Anatomy of the Cotton Leaf and Effects Induced by 2,4-Dichlorophenoxyacetic Acid

Histological Responses of the Rice Plant (Oryza sativa) to 2,4-D

“…Relatively recent studies emphasize the occurrence of striking responses in dicotyledons as contrasted with relatively inconspicuous3 responses in monocotyledons (Beal, 1951;Watson, 1948Watson, , 1950Eames, 1949aEames, , 1950Eames, , 1951aBurton, 1950;Struckmeyer, 1951;Wardlaw, 1952;Gifford, 1953). Hyperplastic proliferations in the vascular cambium, phloem parenchyma, interfascicular parenchyma, and the socalled pericycle; destruction of primary phloem; 1 Received for publication February 7, 1955.…”

“…and development of massive adventitious roots and tumor-like tissues have been described for stems of various plants (Eames, 1949a(Eames, , 1950Watson, 1950;Beal, 1951;Struckmeyer, 1951;Wardlaw, 1952). The inhibition of plate meristem activity, intercellular space formation, and chloroplast development; the occurrence of colorless parenchyma ("replacement tissue") between closely associated vascular bundles; the alteration of adaxial and marginal meristem activity; and the appearance of accessory vascular bundles have been observed in leaves of 2,4-D-treated plants (Burton, 1950;Watson, 1948;Eames, 1949bEames, , 1951bGifford, 1953). The present study presents new details regarding the effect of 2,4-D on the activity of meristems in the leaf, the formation of tubular leaves, cellular proliferation in the axis, and the development of adventitious roots in the rice plant.…”

Histological Responses of the Rice Plant (Oryza Sativa) to 2,4‐d

“…The literature on histological responses of plants to 2,4-D and related phenoxy analogues reveals that profound morphologic changes may be evoked in meristems and differentiating tissues. Relatively recent studies emphasize the occurrence of striking responses in dicotyledons as contrasted with relatively inconspicuous responses in monocotyledons IEeal, 1951;Watson, 1948Watson, , 1950Eames, 1949aEames, , 1950Eames, , 1951aBurton, 1950;Struckmeyer, 1951;Wardlaw, 1952;Gifford, 1953). Hyperplastic proliferations in the vascular cambium, phloem parenchyma, interfascicular parenchyma, and the socalled pericycle; destruction of primary phloem;…”

“…and development of massive adventitious roots and tumor-like tissues have been described for stems of various plants (Eames, 1949a(Eames, , 1950Watson, 1950;Beal, 1951;Struckmeyer, 1951;Wardlaw, 1952). The inhibition of plate meristem activity, intercellular space formation, and chloroplast development; the occurrence of colorless parenchyma ("replacement tissue") between closely associated vascular bundles; the alteration of adaxial and marginal meristem activity; and the appearance of accessory vascular bundles have been observed in leaves of 2,4-D-treated plants (Burton, 1950;Watson, 1948;Eames, 1949bEames, , 1951bGifford, 1953). The present 'Study presents new details regarding the effect of 2,4-D on the activity of meristems in the leaf, the formation of tubular leaves, cellular proliferation in the axis, and the development of adventitious roots in the rice plant.…”