Science Shared: October 3

This week a good section of the selection are from bioRxiv, so they're free to access. They're unreviewed, but I tend to assume of a lot of people are sharing a pre-print, there's something worth reading in it. As usual, papers behind a paywall are marked 💰 otherwise they're free to access at time of checking.

1. NO VEIN is an ancestral immunity protein involved in plant-virus interaction
Lågeide, E. et al. · bioRxiv · 2 posts · 83 likes · 48 reposts on Bluesky

Here we show that NO VEIN (NOV), a plant protein previously characterized for its essential developmental roles in Arabidopsis thaliana, shares domain composition and structural similarity with Tiamat, a bacterial antiphage protein.

2. Stepwise evolution of the developmental and symbiotic functions of DELLA in land plants
Melkonian, K. et al. · New Phytologist · 2 posts · 44 likes · 33 reposts on Bluesky

In flowering plants, DELLA (named after a conserved amino acid motif containing Aspartate (D), Glutamate (E), Leucine (L), Leucine (L), and Alanine (A)) proteins are GIBBERELLIN INSENSITIVE, REPRESSOR OF GA1-3, and SCARECROW (GRAS) transcription factors and play multiple functions mediated by the plant hormone gibberellin (GA).

3. Divergence in wilt tolerance across the range of Mimulus guttatus in the absence of stomatal regulation
Branch, H. A. et al. · bioRxiv · 4 posts · 56 likes · 18 reposts on Bluesky

Whether phenotypes and environments predict performance under stress is central to ecology and evolution and can reveal species' vulnerability to global change. We sampled Mimulus guttatus range-wide to test whether reproductive, morphological, and physiological traits predict drought responses. Surprisingly, we find that stomatal response, a key mediator of water balance, did not change as drought intensified.

4. Targeting of the barley cell-surface receptor SRF3 by the Blumeria hordei effector AVR_A13 overlaps with AVR_A13 recognition by MLA and the induction of NLR-mediated cell death.
Shi, W. et al. · bioRxiv · 1 post · 26 likes · 15 reposts on Bluesky

Pathogens secrete effector proteins to promote virulence. Despite their recognition by barley Mla resistance genes, the structurally-related Blumeria hordei ( Bh ) AVR a effectors are maintained in the Bh genome, suggesting virulence functions critical for fungal pathogenicity. Using proximity-dependent protein labelling in transgenic barley, we detected distinct host protein interactomes for five AVR A s despite their structural homology and convergence on MLAs. We report the specific interaction of the highly conserved AVR A13 effector with the barley cell-surface receptor SRF3. AVR A13 disrupts HvSRF3-HvBAK1 interaction and alters HvSRF3 plasma membrane levels.

Isabel saur @izzysaurlab.bsky.social · on Bluesky

Great to present a major update to our manuscript: www.biorxiv.org/content/10.6...
In collaboration with @grandpahiro.bsky.social,
@sara-stolze.bsky.social, Matthieu Platre & the teams of Götz Hensel & Gunther Döhlemann we demonstrate that….. (1/x)

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5. Linking genomic variation to floral trait adaptation across species boundaries
Acoca‐Pidolle, S., Wessinger, C. A., Hileman, L. C. · New Phytologist · 2 posts · 21 likes · 15 reposts on Bluesky

In this review, we take a quantitative genetic perspective and ask whether and how the genetic architecture of floral trait divergence depends on adaptation to specific pollination systems and how it informs on the dynamics of the assembly of floral traits during divergence. After reviewing results from studies mapping divergent floral traits in closely related species, we emphasise the value of combining trait mapping approaches with approaches that identify genomic variation differentiating species boundaries.

New Phytologist @newphyt.bsky.social · on Bluesky

Linking genomic variation to floral trait adaptation across species boundaries

#TansleyReview by Acoca-Pidolle et al. @carriewessi.bsky.social

nph.onlinelibrary.wiley.com/doi/10.1111/...

#plantscience

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6. Synthetic FLS2 receptor oligomer boosts plant innate immunity
Ma, Z. et al. · Science Advances · 1 post · 23 likes · 14 reposts on Bluesky

The gradual assembly and oligomerization of cell surface receptors are critical for regulating immune activation and turnover. Yet, how dynamic, spatiotemporally regulated assembly enables rapid and sustained signaling in plant innate immunity remains unclear, owing to the inherent complexity of their dynamic associations. Using a synthetic engineering approach, we precisely controlled the oligomerization states of the Arabidopsis FLS2 receptor.

