POC Conf. Call 2-22-11
POC meeting, Webex Conference Call; Date: Tuesday Feb 22th, 2011 10am (PST)
In attendance:
POC members:
Absent:
Collaborators:
Acceptance of the minutes from the POC_Conf._Call_2-15-11?
Restructuring descendants of leaf (PO:0025034)
-Some of the part_of children of vascular leaf can also be part of non-vascular leaf. This needs to be done before we can add terms for bryophytes.
-Need to double check the is_a children of leaf.
current is_a children of leaf
- prophyll (PO:0009042) is_a phyllome and scale leaf (PO:0006003) is_a phyllome (see prophyll and scale leaf).
Suggest making prophyll a child of vascular leaf.
Suggest making scale leaf is_a leaf (because the term could be used to refer to non-vascular leaves, even though it is usually used for vascular leaves.
We decided it was best to leave prophyll as a phyllome. It is the first leaf on a shoot system in vascular plants, but it may not be a true vascular leaf/may not have fully developed vascular system. Better to leave it with a more general parent since exact nature of organ is not known.
We decided to leave scale leaf as a phyllome too, because it is not clear whether it is a true leaf or a bract. Definition of scale leaf needs to be redone. Will post new definition on SF.
- non-vascular leaf - ok as is - Physco group has asked us to add phyllid as exact synonym. Can also add gametophyll.
- vascular leaf - ok as is - Suggest adding frond and needle as exact synonyms of vascular leaf
current part_of children of leaf
- leaf apex - ok as is - applies to both vascular and non-vascular leaf
- leaf base - ok as is - applies to both vascular and non-vascular leaf
- leaf epidermis - ok as is - The term may be used for non-vascular leaves, even though many are only one cell thick.
Need to consider if the definition of epidermis works bryophytes (see section below on Physco terms).
- leaf endodermis -- Is there ever an endodermis in non-vascular leaves? This should probably be part_of vascular leaf, not leaf.
current is_a children of vascular leaf
Is there heteroblasty in non-vascular leaves? do these terms apply?
- juvenile leaf
- transition leaf
- adult leaf
Physco group has included these terms in their ontology, but said they are not sure if they are necessary. Said there are differences among phyllids based on their position on the stem (more basal versus more terminal), but the terms juvenile and adult are not normaly used to describe them. If we want to use them for non-vascular leaves, we either need to make them children of leaf instead of vascular leaf, or add separate terms for vascular and non-vascular juvenile, transition and adult leaves.
Do we want to keep these (as phenotype terms)? At one point we discussed getting rid of them.
- simple leaf
- compound leaf
Terms that are probably okay as children of vascular leaf:
- cotyledon - ok
- leaf spine - ok
- cigar leaf - ok
- rosette leaf - probably ok as child of vascular leaf - Are there ever rosette's in gametophytes?
- cauline leaf - definition is a bit weird, actually applies to leaves that are part of an inflorescence (which we define as bracts)
Current def: Leaf or pairs/whorls of leaves borne on the stem. [source: TAIR:ki]. Comment: In Arabidopsis, refers to the leaves that are borne on the elongated inflorescence branches.
Suggest we flag this definition for later, but not deal with it for now, and leave it as is_a vascular leaf.
current part_of children of vascular leaf
Terms that are probably okay (only occur in vascular leaves):
- auricle - ok
- bundle sheath - ok
- leaf abscission zone - ok
- leaf collar - ok
- leaf vascular system - ok
- ligule - ok
- petiole - ok
- stipule - ok
- leaf intercalary meristem - probably ok - does it ever occur in non-vascular leaves? Normal growth in non-vascular leaves if from the tip.
- leaf sheath - probably ok - does it ever occur in non-vascular leaves?
(see part_of children of leaf)
Terms I'm not sure about:
- leaf aerenchyma- is there ever aerenchyma in non-vascular leaves?
- leaf mesophyll - should probably be part of leaf. Is there a mesophyll in non-vascular leaves?
Terms that are part of vascular leaf but should be part of leaf:
- leaf lamina - should be part_of leaf
- leaf margin - should be part_of leaf
- leaf base and leaf apex are already part of leaf (rather than vascular leaf)
Do we keep these terms for vascular leaf and rename them, move them to non-vascular leaf, or obsolete them and create new children of leaf?
New items for Physco
Shoot apical meristem/apical cell/phyllome
MO has requested the term apical cell.
We already have the term apical cell (PO:0004000), which is an embryonic cell: "An embryonic plant cell that is the uppermost cell formed after the first division of the zygote." Suggest renaming PO:0004000 "embryonic apical cell" for clarity. The embryonic apical cell can also be found in non-angiosperms.
Growth in mosses (and other bryophytes?) results from divisions of a single apical cell. Branches or leaves form from division and differentiation of sub-apical cells. Mosses do not have an apical meristem in the same sense as vascular plants.
