Ectomycorrhiza and hydrogel protect hybrid poplar from water deficit and unravel plastic responses of xylem anatomy
Ectomycorrhiza and hydrogel protect hybrid poplar from water deficit and unravel plastic responses of xylem anatomy
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DOI：
10.1016/j.envexpbot.2010.02.005
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发表时间：
2010-11-01
影响因子：
5.7
通讯作者：
Polle, Andrea
中科院分区：
文献类型：
--
作者：
Beniwal, Rajender Singh;Langenfeld-Heyser, Rosemarie;Polle, Andrea
为探讨灰杨（Populus x canescens）的耗水特性是否能通过接种外生菌根菌（Paxillus involutus ectomycorrhizas，EM）和添加保水聚合物（hydrogel）的土壤改良剂得到改善，研究了干旱胁迫和充分灌溉条件下灰杨的黎明前水势、生长性能和水力结构。无论水凝胶的存在与否，灌溉良好的植物的根约75%被渐开线原球茎定殖。干旱胁迫导致EM损失约10%。未接种的植物表现出边缘EM定植（3%）。EM白杨在水凝胶改良土壤保持最高的黎明前水势干旱胁迫下，表现出最低的生物量损失，并保持几乎完全的光合活性，而非EM植物在土壤中没有水凝胶表现出严重的叶片损失在这些条件下，并没有表现出净CO2同化。非EM植物在水凝胶修正的土壤和EM植物没有水凝胶表现出中间应力症状。干旱胁迫下，根系可溶性碳水化合物含量与渗透调节的黎明前电位相关。EM植物表现出更大的船舶横截面积和增加径向船尾的增长与非EM植物相比。EM植物含有最低数量的导管（mm（-2）），但最大的导管直径，而非EM干旱胁迫植物在土壤中没有水凝胶显示最小的导管直径和最高的导管数量。血管直径和血管数量呈严格的负相关，这表明这两个参数之间的强烈发展协调。这一发现，无论是血管直径，也没有血管数量与黎明前的水势表明，这些木材功能之间的协调可以实现独立的急性水胁迫的信号。总的来说，EM和水凝胶，特别是组合，有助于避免干旱胁迫。因此，这些土壤改良剂提高植物的性能，并可能是有用的建立在边缘网站的种植园。(C)2010爱思唯尔有限公司版权所有。
To investigate whether the performance of Populus x canescens, a water-spending species, can be improved by Paxillus involutus ectomycorrhizas (EM) and soil amendment with water-retaining polymers (hydrogel), the pre-dawn water potential, growth performance and the hydraulic architecture of well-irrigated and drought-stressed plants were studied. Roots of well-irrigated plants were about 75% colonized with P. involutus regardless the presence of hydrogel. Drought stress resulted in an about 10% loss of EM. Non-inoculated plants showed marginal EM colonization (3%). EM poplar in hydrogel-amended soil maintained the highest pre-dawn water potential under drought stress, showed lowest biomass loss and kept almost full photosynthetic activity, whereas non-EM plants in soil without hydrogel exhibited severe leaf loss under these conditions and did not show net CO2 assimilation. Non-EM plants in hydrogel-amended soil and EM plants without hydrogel showed intermediate stress symptoms. The soluble carbohydrate content of roots was correlated with the pre-dawn potential indicating osmotic regulation under drought stress. EM plants displayed larger vessel cross-sectional areas and increased radial stern growth compared with non-EM plants. EM plants contained the lowest numbers of vessels (mm(-2)) but the largest vessel diameters, whereas non-EM drought-stressed plants in soil without hydrogel showed the smallest vessel diameters and highest vessel numbers. Vessel diameter and vessel numbers were strictly inversely correlated suggesting strong developmental coordination between these two parameters. The finding that neither vessel diameters nor vessel numbers were correlated with the pre-dawn water potential suggests that the coordination between these wood features may be achieved by signals acting independent of acute water stress. Overall, EM and hydrogel, especially in combination, help to avoid drought stress. Thereby, these soil amendments improve plant performance and may be useful for the establishment of plantations on marginal sites. (C) 2010 Elsevier B.V. All rights reserved.