Question

root of plant grow away from light

Answer 1

It is the phototrophic reaction which the roots do because they are attracted or their stimulus becomes sensitive towards light .
If I am wrong or my answer is inappropriate then extremely sorry !

Answer 2

the roots present under the soil it help to plant transfering the water from surface and the root are presnt in under the earth bcoz it never want sunlight ,the sunlight want the leaves and plant whole body the work of root only tranfer the water the xylem tissue transfer the water .and the sun rays plants want for photosynthesis.