1. Plant Development How does plant development differ from animal development? Where do the various parts of a plant come from?

4. = hemicellulose Plant Cell Wall

5. Cellulose microfibrils in cell wall Microtubules beneath plasma membrane

6. Cellulose microfibril synthesis

7. Cellulose microfibrils of primary cell wall Plant cell expansion: Loosen wall in a particular dimension Drive expansion with turgor pressure

9. Secondary walls have more layers of polysaccharides, lignin cross-linking. A thicker wall cannot stretch. Zhong and Ye (2007) Current Opinion in Plant Biology 10: 564-572

10. Arabidopsis embryo development inside the seed

12. Embryo fate map

14. Vegetative Shoot apical meristem (SAM)

15. Vegetative shoot apical meristem (SAM)

20. Bushy mutants of pea Morris et al. (2001) Plant Physiology 126: 1205-1213

21. Umehara et al. (2008) Nature 455, 195-200 Mutants define the strigolactone biosynthetic pathway in Arabidopsis, pea, and rice Synthesis Response

22. Umehara et al. (2008) Nature 455, 195-200 GR24 inhibits bud outgrowth in strigolactone-deficient mutants Rice Arabidopsis

23. Model for mechanism of apical dominance Shoot apical meristem, leaf primordia Root, Stem Lateral bud Strigolactone transport Auxin transport Auxin transport (PIN proteins) Strigolactone inhibits transport from lateral bud Bud grows if it can export auxin

24. Root meristem

26. Confocal microscope image of Arabidopsis root

27. Cyclin::GFP

28. Which cells are the stem cells?

29. * * * * * * * * * * * * *** * **

30. 0d 1d 3d 5d Effect of ablation of quiescent center (QC) on tissue- specific marker gene expression (from Sabatini et al., 1999, Cell 99: 463-472) The Quiescent Center is the stem cell niche

31. Whole embryos can self-organize from somatic cells

32. Friday, April 9 th – Class will be in 101 Greenlaw

33. Regulatory function of Rb protein

34. Wild type Rb-related RNAi silenced Silencing Rb-related gene results in extra stem cells Wildwater et al. (2005) Cell 123: 1337-1349 (Brown marks starch in differentiated root cap cells.)

35. Control Ectopic Rb-related expression Ectopic expression of Rb-related gene results in loss of stem cells Wildwater et al. (2005) Cell 123: 1337-1349 (slight overexpression) (strong overexpression)