If we define apical cell as is_a meristematic cell, we will have a problem. Even though apical cell is consistent with the definition of meristematic cell (synthesizing protoplasm and producing new cells by division and with only a primary cell wall), it is not consistent with the relation meristematic cell part_of meristem. A meristem is a portion of tissue and therefore two or more cells. We could solve this problem by changing meristematic cell part_of meristem to meristem has_part meristematic cell.
Proposed def. of apical cell: A meristematic cell at the apex of a gametophore or non-vascular leaf (phyllid).
Comment: Occurs in mosses and other bryophytes.
Apical cells also cause an issue with or definition of phyllome (PO:0006001): "A lateral plant organ produced by a shoot apical meristem." This definition is not strictly applicable to non-vascular leaves, which are phyllomes. Suggest we tweak the definition of phyllome to allow for this.
Proposed def. of phyllome: A plant organ produced by the lateral portion of a shoot apex.
Comment: In vascular plants, phyllomes arise from the shoot apical meristem. In non-vascular plants, phyllomes arise from division of a sub-apical cell (sometimes referred to as a leaf initial).
Whole plant structures
protonema - The filamentous stage of gametophyte development. Protonemal tissue is produced following spore germination or the regeneration of most tissues (whether gametophytic or sporophytic). In most moss species, protonemal filaments comprise two cell types, caulonema (q.v.) and chloronema (q.v.). Both types of filament extend by the serial division of their apical cells. Sub-apical cells may branch. (MO definition, from Celia Knight,Pierre-François Perroud,David Cove (2009): The moss Physcomitrella patens. The Annual Plant Review 36, Glossary)
Protonemata may develop from a spore or from a fragment of gametophytic tissue.
The Physco group classified protonema as whole plant, but could be considered a life-cycle phase (part of gametophytic phase). Need to decide how to handle it. After the leafy part of the gametophyte develops from the protonema, the protonema still persists, so there is some part of the life cycle in which the protonema is not the whole plant.
chloronema - The assimilitory filaments of the protonemal stage of gametophyte development. Compared to caulonmeal filaments, the cells of P. patens chloronemal filaments contain many well developed chloroplasts. The cross walls of adjacent cells in chloronemal filaments are perpenicular to the filament axis. (MO definition, from Celia Knight,Pierre-François Perroud,David Cove (2009): The moss Physcomitrella patens. The Annual Plant Review 36, Glossary)
caulonema - The adventitious filaments of the protonemal stage of gemtophyte development. Compared to chloronemal filaments, the cells of P. Patnes caulonemal filaments contain only fewer, less well developed chloroplasts. The cross walls of adjacent cells in caulonemal filaments are oblique to the filament axis. (MO definition, from Celia Knight,Pierre-François Perroud,David Cove (2009): The moss Physcomitrella patens. The Annual Plant Review 36, Glossary)
The MO classified chloronema and caulonema as is_a protonema, therefore is_a whole plant, but maybe they could be considered portions of tissue. They also have terms for chloronema cell and caulonema cell, but those are pretty straight-forward.
Proposed definition of chloronema:
Proposed definition of caulonema:
Collective plant structures
gametophore - The leafy moss plant. The gametophore is the adult form of the moss gametophyte and bearer of the sex organs (gametangia). Reski (1998): Development, genetics and molecular biology of mosses. Botanica Acta 111, 1-15. (definition supplied by MO)
Suggest is_a shoot system.
Proposed def.: A shoot system that consists of the shoot axes and non-vascular leaves of a plant in the gametophytic phase. participates_in gametophytic phase
Comment: A gametophore is the leafy part of a moss gametophyte, without the protonema.
bud - A structure produced by a caulonema and able to develop into a gametophore or a stem that includes an apical cell able to develop into a gametophore. The earliest recognizable stage of gametophore development. Bill and Nancy Malcolm (2006): Mosses and other Bryophytes, an illustrated glossary, second edition and altered by David Cove (definition supplied by MO)
Suggest a new term gametophore bud. This could be a child of bud (PO:0000055: An undeveloped shoot system).
Proposed def.: A bud on a protonema that develops into a gametophore. participates_in gametophytic phase
Comment: Occurs in mosses.
should we add develops_from protonema?
New items
Plant organs
cauloid - This is the term used for the gametophore stem or axis.
Suggest using gametophore axis as primary name, cauloid as synonym.
Proposed definition: A plant axis that is part of a gametophore. is_a plant axis, part_of gametophore, participates_in gametophytic phase
Synonyms: cauloid, gametophyte axis
Also suggest adding terms for gametophore stem and gametophore branch (similar to stem and branch).
perigonial bract - The specialized phyllids surrounding the antheridia. Bill and Nancy Malcolm (2006): Mosses and other Bryophytes, an illustrated glossary, second edition (MO definition)
A bract (PO:0009055) is defined as: A phyllome, usually different in form from the foliage leaves, subtending a reproductive structure. [source: POC:curators] Comment: Often used to refer to what is called here floral bract.
