title: Submergence Causes Similar Carbohydrate Starvation but Faster Post-Stress Recovery than Darkness in Alternanthera philoxeroides Plants.
abstract: Carbon assimilation by submerged plants is greatly reduced due to low light levels. It is hypothesized that submergence reduces carbohydrate contents and that plants recover from submergence in the same way as darkness-treated plants. To test this hypothesis, the responses of plants to submergence and darkness were studied and compared. Plants of a submergence-tolerant species, Alternanthera philoxeroides, were exposed to well drained and illuminated conditions, complete submergence conditions or darkness conditions followed by a recovery growth period in a controlled experiment. The biomass maintenance and accumulation, carbohydrate content dynamics and respiration rate in the plants were assessed to quantify the carbohydrate utilization rate and regrowth. The submerged plants maintained higher chlorophyll contents, more green leaf tissue and more biomass; recovered more quickly; and accumulated more carbohydrates and biomass than darkness-treated plants. The respiration rate was continuously reduced in the same pattern under both stress conditions but was maintained at a significantly lower level in the submerged plants; the total soluble sugar and total fructan contents were decreased at approximately the same rate of decrease, reaching similar low levels, in the two stress treatments. The A. philoxeroides plants were more tolerant of submergence than darkness. The faster recovery of desubmerged plants could not be explained by the similar carbohydrate contents at the start of recovery. Other types of carbon reserves besides carbohydrates or other mechanisms such as higher post-stress photosynthetic performance might be involved.
authors: Institute of Subtropical Forestry, Chinese Academy of Forestry/Research Station of Hangzhou Bay Wetlands Ecosystem, National Forestry Bureau, Fuyang, China.|Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Science, Southwest University, Chongqing, China.
authors: Xiao Qi
authors: XQ
authors: Ye
authors: Institute of Subtropical Forestry, Chinese Academy of Forestry/Research Station of Hangzhou Bay Wetlands Ecosystem, National Forestry Bureau, Fuyang, China.
authors: Jin Liu
authors: JL
authors: Meng
authors: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Science, Southwest University, Chongqing, China.
authors: Bo
authors: B
authors: Zeng
authors: Institute of Subtropical Forestry, Chinese Academy of Forestry/Research Station of Hangzhou Bay Wetlands Ecosystem, National Forestry Bureau, Fuyang, China.
authors: Ming
authors: M
authors: Wu
authors: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Science, Southwest University, Chongqing, China.
authors: Ye Yi
authors: YY
authors: Zhang
authors: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources in Three Gorges Reservoir Region, School of Life Science, Southwest University, Chongqing, China.
authors: Xiao Ping
authors: XP
authors: Zhang
mesh_terms: D027703:Amaranthaceae / Q000378:metabolism* / Q000502:physiology; D018533:Biomass; D050260:Carbohydrate Metabolism; D002734:Chlorophyll / Q000378:metabolism; D003624:Darkness; D013312:Stress, Physiological
chemical_list: D002734:Chlorophyll