[Staged strategy of plants in response to drought stress]

Drought is one of the most important abiotic factors limiting plant growth, development and survival. Due to global warming, the drought episodes in the future will become more frequent and severe. Therefore, the plant responses to drought stress, especially the drought-resistant mechanisms, have been a focus of the studies. This paper summarized the plant growth and physiological responses to drought stress, and proposed a staged response strategy of plants for the adaptation to natural drought stress. Overall, from drought initiation to drought-induced death, plants experienced five stress stages with increasing drought intensity, i. e., drought initiation-mild drought-moderate drought-severe drought-extreme drought, and the plant responsive and adaptive process in this whole event could be acute response-active adaptation to mild and severe drought stresses-passive adaptation to extreme drought stress. The essential function of the plant drought-resistant mechanisms varied with drought stress stages. Some key scientific problems and research directions about the staged response characteristics of plants to drought stress needed to be solved urgently in the future were pointed out.