Proposed definition: A bract that subtends an antheridium. part_of gametophore, participates in gametophytic phase
Comment: When an antheridium occurs on a specialized lateral branch of the gametophore, all of the phyllomes on that branch are usually perigonial bracts. If an antheridium occurs on a main axis of the gametophore, usually only the terminal phyllomes are perigonial bracts.
perichaetal bract - MO did not request this term, but it is commonly used in mosses, so suggest adding it at the same time.
Proposed definition: A bract that subtends and archegonium. part_of gametophore, participates_in gametophytic phase.
Comment: When an archegonium occurs on a specialized lateral branch of the gametophore, all of the phyllomes on that branch are usually parichaetal bracts. If an archegonium occurs on a main axis of the gametophore, only the terminal phyllomes are usually parichaetal bracts. The two or three terminal-most perichaetal bracts may fuse to form a gametophytic perianth.
Suggest adding the term gametophytic perianth as well.
Proposed definition of gametophytic perianth: A collective phyllome structure that consists of two or more of the most distal parachaetal bracts that are fused laterally and surround the calyptra (or should it be surrounds the capsule, in case no calyptra is present). has_part parachaetal bract, part_of gametophore, participates_in gametophytic phase, disjoint from perianth (PO:0009058)
Comment: The gametophytic perianth is not the same structure as a perianth (PO:0009058) in angiosperms.
seta- The stalk of a moss sporophyte. Bill and Nancy Malcolm (2006): Mosses and other Bryophytes, an illustrated glossary, second edition (MO definition)
Suggested definition: A plant axis that is a stalk that hold up a spore capsule. participates_in sporophytic phase
Cardinal organ parts
Terms requested by MO:
calyptra
base
peristome
theca
lid
foot
neck canal
Other terms, not from MO
epiphram
spore capsule mouth
pseudopodium
venter
Plant Tissues
paraphyllium - Tiny filaments, scales or leaf-like structures scattered on the stems of some leafy bryophytes. Bill and Nancy Malcolm (2006): Mosses and other Bryophytes, an illustrated glossary, second edition (MO definition)
Crum defines them as "Small green outgrowths formed between the leaves on stems and branches of some pleurocarps (mosses that produce archegonia and sporophytes laterally, rather than on the tips of their axes) and a very few leafy liverworts."
Schofield describes paraphyllia as outgrowths of the epidermis, but he also describes leaves that way.
MO has this listed as a plant organ
Proposed definition: A phyllome/portion of plant tissue that is a small filamentous, scale-like, or leaf-like outgrowth from the epidermis between the leaves of a gametophore axis.
Comment: Paraphyllia are much smaller than leaves. Found in pleurocarpous mosses and a few leafy liverworts.
The paraphyllia are the small, dark structures between the leaves.
midrib
rhizoid
archesporium
amphithecium
endothecium
jacket layer
paraphysis
axilliary hair
tmema
Gametangium, antheridium, archegonium
Plant Cells
Terms requested by MO:
archesporial cell
apical cell
shoot apical cell
phyllid apical cell
alar cell
brachycyte
chloronema cell
caulonema cell
tmema cell
jacket layer cell
axillary hair terminal cell
axillary hair base cell
neck canal cell
side branch initial
Other terms, not requested by MO:
hyrdoid
leptoid
rhizoid initial
Upcoming meetings 2011:
- Phenotype Ontology RCN Summit
February 25-27, 2010 at the National Evolutionary Synthesis Center in Durham, NC,
Laurel and Pankaj will be attending.
From RW: -What is official PO strategy for dealing with phenotypes?
-Should it differ between description of mutant phenotypes and descriptions needed for systematic studies?
-Should PO develop a list of terms to be submitted to PATO (rather than our current piecemeal suggestions)?
-Possible case study: description of inflorescence types.
* ICBO 2011 Second International Conference on Biomedical Ontology
July 26-30, 2011
Buffalo, New York
CALL FOR WORKSHOP AND TUTORIAL PROPOSALS: The deadline for workshop and tutorial proposals for the ICBO conference has been extended to February 15th, 2011
- We decided we are too shorthanded to put together a PO workshop, but Melissa, Alan and Chris are organizing an anatomy ontology workshop.
- LC will attend and represent the PO. Invite other plant people?
-BS suggested we might want to submit a short paper which could be published in longer form later- see above
* International Botanical Congress (IBC2011)
July 23rd-30th 2011, Melbourne, Australia
Registration is open Important dates
Symposium proposal was accepted, 'Bio-Ontologies for the Plant Sciences' under the Genetics, Genomics and Bioinformatics theme.
Dennis, Alejandra, Pankaj and Ramona are planning to attend.
See IBC 2011 Bio-Ontologies Symposium wiki page for more details