7. Rice blast fungus hijacks a rice RALF peptide to initiate infection
Fukada, F. et al. · bioRxiv · 1 post · 22 likes · 13 reposts on Bluesky

Plant-derived peptides regulate immunity and host-microbe interactions, but whether fungal pathogens exploit endogenous plant peptides for infection-site selection remains largely unknown. Rapid alkalinization factors (RALFs) are a family of plant peptide hormones that contribute to plant development, reproduction, stress responses, and cell-wall organization. Here, we show that OsRALF7, which is an immune-activating peptide in rice ( Oryza sativa ), is co-opted by the rice blast fungus Magnaporthe oryzae as a host-derived cue for appressorium formation, specialized infection structures required for host penetration. While synthetic OsRALF7 peptide induced defense responses in rice suspension cells, the same peptide induced appressorium formation in M. oryzae.

8. Identifying, phasing, and structurally annotating sex chromosomes for genome assemblies using CBS-tools
Whitt, L. et al. · bioRxiv · 1 post · 20 likes · 12 reposts on Bluesky

A complete reference genome for species with chromosomally-determined separate sexes should contain scaffolds for all sex chromosome homologs. However, sex chromosomes present distinct computational challenges compared to autosomes. Here we present a k-mer based analysis that utilizes whole-genome sequencing of a few sex-identified isolates: Cytogenetics-By-Sequencing (CBS) tools. Unlike other approaches that typically address one aspect of the sex chromosomes, CBS-tools strives to guide users from the discovery of the heterogametic sex through identifying the sex-determination region (SDR).

9. Chromosomal breakage in Arabidopsis thaliana neo-polyploids occurs preferentially at candidate fragile sites colocalized with ancient genome rearrangements
Srikant, T. et al. · bioRxiv · 1 post · 22 likes · 9 reposts on Bluesky

Newly formed polyploids often suffer extensive aneuploidy and chromosome rearrangement. We explored whether these are predictable and conserved across genotypes. We quantified whole-chromosome and segmental aneuploidy in progeny arrays of neo-polyploid Arabidopsis thaliana from two accessions (Col-0 and L er ). 29% of progeny had whole-chromosome and/or segmental aneuploidies. Strikingly, segmental aneuploidy arose exclusively from L er , preferentially maternally, showing that genotype and sex of origin matter.

PlantEvolution 🌱🌾 @plantevolution.bsky.social · on Bluesky

Cool new work from @thanvisrikant.bsky.social & @kbomblies.bsky.social: Chromosomes in #Arabidopsis thaliana neo-polyploids break preferentially at fragile sites that correspond to ancient genome rearrangements
#plantscience
www.biorxiv.org/content/10.6...

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10. Maternal plant exposure to fire enhances offspring germination
Gegunde, J., Castellanos, M. C., Pausas, J. G. · Ecology · 1 post · 19 likes · 7 reposts on Bluesky

Plants that resprout after fire experience drastically altered conditions in post‐fire environments. However, the effects of plant exposure to fire on offspring traits remain understudied. Many resprouting species are herbaceous plants that flower and fruit rapidly after fire (i.e., fire‐stimulated flowering), developing their seeds under increased resource availability and modified biotic interactions, particularly enhanced pollination. We hypothesize that these changes may improve early offspring development through maternal provisioning and increased quality of floral visitation and pollen deposition. To test this, we selected three Mediterranean geophytes ( Asphodelus cerasifer , Drimia maritima , Narcissus assoanus ) and compared seed mass (3161 seeds) and total germination (2262 seeds) between paired burned and adjacent unburned plants during the first post‐fire fruiting season, sampling six populations over 4 years.

11. Engineering a TurboID‐based proximity labeling tool to track the dynamic secretomes under salt stress 💰
Lin, D. et al. · New Phytologist · 1 post · 19 likes · 7 reposts on Bluesky

Secretory proteins are essential for plant development and environmental adaptation, yet selectively profiling cargoes transported through the conventional endoplasmic reticulum (ER)–Golgi pathway remains technically challenging because apoplastic secretomes contain proteins from multiple secretion routes. We developed an ER‐anchored TurboID proximity labeling method to selectively enrich proteins entering the conventional secretory pathway in Arabidopsis thaliana.

12. A seed atlas of Hypoxis from eastern North America 💰
Zona, S. et al. · The Journal of the Torrey Botanical Society · 1 post · 27 likes · 4 reposts on Bluesky

The micromorphology of the seeds of six species of Hypoxis (Hypoxidaceae) from eastern North America (east of Texas) was studied with low vacuum, scanning electron microscopy using the backscatter detector. The shape of the cells of the seed coat and the configuration of the cuticle appeared characteristic for a particular species.

