Key message

Physiological and metabolic analysis showed the difference in drought tolerance and revealed the common and specific metabolic regulations in Salix sinopurpurea and Salix suchowensis.

Abstract

Willows (Salix spp.) are important woody plants as promising sources for sustainable and renewable biomass. However, drought is highly detrimental to their growth and development. Deciphering the adaptation mechanism of willows to drought will provide a theoretical basis for the cultivation of drought-tolerant varieties. In this work, we investigated the physiological and metabolic responses to drought stress in Salix sinopurpurea and Salix suchowensis. The drought experiment was conducted on clonal plants from cuttings of the two willow species under greenhouse conditions. S. sinopurpurea exhibited higher drought tolerance, as evidenced by lower growth reduction, and higher leaf relative water content, water use efficiency and net photosynthesis rate than those of S. suchowensis under the same drought conditions. Metabolic profiling identified 67 and 64 differentially accumulated metabolites in S. sinopurpurea and S. suchowensis, respectively. These metabolites function as compatible solutes and energy reserves and in antioxidant protection to defend against drought stress. Carbohydrate, amino acid and lipid metabolic pathways were central in the metabolic regulations of the drought response in the two willow species. The accumulation of aspartate, glutamate, serine, threonine, and sedoheptulose particularly in S. sinopurpurea might equip this species with drought tolerance. Meanwhile, phenylalanine and phytosterols were specifically inhibited in S. suchowensis, which might be associated with its susceptibility to drought stress. Taken together, these results provide a framework for better understanding the metabolic responses of willow to drought stress.

中文翻译：

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紫柳和苏柳对干旱胁迫的生理代谢响应

关键信息

生理和代谢分析显示了柳（Salix sinopurpurea）和柳柳（Salix sowensis）的抗旱性差异，揭示了共同的和特定的代谢规律。

抽象

柳树（柳属）是重要的木本植物，是可持续和可再生生物量的有希望的来源。但是，干旱严重不利于其增长和发展。阐明柳树对干旱的适应机制，将为耐旱品种的培育提供理论依据。在这项工作中，我们调查了柳柳和柳柳对干旱胁迫的生理和代谢反应。在温室条件下，对来自两种柳树的插条的无性植物进行了干旱试验。中华紫。在相同的干旱条件下，其生长耐受性降低，且叶片相对含水量，水分利用效率和净光合速​​率均高于S.owowensis。代谢轮廓确定了67种64的差异累积代谢物S.紫花雪山和S.簸箕，分别。这些代谢产物可作为相容的溶质和能量储备，并具有抗氧化保护作用，以防御干旱胁迫。碳水化合物，氨基酸和脂质的代谢途径是两种柳树干旱反应代谢调控的核心。天冬氨酸，谷氨酸，丝氨酸，苏氨酸的积累，在特别景天庚酮糖S.紫花雪山可能使该物种具有抗旱性。同时，苯丙氨酸和植物甾醇在沙门氏菌中被特异地抑制，这可能与其对干旱胁迫的敏感性有关。综上所述，这些结果为更好地了解柳树对干旱胁迫的代谢反应提供了框架。