Fig. 1
Phenotypic and molecular analyses of SAG202 in Arabidopsis. (a) qPCR analysis of the transcript levels of SAG202/SARD1 in WT leaves at different developmental stages. NS, fully expanded non-senescing stage; ES, early senescence stage (< 25% yellowing); MS, mid-senescence stage (~ 50% yellowing); LS, late senescence stage (> 75% yellowing). Relative expression levels were calculated and normalized with respect to Actin 2 (ACT2) transcripts. Error bars indicate SD of three biological repeats. (b) GUS staining of the fifth leaves from PSAG202-GUS transgenic plants at different senescing stages. (c) Diagram of the T-DNA insertion locations of two sag202 mutants. (d) The expression of SAG202 is knocked out in the mutants shown in C as revealed by RT-PCR. (e) Age-matched 35 DAG WT and sag202 null mutants. DAG, days after germination. (f) Precocious leaf senescence in SAG202-inducible expression line (SAG202in or 8004/7001) (photo was taken 4 days after DEX induction). (g) Leaves detached from the age-matched 35 DAG plants in e (counted from bottom with the oldest leaf as 1 and the youngest leaf as 12). (h) The chlorophyll contents of the fifth and sixth leaves from control (containing pTA7001 only) and SAG202in lines. (i, j) Chlorophyll contents and Fv/Fm of the sixth to tenth rosette leaves of the age-matched 35 DAG plants from WT and the sag202 mutants. Error bars indicate SD of three biological repeats. *P < 0.05 using Student’s t-test