Photosynthate Unloading From Seed Coats of Phaseolus vulgaris L. General Characteristics and Facilitated Transfer

摘要: Summary Using plants of Phaseolus vulgaris L., procedures were developed to examine functional properties photosynthate unloading the apoplast seed coats. The enclosed developing embryos removed and replaced by bathing solutions. solutions served intercept 14 C-photosynthates transferred as well providing a medium for mounting experimental challenges process. It was found that these did not alter in vivo behaviour Lowering sucrose concentration stimulated C-photosynthate unloading. sulfhydryl-modifying compounds, NEM PCMBS, strongly inhibited release apoplast. PCMBS inhibition occurred absence changes cellular metabolism reversed fully thiol reducing agent, DTE. Reductions energy lowered temperature, CCCP significantly This energised efflux sustained net against gradient up apoplastic concentrations 200 mM beyond which it offset passive back diffusion.