Lecture 16 - Plant Development Flashcards
What is Plant Development?
Making different parts of the plant
Where does plant development start?
From a zygote
Why is plant development important?
With growing population more crops for food are needed
How is is plant development different from animal development?
- Some embryogenesis
- Mostly Post-embryonic development
How is the development of lateral organs in plants?
It is continuous even after embryogenesis
What is in a phytomer? [3]
- Axillary bud
- Internode (stem)
- Leaf.
True or False? Continuous development of plants constantly produces phytomers
True
What two organs allow for continuous development for a plant? [2]
- Shoot apical meristem (SAM)
- Root apical meristem (RAM)
Which part of the shoot apical meristem do the leaves form?
The periphery
Why can’t plant cells move?
They have a very thick cell wall
What are the two orientations of cell division in a plant? [2]
- Anticlinal: At right angles to the surface
- Periclinal: Parallel to the surface
What controls the direction of elongation in leaves?
- Rotudifolia (Rot)
- Anguistofolia (An)
Hoes does Anguistofolia effect elongation?
Controls sideways elongation
How does Rotudifolia effect elongation?
Controls leaf axis elongation
What is embryogenesis?
The process by which the embryo forms and develops
What is in a plant embryo? [5]
- Cotyledons
- Shoot meristem
- Hypocytol
- Radicle (Root)
- Has polarity (apical/basal)
Why is embryogenesis important?
The embryo holds the body plan of the adult plant
What are the stages of embryo shape in a plant? [5]
- Globular
- Heart
- Torpedo
- Linear cotyledon
- Bending cotyledon
What is created after the 4th set of divisions?
The start of the epidermis lineage
In a 8-cell stage embryo of a plant, what does the upper 4 cells become?
- Cotyledons
- Stem apical meristem
In a 8-cell stage embryo of a plant, what does the lower 4 cells become?
- Hypocotyl
- Root
What are WUSCHEL like homeobox (WOX) genes?
Act like Hox genes in plant embryogenesis
What is the main task Wox genes perform?
They determine the cell division program in the cells
What can the loss of Wox8 and Wox9 cause?
Abnormal cell divisions in the embryo
What does ectopic Wox2 expression in the embryo and suspensor cause?
Anticlinal divisions
Where is ATML1 primarily expressed?
The L1 layer
What happens to a ATML1 mutant?
It is lethal since early division are defective
Where is CUC3 expressed?
In the upper half of embryo cells
What is the role of CUC3?
- Later turn on STM1 gene in the centre
- These centre cells become the SAM
What happens to STM1 mutants?
They can not make any SAM
What establishes the Cotyledon lineage?
- PHAB (adaxially)
- FIL, KAN (abaxially)
What are the key genes during the development of the root lineage? [3]
- PLT1
- SRT
- SCR
What happens to a LOF PLT mutant?
The roots do not grow
What during PLT2 over expression?
Forms an ectopic root on shoot
How can you create a shoot in the root?
Express Revoluta in the root area using a Plethora promoter
What is the role of Topless?
Give apical basal patterning to the embryo
What is the role of auxin?
To promote cotyledon and root development and growth
What is the role of leafycotyledon1 (LEC1)?
Important during Late embryogenesis
What happens to a LOF leafycotyledon1 (LEC1) mutant?
The cotyledons gain trichomes
What happens when LEC1 is overexpressed?
Embryos form everywhere
