TY  - JOUR
A1  - Sakuraba, Yasuhito
A1  - Balazadeh, Salma
A1  - Tanaka, Ryouichi
A1  - Müller-Röber, Bernd
A1  - Tanaka, Ayumi
T1  - Overproduction of Chl b retards senescence through transcriptional reprogramming in arabidopsis
JF  - Plant & cell physiology
N2  - Leaf senescence is a developmentally and environmentally regulated process which includes global changes in gene expression. Using Arabidopsis as a model, we modified Chl arrangement in photosystems by overexpressing the catalytic domain (the C domain) of chlorophyllide a oxygenase (CAO) fused with the linker domain (the B domain) of CAO and green fluorescent protein (GFP). In these plants (referred to as the BCG plants for the B and C domains of CAO and GFP), the Chl a/b ratio was drastically decreased and Chl b was incorporated into core antenna complexes. The BCG plants exhibited a significant delay of both developmental and dark-induced leaf senescence. The photosynthetic apparatus, CO2 fixation enzymes and the chloroplast structure were lost in wild-type plants during senescence, while BCG plants retained them longer than the wild type. Large-scale quantitative real-time PCR analyses of 1,880 transcription factor (TF) genes showed that 241 TFs are differentially expressed between BCG plants and wild-type plants at senescence, similar to 40% of which are known senescence-associated genes (SAGs). Expression profiling also revealed the down-regulation of a large number of additional non-TF SAGs. In contrast, genes involved in photosynthesis were up-regulated, while those encoding Chl degradation enzymes were down-regulated in BCG plants. These results demonstrate that alteration of pigment composition in the photosynthetic apparatus retards senescence through transcriptional reprogramming.
KW  - Arabidopsis
KW  - Chloroplast
KW  - Chlorophyllide a oxygenase
KW  - Photosynthesis
KW  - Senescence
Y1  - 2012
U6  - https://doi.org/10.1093/pcp/pcs006
SN  - 0032-0781
VL  - 53
IS  - 3
SP  - 505
EP  - 517
PB  - Oxford Univ. Press
CY  - Oxford
ER  -