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SLIDES BY:

RODRIGO RENE RAI MUNOZ ABUJDER

Plants in Space

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WHAT ARE PLANTS?

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Plants:

    • Grow almost anywhere on Earth
    • Absorb water and inorganic substances through its roots
    • Mix nutrients in its leaves via photosynthesis (or light) and carbon dioxide

Plants are living organisms with many different species including shrubs, herbs, trees, and flowers.

Most importantly, plants create oxygen for us to breathe and different types of food for us to eat!

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PLANT PHYSIOLOGY

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What is the function of…

Roots?

Leaves?

Fruit?

Roots take nutrients and water from soil and transport them to the plant to allow it to grow

Leaves perform photosynthesis, meaning they take light energy to create sugars

Fruits allow plants to spread their seeds and reproduce

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WHAT DO PLANTS HAVE TO DO WITH SPACE?

Plants provide both food and oxygen.

This is especially critical for astronauts living in the space station a long durations and eventually life in space!

Currently, several plants such as Arabidopsis, rice seeds, red lettuce, cabbage have been grown.

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NASA Veggie System growing Red Lettuce

NASA European Modular Cultivation System

Video: Plants grown in space https://youtu.be/CN5PA3Mq-SE

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WHAT DO WE OBSERVE ABOUT SPACE PLANTS?

Research on the space station has shown that microgravity has a weird effect on plants! Can you guess what these influences might be?

    • Photosynthesis

    • Root growth

    • Leaf growth

    • Nutrient transport

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So far, no studies have shown a difference in photosynthesis in space

Usually, plant roots grow downward into soil. In microgravity, they don’t know which way to grow!

In space, leaves tend to droop. This is called leaf epinasty.

Nutrient transport is disrupted in microgravity, and plants suffer from hypoxia: a lack of oxygen in the tissues

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PLANT GROWTH IN SPACE

How do plants sense gravity?

Scientists think the tips of roots have special cells containing starch. The starch flows in the direction of gravity, providing a signal to the plant which direction is down

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Gravitropism: The behavior of plants where roots grow downwards and stems grow upwards

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EXTERNAL EFFECTS ON PLANTS

  • Many of the effects on plants in microgravity are actually not caused by the plants themselves, but to differences in how the air, water, and soil behaves in microgravity.

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These external effects can make it difficult to separate out which behaviors of plants are due to microgravity

Plant Epinasty

Does microgravity cause leaves/stems to grow incorrectly? Or, does it occur because ethylene (a contaminant found in spacecraft) is elevated in space?

Nutrient Transport

Does microgravity cause lhypoxia? Or is difficult for plants to get nutrients because of how water behaves in space?

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CLASS EXERCISE (20 MINS)

  1. Split into groups of 4
  2. Pick a plant (arabadopsis, ginger, potatoes, etc.) that you think will be important for space travel
  3. What does this plant need to grow? How would you design a space experiment that eliminates external effects and lets you study the effect of microgravity?
  4. Draw a picture or diagram explaining your idea

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MICOGRAVITY PLANT GROWTH

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A microgravity horticulture design to spray nutrients and water directly onto plant roots, and therefore eliminate problems with transport to the roots

Plants don’t need a pot in space, a plastic baggy is enough to contain their roots, water, and nutrients!

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THE FUTURE OF PLANTS IN SPACE

Advanced Plant habitat, largest plant chamber made, which will be sent to the ISS in 2018

NASA Future Martian space farm, These photos are showing future designs of building a space farm on Mars

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REFERENCES AND RESOURCES

  • Scientific investigations with plants in space:
    • Tropi (2006), used Arabidopsis plants to investigate how roots respond to different levels of light and gravity.
    • Plant Signaling Space Experiment (2013), used genetically modified Thale cress plants to study how they grow in 1g and microgravity
    • Biomass Production System (BPS, 2001) is a system capable of keeping plants growing for more than 90 days.
  • A researcher’s guide to Plant Science on the ISS, pdf: https://www.nasa.gov/sites/default/files/atoms/files/np-2016-06-016-jsc_plant_research_mini_book508c.pdf

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SOME EXAMPLES

Conceptual Design of Autonomous Germination Habitat

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ARABIDOPSIS PLANT GERMINATION/PLANT GROWTH

Camera

Images

Light

Absorbed by

Plants

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Day 5

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