George R. L. Greiff

27 July

Haplomitrium hookeri (Hooker's Flapwort) growing on the edge of the afon Wysg 19.7.26 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @bbsbryology.bsky.social

George R. L. Greiff reposted

27 July

Marchantia polymorpha subsp.Polymorpha (star-headed Liverwort) growing on the edge of the afon wysyg 19.7.26 ,love that broad conspicuous black midrib 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @bbsbryology.bsky.social

Happy to announce our study that has just been published from work done during my PhD at the University of Bristol working in Prof. Jill Harrison's lab. It's about WOX genes and sporophyte development in the model moss, Physcomitrium patens. Take a look 🧵👇

@jillharrison.bsky.social

For more info, do check out the link. Huge thanks to everyone involved, especially Jill for all the help and support, James Clark for his phylogenetic expertise, and Max Bethell for a manic lab grind to make the reporters. Thanks also to the SWBio DTP / BBSRC for funding my PhD at Uni of Bristol.13/

cell.comWOX neofunctionalization following an ancient duplication in mossesWOX genes are key regulators of Arabidopsis development and embryogenesis. Moss (Physcomitrium patens) WOX13LA/B genes promote embryonic growth, but PpWOX13LC was previously considered a pseudogene. G...

Link: www.cell.com/current-biol... /End

This fascinating phenotype is opposite to the Ppwox13lab phenotype of no sporophytes reported before. It suggests that -c opposes A/B to suppress the formation of more than one offspring per shoot. But why would moss want to do this? 11/

Plants bearing multiple sporophytes fail to support all offspring efficiently. Sporophytes on polysetous shoots take longer to mature and are smaller than those of monosetous shoots. It is better for the majority of mosses to put all their energy into a single sporophyte. 12/

However, when plants with very early embryos were examined after fertilisation, the embryos lacked expression while surrounding inactive eggs/zygotes stained strongly. Expression was therefore absent from the one egg of several that eventually becomes the single embryo/sporophyte of the moss... 9/

When we knocked out -C using CRISPR, all lines grew like WT and had similar shapes and numbers of gametangia. However, all 4 -c mutants had an increase in polysety - twin and triplet sporophytes originating from different fertilised eggs on the same plant apices! 10/

Checking recent moss expression browser datasets indicated that -C transcripts accumulate specifically in sexual reproductive organs and not in photosynthetic tissues. This cell-type specificity may be why it was not picked up previously. We validated this using RT-PCR in plants with gametangia.. 7/

Next, we further validated this by generating and examining promoter-reporter lines. Here, we visualised promoter activity in reproductive organs, particularly in eggs... 8/

We sampled 19 moss genomes and were surprised to find that PpWOX13LC belonged to a larger clade of similar truncated moss WOX genes present in all sampled genomes except for Sphagnum and Takakia. These genes are present in 99% of extant mosses, indicating that they may indeed be functional! 5/

We investigated predicted 3D protein structures of the two classes of genes and found that the DNA-binding homeodomains (HDs) of the -C genes were conserved and intact. All -C genes lacked 3-prime motifs but gained a small, postitive charged extension to the HD. This again suggested function... 6/

A previous study found that PpWOX13LA and -B, which are paralogues, are redundantly required for embryogenesis to occur in the moss reproductive cycle. Mutant zygotes do not or very rarely develop into sporophytes (Sakakibara et al. 2014)... 3/

The third gene, PpWOX13LC, was considered a pseudogene as it is truncated and was not detected in RT-PCR in several tissue types. This is where out study kicks off... 4/

@nathanprobably.bsky.social

The background: P. patens moss has 3 WOX genes, PpWOX13LA, -B and -C. They all belong to the so-called T1 clade that are present in all land plant genomes. T3 genes like the famous WUSCHEL gene, which is vital for maintaining the growing tips of flowering plants, are lacking in bryophytes... 2/

George R. L. Greiff reposted

Nathan Probably

1 June

Big congrats to the exceedingly fungal @ilichenmoss2.bsky.social for their BBC debut. Was really fun to work together on this and a real tribute to the excellent work that George does (and continues to do!) 🍄 www.youtube.com/watch?v=nRHz...

youtube.com'Killer fungus' destroying invasive plant in UK | BBC NewsYouTube video by BBC News

bbc.co.ukKiller fungus discovered that destroys UK invasive plantA newly discovered species raises hope that some native British habitats could be restored.

31 May

Thank Astrid! Great to see the small stuff get some time in the spotlight and hopefully we can continue to learn more about the fungus, its host range and its ecological impact.