13. Petal to the metal: The slow road to automating large‐scale phenology labeling for herbarium specimens
Grady, E. L. et al. · Applications in Plant Sciences · 1 post · 19 likes · 6 reposts on Bluesky

Here, we present a machine learning pipeline that uses an ensemble modeling approach to detect flowers on herbarium specimens and deliver these data to the phenology research community. After testing multiple strategies for generating training data, we found that in‐house expert‐curated annotations were essential for producing reliable results.

14. Immature fruit abscission is triggered by hormonal changes in the seed coat of avocado
Haberman, A. et al. · Journal of Experimental Botany · 1 post · 7 likes · 7 reposts on Bluesky

Here, we show that fruitlets fated to abscise undergo growth arrest before shrinking and detaching from the tree. Comparative RNA-seq analysis indicated that growth arrest is associated with a transcriptome reprogramming that is first initiated in the seed coat and then transmitted to pericarp and embryo. Gene-expression and hormone-profiling results indicated that fruitlet growth arrest is associated with a decline in auxin activity and an increase in abscisic acid, the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid, and the bioactive jasmonate jasmonoyl-isoleucine in the seed coat.

15. High-resolution microscopy of whole plant cells reveals virus-induced changes to intercellular connectivity
Reagan, B. C. et al. · bioRxiv · 1 post · 15 likes · 4 reposts on Bluesky

Plasmodesmata (PD) provide plant viruses a direct route for cell-to-cell spread. Viral infection increases intercellular trafficking via PD, termed gating, but the mechanism involved remains unclear. Here, using a combination of high-resolution volume electron microscopy and live cell imaging, we demonstrate that diverse viruses increased the number of PD in infected leaves.

16. Differential ubiquitin modifications of ESCRT‐I subunits VPS37‐1 and VPS28‐2 positively regulate plant immunity
Wang, C. et al. · New Phytologist · 2 posts · 9 likes · 4 reposts on Bluesky

In this study, we demonstrate that XBAT35.2 interacts in vivo with two key ESCRT‐I complex components, VPS37‐1 and VPS28‐2. XBAT35.2 ubiquitinates VPS37‐1 with K48‐linked polyubiquitin chains, leading to its proteasomal degradation, and modifies VPS28‐2 with K63‐linked chains, reducing its interaction with FLS2.

17. From ice age to present: Clonal expansion and genetic variation in the world's oldest conifer stand 💰
Marthick, J. R. et al. · American Journal of Botany · 1 post · 6 likes · 6 reposts on Bluesky

Clonality is widespread among plants, yet the processes governing genetic diversity within the most ancient clones remains understudied. We investigated these dynamics using a reputed 10,500‐year‐old clonal stand of one of the world's longest‐lived tree species, the paleoendemic conifer Lagarostrobos franklinii at Mt Read in Western Tasmania.

18. Understanding and engineering receptor–ligand interactions
Doblas, V. G. et al. · The Plant Journal · 1 post · 9 likes · 5 reposts on Bluesky

In this special issue, a series of timely reviews highlights new and emerging themes in receptor–ligand interactions, as well as new depth regarding classical receptor pathways. By understanding molecular mechanisms of receptor function, the engineering of recognition and signaling networks becomes feasible.

19. Single-nucleus RNA sequencing reveals the developmental trajectory and transcriptional regulatory networks of trichomes in
Artemisia annua
Lv, Z. et al. · Journal of Experimental Botany · 1 post · 10 likes · 4 reposts on Bluesky

Sweet wormwood (Artemisia annua) produces and deposits artemisinin in its glandular trichomes but the molecular mechanisms of trichome development remain poorly understood. Here, we conduct single-nucleus RNA sequencing of 10-day-old A. annua seedlings, revealing the specific RNA expression of the leaf trichome cells.

20. Nitrate transiently rewires transcription in developing xylem of Populus wood to promote cell expansion via CRF4
Choudhary, S. et al. · The Plant Cell · 2 posts · 5 likes · 4 reposts on Bluesky

Nitrate functions both as a nutrient and a signaling molecule, but how nitrate is perceived and translated into developmental outputs within woody tissues is unknown. Here, we show that developing xylem in hybrid aspen (Populus tremula × P. tremuloides) mounts a rapid, cell-type-specific transcriptional response to nitrate that promotes xylem cell expansion.

Cover image: Clip art.