TY - JOUR
T1 - Appearance of a State 1 – State 2 transition during chloroplast development in the wheat leaf
T2 - Energetic and structural considerations
AU - Webber, Andrew N.
AU - Baker, Neil R.
AU - Platt‐Aloia, Kathryn
AU - Thomson, William W.
PY - 1984/2
Y1 - 1984/2
N2 - The ability of developing chloroplasts to dynamically regulate the distribution of excitation energy between photosystem 1 and photosystem 2, and thus perform a State 1 – State 2 transition, was examined from analyses of chlorophyll fluorescence kinetics in 4‐ and 8‐day‐old Triticum aestivum L. cv. Maris Dove leaves grown under a diurnal light regime. Chloroplasts at all stages of development in the two leaf systems could undergo a State 1 – State 2 transition, except those found in the basal 0.5 cm of the 4‐day‐old leaf. The ability to physiologically modify the excitation energy distribution between the chlorophyll matrices of the two photosystems developed after the development of mature, fully photochemically competent photosystem 2 units and the appearance of excitation energy transfer between photosystem 2 and photosystem 1. Also, changes in the degree of energetic interaction between the two photosystems, in vivo rates of electron transport and the chlorophyll a/b ratio could not be correlated with the appearance of a State 1 – State 2 transition. Ultrastructural studies demonstrated a 32% increase in the degree of thylakoid appression in chloroplasts at the base of the 8‐day‐old leaf compared to the situation in the basal 0.5 cm of the 4‐day‐old leaf. This difference in thylakoid stacking can account for the differing abilities of these two tissues to perform a State 1 – State 2 transition when considered in the context of the distribution of the two photosystems within appressed and non‐appressed regions of thylakoid membranes.
AB - The ability of developing chloroplasts to dynamically regulate the distribution of excitation energy between photosystem 1 and photosystem 2, and thus perform a State 1 – State 2 transition, was examined from analyses of chlorophyll fluorescence kinetics in 4‐ and 8‐day‐old Triticum aestivum L. cv. Maris Dove leaves grown under a diurnal light regime. Chloroplasts at all stages of development in the two leaf systems could undergo a State 1 – State 2 transition, except those found in the basal 0.5 cm of the 4‐day‐old leaf. The ability to physiologically modify the excitation energy distribution between the chlorophyll matrices of the two photosystems developed after the development of mature, fully photochemically competent photosystem 2 units and the appearance of excitation energy transfer between photosystem 2 and photosystem 1. Also, changes in the degree of energetic interaction between the two photosystems, in vivo rates of electron transport and the chlorophyll a/b ratio could not be correlated with the appearance of a State 1 – State 2 transition. Ultrastructural studies demonstrated a 32% increase in the degree of thylakoid appression in chloroplasts at the base of the 8‐day‐old leaf compared to the situation in the basal 0.5 cm of the 4‐day‐old leaf. This difference in thylakoid stacking can account for the differing abilities of these two tissues to perform a State 1 – State 2 transition when considered in the context of the distribution of the two photosystems within appressed and non‐appressed regions of thylakoid membranes.
KW - Chlorophyll fluorescence
KW - Triticum aestivum
KW - excitation energy transfer
KW - photosystems 1 and 2
KW - thylakoid
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U2 - 10.1111/j.1399-3054.1984.tb04560.x
DO - 10.1111/j.1399-3054.1984.tb04560.x
M3 - Article
AN - SCOPUS:84989682625
SN - 0031-9317
VL - 60
SP - 171
EP - 179
JO - Physiologia Plantarum
JF - Physiologia Plantarum
IS - 2
ER -