The effect of several stress conditions and growth regulators on photosynthesis and translocation of assimilates in the bean plant

Abstract

Studies were performed on young bean plants, grown in water culture. The effect of salt stress, X-flays and flooding on growth, photosynthesis and translocation of assimilates was investigated. Salt stress (NaCl and Na₂SO₄), especially at - 4.5 atm. of water potential, depressed all the mentioned processes, but most dramatically - photosynthesis. Export of photosynthetes from the blades decreased. Salt stress not only reduced the rate of translocation, but also influenced the pattern of ¹⁴C-distoibution, especially inhibited transport to apical part, with growth seriously retarded. Gibberellin (GA₃, 100 ppm sprayed on leaves) counteracted the negative effects caused by salinization, but did not affected either photosynthesis, or translocation in plants from normal nutrient solution. The conclusion may be advanced, that salt stress disturbed the balance of plant hormones especially gibberellins, which probably participate in. regulation of assimilate translocation.