ABA accumulation above endogenous levels is necessary for desiccation tolerance in Physcomitrella patens
作者单位：School of Life SciencesCapital Normal University Shanghai Center for Plant Stress BiologyChinese Academy of Sciences Plant Genetics Research UnitMidwest AreaAgricultural Research ServiceUnited States Department of AgricultureUniversity of Missouri Department of BiologyUniversity of South Dakota
会议名称：《2016年全国植物生物学大会》
会议日期：2016年
学科分类：09[农学] 0903[农学-农业资源与环境]
关 键 词：Physcomitrella patens desiccation tolerance gradual dehydration equilibrium dehydration abscisic acid
摘 要：The moss Physcomitrella patens,a model system for basal land plants,highly tolerates several abiotic stresses,including dehydration. We previously reported that Physcomitrella survives dehydration to-13 MPa under controlled drying regimes that bring the water potential of the moss to equilibrium with the air in 6 days. Tolerance of more rapid desiccation to water potentials below-100 MPa was only achieved by pre-treatment with exogenous ABA. We now report that gametophores can survive desiccation below-100 MPa under a gradual drying regime that more closely mimics the dehydration dynamics it would experience in its natural habitat. To explain the difference in response to drying rate,we hypothesized that gradual drying allows P. patens plants to progressively synthesize to reach levels that are required for the induction of desiccation tolerance. To address this hypothesis,we measured the endogenous ABA levels of protonemata and gametophores under different drying regimes. We also assessed the minimum concentration of exogenous ABA and the length of exposure to ABA required for induction of desiccation tolerance in the moss. Results from this work will provide insight into ongoing studies to uncover the underlying mechanisms of desiccation tolerance in this bryophyte.