title: Assimilative branches and leaves of the desert plant Alhagi sparsifolia Shap. possesses a different adaptation mechanism to shade.
abstract: Leaves and assimilative branches are crucial to the life cycle of Alhagi sparsifolia Shap. (Fabaceae), which grows in high-irradiance environments and is the main vegetation in the forelands of the Taklamakan Desert. This plant has an important role in wind protection and sand fixation at the oasis-desert transition zone. The morphology, physiology, and photosynthesis of A. sparsifolia leaves growing under low-light conditions have been extensively investigated. However, whether the plant's assimilative branches adapt similarly to low light levels is unclear, as are its specific light adaptation mechanisms. In this report, we characterized the biomass allocation, morphology, and chlorophyll a fluorescence of leaves and assimilative branches of A. sparsifolia. The results indicated that low-light conditions limited the normal growth of A. sparsifolia. The fraction of biomass allocated to leaves increased, whereas that to assimilative branches decreased. In addition, leaf thickness and assimilative branch diameter decreased, resulting in higher specific leaf area, specific assimilative branch length, and area for higher light absorbing and higher efficiency of light-usage. The assimilative branches and leaves were responded oppositely under low-light conditions in that leaves had lower photosystem II activity and assimilative branches had higher light-use efficiency to maximize light energy absorption for growth of A. sparsifolia.
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 100049, China; Cele National Station of Observation & Research for Desert-Grassland Ecosystem in Xinjiang, Cele, 848300, China.
authors: Li
authors: L
authors: Lei
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Cele National Station of Observation & Research for Desert-Grassland Ecosystem in Xinjiang, Cele, 848300, China. Electronic address: lixy@ms.xjb.ac.cn.
authors: Li
authors: L
authors: Xiang-yi
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
authors: Xu
authors: X
authors: Xin-wen
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Cele National Station of Observation & Research for Desert-Grassland Ecosystem in Xinjiang, Cele, 848300, China.
authors: Lin
authors: L
authors: Li-sha
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Cele National Station of Observation & Research for Desert-Grassland Ecosystem in Xinjiang, Cele, 848300, China.
authors: Zeng
authors: Z
authors: Fan-jiang
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Chen
authors: C
authors: Feng-li
mesh_terms: D000222:Adaptation, Physiological; D018533:Biomass; D003624:Darkness; D007887:Fabaceae / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology*
keywords: Alhagi sparsifolia Shap.; Biomass allocation; Chl; Chlorophyll a fluorescence; Leaves and assimilative branches; Light adaptation; PAR; PEA; PSII; Q(A); Q(B); RC; SAA; SAL; SLA; chlorophyll; photosynthetic active radiation; photosystem II; plant efficiency analyzer; primary quinine electron acceptors of PSII; reaction center; second quinine electron acceptors of PSII; specific assimilative branch area; specific assimilative branch length; specific leaf area