Plant Hormones

Auxin is a plant growth hormone, its major function is to help the plant grow by changing the plant wall plasticity making it easier for the plant to grow upward. Auxin also helps the root formation. Auxin is also the hormone responsible for phototropism, the process by which auxin is degraded on the outside of the plant, allowing the plants to slope towards the light. Auxin is also credited for growing quickly the plants central shaft, which is also known as apical dominance.

http://preuniversity.grkraj.org/html/6_PLANT_GROWTH_AND_DEVELOPMENT.htm

 

 

 

Abscisic acid (ABA) is produced to counter stress of environmental conditions such as dehydration, cold temperatures, and shortening day lengths. ABA counters the effect of hormones like auxins and inhibits stem elongation and induces dormancy in lateral buds. Abscisic acid also allows the plants to adapt to the stress in the environment. ABA blocks germination in buds and promotes storage of proteins, it protects young plants from sprouting too early during warm weather in winter.

https://labs.mcdb.ucsb.edu/finkelstein/ruth/

 

 

Ethylene is associated with fruit ripening, flower wilting, and leaf fall. It is also a volatile gas (C₂H₄₎. It is a growth hormone that helps convert starch and acids to sugars. Ethylene also triggers leaf and fruit abscission.

http://isopaninsulation.com/technologies/fruit-ripening-plants