Question

what will happen to a plant if the xylem is removed

Answer 1

if xylem is removed then transportion of water stopped and plant do not get water for the process inside it as a result plant get died.

Answer 2

If the xylem is not present in the plant then the plant will die for some time because xylem is a water transport system in plant
if it is not present then the water didn't supply to all parts of the plant
then the plant will die