Abaxial vs Adaxial

[planteome-user]

Hi,

I have a request regarding PO:0000049: leaf lamina abaxial epidermis and PO:0000050 leaf lamina adaxial epidermis.

Both of these terms have the same child terms: PO:0006504: lesf trichome, PO:0000332: pavement cell, PO:0002000 stomatal complex.

I was wondering whether these child terms can be split by adding the term abaxial or adaxial (e.g. abaxial stomatal complex, abaxial stomatal complex) to distinguish the child terms.

Your feedback is appreciated.

Thanks, Raymond DiDonato BIOBASE Corporation

Reported by: rdidonat

Original Ticket: "obo/plant-ontology-po-term-requests/32":https://sourceforge.net/p/obo/plant-ontology-po-term-requests/32

[planteome-user]

Logged In: YES user_id=561361 Originator: NO

We can add it but can you shed some light on how different is the gene expression in the plant structures that are listed as children terms if they are on the abaxial/adaxial side.

Original comment by: jaiswalp

[planteome-user]

Logged In: YES user_id=1903090 Originator: YES

Hi Pankaj,

Thanks for your response.

PMID:11908517 describes phenotypic characteristics of the abaxial and adaxial surfaces of the leaf sheath. In this case there are phenotypic effects on both sides, but the authors do distinguish abaxial and adaxial structures. I would also point out studies showing differential effects of GA or ABA on adaxial vs abaxial structures (PMID: 8756507,PMID: 9847117), suggesting an underlying, though perhaps subtle, difference in the sides. A maize paper, while not speaking to the level of detail of stomata and trichomes, does characterize a mutant showing defects specifically in abaxial fate (PMID:17612519), in this case in relation to macrohairs and smooth cell wall, suggesting that it might be useful to distinguish adaxial and abaxial structures.

So, I can't necessarily point to a paper that necessarily shows an expression difference between the two sides, but because the 11908517 discusses phenotypes of structures on both sides, we'd find the level of detail useful.

Thanks! Ray

Original comment by: rdidonat

[planteome-user]

PO group any suggestions?

Original comment by: jaiswalp

[planteome-user]

trichomes, pavement cells, and stomatal cells are generally quite different on the adaxial versus abaxial side of the leaf, suggesting that gene expression is different on the two sides.

I agree that adding specific children would be useful.

New structure: leaf trichome (PO:0006504) > abaxial leaf trichome: A leaf trichome that is part of a leaf abaxial epidermis (PO:0006019) > adaxial leaf trichome: A leaf trichome that is part of a leaf adaxial epidermis (PO:0006018)

pavement cell (PO:0000332) > abaxial pavement > adaxial pavement cell

stomatal complex (PO:0002000) > abaxial stomatal complex > adaxial stomatal complex

stomatal pore (PO:0008032) > abaxial stomatal pore > adaxial stomatal pore

Original comment by: rlwalls2008

[planteome-user]

Agree with Ramona (again). In this particular case we need to be specific. The terms Adaxial (upper) and abaxial (lower) epidermis are basically indicating that the adaxial surface is the one toward the axis while the opposite side (back, underside) is the abaxial surface and therefore away from the axis. There are leaves that can be amphistomatic (stomata are on both sides), while there are other (like Hakea, in the Proteaceae) that are cylindrical and therefore they show no adaxial or abaxial epidermis.

Original comment by: magandolfo

[planteome-user]

We will add terms for leaf ab/adaxial trichome, ab/adaxial pavement cell, and leaf ab/adaxial stomatal complex.

I am closing this item.

Original comment by: rlwalls2008

[planteome-user]

• status: open --> closed

Original comment by: rlwalls2008