Research Progress in Mechanism of Xylem Embolism Based on Characteristics of Bordered Pit Membrane

Xylem embolism refers to the interrupt of plant water transport function caused by external air bubbles entering the xylem water-filled conduits. Bordered pit membrane is the crucial location where xylem embolism, spread and fatigue occur. In recent years, the characteristics of bordered pit membrane have received increasing attention in the study of xylem embolism mechanisms. In order to have more comprehensive and clear understanding of the role of bordered pit membrane in the formation, spread and fatigue of xylem embolism, we firstly discussed the formation mechanism and diffusion pattern of xylem embolism in angiosperms and gymnosperms, based on relevant research on xylem embolism at home and abroad. We elucidated the "air seeding hypothesis" in xylem embolism formation and diffusion, and clarified the crucial role of the bordered pit membrane; we also reviewed the main characteristics of the structural, chemical, physical and micromechanical properties of the bordered pit membrane, as well as the interr