Plant reproductive development during spaceflight.

Area of Science:

• Plant reproductive biology
• Space biology
• Gravitational biology

Background:

• Reproductive development in microgravity has been studied in plants like Arabidopsis, Brassica, and Triticum.
• Previous suggestions that gravity is essential for plant reproduction have been disproven.
• The spaceflight environment poses unique challenges to plant reproduction, including hardware limitations and lack of convective air movement.

Purpose of the Study:

• To investigate the effects of microgravity on plant reproductive development.
• To identify challenges in spaceflight hardware and environmental conditions that affect plant reproduction.
• To understand the role of gravity in microenvironments during plant reproductive development.

Main Methods:

• Studies on Arabidopsis, Brassica, and Triticum reproductive development in microgravity.
• Analysis of environmental factors in spaceflight, such as air movement and ethylene concentrations.
• Examination of androecium, gynoecium, anther, and pistil development under microgravity conditions.
• Assessment of storage reserve deposition during seed development in space.

Main Results:

• Plant reproductive development, including the production of functional propagules, occurs normally in microgravity.
• Pollen development is sensitive to high ethylene concentrations found on orbital platforms.
• Qualitative changes observed in anther and pistil development.
• Significant qualitative changes in storage reserve deposition during seed development.

Conclusions:

• While plants can reproduce in microgravity, environmental challenges can compromise seed quality.
• Understanding gravity's role in microenvironments is crucial for developing countermeasures.
• Improved understanding will enhance the utility of plant-based life support systems and have agricultural significance.