Zinc, an important micronutrient, offers a crucial role in plant growth and development. However, its deficiency can significantly impair plant growth by disrupting essential physiological processes, leading to stunted growth and reduced reproductive capacity. Agronomic Zn biofortification offers the dual benefits of enhancing yield and improving grain Zn concentration. In this study, we evaluated various doses of zinc sulfate (ZnSO4; 0, 100, 200, 300, 400, and 500 mM) for their effectiveness in improving the performance of rice cultivars (Basmati-198 and PK-386) in alkaline Zn-deficient soil. Our results showed that ZnSO4 application significantly enhanced seedlings performance where 400 mM dose outperformed other treatments. Notably, ZnSO4 application at 400 mM increased seedling Zn accumulation by 152.40% and 125.96% in Basmati-198 and PK-386, respectively, over control. This dose also improved root dry weight by 74.52%, net photosynthesis by 41%, the activities of catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) by 79.88%, 23.80%, 58.77% and 75.72%, respectively, in Basmati-198 compared with PK-386. Moreover, ZnSO4 application (at 400 mM) alleviated oxidative damage by reducing malondialdehyde (58.12% and 56.63%), hydrogen peroxide (60.13% and 58.15%), and electrolyte leakage (31.39% and 29.06%) in Basmati-198 and PK-386, respectively, compared with the control without ZnSO4 supplementation. This study also demonstrated that ZnSO4 application increased the expression of bZIP genes, including OsbZIP08, OsbZIP16, OsbZIP21, and OsbZIP60, which are highly responsive to Zn deficiency in rice. Notably, the expression levels of these genes were highest following ZnSO4 application at 400 mM, resulting in a 7.1- and eightfold increase in OsbZIP21 expression, a 6.2- and 7.4-fold increase in OsbZIP16 expression, a 5- and 6.3-fold increase in OsbZIP08 expression, and a 4.5- and fivefold increase in OsbZIP60 expression in PK-386 and Basmati-198, respectively, compared to the control. The highest fold-change expression was observed for OsbZIP21 gene in Basmati-198, followed by OsbZIP16 and OsbZIP08, while OsbZIP60 exhibited the lowest fold change in the same cultivar. These findings contribute to ongoing efforts to enhance plant nutrient uptake efficiency and deepen our understanding of the mechanisms governing Zn assimilation in plants.

Role of ZnSO₄ in Modulating Physiochemical Traits and bZIP Genes Expression in Rice Varieties Grown in Zinc-Deficient Soil

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发表日期：

2025年4月15日

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Bushra Rehman,
Asma Zulfiqar,
Muhammad Zafar Saleem,
Maqsood Ul Hussan,
Manzer H. Siddiqui,
Sadam Hussain

摘要

Zinc, an important micronutrient, offers a crucial role in plant growth and development. However, its deficiency can significantly impair plant growth by disrupting essential physiological processes, leading to stunted growth and reduced reproductive capacity. Agronomic Zn biofortification offers the dual benefits of enhancing yield and improving grain Zn concentration. In this study, we evaluated various doses of zinc sulfate (ZnSO₄; 0, 100, 200, 300, 400, and 500 mM) for their effectiveness in improving the performance of rice cultivars (Basmati-198 and PK-386) in alkaline Zn-deficient soil. Our results showed that ZnSO₄ application significantly enhanced seedlings performance where 400 mM dose outperformed other treatments. Notably, ZnSO₄ application at 400 mM increased seedling Zn accumulation by 152.40% and 125.96% in Basmati-198 and PK-386, respectively, over control. This dose also improved root dry weight by 74.52%, net photosynthesis by 41%, the activities of catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) by 79.88%, 23.80%, 58.77% and 75.72%, respectively, in Basmati-198 compared with PK-386. Moreover, ZnSO₄ application (at 400 mM) alleviated oxidative damage by reducing malondialdehyde (58.12% and 56.63%), hydrogen peroxide (60.13% and 58.15%), and electrolyte leakage (31.39% and 29.06%) in Basmati-198 and PK-386, respectively, compared with the control without ZnSO₄ supplementation. This study also demonstrated that ZnSO₄ application increased the expression of bZIP genes, including OsbZIP08, OsbZIP16, OsbZIP21, and OsbZIP60, which are highly responsive to Zn deficiency in rice. Notably, the expression levels of these genes were highest following ZnSO₄ application at 400 mM, resulting in a 7.1- and eightfold increase in OsbZIP21 expression, a 6.2- and 7.4-fold increase in OsbZIP16 expression, a 5- and 6.3-fold increase in OsbZIP08 expression, and a 4.5- and fivefold increase in OsbZIP60 expression in PK-386 and Basmati-198, respectively, compared to the control. The highest fold-change expression was observed for OsbZIP21 gene in Basmati-198, followed by OsbZIP16 and OsbZIP08, while OsbZIP60 exhibited the lowest fold change in the same cultivar. These findings contribute to ongoing efforts to enhance plant nutrient uptake efficiency and deepen our understanding of the mechanisms governing Zn assimilation in plants.

Role of ZnSO4 in Modulating Physiochemical Traits and bZIP Genes Expression in Rice Varieties Grown in Zinc-Deficient Soil

摘要

Role of ZnSO₄ in Modulating Physiochemical Traits and bZIP Genes Expression in Rice Varieties Grown in Zinc-Deficient Soil