POC Conf. Call 11-18-13

POC meeting, Skype Conference Call; Date: Tuesday Dec 3rd, 2013 10:30am PST/1:30pm EST

In attendance:

Absent:

Wrapping up the vascular leaf development stages:

vascular leaf differentiation stage (new PO:0025574)

• Revised def'n: vascular leaf differentiation stage (new PO:0025574): A vascular leaf development stage (PO:0025570) that begins with the formation of procambium (PO:0025275) and protoderm (PO:0006210) and ends with the formation and differentiation of the leaf epidermis (PO:0006016) and leaf vascular system (PO:0000036) and all the specialized cells of the vascular leaf.

Last week we discussed utilizing the meristem layers L1, L2, and L3 in the definition, but these are really part of the shoot apical meristem at an earlier stage. Are these layers also part of the leaf primordium???

vascular leaf expansion stage PO:0001052

old name and def'n: 2 leaf expansion stage (PO:0001052): Stage of leaf development which begins when cell differentiation and cell expansion occurs and finishes when the leaf reaches its full size.

Proposed revised name and def'n vascular leaf expansion stage (PO:0001052): A vascular leaf development stage (PO:0025570) during which vascular leaf size increases primarily through cell expansion.

Proposed comment: During this stage leaf shaping (GO:0010358) occurs which is defined as the developmental process that pertains to the organization of a leaf in three-dimensional space once the structure has initially formed.

• Note: The majority of cell division occurs early in leaf development and cell expansion is the major agent of leaf expansion link or see above image.

Refer to the GO term: cell growth GO:0016049: The process in which a cell irreversibly increases in size over time by accretion and biosynthetic production of matter similar to that already present. synonym: cell expansion.

Revised comment: During this stage, the process of cell growth (GO:0016049) occurs, defined as the process in which a cell irreversibly increases in size over time by accretion and biosynthetic production of matter similar to that already present. synonym: cell expansion.

Children of vascular leaf expansion stage:

See Leaf Development Stages gDoc

• rapid elongation of leaf sheath stage (PO:0001024): Stage of leaf development during which a rapid elongation of the leaf sheath occurs, as in Poaceae.

• rapid elongation of vascular leaf lamina stage (PO:0001023): A vascular leaf expansion stage (PO:0001052) during which a rapid elongation of the leaf lamina (PO:0020039) occurs.

These are stages of development of the parts of the leaf; currently is_a children of leaf expansion stage:

• formation of ligule primordium stage (PO:0001021): A vascular leaf expansion stage (PO:0001052) when conical P3 leaf completely encloses SAM, and the ligule (PO:0020105) primordium is visible.

• formation of vascular leaflet primordia stage (PO:0004500): A vascular leaf expansion stage (PO:0001052) at which a leaflet primordium (PO:0025481) is initiated on the leaf rachis (PO:0020055) of a compound leaf (PO:0020043).

• hood-shaped primordium stage (PO:0001020): Stage of leaf development when a hood-shaped primordium is formed, partially enclosing P1 and SAM, as in Poaceae.

vascular leaf post-expansion stage (PO:0001053):

old name and def'n: 3 leaf fully expanded stage (PO:0001053): Stage of leaf development when leaf is fully expanded.

Proposed new Name and def'n: vascular leaf post-expansion stage: A vascular leaf development stage (PO:0025570) that begins when the vascular leaf (PO:0009025) is fully expanded and ends with the onset of the vascular leaf senescence stage (PO:0001054).

from 9-10-13: Perhaps change term to "vascular leaf mature stage", or maybe keep the "leaf fully expanded stage"???. Examples of leaves with indeterminate growth, ferns, viney leaves, some Mahogany plants, but they are the exceptions. Could add as a comment (get names from DWS).

vascular leaf senescent stage (PO:0001054)

• vascular leaf senescent stage (PO:0001054): A vascular leaf development stage (PO:0025570) that begins with the formation of a abscission zone at the base of a vascular leaf (PO:0009025) and ends with leaf separation and death.

Would omit formation of a abscission zone. Perhaps say ends with death of vascular leaf. Need to add the references to the GO terms.

Need to look at this more- abscission zone (PO:0000146) starts in the petioles (are part of the leaf), starts with cell senescence, should refer to 'point of attachment'. Don't need to specify where the abscission zone forms. Note all leaves abscise, end with death of the vascular leaf

Need to review leaf senescence- see plant cell resource

Links to Relevant References- vascular leaf development

• • Genetic Control of Leaf Development- Plant Cell teaching tools
  • Uchida et al (2010) Coordination of leaf development via regulation of KNOX1 genes. Journal of Plant Research 123: 7–14
  • Comparative plant development: the time of the leaf? Tsiantis & Hay, 2003 Nature Reviews Genetics
  • Li, Brutnell et al (2010) The developmental dynamics of the maize leaf transcriptome. Nat Genet 42: 1060–1067
  • Leaf adaxial–abaxial polarity specification and lamina outgrowth: evolution and development, Plant and Cell Physiology, 2012
  • Gleissberg 2002
  • FERNS Barbara A. Ambrose: The evolution, morphology, and development of fern leaves, Vasco et al 2013
  • Independent recruitment of a conserved developmental mechanism during leaf evolution
  • Gonzalez et al, Trends in Plant Science 2012

Upcoming meetings and Presentations 2013-2014:

• PAG 2014 January 11-15, 2014 - San Diego, CA, USA

• • Registration is now open: PAG 2014.

The deadline for Early Pre-Registration was November 1, 2013. Poster abstract submission date is Nov. 12

Systems Biology and Ontologies Workshop

Link to: Googledoc

Confirmed speakers:

• Barbara Ambrose, NYBG
• Stefan Rensing, Marlburg Germany
• Trey Ideker, UCSD School of Medicine, San Diego, CA
• Jim Beynon, Warwick University, Coventry, United Kingdom
• Sushma Naithani, Oregon State University
• Laurel Cooper, Oregon State University