signify a major metabolic flux towards indolic compounds after infection, potentially serving as bioactive phytoalexins. Additional microbial interactions using a biotrophic fungus (Blumeria hordei; powdery mildew), a hemibiotrophic bacterium (Pseudomonas syringae), and alternative cultivars suggest that these pathways represent a generally activated resistance response in barley. These results provide new insights within the barley defense response relevant for the development of disease resistant traits in cereal crops.

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

Ca2+/Calmodulin Dependent Protein Kinase Kinase-2 (CaMKK2) promotes Protein Kinase G (PKG)-dependent actin cytoskeletal assembly to increase tumor metastasis

Triple-negative breast cancers (TNBCs) tend to become highly invasive early during cancer development. Despite some successes in the initial treatment of patients diagnosed with early-stage localized TNBC, the rate of metastatic recurrence remains high with poor long-term survival outcomes. Here we show that elevated expression of the serine/threonine-kinase, Calcium/Calmodulin (CaM)-dependent protein kinase kinase-2 (CaMKK2), is highly correlated with tumor invasiveness. We determined that genetic disruption of CaMKK2 expression, or inhibition of its activity, disrupted spontaneous metastatic outgrowth from primary tumors in murine xenograft models of TNBC. High-grade serous ovarian cancer (HGSOC), a high-risk, poor-prognosis ovarian cancer subtype, shares many genetic features with TNBC, and importantly, CaMKK2 inhibition effectively blocked metastatic progression in a validated xenograft model of this disease. Probing the mechanistic links between CaMKK2 and metastasis we defined the elements of a new signaling pathway that impacts actin cytoskeletal dynamics in a manner which increases cell migration/invasion and metastasis. Notably, CaMKK2 increases the expression of the phosphodiesterase PDE1A which decreases the cGMP-dependent activity of protein kinase G1 (PKG1). This inhibition of PKG1 results in decreased phosphorylation of Vasodilator-Stimulated Phosphoprotein (VASP), which in its hypophosphorylated state binds to and regulates F-actin assembly to facilitate contraction/cell movement. Together, these data establish a targetable CaMKK2-PDE1A-PKG1-VASP signaling pathway that controls cancer cell motility and metastasis. Further, it credentials CaMKK2 as a therapeutic target that can be exploited in the discovery of agents for use in the neoadjuvant/adjuvant setting to restrict tumor invasiveness in patients diagnosed with early-stage TNBC or localized HGSOC.

cancer biology↗

bioRxiv2022

Glucosinolate catabolism maintains glucosinolate profiles and transport in sulfur-starved Arabidopsis

Glucosinolates (GSL) are sulfur (S)-rich specialized metabolites produced by plants of the Brassicales order. Our previous study found that in Arabidopsis seedlings, S deficiency (-S) promoted GSL catabolism by activating two {beta}-glucosidases (BGLU), BGLU28 and BGLU30. The induced GSL catabolism was a survival strategy for seedlings grown under -S, because S released from GSL was reincorporated into primary S metabolites which are essential for plant growth. However, as GSL profile in plants vary among growth stages and organs, we set out to test a potential contribution of BGLU28/30-dependent GSL catabolism at the reproductive growth stage. Thus, in this study, we assessed growth, metabolic, and transcriptional phenotypes of mature bglu28/30 double mutants grown under different S conditions. Our results showed that compared to wild-type plants grown under -S, mature bglu28/30 mutants displayed impaired growth and accumulated increased levels of GSL in their mature seeds, siliques, flowers, and rosette leaves of before bolting plants. In contrast, the levels of primary S-containing metabolites, glutathione and cysteine, were decreased in mature seeds. Furthermore, the transport of GSL from rosette leaves to the reproductive organs was stimulated in the bglu28/30 mutants under -S. Transcriptome analysis revealed that genes related to other biological processes, such as phytohormone signaling and plant response to heat, responded differentially to -S in the bglu28/30 mutants. Altogether, these findings broadened our understanding of the roles of BGLU28/30-dependent GSL catabolism in plant adaptation to nutrient stress. One-sentence summaryDisruption of glucosinolate catabolic genes, BGLU28 and BGLU30, in sulfur-starved mature Arabidopsis impaired growth, affected glucosinolate distribution, and altered transcriptional profiles.

plant biology↗

bioRxiv2022

Heterologous expression of PtAAS1 reveals the metabolic potential of the common plant metabolite phenylacetaldehyde for auxin synthesis in planta

