Introduction of Seed Development and Arabidopsis Embryo Development

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Introduction of Seed Development and Arabidopsis
Embryo Development

• By Bekah Charney and Thi Nguyen
• HC70AL Spring 2006

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What is the life cycle of an Arabidopsis Plant?
2n Adult Sporophyte
2n Adult Sporophyte
Meiosis
Meiosis
Many mitosis
Many mitosis
n n n n Haploid spores
n n n n Haploid spores
n Adult Gametophyte
n Adult Gametophyte
Mitosis
Mitosis
n Gametes
n Gametes
2n Zygote
2n Zygote
Many Mitosis
Many Mitosis
2n Adult Sporophyte
2n Adult Sporophyte
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How do seeds form during the life cycle of a
plant?
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Double Fertilization of cells leads to seed
formation
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Embryo Development
EMBRYO SAC
TORPEDO
GLOBULAR
HEART
MATURATION
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Globular Stage

• Stage which precedes cotyledon development
• Embryo proper is spherical
• Note the suspensor

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Heart Stage

• Globular embryo develops into two-lobed form
• Suspensor acts as an umbilical cord, providing
  nutrients to the embryo.

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Torpedo Stage

• Cotyledons and axis grow longer
• Embryo may remain straight or become curved

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Mature Embryo

• Cotyledons curve and provides nutrition to plant,
  enough to get plant started with photosynthesis
• Suspensor disappears
• Endosperm has been used for nutrients and now is
  used up

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Mutations that are Lethal
Lethal to Zygote
Lethal to Gamete
Phenotype live to dead seeds 31 Genotype AA
to Aa 12
Phenotype live to dead seeds 11 Genotype AA
to Aa 11
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Acknowledgements

• We would like to thank Ria, Jon, XingJun and Tomo
  for allowing us to use their Nomarski photographs
  and their assistance in general in helping to
  make to this presentation
• We would also like to thank Mike, Brandon,
  Jessica, the rest of the HC70AL class and Dr.
  Goldberg for being there for us all quarter!