Scholarlink

<p>Perennial species frequently experience repeated droughts; however their physiological and biochemical responses to sequential drought exposure remain poorly understood. This study investigated whether prior drought exposure enhances subsequent drought tolerance in <i>Karelinia caspia</i> seedlings by comparing primed [double drought: 50-day drought followed by 60-daydrought] and unprimed [single 60-day drought] treatments. Compared with unprimed seedlings, primed seedlings exhibited significantly higher shoot biomass, leaf relative water content, and chlorophyll <i>a</i>, and Rubisco activity. These improvements were associated with enhanced antioxidant defense system, including increased activities of superoxide dismutase, peroxidase, monodehydroascorbate peroxidase, and ascorbate peroxidase, together with higher ascorbate/dehydroascorbate and glutathione/oxidized glutathione ratios, resulting in lower superoxide anion, hydrogen peroxide and lipid peroxidation. Roots showed stronger antioxidant responses than leaves, with increased catalase, polyphenol oxidase, glutathione peroxidase, and glutathione reductase activities under double drought. Hormonal regulation also contributed to priming-induced drought-tolerance. Primed seedlings showed increased levels of growth- promoting hormones, including indole-3-acetic acid, gibberellin, zeatin riboside, and brassinosteroids, which likely supported growth under stress conditions. Moreover, proline, and glycine betaine, accumulation increased significantly in primed seedlings, contributing to improved osmotic adjustment. Elevated strigolactones levels further suggested a role in drought adaptation and root shoot functional responses. Principal component analysis demonstrated that drought priming enhanced antioxidant defense and osmotic regulation, protecting leaf photosynthetic machinery, while strengthening root antioxidant capacity. Collectively, these coordinated responses enabled primed <i>K. caspia</i> seedlings to maintain better growth and physiological stability under repeated drought. These findings improve our understanding of drought acclimation in perennial plants under hyper-arid environments and may support future ecological restoration strategies under climate change.</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

Drought priming enhances subsequent drought tolerance in Karelinia caspia through coordinated leaf-root hormonal, osmotic, and antioxidant regulation

  • 期刊论文

  • 发表日期：

    2026年8月4日

查看全文
  • Abd Ullah,
  • Akash Tariq,
  • Fanjiang Zeng,
  • Muhammad Ahsan Asghar,
  • Jordi Sardans,
  • Josep Peñuelas

摘要

Perennial species frequently experience repeated droughts; however their physiological and biochemical responses to sequential drought exposure remain poorly understood. This study investigated whether prior drought exposure enhances subsequent drought tolerance in Karelinia caspia seedlings by comparing primed [double drought: 50-day drought followed by 60-daydrought] and unprimed [single 60-day drought] treatments. Compared with unprimed seedlings, primed seedlings exhibited significantly higher shoot biomass, leaf relative water content, and chlorophyll a, and Rubisco activity. These improvements were associated with enhanced antioxidant defense system, including increased activities of superoxide dismutase, peroxidase, monodehydroascorbate peroxidase, and ascorbate peroxidase, together with higher ascorbate/dehydroascorbate and glutathione/oxidized glutathione ratios, resulting in lower superoxide anion, hydrogen peroxide and lipid peroxidation. Roots showed stronger antioxidant responses than leaves, with increased catalase, polyphenol oxidase, glutathione peroxidase, and glutathione reductase activities under double drought. Hormonal regulation also contributed to priming-induced drought-tolerance. Primed seedlings showed increased levels of growth- promoting hormones, including indole-3-acetic acid, gibberellin, zeatin riboside, and brassinosteroids, which likely supported growth under stress conditions. Moreover, proline, and glycine betaine, accumulation increased significantly in primed seedlings, contributing to improved osmotic adjustment. Elevated strigolactones levels further suggested a role in drought adaptation and root shoot functional responses. Principal component analysis demonstrated that drought priming enhanced antioxidant defense and osmotic regulation, protecting leaf photosynthetic machinery, while strengthening root antioxidant capacity. Collectively, these coordinated responses enabled primed K. caspia seedlings to maintain better growth and physiological stability under repeated drought. These findings improve our understanding of drought acclimation in perennial plants under hyper-arid environments and may support future ecological restoration strategies under climate change.