Plant Science Division, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia.
Statistical Consulting Unit, The Australian National University, Acton, ACT, 2601, Australia.
New Phytol. 2019 Dec;224(4):1504-1511. doi: 10.1111/nph.16126. Epub 2019 Sep 17.
The significance of shoot surface water uptake (SSWU) has been debated, and it would depend on the range of conditions under which it occurs. We hypothesized that the decline of leaf hydraulic conductance (K ) in response to dehydration may be recovered through SSWU, and that the hydraulic conductance to SSWU (K ) declines with dehydration. We quantified effects of leaf dehydration on K and effects of SSWU on recovery of K in dehydrated leaves of Avicennia marina. SSWU led to overnight recovery of K , with recovery retracing the same path as loss of K in response to dehydration. SSWU declined with dehydration. By contrast, K declined with rehydration time but not with dehydration. Our results showed a role of SSWU in the recovery of leaf hydraulic conductance and revealed that SSWU is sensitive to leaf hydration status. The prevalence of SSWU in vegetation suggests an important role for atmospheric water sources in maintenance of leaf hydraulic function, with implications for plant responses to changing environments.
叶片表面水分摄取（SSWU）的意义一直存在争议，这取决于其发生的条件范围。我们假设，叶片水力传导率（K）对脱水的响应下降可能通过 SSSU 得到恢复，并且 SSSU 的水力传导率（K）随脱水而下降。我们量化了叶片脱水对 K 的影响以及 SSSU 对脱水叶片 K 恢复的影响在红海榄中。SSWU 导致 K 在一夜之间恢复，恢复的路径与脱水导致 K 丧失的路径相同。SSWU 随脱水而下降。相比之下，K 随复水时间而下降，但不受脱水影响。我们的结果表明 SSSU 在叶片水力传导率的恢复中起作用，并揭示了 SSSU 对叶片水合状态敏感。植被中 SSSU 的普遍存在表明大气水源在维持叶片水力功能方面起着重要作用，这对植物对环境变化的响应有影响。
