CHANGES IN CHEMICAL COMPOSITION OF THE LEAVES AND ROOTS OF RED KIDNEY BEAN PLANTS TREATED WITH 2, 4-DICHLOROPHENOXYACETIC ACID

Investigators (2, 6, 7, 11) have shown that there is a depletion of carbohydrates and an accumulation of nitrogen in plants treated with 2, 4-dichlorophenoxyacetic acid (2, 4-D). SELL et al. (10) have observed similar trends in the abnormally proliferated stem tissue of red kidney bean plants treated with 2, 4-D. Recently, LUECKE et at. (4) have reported that there are also pronounced changes in the content of some members of the vitanlin B complex and carotene in the leaf and stem tissue of red kidney bean plants treated with 2, 4-D. In view of these observations analyses were made to determine whether the leaf and root tissues of plants treated with 2, 4-D showed the marked differences in amino acids, ether extract, carbohydrates, ash and crude fiber content observed in the abnormally proliferated stem tissue of the treated plants (10). The results of these analyses are presented in this report. Materials and methods SAMPLES OF LEAF AND ROOT TISSUES Seeds of the red kidney bean were selected for uniformity of size and planted in 4-inch pots in the greenhouse. Each pot contained two plants which were treated when the first trifoliate leaves were expanding. Two replications of 200 plants each were used as a source of both treated and non-treated (control) plant material. One drop (.05 ml.) of a 0.1% solution of 2, 4-D was applied to the base of the blade of a primary leaf of each treated plant (6). The plants were harvested six days after treatment. At this time the stem tissue had proliferated considerably but there were no signs of necrosis. The material was dried according to the procedure given by LINK (3) and then segregated into the various parts, the hypocotyl, first internode and leaf petioles being grouped together as stem tissue. Analyses were made of leaves and roots separately.