1. Plant fertilization and transgenic plants How does fertilization occur in plants? How do you make a transgenic plant?

2. Flowering plant life cycle

3. Meiosis in female produces four megaspores. One of these makes the gametophyte.

4. Female gametophyte: Megaspore nucleus divides three times to produce 8 nuclei. Then the gametophyte cellularizes.

5. Male gametophyte: pollen grains

6. Fertilization: Pollen tube fuses with a synergid. Sperm cells are released.

7. Fertilization: The egg is fertilized to produce the embryo. The central cell is fertilized to produce the triploid endosperm embryo endosperm (central cell)

8. ovule transmitting tract Pollination viewed with pollen-specific GUS marker line

9. (from Johnson et al., 2004, Genetics 168: 971-982)

10. Pollen tube attraction to Tourenia micropyle Higashiyama and Hamamura (2008) Sexual Plant Reproduction 21: 17-26

11. Pollen tube attraction to Tourenia fournerii micropyle (movie) Higashiyama and Hamamura (2008) Sexual Plant Reproduction 21: 17-26

12. Small peptide applied at time 0 (Fluorescent dye allows visualization of possible gradient) (Okuda et al. (2009) Nature 458: 357-361) Small peptides made in the synergids attract pollen

13. (Okuda et al. (2009) Nature 458: 357-361) The peptides are needed to attract pollen Knock down expression of peptide genes in embryo sacs

14. Double fertilization Sperm nuclei marked with red fluorophore, female nuclei with green (movie) (Berger et al. (2008) Trends in plant Science 13: 437-443)

15. Making transgenic plants

16. Agrobacterium tumefaciens causes crown gall tumors

17. Making transgenic plants

18. Agrobacterium-mediated plant transformation kanamycin resistant Gene conferring kanamycin resistance your favorite gene

19. Making transgenic plants

20. Regenerating plants from cultured (transformed) cells

21. Agrobacterium-mediated Arabidopsis transformation Select among progeny seeds for transgenic plants (herbicide or antibiotic resistance) Dip Arabidopsis flowers in solution of engineered Agrobacterium

22. Examples of transgenic plants Widely grown: Herbicide resistant Pest resistant Other ideas: Improved nutrition (golden rice) Delayed ripening Salt tolerance Phytoremediation (decontaminate soils)

23. http://www.isaaa.org/Resources/Publications/briefs/35/executivesummary/default.html