Dr Astrid Biddle@astridbiddle.bsky.social

@ilichenmoss2.bsky.social George Greiff in the BBC News headlines on Sunday morning. A fantastic discovery, and hopefully a way to moderate invasive (INNS) Campylopus introflexus (Heath Star Moss). Well deserved recognition for some very interesting bryological work. 🎉🙌 www.bbc.co.uk/news/article...

blog.stephenturner.usFree and open-source images, icons, and tools for creating scientific illustrationsPhylopic, NIH Bioart, Bioicons, Scidraw, Open Science Art, Health Icons, Servier Medical Art, Biodiversity Heritage Library, the Noun Project, Segment Anything, Excalidraw, draw.io, Biographics

31 May

*Thanks. Gosh, didn't see that slip-up for a while!

George R. L. Greiff reposted

Plant Science Spotlight

@plant-sci.bsky.social

5 May

Don’t reach for ChatGPT Images or Nano Banana as your first option when creating scientific images There are multiple free and open-source images, icons, and tools for creating scientific illustrations. #plantscience @stephenturner.us blog.stephenturner.us/p/free-open-...

George R. L. Greiff reposted

Jake Dalzell

@bitheolaidhe.bsky.social

6 May

I was very excited to find Pignut growing out of a cowpat today that had its undescribed Plasmopara. It's amazing what shows up in a quadrat! #FungiFriends #WildPlantDisease

George R. L. Greiff reposted

Johannes Merz

@mosssoup2.bsky.social

19 Apr

Sphaerocarpos cf europaeus, a strange looking liverwort growing on bare disturbed soil in extensively managed arable fields, endangered across Europe 🌿

10 Apr

One often sees microscopic fibres in moss samples, unfortunately.

UK Centre for Ecology & Hydrology (UKCEH)@ukceh.bsky.social

The first national-scale study of its kind, led by UKCEH, has found detectable microplastics in moss at 94% of UK rural sites surveyed. Lead author @richardkcross.bsky.social discusses the findings & importance of such surveys as production/use of plastics increases. 🔗 tinyurl.com/yc2acct4 🧪 1/

6 Apr

Nice to find good material of a tiny fungus, Bryobroma caudatum, on the liverwort Diplophyllum albicans yesterday. The fungus produces tiny fruitbodies up to only 75 microns diam. and spores with little tails. The distinctive mycelium forms a network over the host cell walls without killing them.

7 Apr

Some macro photos of infected shoots.

7 Apr

Habitat of vertical rock faces near waterfall. The fungus wasn't possible to see in the field - I only noticed some of the other, larger fungi on the plant.

George R. L. Greiff reposted

Marc Somssich

@somssich.bsky.social

@huguesrenault.bsky.social

#PlantScienceClassics #20: Kinetin & Cytokinins. In 1955 Carlos Miller, Folke Skoog & co-workers describe the first #Cytokinin and its role in promoting cell division and growth promotion. #Phytohormones #PlantScience #PlantDevelopment pubs.acs.org/doi/abs/10.1... pubs.acs.org/doi/abs/10.1...

George R. L. Greiff reposted

Hugues Renault

28 Mar

Ever wondered how the #cuticle, a hallmark of land plants, was established? In our latest study, we show that the CUTIN SYNTHASE enzyme family was a key driver of this evolutionary innovation. #plantscience ▶️ www.biorxiv.org/content/10.6... A thread 🧵 [1/8]

George R. L. Greiff reposted

Chris Thorogood

@christhorogood.bsky.social

28 Mar

We sequenced the genome of 'desert ginseng' (Cistanche deserticola) - a leafless parasitic plant that gave up photosynthesis - and found it lost huge chunks of its own genome…but started stealing genes from its host! Thanks to my collaborators Prof Huang + her talented team👏🏻 lnkd.in/evF5iU9G

George R. L. Greiff reposted

Moi Expósito-Alonso (MOILAB)

@mexpositoalonso.bsky.social

26 Mar

Our new experimental evolution study across 30+ locations using the plant Arabidopsis thaliana —— we direct "see" adaptation and extinction to different climates at the genetic as it happens! Read it in Science dx.doi.org/10.1126/scie... @ucberkeleyofficial.bsky.social @hhmi-science.bsky.social

George R. L. Greiff reposted

A return visit to the Llyn peninsula for a ten day mossing Sesh, Saturday was back at Mynydd Tir-y Cwmwd were last year i discovered a new site for the nationally Scarce liverwort Cephaloziella dentata (toothed Threadwort) here it is amongst Cladonia @bbsbryology.bsky.social

George R. L. Greiff reposted

Nice to find Riccia beyrichiana (Purple Crystalwort) on Saturday at Mynydd Tir-y Cwmwd,a new site for it on the Llyn Peninsula,a lovely chunky Riccia and in good amounts,nice @bbsbryology.bsky.social

George R. L. Greiff reposted

Entosthodon attenuatus (Thin Chord-moss) on wet peaty soil on Mynydd Tir-y Cwmwd on Saturday,nice to see fruiting nicely , lovely cherry-red Rhyzoids on this species,I didn't look at those as only this patch so left alone @bbsbryology.bsky.social

George R. L. Greiff reposted