Regulation of Flowering - Bioinformatics and Genomics | BSCI 411, Study notes of Biology

Download Regulation of Flowering - Bioinformatics and Genomics | BSCI 411 and more Study notes Biology in PDF only on Docsity! Rosette leaf 20 shoots Inflorescence IM 1 2 3 4 Inflorescence Meristem (IM) Arabidopsis plant Lecture 14: Regulation of flowering Read: chapter 19, page 990-995 Fig. 19.2, 3, 4, 5, 6, 7, 8 Page:948-949 Four pathways 1. Photoperiod 2. Vernalization 3. Autonomous 4. GA Decision to flower (activation of meristem identity genes) Fig. 18.23 A-C Phytochromes are photoreceptors that sense both photoperiod and light quality tetrapyrrole TKD: transmitter kinase domain Cryptochrome http://www.sciencemag.org/cgi/content/full/284/5415/760 CRY1 and CRY2 encodes homologues of DNA photolyases which are flavin proteins that carry blue- light dependent electron transfer PhyB D,E Floral initiation PhyA Cry Far red Red Blue In leaves Light perception by PhyA-E and CRY Circadian clock: CCA1 and LHY Activation of CO Florigen? In Shoot Apical Meristem Activation of meristem identity genes LFY and AP1 Transport through the phloem Four pathways 1. Photoperiod 2. Vernalization 3. Autonomous 4. GA Decision to flower (activation of meristem identity genes) (2) Vernalization pathway (A) (B) 0 days of 100 days of vernalization at 4°C vernalization at 4°C Fig. 19.7 FRIGIDA (FRI) plants ABC gene Meristem Identity Genes LFY and AP1 Long day pathway Autonomous pathway Vernalization pathway GA pathwayCO FLC FRI lfy-6 ap1-1 lfy-6 ap1-1 LEAFY (LFY) Encode a novel protein Can bind DNA in specific sequence in vitro RNA expressed in early floral meristem LFY protein localizes to nuclei LFY mRNA LFY