plant spore

[planteome-user]

proposed def'n: A reproductive cell, usually unicellular, capable of developing into an adult without fusion with another cell. (Raven, Evert, Eichorn, 4th Ed)

comments: the product of meiosis, is_a plant cell, parent of megaspore, microspore, develops into the gametophyte

Reported by: cooperl09

Original Ticket: obo/plant-ontology-po-term-requests/74

[planteome-user]

• priority: 7 --> 8

Original comment by: rlwalls2008

[planteome-user]

How about: A plant cell that arrises through meiosis and develops into the gametophyte.

Original comment by: rlwalls2008

[planteome-user]

Look at the APweb glossary maintained by Peter Stevens at MBOT. Dennis knows him and actually Peter was a senior person on the previous round. Many of the current defs come from this glossary. http://www.mobot.org/mobot/research/apweb/top/glossaryq\_z.html From APweb glossary. spore: a haploid reproductive structure produced after meiosis marking the end of the sporophytic phase of the life cycle, germinating to produce the gametophyte, see megaspore and microspore/pollen (kinds of spores) and endosporic and exosporic (development of spores).

Original comment by: jaiswalp

[planteome-user]

Haploid cannot be part of this definiion. Meiosis is essential. To include haploid just demonstartes ignorance of plant polyploidy, which is fundamental tio speciation in many groups. We have been through this before.

Original comment by: nobody

[planteome-user]

Haploid is used with reference to its set of chromosomes it carries compared to the sporophytic structure. This is not in reference to the actual ploidy.

Anonymous, may you please login.

Original comment by: jaiswalp

[planteome-user]

That is not true. haploid refers to 1n, diploid to 2n, triploid 3n, tetraploid 4n, etc. thus the product of meiosis of a tertraploid is 2n, ie diploid.

Original comment by: dws409

[planteome-user]

See the definition that Lol and I proposed below, which does not include haploid, but meiosis. We tried to parallel the gametophyte definition. Also, we emphasized that the spore is the beginning of the gametophytic phase, rather than the end of the sporophytic phase as in the APweb definition.

Original comment by: rlwalls2008

[planteome-user]

Final def'n: A plant cell that arises through meiosis and develops into a gametophyte. (POC Curators)

Original comment by: cooperl09

[planteome-user]

Discussed at POC conference call 4-1-10: Final def'n: A plant cell that arises through meiosis and develops into a gametophyte Item is accepted and closed

Original comment by: cooperl09

[planteome-user]

• priority: 8 --> 1
• status: open --> closed-accepted

Original comment by: cooperl09

[planteome-user]

Re-opening this item.

I just suggested adding a term for plant spore development stage, is_a gametophyte stage. I would like to also suggest some changes to spore (PO:0025017).

Spore is_a cell, which is correct, but it is also a whole plant. Just as we changed the definition of plant zygote to reflect its dual nature (see https://sourceforge.net/tracker/?func=detail&aid=3459493&group\_id=76834&atid=835555), I suggest we change spore. Also suggest that we rename it plant spore, for consistency.

Current definition: A plant cell that arises through meiosis and develops into a gametophyte.

New proposed name and definition: plant spore (PO:0025017): A single-celled whole plant that arises through meiosis and develops into a multi-celluar gametophyte.

Need to check if gametophytes are always multicellular in green algae.

Original comment by: rlwalls2008

[planteome-user]

• priority: 1 --> 8
• status: closed-accepted --> open-later

Original comment by: rlwalls2008

[planteome-user]

At the POC meeting on 1-17-12, we revised our proposed definition, because spores can be multicelluar (they divide before they germinate).

Revised proposeddefinition: A whole plant that arises through meiosis and develops into a gametophyte. Comment: A spore is usually single-celled in homosporous forms but may be multicellular in heterosporous plants.

I am concerned that the definition is too vague. Perhaps we should add some more distinguishing characters, like that it has an exine. Could also add comment that in some plant, diploid (or polyploid) spores are produced by apospory.

Original comment by: rlwalls2008

[planteome-user]

Revised definition from POC meeting on 1-31-12: plant spore (PO:0025017): A whole plant that arises through meiosis and is contained in a spore wall. comment: A spore is usually single-celled in homosporous plants but may be multicellular in heterosporous plants. May have a spore wall (GO:0031160) made of sporopollenin.

We will keep this term as is. It was suggested that we add specific terms for uni- and multicellular spores if needed, since most spores are a single cell. This will lead to complicated multiple inheritance pathways.

Original comment by: rlwalls2008

[planteome-user]

• summary: spore --> plant spore
• priority: 8 --> 5
• assigned_to: cooperl09 --> rwalls

Original comment by: rlwalls2008

[planteome-user]

This was resolved earlier. Closing.

Original comment by: rlwalls2008

[planteome-user]

• priority: 5 --> 1
• status: open-later --> closed-fixed

Original comment by: rlwalls2008