Which part of the tobacco plant is infected by Meloidegyne incognita?

Meloidogyne incognita causes root knot disease by infesting the roots of tobacco plants. It harbours in the vascular zone and forms giant cells. The swollen regions of the root are referred to as knots.
(1), (3), (4) Meloidogyne incognita does not infect any other part of tobacco plant, except roots.