Stem Abnormality Induced by DCPA

Dimethyl tetrachloroterephthalate (DCPA) caused swelling of a localized region of the hypocotyls of cucumber (Cucumis sativusL., var. Wis. SMR-15), tomato (Lycopersicon esculentumMill., var. Heinz 1370), and jimsonweed (Datura stramoniumL.). DCPA caused stem swelling in jimsonweed by affecting dividing and/or differentiating cells in the vascular cambium. As swelling proceeded, xylem tissue was increased over the controls and xylem cells were disorganized and no longer continuous. Swelling was induced at the site of DCPA application, and was reduced when DCPA concentration per unit of stem was lowered, even though the same amount per plant was applied. Uptake of14C-DCPA from the treated stem region was slow, but the treated area had the highest specific activity.