title: A self-photoprotection mechanism helps Stipa baicalensis adapt to future climate change.
abstract: We examined the photosynthetic responses of Stipa baicalensis to relative long-term exposure (42 days) to the predicted elevated temperature and water availability changes to determine the mechanisms through which the plant would acclimate to future climate change. Two thermal regimes (ambient and +4 °C) and three irrigation levels (partial, normal and excess) were used in environmental control chambers. The gas exchange parameters, light response curves and A/Ci curves were determined. The elevated temperature and partial irrigation reduced the net photosynthetic rate due to a limitation in the photosynthetic capacity instead of the intercellular CO2 concentration. Partial irrigation decreased Rubisco activation and limited RuBP regeneration. The reduction in Vcmax increased with increasing temperature. Excess irrigation offset the negative effect of drought and led to a partial recovery of the photosynthetic capacity. Although its light use efficiency was restricted, the use of light and dark respiration by Stipa baicalensis was unchanged. We concluded that nonstomatal limitation was the primary reason for photosynthesis regulation in Stipa baicalensis under relative long-term climate change conditions. Although climate change caused reductions in the light use efficiency and photosynthetic rate, a self-photoprotection mechanism in Stipa baicalensis resulted in its high ability to maintain normal live activities.
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China.|University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
authors.forename: Xiliang
authors.initials: X
authors.lastname: Song
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China.|Chinese Academy of Meteorological Sciences, China Meteorological Administration, 46 Zhongguancun South Street, Haidian, Beijing 100081, China.
authors.forename: Guangsheng
authors.initials: G
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China.
authors.forename: Zhenzhu
authors.initials: Z
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China.|University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Lv
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China.
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000222:Adaptation, Physiological / Q000528:radiation effects; D057231:Climate Change; D005740:Gases / Q000378:metabolism; D008027:Light; D055668:Photochemical Processes / Q000528:radiation effects; D010788:Photosynthesis / Q000528:radiation effects; D018515:Plant Leaves / Q000502:physiology / Q000528:radiation effects; D006109:Poaceae / Q000502:physiology* / Q000528:radiation effects*; D012987:Soil; D013696:Temperature; D014867:Water
chemical_list: D005740:Gases; D012987:Soil; D014867:Water