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Protection of the photosynthetic apparatus against dehydration stress in the resurrection plant Craterostigma pumilum
Author(s) -
Zia Ahmad,
Walker Berkley J.,
Oung Hui Min Olivia,
Charuvi Dana,
Jahns Peter,
Cousins Asaph B.,
Farrant Jill M.,
Reich Ziv,
Kirchhoff Helmut
Publication year - 2016
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13227
Subject(s) - photosynthesis , thylakoid , photosystem ii , electron transport chain , reactive oxygen species , plastoquinone , photosystem i , biophysics , oxygen evolution , dehydration , desiccation , chemistry , botany , biology , chloroplast , biochemistry , electrode , electrochemistry , gene
Summary The group of homoiochlorophyllous resurrection plants evolved the unique capability to survive severe drought stress without dismantling the photosynthetic machinery. This implies that they developed efficient strategies to protect the leaves from reactive oxygen species ( ROS ) generated by photosynthetic side reactions. These strategies, however, are poorly understood. Here, we performed a detailed study of the photosynthetic machinery in the homoiochlorophyllous resurrection plant Craterostigma pumilum during dehydration and upon recovery from desiccation. During dehydration and rehydration, C. pumilum deactivates and activates partial components of the photosynthetic machinery in a specific order, allowing for coordinated shutdown and subsequent reinstatement of photosynthesis. Early responses to dehydration are the closure of stomata and activation of electron transfer to oxygen accompanied by inactivation of the cytochrome b 6 f complex leading to attenuation of the photosynthetic linear electron flux ( LEF ). The decline in LEF is paralleled by a gradual increase in cyclic electron transport to maintain ATP production. At low water contents, inactivation and supramolecular reorganization of photosystem II becomes apparent, accompanied by functional detachment of light‐harvesting complexes and interrupted access to plastoquinone. This well‐ordered sequence of alterations in the photosynthetic thylakoid membranes helps prepare the plant for the desiccated state and minimize ROS production.