State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China.
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China.
Physiol Plant. 2021 Jun;172(2):528-539. doi: 10.1111/ppl.13334. Epub 2021 Jan 31.
Investigating plant morphological traits can provide insights into plant drought tolerance. To date, many papers have focused on plant hydraulic responses to drought during dehydration, but atmospheric water absorption by trichomes to mitigate drought stress by influencing leaf hydraulics in plant species that inhabit arid environments has been largely ignored. The experiment in this study was designed to assess how dew absorbed by leaf trichomes helps Caragana korshinskii withstand drought. The results showed that under a drought stress and dew (DS & D) treatment, C. korshinskii displayed a strong capacity to absorb dew with trichomes; exhibited slow decreases in leaf water potential (Ψ ), leaf hydraulic conductivity (K ), and gas exchange; experienced 50% K and gas exchange losses at lower relative soil water content levels than plants treated with drought stress and no dew (DS & ND); and experienced 50% K loss (K P ) at similar Ψ levels as DS & ND plants. Its congener C. sinica, which does not have leaf trichomes, displayed little ability to absorb dew under drought stress and did not show any remarkable improvement in the above parameters under the DS & D treatment. Our results indicated that leaf trichomes are important epidermal dew-uptake structures that assist in partially sustaining the leaf hydraulic assimilation system, mitigate the adverse effects of drought stress and contribute to the distribution of C. korshinskii in arid environments.
研究植物形态特征可以深入了解植物的耐旱性。迄今为止，许多论文都集中研究了植物在脱水过程中对干旱的水力响应，但大气水分通过毛状体吸收来影响生活在干旱环境中的植物的叶片水力，从而减轻干旱胁迫，这一现象在很大程度上被忽视了。本研究中的实验旨在评估叶毛状体吸收的露水如何帮助锦鸡儿抵御干旱。结果表明，在干旱胁迫和露水（DS&D）处理下，锦鸡儿表现出很强的毛状体吸收露水的能力；叶片水势（Ψ）、叶片水力传导率（K）和气体交换缓慢下降；在相对土壤水分含量较低的情况下，K 和气体交换损失达到 50%，比仅受干旱胁迫和无露水处理（DS&ND）的植物低；在与 DS&ND 植物相似的 Ψ水平下，K 损失达到 50%（Kp）。它的同属植物柠条，没有叶片毛状体，在干旱胁迫下吸收露水的能力很弱，在 DS&D 处理下，上述参数没有明显改善。我们的结果表明，叶片毛状体是重要的表皮露水吸收结构，有助于部分维持叶片水力吸收系统，减轻干旱胁迫的不利影响，并有助于锦鸡儿在干旱环境中的分布。
