Scholarlink

<p>The ornamental grass <i>Hordeum jubatum</i> L. is noted for its tolerance to salinity, alkalinity, and drought. This study compared root physiological and metabolic responses under iso-osmotic salt, alkali, and polyethylene glycol (PEG)-simulated drought stresses (hereafter “water stress”) to clarify stress-specific tolerance mechanisms.&#xa0;Seedlings were exposed to iso-osmotic treatments at − 0.2, − 0.4, and − 0.8&#xa0;MPa. We measured root biomass and morphology, lipid peroxidation (malondialdehyde, MDA), osmolytes (proline and soluble sugars), antioxidant enzymes (superoxide dismutase, SOD; peroxidase, POD; ascorbate peroxidase, APX; catalase, CAT; Na⁺ and K⁺ contents, and profiled root metabolites by untargeted liquid chromatography–mass spectrometry (LC–MS).&#xa0;Showed that all treatments reduced root biomass and activity, with the most significant declines occurring under alkali stress and the smallest under water stress. MDA increased under all stresses, particularly under alkali. Proline increased significantly only under alkali stress, while it remained similar to control under salt and water stresses. Salt and alkali stresses caused substantial Na⁺ accumulation and K⁺ loss in roots. In contrast, water-stressed roots maintained low Na⁺ and relatively higher K⁺. Antioxidant defenses (SOD, POD, APX) were upregulated — especially under alkali stress — while CAT activity declined at severe water potential. Metabolomic analysis at − 0.8&#xa0;MPa revealed treatment-specific shifts: salt and alkali stresses were enriched in the tricarboxylic acid (TCA) cycle and related organic acid pathways, whereas water stress was associated with enrichment in amino acid metabolism pathways.&#xa0;Under iso-osmotic conditions, root physiological indicators of <i>H. jubatum</i> were less inhibited by PEG-simulated water stress than by salt or alkali stresses. However, salt and alkali induced broader metabolic reprogramming — notably in TCA and organic-acid metabolism — indicating stress-specific differences in ionic balance and metabolic regulation.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Physiological and Metabolomic Analysis in Roots of Hordeum jubatum L. In Response to Iso-osmotic Stress

  • 期刊论文

  • 发表日期：

    2025年12月6日

查看全文
  • Peilin Han,
  • Xiaolin Di,
  • Bing Gao,
  • Jinji Han,
  • Yueming Li,
  • Xiaoxia Deng,
  • Zhuoran Tan,
  • Jingnan Zhang,
  • Jinghong Wang

摘要

The ornamental grass Hordeum jubatum L. is noted for its tolerance to salinity, alkalinity, and drought. This study compared root physiological and metabolic responses under iso-osmotic salt, alkali, and polyethylene glycol (PEG)-simulated drought stresses (hereafter “water stress”) to clarify stress-specific tolerance mechanisms. Seedlings were exposed to iso-osmotic treatments at − 0.2, − 0.4, and − 0.8 MPa. We measured root biomass and morphology, lipid peroxidation (malondialdehyde, MDA), osmolytes (proline and soluble sugars), antioxidant enzymes (superoxide dismutase, SOD; peroxidase, POD; ascorbate peroxidase, APX; catalase, CAT; Na⁺ and K⁺ contents, and profiled root metabolites by untargeted liquid chromatography–mass spectrometry (LC–MS). Showed that all treatments reduced root biomass and activity, with the most significant declines occurring under alkali stress and the smallest under water stress. MDA increased under all stresses, particularly under alkali. Proline increased significantly only under alkali stress, while it remained similar to control under salt and water stresses. Salt and alkali stresses caused substantial Na⁺ accumulation and K⁺ loss in roots. In contrast, water-stressed roots maintained low Na⁺ and relatively higher K⁺. Antioxidant defenses (SOD, POD, APX) were upregulated — especially under alkali stress — while CAT activity declined at severe water potential. Metabolomic analysis at − 0.8 MPa revealed treatment-specific shifts: salt and alkali stresses were enriched in the tricarboxylic acid (TCA) cycle and related organic acid pathways, whereas water stress was associated with enrichment in amino acid metabolism pathways. Under iso-osmotic conditions, root physiological indicators of H. jubatum were less inhibited by PEG-simulated water stress than by salt or alkali stresses. However, salt and alkali induced broader metabolic reprogramming — notably in TCA and organic-acid metabolism — indicating stress-specific differences in ionic balance and metabolic regulation.