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Root system of kava (Piper methysticum)  with swollen roots due to infection by root-knot nematodes (Meloidogyne sp.), which cause both hypertrophy at the feeding sites (the "giant cells") and hyperplasia around the feeding sites.

Root of kava (Piper methysticum)  swollen due to infection by root-knot nematodes (Meloidogyne sp.), which cause both hypertrophy at the feeding sites (the "giant cells") and hyperplasia around the feeding sites.

Definition

Hypertrophy is an abnormal increase in the size of cells in a tissue or organ, often resulting in the formation of galls or tumors.

Etymology ("hyper"). from Gk. hyper (prep. and adv.) "over, beyond, overmuch, above measure." As a word by itself, meaning "overexcited," it is attested from 1942, short for hyperactive.

Etymology ("trophy"). comb. form meaning "food, nourishment," from Gk. trophe "food, nourishment," related to trephein "to make solid, congeal, thicken."

Discussion

Root-knot nematodes (Meloidogyne spp.) cause hypertrophy of root cells to occur as the nematodes establish their feeding sites within roots.  These hypertrophied cells are referred to as "giant cells" and in the case of cyst nematodes (Heterodera app.), "nurse cells."