Scholarlink

Background and Aims <p>Nitrate plays a dual role in plants—as a vital nutrient and a signaling molecule that modulates the tolerance against abiotic stresses. Understanding nitrate’s involvement in root thermotolerance and stress signaling is critical for enhancing nitrogen use efficiency (NUE) and heat stress (HS) tolerance in wheat. Here, we studied the effects of differential nitrogen (N) supply and HS on root system architecture (RSA), nitrate metabolism, antioxidant responses, and expression of stress-associated gene (SAG) in contrasting wheat <i>cvs</i>.</p> Methods <p>Wheat cultivars (HD2967, HD2329, HI1500 and GW322) were grown hydroponically under three N regimes—N-deficient (G<sub>1</sub>), N-normal (G<sub>2</sub>), and N-sufficient (25% extra N, G<sub>3</sub>). Plants were subjected to control and heat stress (38 ± 2&#xa0;°C) conditions. Root nitrate/nitrite content, nitrate reductase (NR) activity, RSA traits, antioxidant enzyme activities (SOD, CAT, GPx), total antioxidant potential (TAP), and expression of SAGs (<i>HSP17</i>, <i>HSP70</i>, <i>CDPK</i>, <i>SOD</i>) were assessed.</p> Results <p>Under G<sub>3</sub>, HD2967 showed maximum root nitrate (0.17&#xa0;μmol/mL) and TAP (35.1&#xa0;mM/g) during HS. HI1500 accumulated the maximum nitrite (9.2&#xa0;nmol/mL) and showed the most proliferated RSA. NR activity peaked under G<sub>2</sub> in HI1500, but declined under HS in all the cvs. Antioxidant enzyme activities and SAG expression increased under G<sub>3</sub> + HS, particularly in HD2967. Correlation analysis linked nitrate with RSA traits and TAP, and nitrite with SOD, <i>HSP17</i>, and <i>CDPK</i> expression.</p> Conclusion <p>Nitrate availability significantly shapes the RSA and boosts root thermotolerance via antioxidant defense and SAG expression. Enhanced nitrate signaling could support the development of climate-resilient, high-NUE wheat cultivars.</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

Nitrate flare in root – shielding the stress effect by shaping the root system architecture and triggering the antioxidant defense network in wheat under heat

  • 期刊论文

  • 发表日期：

    2025年10月11日

查看全文
  • Ranjeet R. Kumar,
  • Suneha Goswami,
  • Vinutha Thimmegowda,
  • Rakesh Pandey,
  • Sudhir Kumar,
  • Monika Dalal,
  • Bhupinder Singh,
  • Soora Naresh Kumar,
  • Girish K. Jha,
  • Gyan P. Mishra,
  • Viswanathan Chinnusamy

摘要

Background and Aims

Nitrate plays a dual role in plants—as a vital nutrient and a signaling molecule that modulates the tolerance against abiotic stresses. Understanding nitrate’s involvement in root thermotolerance and stress signaling is critical for enhancing nitrogen use efficiency (NUE) and heat stress (HS) tolerance in wheat. Here, we studied the effects of differential nitrogen (N) supply and HS on root system architecture (RSA), nitrate metabolism, antioxidant responses, and expression of stress-associated gene (SAG) in contrasting wheat cvs.

Methods

Wheat cultivars (HD2967, HD2329, HI1500 and GW322) were grown hydroponically under three N regimes—N-deficient (G1), N-normal (G2), and N-sufficient (25% extra N, G3). Plants were subjected to control and heat stress (38 ± 2 °C) conditions. Root nitrate/nitrite content, nitrate reductase (NR) activity, RSA traits, antioxidant enzyme activities (SOD, CAT, GPx), total antioxidant potential (TAP), and expression of SAGs (HSP17, HSP70, CDPK, SOD) were assessed.

Results

Under G3, HD2967 showed maximum root nitrate (0.17 μmol/mL) and TAP (35.1 mM/g) during HS. HI1500 accumulated the maximum nitrite (9.2 nmol/mL) and showed the most proliferated RSA. NR activity peaked under G2 in HI1500, but declined under HS in all the cvs. Antioxidant enzyme activities and SAG expression increased under G3 + HS, particularly in HD2967. Correlation analysis linked nitrate with RSA traits and TAP, and nitrite with SOD, HSP17, and CDPK expression.

Conclusion

Nitrate availability significantly shapes the RSA and boosts root thermotolerance via antioxidant defense and SAG expression. Enhanced nitrate signaling could support the development of climate-resilient, high-NUE wheat cultivars.