Developmental and water deficit-induced changes in hydraulic properties and xylem anatomy of tomato fruit and pedicel

Xylem water transport from the parent plant into the fruit plays a crucial role in fruit growth, development, and quality formation. Current research on fruit hydraulics has attempted to partition the hydraulic resistance of the pathway over development. However, no consensus has been reached and this question has not been addressed in the context of changing plant and fruit water status under water deficit. We rigorously investigated the developmental changes of hydraulic property of the fruit and pedicel under well-irrigated condition and water deficit based on hydraulic measurements, fruit rehydration, dye tracing, light and electron microscopy, and flow modeling. A decline in water transport capacity did not occur in the pathway prior to the fruit, but within the fruit itself, which might lie in the xylem and/or outside-xylem pathway. The developmental pattern of pathway hydraulic resistance was not significantly influenced by water deficit. The changed xylemic water flow between th...母体植物向果实的木质部水分运输，对果实的生长、发育及品质形成至关重要。当前果实水力特性研究尝试解析发育过程中该运输通路的水力阻力分布。然而，目前尚未达成统一共识，且在水分胁迫下植物与果实水分状态动态变化的背景下，这一问题仍未得到解决。本研究通过水力特性测定、果实复水实验、染料示踪、光学显微镜与电子显微镜观察以及流动模拟等手段，系统探究了正常灌溉与水分胁迫条件下果实及果柄（pedicel）水力特性的发育动态变化。研究发现，果实上游的运输通路并未出现水分运输能力下降，而水分运输能力的衰减发生在果实内部，该现象可能与果实内的木质部及/或非木质部运输通路有关。水分胁迫并未显著改变运输通路水力阻力的发育模式。果实与母体间的木质部水分流动变化……