The Journal of Experimental Botany publishes high-quality primary research and review papers in the plant sciences. These papers cover a range of disciplines from molecular and cellular physiology and biochemistry through whole plant physiology to community physiology. Full-length primary papers should contribute to our understanding of how plants develop and function, and should provide new insights into biological processes. The journal will not publish purely descriptive papers or papers that report a well-known process in a species in which the process has not been identified previously. Articles should be concise and generally limited to 10 printed pages.
José López‐Bucio, Joseph Dubrovsky, Javier Raya‐González, Yamel Ugartechea‐Chirino, L.A. de Luna-Valdez, M. Ramos-Vega, Patricia León, Ángel Arturo Guevara-García
AbstractTaking the long-held view that photoinhibition embraces several processes leading to a reduction in the efficiency of light utilization in photosynthesis, and that photorespiration embraces several processes associated with O2 uptake in the light, photoinhibition and photorespiration now can be considered as inevitable, but essential inefficiencies of photosynthesis which help preserve photosynthetic competence in bright light. Photorespiratory O2 uptake via Rubisco, and O2 uptake via the Mehler reaction, both promote non-assimilatory electron transport, and stimulate photon utilization during CO2-limited photosynthesis in bright light. Although fluorescence studies show that the proportion of total photon use via oxygenase photorespiration in air may decline to only about 10% in full sunlight, mass spectrometer studies show that O2 uptake in Mehler reaction photorespiration in C3 and CAM plants can still account for up to 50% of electron flow in saturating CO2 and light. The Mehler-ascorbate peroxidase reaction has an additional role in sustaining membrane energization which promotes dynamic photoinhibition and photon protection (rapidly reversible decrease in PSII efficiency involving dissipation of the energy of excess photons in the antennae). Net CO2 and O2 exchange studies evidently underestimate the extent of total electron transport, and hence overestimate the extent of photon excess in bright light, leading to overestimates of the role of energy-dependent photon dissipation through dynamic photo-inhibition. Nevertheless, in C3 plants in air all of these processes help to mitigate chronic photoinhibition and photon damage (slowly reversible decrease in PSII efficiency involving loss of reaction centre function). The possibility remains that residual electron transport to O2 from intermediates in the vicinity of PSII may also lead to reactive O2 species that potentiate this photon damage.
J. E. Schmitz, Luisa Heinrichs, Federico Scossa, Alisdair R. Fernie, Marie-Luise Oelze, Karl‐Josef Dietz, Maxi Rothbart, Bernhard Grimm, Ulf‐Ingo Flügge, Rainer E. Häusler
Kora Vyse, Majken Pagter, Ellen Zuther, Dirk K. Hincha
We review current knowledge of plant deacclimation after cold acclimation, highlighting its role in the winter survival of both woody and herbaceous plants and the molecular basis of its regulation.