Gas exchange of Sedum lineare under drought condition
ZENG Xiao-ping1, ZHAO Ping1, CAI Xi-an1, YU Meng-hao1, MEI Ting-ting1, ZOU Lu-liu1, ZHU Li-wei1, YANG Shui-long2
1. Key laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; 2. Guangdong Yuyu Environmental Protection Technology Limited Company, Guangzhou 510510, China
To investigate ecophysiological adaptability of roof greening plant Sedum lineare of one,four,five and six years old,relative water content(RWC),mass per unit leaf area(LMA),and diurnal variation of gas exchange parameters in leaf were measured under drought condition in Guangzhou,China.Both RWC and LMA were low,and their values were 81.79% 87.58% and 0.0590.072 kg·m-2, respectively.S.lineare in different growth stages did not show significant change in leaf RWC and LMA(P<0.05).Gas exchange parameters including CO2 assimilation rate(A),stomatal conductance(gs),and transpiration(E)presented similar diurnal variation pattern in different growth stages of plant.There was also no significant variation in A,gs and E(P<0.05)in different growth stages.A, gs and E were significantly correlated with each other during a 24 h time-course(P<0.01).S.lineare is considered to be a facultative crassulacean acid metabolism(CAM) plant according to its characteristics of RWC and gas exchange parameters.There are similar major ecophysiological indices in 5.lineare in different growth stages.
[3] Winter K,Garcial M,HoltumJ A M.On the nature of facultative and constitutive CAM:environmental and developmental control of CAM expression during early,growth of Clusia,Kalanchoё,and Opuntia[J].Journal of Experimental Botany,2008,59(7):1829-1840.
[4] Herrera A.Crassulacean acid metabolism and fitness under water deficit stress:if not for carbon gain,what is facultative CAM good for[J]?Annals of Botany,2009,103:645-653.
[5] LUttge U.Ecophysiology of crassulacean acid metabolism(CAM)[J].Annals of Botany,2004,93:629-652.
[6] Getter K L,Rowe D B,RobertsonG B CreggB M,Andresen J A,Carbon sequestration potential of extensive green roofs[J].Environmental Science & Technology,2009,43:7564-7570.
[11] Conti S,Smimoff N.Rapid triggering of malate accumulation in the C3/CAM intermediate plant Sedum telephium:relationslup with water status and phosphoenolpyruvate carboxylase[J].Journal of Experimental Botany,1994,45(280):1613-1621.
[12] Borland A M.A model for the partitioning of photosynthetically fixed carbon during the C3-CAM transition in Sedum telephium[J].New Phytologist,1996,134:433-444.
[13] Fondom N Y,Castro-Nava,HuertaA J.Seasonal variation in photosynthesis and diel carbon balance under natural conditions in two Peperomia species that differ with respect to leaf anatomy[J].Journal of the Torrey Botanical Society,2009,136(1):57-69.
[14] Ceusters J,Borland A M,Londers E,Verdoodt V,Godts C.Differential usage of storage carbohydrates in the CAM bromeliad Aechmea 'Maya' during acclimation to drought and recovery from dehydration[J].Physiologia Plantarum,2009,135:174-184.
[15] Wahl S,Ryser P.Root tissue structure is linked to ecological strategies of grasses[J].New Phytologist,2000,148:459-471.
[16] Westoby M,Falster D S,Moles A T,Vesk P A,Wright U.Plant ecological strategies:some leading dimensions of variation between species[J].Annual Review of Ecology and Systematics,2002,33:125-159.
[17] Grime J P.The role of plasticity in exploiting environmental heterogeneity[M].In:Caldwell M M and Pearcy R W,eds.Exploitation of Environmental Heterogeneity by Plants:Ecophysiological Processes Above-and Below-ground.New York:Academic Press,1994.1-19.
[18] Winter K,Aranda J,Holtum J A M.Carbon isotope composition and water-use efficiency in plants with crassulacean acid metabolism[J].Functional Plant Biology,2005,32:381-388.
[19] Gravatt D A,Martin C E.Comparative ecophysiology of five species of Sedum (Crassulaceae) under well-watered and drought-stressed conditions[J].Oecologia,1992,92:532-541.
[20] von Caemmerer S,Griffiths H.Stomatal responses to CO2 during a diel crassulacean acid metabolism cycle in Kalanchoe daigremontiana and Kalanchoe pinnata[J].Plant,Cell and Environment,2009,32:567-576.
[21] Baroli I,Price G D,Badger M R,von Caemmerer S.The contribution of photosynthesis to the red light response of stomatal conductance[J].Plant Physiology,2008,146:737-747.