Scholarlink

<p>Soil salinization is a major abiotic stress that impairs plant growth and damages the photosynthetic apparatus. Plant growth promoting rhizobacteria (PGPR) are known to enhance plant tolerance to salinity, despite their mechanistic effects on photosynthesis remain unclear. Therefore, this study investigates the effects of <i>Bacillus subtilis</i> inoculation on the photosynthetic activity of <i>Sulla carnosa</i> under salt stress, with a focus on the functional performance of photosystems I and II.&#xa0;Seeds were either inoculated or not and grown in sterilized soil for one month, before exposure to 0 or 200 mM NaCl salinity for an additional month.&#xa0;Salinity severely reduced shoot and root dry weights by 32% and 45%, respectively, and impaired water status and physiological traits related to water status, K<sup>+</sup> nutrition and photosynthesis. However, inoculation with <i>B. subtilis</i> mitigated these adverse effects, since increasing shoot and root dry weights (+ 52% and + 146%, respectively) along with higher leaf pigment contents, shoot water status, leaf gas exchanges, and shoot K⁺ content. In addition, <i>B. subtilis</i> reduced Na⁺ uptake and decreased the accumulation of oxidative stress markers: hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and malondialdehyde (MDA) (-24% and − 71%, respectively), compared with salt-stressed non inoculated plants. Salinity decreased the quantum yields and electron transport rates of PSI [Y(I), ETR(I)] and PSII [Y(II), ETR(II)], while increasing PSI donor-side limitation [Y(ND)] and non-regulated energy dissipation [Y(NO)]. Inoculation restored all parameters to control levels and enhanced PSI oxidation (P700ox).&#xa0;<i>B. subtilis</i> effectively mitigates salinity-induced damage to Photosystems I and II, resulting in significant restoration of growth and photosynthetic performance in salt-challenged <i>S. carnosa</i>, which highlights its potential as a bioinoculant for saline soils.</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

Restored Photosystem I and II Functional Integrity Largely Accounts for the Mitigation of Salinity Impact on the Facultative Halophyte Sulla Carnosa When Inoculated With Bacillus Subtilis

  • 期刊论文

  • 发表日期：

    2026年1月16日

查看全文
  • Rabaa Hidri,
  • Farah Bounaouara,
  • Walid Zorrig,
  • Najla Hidri,
  • Ahmed Debez,
  • Chedly Abdelly,
  • Ouissal Metoui Ben Mahmoud

摘要

Soil salinization is a major abiotic stress that impairs plant growth and damages the photosynthetic apparatus. Plant growth promoting rhizobacteria (PGPR) are known to enhance plant tolerance to salinity, despite their mechanistic effects on photosynthesis remain unclear. Therefore, this study investigates the effects of Bacillus subtilis inoculation on the photosynthetic activity of Sulla carnosa under salt stress, with a focus on the functional performance of photosystems I and II. Seeds were either inoculated or not and grown in sterilized soil for one month, before exposure to 0 or 200 mM NaCl salinity for an additional month. Salinity severely reduced shoot and root dry weights by 32% and 45%, respectively, and impaired water status and physiological traits related to water status, K+ nutrition and photosynthesis. However, inoculation with B. subtilis mitigated these adverse effects, since increasing shoot and root dry weights (+ 52% and + 146%, respectively) along with higher leaf pigment contents, shoot water status, leaf gas exchanges, and shoot K⁺ content. In addition, B. subtilis reduced Na⁺ uptake and decreased the accumulation of oxidative stress markers: hydrogen peroxide (H2O2) and malondialdehyde (MDA) (-24% and − 71%, respectively), compared with salt-stressed non inoculated plants. Salinity decreased the quantum yields and electron transport rates of PSI [Y(I), ETR(I)] and PSII [Y(II), ETR(II)], while increasing PSI donor-side limitation [Y(ND)] and non-regulated energy dissipation [Y(NO)]. Inoculation restored all parameters to control levels and enhanced PSI oxidation (P700ox). B. subtilis effectively mitigates salinity-induced damage to Photosystems I and II, resulting in significant restoration of growth and photosynthetic performance in salt-challenged S. carnosa, which highlights its potential as a bioinoculant for saline soils.