Wednesday, 6 April 2016


Auxin and Gravitropism in shoots and roots!


This is just an update on what I have learn about auxin and gravitropism in roots and shoots. Gravitropism helps the plant grow in the right direction for example in plants the leaves don't just stand up without the help of auxin and gravitropism. And this is known as a negative gravitropism.
So what is the role of auxin and in Gravitropism Response, experiments on shoot tips provide evidence that gravitropism is due to the different growth rates of upper and lower sides of the stem or root in response to auxin. While the roots grows down because roots elongation is inhibited by high levels of auxin on the lower surface.
Why gravitropism is important? From what I learned from our independent learning lesson, Gravitropism allowed the stem system to grow towards the surface while the root system extends further into the soil. It important for plant to adapt in this way to avoid the plant growing in the wrong direction, for example so the stem would not grow downwards. Or another good example in the roots without gravitropism the roots wouldn't be able to dig into the soil where they get nutrients. Both actions are imporatant and needed for the survival of the plant.

Thank you for reading


  1. Excellent explanation! I came here looking for any mistakes but I can't really find any, I'm just impressed :) Gravitropism is important so that shoots grow upwards to reach sunlight for phototropism, where they produce their own glucose, and for roots to grow into soil (like you said) to reach water and nutrients in soil (such as nitrogen, phosphorus etc) AS WELL as providing stability for the plant above it! This happens because of the difference between how root cells respond to auxin (cell elongation is inhibited) and shoot cells (elongate). You did a great summary :)

    1. Thank you best teacher in the whole world!!

    2. Aw you're sweet :) Hey can you please add the link to the presentation that you made? Ta! See you tomorrow.