Premium
Functional and molecular changes in the photosynthetic apparatus during senescence of flag leaves from field‐grown barley plants
Author(s) -
HUMBECK K.,
QUAST S.,
KRUPINSKA K.
Publication year - 1996
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1996.tb00256.x
Subject(s) - anthesis , cytochrome f , photosynthesis , senescence , hordeum vulgare , biology , photosystem ii , botany , rubisco , horticulture , photosystem , photosystem i , poaceae , microbiology and biotechnology , cultivar
Changes in the function and composition of the photosynthetic apparatus were analysed during maturation and senescence of barley ( Hordeum vulgare L.) flag leaves under field conditions. At about 8 d post‐antbesis. photo‐synthetic capacity, measured as oxygen evolution under light‐saturating conditions, and the D 1 protein level started to decrease. At about 14 d post‐anthesis, the pigment content, photosystem II efficiency ( F v / F m ) and levels of cytochrome f and the large subunit of ribulose‐1,5‐bis‐phosphate carboxylase started to decline. The levels of cytochrome b559 and the small subunit of ribulose‐1,5‐bis‐phosphate carboxylase decreased later, at about 22 d post‐anthesis. High levels of the light‐harvesting complex of pliotosyslem II were still detectable at an even later stage of senescence, at 26 d post‐anthesis. There were also differences in the kinetics of the declines in the levels of transcripts coding for components of the photosynthetic apparatus. rbc S mKNA abundance had already decreased when flag leaves reached their final lengths, at about 4 d post‐unthesis, whereas levels of psb A and pet C transcripts did not decrease until 16 d post‐anthesis. In contrast, a senescence‐related transcript, pHvS40 (Becker & Apel 1993), accumulated in the flag leaves 14 d post‐anthesis. Several senescence‐related processes which differ in their kinetics are described. The interrelationships among these processes and their regulation are discussed.