Aromatic aldehydes and amines are common plant metabolites involved in several specialized metabolite biosynthesis pathways. Recently, we showed that the aromatic aldehyde synthase PtAAS1 and the aromatic amino acid decarboxylase PtAADC1 contribute to the herbivory-induced formation of volatile 2-phenylethanol and its glucoside 2-phenylethyl-{beta}-D-glucopyranoside in Populus trichocarpa. To gain insights into alternative metabolic fates of phenylacetaldehyde and 2-phenylethylamine beyond alcohol and alcohol glucoside formation, we expressed PtAAS1 and PtAADC1 heterologously in Nicotiana benthamiana and analyzed plant extracts using untargeted LC-qTOF-MS analysis. While the metabolomes of PtAADC1-expressing plants did not significantly differ from those of control plants, expression of PtAAS1 resulted in the accumulation of phenylacetic acid (PAA) and PAA-amino acid conjugates, identified as PAA-aspartate and PAA-glutamate. Moreover, targeted LC-MS/MS analysis showed that PtAAS1-expressing plants accumulated significant amounts of free PAA. The measurement of PAA and PAA-Asp in undamaged and herbivory-damaged poplar leaves revealed significantly induced accumulation of PAA-Asp while levels of free PAA remained unaltered by herbivore treatment. Sequence comparisons and transcriptome analysis showed that members of a small gene family comprising five putative auxin-amido synthetase GH3 genes potentially involved in the conjugation of auxins like PAA with amino acids were significantly upregulated upon herbivory in P. trichocarpa leaves. Overall, our data indicates that phenylacetaldehyde generated by poplar PtAAS1 serves as a hub metabolite linking the biosynthesis of volatile, non-volatile herbivory-induced specialized metabolites, and phytohormones, suggesting that growth and defense are balanced on a metabolic level.

plant biology↗

bioRxiv2019

Growth under high light and elevated temperature affects metabolic responses and accumulation of health-promoting metabolites in kale varieties

Plants are highly sensitive to changes in the light environment and respond to alternating light conditions by coordinated adjustments in foliar gene expression and metabolism. Here we assessed how long-term growth under high irradiance and elevated temperature, a scenario increasingly associated with the climate change, affects foliar chemical composition of Brassicaceous plants. Transcript profiling of Arabidopsis suggested up-regulation of phenylpropanoid metabolism and down-regulation of processes related to biotic stress resistance and indole glucosinolates (GSL). These observations prompted metabolite profiling of purple (Black Magic) and pale green (Half Tall) varieties of kale, an economically important crop species. Long-term acclimation to high light and elevated temperature resulted in reduced levels of 4-methoxy-indol-3-yl-methyl GSL in both kale varieties. The total levels of aliphatic GSLs increased under these conditions, although the profiles of individual GSL structures showed cultivar-dependent differences. Black Magic became rich in 4-methylsulfinylbutyl GSL and 2-phenylethyl GSL, which have health-promoting effects in human diet. Additionally, the purple pigmentation of Black Magic became intensified due to increased accumulation anthocyanins, especially derivatives of cyanidin. These findings demonstrate that the potentially stressful combination of high light and elevated temperature can have beneficial effects on the accumulation of health-promoting metabolites in leafy vegetables.

plant biology↗

bioRxiv2017

An evolutionary young defense metabolite influences the root growth of plants via the ancient TOR signaling pathway

To optimize fitness a plant should monitor its metabolism to appropriately control growth and defense. Primary metabolism can be measured by the universally conserved TOR (Target of Rapamycin) pathway to balance growth and development with the available energy and nutrients. Recent work suggests that plants may measure defense metabolites to potentially provide a strategy ensuring fast reallocation of resources to coordinate plant growth and defense. There is little understanding of mechanisms enabling defense metabolite signaling. To identify mechanisms of defense metabolite signaling, we used glucosinolates, an important class of plant defense metabolites. We report novel signaling properties specific to one distinct glucosinolate, 3- hydroxypropyl glucosinolate across plants and fungi. This defense metabolite, or derived compounds, reversibly inhibits root growth and development. 3-hydroxypropyl glucosinolate signaling functions via genes in the ancient TOR pathway. Thus, plants might link evolutionarily new defense metabolites to ancient signaling pathways to optimize energy allocation.

plant biology↗