Variations between the photosynthetic properties of elite and landrace Chinese rice cultivars revealed by simultaneous measurements of 820 nm transmission signal and chlorophyll a fluorescence induction.
The difference between the photosynthetic properties of elite and landrace Chinese rice cultivars was studied, using chlorophyll a fluorescence induction (mostly a monitor of Photosystem II activity) and I820 transmission signal (mostly a monitor of Photosystem I activity) to identify potential photosynthetic features differentiating these two groups, which show different degrees of artificial selection and grain yields. A higher fluorescence (related to PSII) IP rise phase and a lower P700(+) (related to PSI) accumulation were observed in the elite cultivars as compared to the landraces. Using these data, together with simulation data from a kinetic model of fluorescence induction, we show that the high IP rise phase and the low P700(+) accumulation can be a result of transient block on electron transfer and traffic jam on the electron acceptor side of PSI under a high [NADPH]/[NADP(+)] ratio. Considering that the ferredoxin NADP(+) reductase (FNR) transcript levels of XS134 (a representative elite cultivars) remains unaffected during the first few minutes of light/dark transition compared to Q4145 (a representative landrace cultivars), which shows a strong decline during the same time range, we propose that the FNR of elite cultivars may take more time to be inactivated in darkness. During this time the FNR enzyme can continue to reduce NADP(+) molecules, leading to initially high [NADPH]/[NADP(+)] ratio during OJIP transient. These data suggested a potential artificial selection of FNR during the breeding process of these examined elite rice cultivars.
CAS Key Laboratory of Computational Biology, Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Saber
S
Hamdani
CAS Key Laboratory of Computational Biology, Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Mingnan
M
Qu
CAS Key Laboratory of Computational Biology, Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Chang-Peng
CP
Xin
CAS Key Laboratory of Computational Biology, Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
Ming
M
Li
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Chengcai
C
Chu
Department of Biochemistry, Department of Plant Biology, and Center of Biophysics and Quantitative Biology, University of Illinois at Urbana Champaign, Urbana, IL 61801, USA.
Govindjee
CAS Key Laboratory of Computational Biology, Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China. Electronic address: zhuxinguang@picb.ac.cn.
Xin-Guang
XG
Zhu
D002734:Chlorophyll / Q000378:metabolism*; D000077194:Chlorophyll A; D005453:Fluorescence; D018506:Gene Expression Regulation, Plant; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D010788:Photosynthesis; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism
D010940:Plant Proteins; D002734:Chlorophyll; D000077194:Chlorophyll A
820nm transmission; Chlorophyll a fluorescence transient; Ferredoxin NADP(+) reductase; NADP pool; Oryza sativa