Kong Yunxin, Tian Yutian, Liu Kui, Li Xiangwei, Yang Yan, Feng Youhong, Rehman Muzammal, Fahad Shah, Maqbool Zahid, Malik Laraib, Deng Gang, Chen Suiyun
School of Agriculture, Yunnan University, Kunming 650504, China.
Biocontrol Engineering Research Center of Crop Diseases & Pests, School of Ecology and Environmental Sciences, Yunnan University, Yunnan Province, Kunming 650500, PR China.
ACS Omega. 2025 Jun 5;10(23):24832-24846. doi: 10.1021/acsomega.5c02028. eCollection 2025 Jun 17.
Drought stress severely limits plant growth and productivity, prompting the need for suitable mitigation strategies. This study investigates the role of selenium in improving drought tolerance in Nicotiana tabacum (tobacco) through morphophysiological adjustments and a strengthened antioxidant defense system. Therefore, a pot experiment was conducted to investigate the effects of varying levels of sodium selenite (0, 5, 10, 15, 20 mg L) on morphophysiological growth, oxidative stress indicators, antioxidant enzyme activities, and quality attributes of tobacco exposed to different drought conditions, imposed by maintaining soil moisture at 80% (D: no stress), 50% (D: moderate stress), and 30% (D: severe stress) of field capacity. Results revealed that drought stress significantly reduced the growth of tobacco; however, the use of sodium selenite at 15 mg L showed the highest increase in agronomic traits and biomass production of tobacco plants exposed to D, D, and D. After the 6 days and 20 days of drought stress, the highest decrease in malondialdehyde (MDA) content was achieved at 15 mg L sodium selenite under D (47.2% and 40%); however, the maximum decrease in hydrogen peroxide (HO) (44.4% and 25%) and superoxide (O ) contents (28% and 17.5%) was recorded at 15 mg L sodium selenite under D. The highest increase in antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) in tobacco plants was observed with sodium selenite at 15 mg L under D, D, and D. Electrolyte permeability in tobacco plants was also decreased by 21.5%, 29.1%, and 37.0% with 15 mg L sodium selenite under D, D, and D, respectively. Meanwhile, nicotine contents were increased by 4.59%, 6.91%, and 1.01% at 20 mg L sodium selenite under D, D, and D, respectively. Use of sodium selenite at 15 mg L showed the maximum increase in sugar contents (13.91%, 12.13%, 16.72%) and reducing sugar contents (15.03%, 15.09%, 5.46%) in tobacco plants exposed to D, D, and D, respectively, as compared to the control. Present findings reveal that sodium selenite at 15 mg L significantly enhances drought resilience in tobacco by modulating growth, antioxidant defense, and physiological responses.
干旱胁迫严重限制了植物的生长和生产力，因此需要合适的缓解策略。本研究通过形态生理调节和强化抗氧化防御系统，研究了硒在提高烟草抗旱性中的作用。为此，进行了盆栽试验，以研究不同水平的亚硒酸钠（0、5、10、15、20 mg/L）对处于不同干旱条件下烟草的形态生理生长、氧化应激指标、抗氧化酶活性和品质属性的影响，通过将土壤湿度维持在田间持水量的80%（D：无胁迫）、50%（D：中度胁迫）和30%（D：重度胁迫）来施加干旱条件。结果表明，干旱胁迫显著降低了烟草的生长；然而，在15 mg/L的亚硒酸钠处理下，处于D、D和D条件下的烟草植株的农艺性状和生物量产量增幅最大。在干旱胁迫6天和20天后，在D条件下，15 mg/L的亚硒酸钠处理使丙二醛（MDA）含量下降幅度最大（分别为47.2%和40%）；然而，在D条件下，15 mg/L的亚硒酸钠处理使过氧化氢（HO）含量（分别为44.4%和25%）和超氧阴离子（O）含量（分别为28%和17.5%）下降幅度最大。在D、D和D条件下，15 mg/L的亚硒酸钠处理使烟草植株中超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）和抗坏血酸过氧化物酶（APX）等抗氧化酶活性增幅最大。在D、D和D条件下，15 mg/L的亚硒酸钠处理分别使烟草植株的电解质渗透率下降了21.5%、29.1%和37.0%。同时，在D、D和D条件下，20 mg/L的亚硒酸钠处理分别使尼古丁含量提高了4.59%、6.91%和1.01%。与对照相比，15 mg/L的亚硒酸钠处理使处于D、D和D条件下的烟草植株的糖分含量（分别为13.91%、12.13%、16.72%）和还原糖含量（分别为15.03%、15.09%、5.46%）增幅最大。目前的研究结果表明，15 mg/L的亚硒酸钠通过调节生长、抗氧化防御和生理反应，显著提高了烟草的抗旱能力。
