1. Beauty and Sex: Flowering

2. Flowers are derived from the process of transition from vegetative to generative meristems

3. Primary and secondary inflorescences

4. Vegetative and generative meristems Sepals Petals Stamens Carpels Leaves SAM Vegetative meristemGenerative meristem FM

5. Flower primordiumSepal primordiumAnthersCarpels Petals SiliqueSeeds ASPB Arabidopsis book

6. Early flower development (ca. stage 6) ASPB Arabidopsis book

7. Floral organs are initiated from the floral meristem in concentric whorls Meristem identity genes → floral organ identity genes → cadastral genes

8. Expression patterns of ABC class genes ASPB Arabidopsis book

9. Early flower development (ca. stage 6) ASPB Arabidopsis book

10. Arabidopsis flower development mutants ASPB Arabidopsis book

11. Floral organ identity genes are responsible for reproductive organ formation No sepals/petals No petals/stamens No stamens/pistils

12. Flowering is regulated by internal and external stimuli Juvenile to adult phase transition is characterized by morphological and physiological characteristics English Ivy (Hedera helix)

13. Juvenile to adult transition requires competence (adult vegetative phase), determination and expression

14. Photoperiodism is an external stimulus of flowering Short-day, long-day and day-neutral plants Night break inhibits floweringNight break of sufficient duration induces flowering

15. Photoperiodism is an external stimulus of flowering

16. Plants are adapted to day-length at different latitudes Phytochromes and cryptochromes are the photoreceptors that regulate flowering West Lafayette

17. Natural variation in Arabidopsis GermanyWest-Africa

18. Plants are adapted to day-length at different latitudes Phytochromes and cryptochromes are the photoreceptors that regulate flowering Ler Cvi Ler Cvi

19. Plants track time with their circadian clock Periodic rhythm of plant processes that is regulated by an internal timepiece

20. CO (CONSTANS) and FT (FLOWERING LOCUS T ) are regulators of flowering in Arabidopsis (long-day plants) CO expression is clock controlled CO protein accumulation is regulated by proteolysis

21. Similar homologs Regulate flowering in short-day plants Rice (short-day plant) - Heading-date1 (Hd1) = CO and Heading-date3 (Hd3) = FT However, Hd1 inhibits Hd3 activation of flowering

22. Vernalization is required before some plants are responsive to photoperiodic-induced floral transition FLC negatively regulates flowering

23. Vernalization is required before some plants are responsive to photoperiodic-induced floral transition FLC negatively regulates flowering

24. Plant Biology (2010) Smith et al. Florigen is the biochemical signal for flowering

25. Zeevart (2007) Taiz and Zeiger Web Essay 25.2 FLOWERING LOCUS T

26. Plant Biology (2010) Smith et al. Integration of flowering stimuli

27. Flower organ development