#596 PO term for "rind" or outer layer of a maize or sorghum stem

[Laurel Cooper]

Question from Sunita Kumari by email:
Here is an image of monocot stem (corn stem). Sorghum will be like this. Here is link for image:

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/Stems.html

This paper provides more clarity. Looks like it is outer cover
of the stalk. Please see Figure 1b.

http://www.sciencedirect.com/science/article/pii/S2090447912000524

[Laurel Cooper]

Laurel Cooper wrote:
They are looking at the epidermis and also the fiber bundles that make up the rind
From the paper: http://www.sciencedirect.com/science/article/pii/S2090447912000524

"3.2. Microscopic investigation Microscopic picture of the cross-section, as seen in Fig. 6 (http://www.sciencedirect.com/science/article/pii/S2090447912000524#f0100)
reveals the microstructure of both, pith and rind, respectively. It can be observed that the pith consists of vascular bundles surrounded by weak tissue of large and thin-walled parenchyma cells, whereas the rind is found to be composed of compacted fibre bundles. By comparison it can also be observed, that the rind reveals higher density of fibre bundles compared to the pith. In fact, it is this higher fibre ratio that provides for higher tensile strength of the rind."

I would recommend: stem epidermis PO:0025178 along with plant fiber cell PO:0025407,

[Laurel Cooper]

From DWS by email:
Dws wrote:

Well, this is interesting. I do not know of any term for this. Rind of
course is interesting and probably appropriate but is also used at least
in the common vernacular for fruits in the squash family such as
watermelon rind, etc.

The area involved in the grasses would be the epidermis plus the outer
cortex. I would also point out that grasses botanically speaking do not
have a "pith". What we have is a continuum of change from the center to
the epidermis where the vascular bundles become more numerous and
parenchyma is reduced and sclerenchyma increased.

I think we can use rind here as the outer cortex in grasses. It would
also include the "woody" part of bamboo, the "rind" of maize and other
grasses. In fact, we could restrict it to grasses in the vegetative
stem.

Not sure how to handle it in fruits but it could be limited to
cucurbits.

[Laurel Cooper]

PJ wrote:

So we need some more terms I guess:

--stem cortex
---is_a--stem outer cortex (NEW)
------is_a--grass stem outer cortex (NEW)

--stem epidermis
---is_a grass stem epidermis (NEW)

--???
---is_a-grass stem rind
----part_of--grass stem outer cortex (NEW)
----part_of--grass stem epidermis (NEW)

I am deliberately suggesting the term prefix 'grass' to suggest the
specific instance that is found in grasses.

[Laurel Cooper]

LC:
I think the term you are requesting is the shoot axis hypodermis (PO:0005057): A portion of ground tissue that is the outermost layer of a portion of a shoot axis cortex.

I would strongly advise against naming anything "grass XYZ", as we worked hard to remove all the taxon-specifc names from the PO over the past few years. I also would hesitant to call it a "rind", since that is a synonym of pericarp, but could add it as a synonym.

[Pankaj Jaiswal]

Not necessarily. Hypodermis does not include epidermis.

My suggested outer cortex is actually hypodermis.

Sent from my Verizon Wireless 4G LTE Smartphone

[Dennis Stevenson]

By definition the hypodermis is the cell layer next to the epidermis, that is immediately interior (I should use the PO term but do not know how to get there from here)and that makes it also the outer layer of the cortex in stems. Because it is one cell layer (in rare instances it can be two), we need something to refer to the zone i these grasses. I talked to some people who specialize in grasses from systematists to rice molecular people and rind is not used in those communities. However, in a sense it seems appropriate. I am unsure what to do here. I agree with Laurel, no taxon adjectives should be used in the terms. Is it possible to have vegetative rind and fruit rind?

[Laurel Cooper]

Proposed new term:
shoot axis tegument layer (PO:0025609): A portion of plant tissue (PO:0009007) that forms a tough, protective outer layer on a shoot axis and includes as parts a shoot axis hypodermis (PO:0005057) and a shoot axis epidermis (PO:0000112).

added exact synonym: shoot axis rind

[Laurel Cooper]

Proposed new term:
stem tegument layer (PO:0025611): A portion of shoot axis tegument layer (PO:0025609) that a tough, protective outer layer on a stem (PO:0009047) and includes as parts a stem hypodermis (PO:0025610) and a stem epidermis (PO:0025178).
OBO_SF2_PO: 596
- added exact synonym: stem rind

[Sunita]

Thanks everyone for the discussion on proposed new term for "stem rind".

Laurel, can you please update PO link at obofoundry with the new additions.

http://palea.cgrb.oregonstate.edu/viewsvn/Poc/tags/live/plant_ontology.obo?view=co

Thanks much.

Sunita

[Laurel Cooper]

That link is for the live version- the new terms are currently available on on development browser- http://dev.plantontology.org/

You can download that version at: http://palea.cgrb.oregonstate.edu/viewsvn/Poc/trunk/ontology/OBO_format/plant_ontology.obo

They won't be on the live version till the next release- probably in a few weeks, maybe by mid July.