Abstract
We have used imaging of chlorophyll fluorescence to screen the T-DNA-tagged Arabidopsis mutants. To isolate mutants defective in high light response, plants were exposed to two types of high light stress; short-term and log-term irradiation. To observe short-term response, transient fluorescence kinetics was monitored during short irradiation (12 sec). For long-term treatment, plants were exposed to high light for 24 hr and then chlorophyll fluorescence was measured. To date, we screened 8,000 seedlings and isolated nine candidates showing different fluorescence kinetics from that of WT. Six out of nine mutants had defects in response to short-term irradiation. The rest of the mutants showed lower fluorescence intensity than WT only after 24 hr of high light. PAM fluorescence measurements indicate that several mutants differ in photosynthetic parameters (qP, qN, ETR, Fv/Fm) from WT, indicating that various types of mutants can be isolated by this screening system.
