Today Plant Reproduction W Genetic Engineering of Plants
- Slides: 40
Today: Plant Reproduction W: Genetic Engineering of Plants http: //plantsinmotion. bio. indiana. edu/plantmotion/flowers/flower. html
Fig 29. 7
Seeds and pollen allow seed plants to reproduce without water Fig 30. 2
Fig 38. 4 Animal pollinators move pollen from one plant to another
Fig 38. 4 Plants reproduce, reward animals with sugar
Fig 38. 2 a typical flower
Fig 38. 2 Angiosperm Life Cycle
Fig 38. 5 Each pollen grain has 3 nuclei, two sperm and one for the pollen tube N N N
Fig 38. 5 Each pollen grain has 3 nuclei, two sperm and one for the pollen tube nuclei N sperm N N
Pollen tubes can grow quite long… corn stigma corn seeds
The pollen tube grows to the egg and the sperm fuse with the egg= zygote and polar nuclei= endosperm Fig 38. 5
Fig 38. 7 The zygote then develops into an embryo surrounded by the endosperm and seed coat = the seed
Fig 38. 8 The seed must contain enough nutrients to nourish the embryo until it can begin photosynthesis
Seed size is a good indicator of how much energy is stored to support early seedling growth.
Which seed likely requires light to germinate?
Fig 38. 11 Seed dispersal can be by wind or often also by animal
Fig 38. 10 Fruits: Animals can get nutrients to disperse seeds
Seed Germination. . . Fig 38. 9
Capsaicin is a deterrent to seed eating mammals
Capsaicin is a deterrent to seed eating mammals
Is this plant reproducing sexually?
Problem of Inbreeding • Close relatives have a higher probability of carrying the same genetic defects • Decreases genetic diversity see pg 813 and/or http: //users. rcn. com/jkimball. ma. ultranet/Biology. Pages/S/Self. Incompatibilty. html
How do plants avoid inbreeding? male plant Some plants, like humans, separate the sexes--i. e. , some plants have only male flowers and others only female flowers. Fig 38. 13 female plant
Some plants physically separate the anthers and stigmas Fig 38. 13
Some plants separate the anthers and stigmas
How do plants avoid inbreeding? • Some plants, like humans, separate the sexes --i. e. , some plants have only male flowers and others only female flowers. • Some plants separate the anthers and stigmas. • Some plants have a cellular mechanism for avoiding inbreeding: self-incompatibility see pg 813
What is self-incompatibility? • Plants, like animals have the ability to distinguish self tissue from non-self tissue. • In humans, generally non-self tissue is rejected, so tissue transplants can be a problem. • In some plants self-pollen is rejected (= self-incompatibility), and only non-self pollen is allowed to fertilize the eggs. see pg 813
Avoiding Inbreeding Sporophytic Self-incompatibility: Stop Germination of Self Pollen on Stigma Found in the Brassica family: mustard, turnips, broccoli… see pg 813
Some signaling steps are known • This SI method requires that a factor from the pollen recognizes a factor from the stigma see pg 813
For sporophytic SI, male factors are made by the parent plant and placed in developing pollen see pg 813
In sporophytic SI the reaction happens on the stigma surface • If the male factor from pollen is recognized as self by the female factor on the stigma surface, then this recognition induces the stigma to secrete a substance that prevents the pollen from germinating. • the substance secreted by the stigma that inhibits self-pollen from germinating is unknown. see pg 813
Only pollen from different plants can germinate see pg 813
Avoiding Inbreeding: Gametophytic Self-incompatibility Stop Pollen Tube Growth in Style Found in the Solanaceae family: tomato, chili, tobacco… see pg 813 stigma style
Avoiding Inbreeding: Gametophytic SI Stop Pollen Tube Growth in Style • To reach the egg, the pollen tube must grow through the transmitting tract of the style, which secretes an enzyme called ribonuclease (RNase) see pg 813
Avoiding Inbreeding: Solution #2 Stop Pollen Tube Growth in Style • The RNase enters pollen tubes of both self and non-self pollen. see pg 813
Avoiding Inbreeding: Solution #2 Stop Pollen Tube Growth in Style • The RNase is inhibited in non-self pollen, but destroys the RNA in self pollen, and thus stops its growth toward the egg. see pg 813
Self-incompatibility • Self-incompatibility (SI) is a method by which some plants avoid inbreeding • The two main mechanisms of SI are different from one another: one stops the pollen on the surface, the other stops the pollen in the style. • Both methods require that a factor from the pollen recognize a female factor made by the flower, and in both methods this recognition initiates the SI reaction. see pg 813
Fig 38. 2 Angiosperm Life Cycle
Evolution does not always go “forward”… Some angiosperms disperse pollen by wind Fig 38. 4
Today: Plant Reproduction W: Genetic Engineering of Plants http: //plantsinmotion. bio. indiana. edu/plantmotion/flowers/flower. html
- Genetic drift
- Genetic programming vs genetic algorithm
- Genetic programming vs genetic algorithm
- What is the difference between genetic drift and gene flow
- What is the difference between genetic drift and gene flow
- Sexual and asexual reproduction venn diagram
- Asexualk
- Asexual vs sexual venn diagram
- Vegetative reproduction plants
- Reproduction system of plants
- Venn diagram sexual and asexual
- Plant
- Non vascular vs vascular plants
- Female part of a flower
- Learning objectives of reproduction in plants
- Flower ovule
- A sexual reproduction in plants
- Today meeting or today's meeting
- Today is class
- Today meeting or today's meeting
- Galton details
- Today's lesson or today lesson
- Example of repitition
- Identify the stamen
- Parts and functions of a flower
- Unit 17 plant reproduction
- Plants reproduce asexually
- Compare and contrast mitosis and meiosis
- Why are seedless plants important
- Plant reproduction virtual lab
- Insulin bacteria genetic engineering
- Section 13-1 changing the living world
- Genetic engineering applications
- Cloning tasmanian tiger
- Purpose of genetic engineering
- Source russia march
- Oryx and crake genetic engineering
- Pros and cons of genetic engineering
- Ethical issues of genetic engineering
- Bioluminescence genetic engineering
- Objectives of genetic engineering for class 10