George R. L. Greiff

@ilichenmoss2.bsky.social

661 Followers 650 Following

Research Associate in the Carella Group at the John Innes Centre. Interested in plant-microbe interactions, evo-devo and natural history. Microbotanist: bryology and bryo-mycology. Views his own.

Data showing that spore capsules from polysetous shoot apices are on average smaller in diameter than those from monosetous apices. This means that they produce significantly fewer spores in addition to having longer maturation times. A disadvantage for mosses.
A wild-type shoot with a single apical sporophyte (left) beside a Ppwox13lc mutant with three sporophytes on the same shoot (right).
A shoot apex of a PpWOX13LC promoter-reporter line containing several archegonia with eggs/zygotes following fertilisation, and a central archegonium containing a very young embryo. As this is WT, only one embryo/sporophyte normally forms per apex. The embryo lacks -C promoter activity while the adjacent archegonia with inactive eggs/zygotes strongly stain. This suggests that -C may have a role in sporophyte activation similar to its full-length counterparts, PpWOX13LA/-B.
Archegonia (egg-producing) and antheridia (spermatozoid-producing) gametangia have C promoter activity in the gametes during development. In archegonia, activity is switched off when the egg is mature.
Motifs and 3D protein structures of PpWOX13LA and -C
Cladogram showing that WOX13LC proteins arose long ago in moss evolution and were retained in most mosses. Interestingly, Sphagnum mosses have independently evolved truncated WOX genes in two clades - they are not C-like and we have no idea what they do.
A wild-type shoot with a single apical sporophyte (left) beside a Ppwox13lc mutant with three sporophytes on the same shoot (right).
A figure panel showing a small waterfall on the left and two macro shots of infected Diplophyllum albicans on the right. No fungi are visible in the latter.
Some detached shoots of Diplophyllum albicans infected by Bryobroma caudatum. There are tiny black fruitbodies and zig-zagging hyphae of the fungus on lower leaves of the plant.
Two shoots of the liverwort, Diplophyllum albicans, under the compound microscope at around x100 total magnification. They have dark reddish-brown stems and green leaves. There are small, black spots on some of the leaves along with tiny open networks of brown, anastomosing hyphae.
Micrograph of liverwort cells, some of which are infected with brown fungal hyphae while others are healthy and contain plastids and oil bodies.
A rhizoidal gall on Bryum sp. from mud in a reservoir draw-down zone. It is club-shaped and curved, containing five chytrid zoosporangia inside it, which are spherical. Some of the zoosporangia have thread-like exit tubes leading to the outside, which liberate zoospores that infect other cells.
A single shoot of Scapania undulata photographed against a white background. The apex is green while the brown lower parts display infection (arrowed). Bryobroma scapaniae presents as clustered black ascomata and infected tissues are covered by a dense, dark brown mycelium network.
The book, "The Structure and Life of Bryophytes" by E. V. Watson. It has a green and white cover with line drawings of bryophytes on it.
Strava map of run route along cycle track with mossy bridge indicated by arrow.
A mat-like, dark green plant with lighter, horn-like structures projecting from it.
A tiny, brown-stalked, orange cup fungus on the tip of a leafy liverwort plant.
Light brown-orange cup fungus on straw-coloured moss shoot.
Two fruitbodies of B. cuneifera emerging from the space between the leaf lamellae.
A patch of bright green moss with a central brown part.
Blue disc fungus on liverwort.
Orange perithecium sitting under leaf of liverwort shown from below, with neck oriented towards the dorsal side of the plant.
Black spots on yellowish moss shoot.
New growth of ivy covering mosses on a wall. At least 6 moss species here are threatened with being out-competed.
Small apical fragments of green Marchantia polymorpha plants growing on soil in a plastic punnet container.