L18 Flashcards
whereas animal dev has embryogenesis, plant dev goes through what else
embryogenesis, and then also post embryonic development to become an adult plant (and then there is also continuous dev. after)
Shoot Modulesare_______
and they
Keep generating_______
phytomers
modules
Continuous plant development happens in the______
meristem
A shoot apical meristem from the top (fast dividing meristem cells (_______) in the center of the meristem and leaves are being generated in the________)
stem cells
periphery
Plant development is more flexible in response to the ___________
environmental cues
animal cells can_____, whereas plant cells cannot _____ bc of their
move
migrate
thick cell wall
__________ fibers which make the plant cell wall very rigid
cellulose and hemicellulose
two different cell division pattern_______
(anticlinal and periclinal cell division)
Epidermis cell have only _______ cell divisions while ground tissue has both ______ cell divisions.
anticlinal
anticlinal and periclinal
In wild-type Arabidopsis leaf, _______ and ________ control the elongation. _______ controls elongation along the leaf axis while_____ controls elongation to the perpendicular direction of the leaf axis.
ROTUNDIFOLIA (ROT) and ANGUISTOFOLIA (AN)
ROT
AN
Unique aspects of plant development
Post-embryonic development
Continuous development
Changeable according to environmental cues
Cells cannot move- Plant development depends on controlled cell divisions and directional elongation
what happens during embryogenesis of plants?
A series of “precise” and “predictable”
cell divisions and gene expressions
Establishes cell lineages and tissue identities
what happens in the 4 divisions of early embryogenesis in plants?
1st division - zygote divide into apical and basal cells- asymmetric division, the apical cell becomes embryo and the basal cell into suspensor
2nd division in embryo- symmetric
3rd divisions - symmetric – makes 8-cell embryo
4th divisions- periclinal division, makes epidermis lineage.
_____ genes play an important role in the early embryogenesis.
WOX
WOX__, WOX__ and WOX__ are particularly important for the early embryogenesis. Expression patterns of these WOX gene determine different cells in an early embryo.
2, 8, 9
WOX __ and __ are expressed in a zygote before the first cell division.
Two cell stage - WOX___ in the apical cell ( this cell will develop into embryo). WOX__, ___ in the basal cell ( this cell will develop into suspensor)
2
8
2
8, 9
In the 8 cell stage , WOX__ is expressed upper 1/2 of the embryo (This part will develop into shoot apical meristem & cotyledons later) and WOX__ is expressed in the bottom ½ of the embryo (This part will develop into hypocotyl and root)
2
9
WOX__ is consistently expressed in the suspensor after 2-cell stage.
8
mutations in WOX__ makes things different _____, whereas mutations in WOX 8, 9 makes things different ____
during cell division
during embryo
Expressing WOX__ “ectopically” in embryo and suspensor lead to_____ divisions
2
anticlinal
After 16 cell embryo stage,______ expression is maintained in the L1 layer throughout the entire plant life time.
ATML1
ATML1 mutant – embryo_______ since cell divison patterns during the early embryogenesis is defective in the atml1 mutant.
lethal
CUPSHAPE COTYLEDON3 (CUC3) is expressed in the _________ of embryo and later (globular stage) CUC3 turns on SHOOTMERISTEMLESS (STM) gene in the______ (and this group of cells will develop into the_____)
upper half cells
center
SAM
STM1 mutant cannot make any_______
SAM
Cotyledon lineage is established by ____ (PHAB) and______ genes (FIL, KAN)
adaxial
abaxial
Root lineage is apparent from the __ cell stage
8
For root lineage,________ is the key genes
PLETHORA1
One gene involved in establishing the apical-basal polarity is______
TOPLESS
When TOPLESS is mutated, the apical-basal polarity is lost and has only ________.
two bottom identities
auxin accumulation is directed by what
pin
