Flowering Time FT

Flower Meristem Identity APETALA1, LEAFY, CAULIFLOWER, (TERMINAL FLOWER) Flower Organ Identity A, B, C

Fruit Development FRUITFULL, SHATTERPROOF INDEHISCENT

Goethe believed that floral organs are derived from leaves

Goethe, 1790 B B A C C A 1 2 3 4 3 2 1

petal petal petal sepal sepal carpel carpel stamen stamen normal flower active in the center offlowers? What gene prevents the Bgene from being

sepal A

petal B

C

stamen carpel C

stamen B

petal A sepal In SUPERMAN mutants (SUP), the B activity expands into the center of the flower and converts the two carpels into two stamens.

B B

A C C A petal petal petal sepal sepal stamen stamen stamen Superman mutant The SUPERMAN gene normally functions to prevent B gene activity in the center of flowers

B B

A C C A petal petal petal petal sepal sepal stamen stamen stamen normal BC mutant ??

B B

A C C A petal petal petal sepal sepal

carpel carpel A A A A stamen stamen normal BC mutant

B B

A C C A petal petal petal sepal sepal

carpel carpel A A A A stamen stamen

* sepal sepal sepal sepal sepal sepal BC double mutant

all organs are sepals inactivated in the tripleABC mutant? What happens if the BandA, Cgenes are all

sepal A

petal B

C

stamen carpel C

stamen B

petal A sepal normal ABC mutant ??

B B

A C C A petal petal petal sepal sepal carpel carpel stamen stamen normal ABC mutant

B B

A C C A petal petal petal sepal sepal carpel carpel stamen stamen * leaf leaf leaf leaf leaf leaf leaf leaf leaf “ABC” triple mutant

all organs are leaves Goethe believed that floral organs are derived from leaves

Goethe, 1790 stamen petal carpel sepal sepal

leaf

The C gene is active in cells that will form stamens and carpels stamen petal carpel sepal sepal

leaf

What would happen if the C gene was mis-expressed in cells that would normally form sepals? C GENE ON/OFF CODING REGION stamens and carpels

remove on/off switch:

add sepal on/off switch: sepals normal

B B

A C C A petal petal petal petal sepal sepal carpel carpel stamen stamen

Ectopic B activity

B B

A C C A petal petal petal sepal sepal stamen stamen stamen

Ectopic B activity

A C C A B B petal petal petal petal petal stamen stamen stamen Ectopic B activity Ectopic B and C activity

B B C C stamen stamen stamen stamen stamen stamen stamen Ectopic B and C activity Ectopic A and B activity in C mutant

A A B B * petal petal petal petal petal petal petal Ectopic A and B activity in a C mutant