The roots are the parts that absorb nutrients and water from the soil, so if they are injured or diseased the plant will probably die - it depends on how many of the roots are damaged.
The plant will wilt because the ROOTS are damage which they absorbed water, minerals and oxygen...
Easy, it will die. But if the plant is big, if its damaged, it will grow back because plants have acids in their roots which help them regrow and dissolve rocks.:)