Woo Ji-In, Adhikari Arjun, Gam Ho-Jun, Jeon Jin Ryeol, Lee Da-Sol, Kwon Eun-Hae, Kang Sang-Mo, Yun Byung-Wook, Lee In-Jung
Department of Applied Biosciences, Kyungpook National University, 41566, Daegu, Republic of Korea.
Department of Applied Biosciences, Kyungpook National University, 41566, Daegu, Republic of Korea.
Plant Physiol Biochem. 2025 Mar;220:109489. doi: 10.1016/j.plaphy.2025.109489. Epub 2025 Jan 7.
Plant growth-promoting rhizobacteria (PGPR) and biochar (BC) are recognized as effective biological agents for enhancing stress tolerance and mitigating heavy metal toxicity in crops. Therefore, this study aims to investigate the effects of the cadmium (Cd)-resistant PGPR strain Leclercia adecarboxylata HW04 (>4 mM Cd resistance) on soybean plants exposed to 300 μM Cd. HW04 was observed to possess the innate ability to synthesize indole-3-acetic acid and exopolysaccharides, which facilitated the absorption of Cd in the medium. Scanning electron microscopy (SEM) images revealed that HW04 effectively colonized the porous structure of BC. Their combined treatment significantly enhanced photosynthesis and improved the morphological characteristics of soybean plants. Additionally, the Cd content in soybean shoots significantly increased following both the sole or combined treatments of BC and HW04. However, the combined treatments significantly reduced Cd content in the roots and soil by 31% and 47%, respectively. HW04 inoculation alone increased Cd content in the roots by 43.7% while lowering it in the soil by 7.4%. Additionally, the co-application of HW04 and BC significantly enhanced calcium (Ca) and magnesium (Mg) assimilation while promoting Cd/Fe accumulation in soybean shoots. The higher expression of signaling cascade genes, including GmCaMK1 and GmCDPK5 (Ca signaling) and GmMAPK4a and GmMAPK7 (MAP kinase signaling), in the co-applied crops further validate the findings. The increase in abscisic acid levels and the decrease in salicylic acid levels after HW04 and BC application were correlated with enhanced stress tolerance in crops. These findings suggest that the combined application of HW04 and BC could serve as an effective, eco-friendly approach for mitigating heavy metal toxicity in crops and promoting phytoremediation.
植物促生根际细菌（PGPR）和生物炭（BC）被认为是增强作物胁迫耐受性和减轻重金属毒性的有效生物制剂。因此，本研究旨在探究抗镉（Cd）的PGPR菌株Leclercia adecarboxylata HW04（耐Cd > 4 mM）对暴露于300 μM Cd的大豆植株的影响。观察到HW04具有合成吲哚 - 3 - 乙酸和胞外多糖的固有能力，这促进了Cd在培养基中的吸收。扫描电子显微镜（SEM）图像显示HW04有效地定殖于生物炭的多孔结构中。它们的联合处理显著增强了光合作用并改善了大豆植株的形态特征。此外，单独或联合施用生物炭和HW04后，大豆地上部的Cd含量均显著增加。然而，联合处理分别使根部和土壤中的Cd含量显著降低了31%和47%。单独接种HW04使根部的Cd含量增加了43.7%，同时使土壤中的Cd含量降低了7.4%。此外，HW04和生物炭的共同施用显著增强了钙（Ca）和镁（Mg）的同化作用，同时促进了大豆地上部Cd/Fe的积累。共同施用作物中信号级联基因，包括GmCaMK1和GmCDPK5（Ca信号）以及GmMAPK4a和GmMAPK7（MAP激酶信号）的更高表达进一步验证了这些发现。施用HW04和生物炭后脱落酸水平的升高和水杨酸水平的降低与作物胁迫耐受性的增强相关。这些发现表明，HW04和生物炭的联合施用可作为一种有效、环保的方法来减轻作物中的重金属毒性并促进植物修复。
