Rates of Photosynthesis in Attached and Detached Bean Leaves, and the Effect of Spraying with Indoleacetic Acid Solution

Abstract

The rate of l)hotosynthesis in a given leaf is ge-lerally conlsi(lered to be limilited either by external or enivironlmilenital factors stnch as light, CO., supply, or temperature, or by inlternal factors such as pigmiient colncenitration, enzymie colncentration and turinover timlle, or somiie other factors associate(d with the lnuitritional status of the planit. However there are rel)orts that rates of p1hotosynthesis may be inlfluelnced 1y the presence or abselnce or developmenital stage of roots (8,11) or 1y stimulation of roots (1). It has also been shown71 that lhormlonie treatmlenit of soybean plants increases their rate of tranislocationi (9)! anid it has been suggested that the demiand for photosyntlhate in roots may inifluenice translocationi (11,16) and lhence p)hotosynthesis. It thus seems possible tllat the rate of plhotosyntlhesis may also be subj ect to initernal control resulting fromii stimiiuli fromi otlher l)arts of the plant. Since nmany photosynthesis experimients are dlonie oni (letaclhed leaves, the work reporte(l here was uindertakeni to compare photosynthetic rates of attached and(l detaclied leaves, anld to search for evi(lence of l)ossil)le internal control miiechaiiismlls of plhotosynlthesis.