Translocation and Distribution of Picloram in Bean Plants Associated with Nastic Movements
Abstract
Nastic responses in bean plants (Phaseolus vulgaris var. Black Valentine) occur rapidly when very low concentrations of picloram (4-amino-3,5, 6-trichloropicolinic acid) are applied to the root systems. Investigations were conducted to quantitatively determine the distribution of picloram in root- treated plants. Sixty-seven micrograms of C14-labeled picloram and 72 micrograms of unlabeled picloram in 300 ml of nutrient solution were applied to roots of 9- day-old bean plants growing in an environmental growth chamber at 24 C and 56% RH. Plants were removed from the treatment solution after uptake periods of 3, 6, and 11 hours. Sections were excised from ten locations on each plant and C14 content was determined by liquid scintillation techniques. As a qualitative indication of picloram mobility, additional plants were treated for 3 hours and autoradiographed. As evidenced by the C14 count data, the translocation of picloram from the roots to the apical part of the plant was very rapid. Picloram was preferentially accumulated in the terminal bud and first trifoliolate leaflets. Very little picloram was transported to the primary leaves and only at the longer treatment periods. Autoradiographs of plants treated for 3 hours showed qualitatively a similar distribution of C14 in the plant.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1969
- Accession Number
- AD0848732
Entities
People
- Charles P. Reid
- Woodland Hurtt