Chlorophyllaforms in mesophyll and bundle sheath chloroplasts ofZea maysleaves grown at low light intensity

摘要

Mesophyll and bundle sheath chloroplasts were prepared from leaves ofZea maysgrown at light intensities of 1.1 and 240μW/cm2, respectively. The mesophyll chloroplasts that developed at the low intensity and bundle sheath chloroplats that developed at both low and high intensities showed higher ratios of chlorophylla/band P700/chlorophylls compared with the normal ratios found for the mesophyll chloroplasts that had developed at the high intensity. Derivative absorption spectrophotometry at 77°K revealed that the low intensity mesophyll chloroplasts contained more of chlorophyllaforms with longer wavelength red bands than high intensity mesophyll chloroplasts. More of the longer wavelength forms of chlorophyllawere also present in the bundle sheath chloroplasts that had developed at low and high intensities. All these four types of chloroplasts showed two peaks of fluorescence, one at 687 hra and the other at 733 or 738 nm. In addition to these peaks, the high intensity mesophyll chloroplasts showed a shoulder at 697 nm, and the two types of bundle sheath chloroplasts showed a shoulder at 680 n