Plant adaptation strategies to prolonged drought are drawing extensive attention due to climate change.Periploca sepium is a native and widespread species in drought-prone regions.To understand plant survival and recovery mechanisms from extreme drought,we investigated the morphology,solutes accumulation and antioxidant enzymes of P.sepium under progressing drought stress (PD) and during subsequent re-watering.Three prolonged constant drought stresses (PCD) were set as comparisons.For PCD,soil moistures were kept at 80%,55% and 35% of field capacity water content,respectively.For PD,seedlings were dehydrated for 15-54 d to reach various drought intensities.(1)Under PCD,P.sepium could adapt and enter into a new steady physiology.Reduced canopy size and higher level of soluble sugars (TSS) and peroxidase (POD) contributed mainly to its drought resistance.(2)Contrast to PCD,P.sepium under PD showed ever-changing morphology and physiology.In drought phase,high accumulated proline,free amino acids (FAA) and TSS conferred tolerance before leaf death.As drought intensifying,morphological changes especially the well-organized organ senescence played pivotal roles in P.sepium survival.(3)When re-watered,new buds appeared and grew significantly faster than normal plants.Surprisingly high level of proline,FAA,superoxide dismutase (SOD) and POD indicate highly active physiology in new buds.Proline,FAA concentrations as well as SOD and POD activities declined rapidly with plant reviving,indicating their important roles in plant recovery and compensatory re-growth.These results exhibit contrasting resistant mechanisms under PCD and PD,and provide new information on plant recovery mechanisms from extremely drought.