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rhizoid #347

Closed planteome-user closed 9 years ago

planteome-user commented 13 years ago

Moss Ontology definition: Filamentous tissue protruding from the gametophore stem with a rooting function.

Rhizoids may also grow from thalli. They arise from an epidermal intial, and so are like trichomes. Like trichomes, they may be uni- or multicellular

'''Proposed def.:''' A trichome that is part of a plant in the gametophytic phase and has positive gravitropism.

Comment: Found in bryophytes and pteridopytes growing from the epidermis of a gametophore or thallus. May also arise directly from a rhizoid initial on a protonema. May be muticellular or unicellur. Usually serve to anchor the plant to the substrate.

develops_from rhizoid initial

Reported by: rlwalls2008

Original Ticket: obo/plant-ontology-po-term-requests/347

planteome-user commented 13 years ago

At the POC meeting on 5-3-11, there was a discussion of how different rhizoids develop, and whether or not they could be grouped together. If rhizoid is defined as a trichome, can't include protonemal rhizoids, because they don't develop from an epidermal initial. There are rhizoids on monocots (wurztelhalsrhizoid) that are not part of a gametophyte. Also need term for pegged rhizoids in liverworts.

We decided to make a new general class for rhizoids, a child of plant structure, that can include them all.

Original comment by: rlwalls2008

planteome-user commented 13 years ago

Made a new term rhizoid (PO:0030078) is_a plant structure. Proposed def.: A plant structure that is a uniseriate filament with positive geotropism and without chlorophyll that grows from an epidermis or protonema. Comment: Serves to anchor the plant to the substrate, and may function in nutrient and water uptake. Includes epidermal rhizoids that grow from the epidermis of bryophytes and pteridophytes in the gametophytic phase or from the stems of some monocots, and protonemal rhizoids that branch from a protonema.

Changed rhizoid (PO:0030071) to epidermal rhizoid Proposed def.: A rhizoid that develops from an epidermal rhizoid initial. Comment: Found in bryophytes and pteridophytes growing from the epidermis of a gametophore or the lower surface of a thallus and in some monocots growing from the stem at the cotyledonary node. May be considered a type of trichome. develops_from epidermal rhizoid initial

New term protonemal rhizoid (PO:0030079) Proposed def.: A rhizoid that develops from a protonemal side branch rhizoid initial. Comment: A protonemal rhizoid is a branch that arises from a protonema that grows into the substrate and lacks chlorophyll. is_a rhizoid, develops_from protonemal side branch rhizoid initial

See separate tracker for rhizoid initials (https://sourceforge.net/tracker/index.php?func=detail&aid=3293302&group\_id=76834&atid=835555)

Original comment by: rlwalls2008

planteome-user commented 13 years ago

Rhizoid (PO:0030078), epidermal rhizoid (PO:0030071), and protonemal rhizoid (PO:0030079) were accepted at the POC meeting on 5-6-11.

For definition of rhizoid, moved phrase about not having chlorophyll to the comment.

Also added new term cotyledonary node rhizoid (PO:0025320): An epidermal rhizoid that grows form a cotyldonary node. Synonym: wurtzelhalsrhizoid

Later, we should add term for pegged rhizoid (in liverworts).

Closing this item

Original comment by: rlwalls2008

planteome-user commented 13 years ago

Original comment by: rlwalls2008

planteome-user commented 13 years ago

Rhizoids can also develop directly from the early cells of a gametophore, before an epidermis has developed. Suggest we change definition and comment to include this possibility.

rhizoid (PO:0030078) is_a plant structure.

Proposed def.: A plant structure that is a uniseriate filament with positive geotropism and without chlorophyll that grows from a plant structure such as an epidermis or protonema.

Comment: Serves to anchor the plant to the substrate, and may function in nutrient and water uptake. Includes epidermal rhizoids that grow from the epidermis of bryophytes and pteridophytes in the gametophytic phase or from the stems of some monocots, protonemal rhizoids that branch from a protonema, as well as rhizoids that develop from a basal cell of a gametophore bud.

Original comment by: rlwalls2008

planteome-user commented 13 years ago

Original comment by: rlwalls2008

planteome-user commented 13 years ago

Original comment by: rlwalls2008