Department of Agronomy, Faculty of Crop Production Sciences, The University of Agriculture, Peshawar, Peshawar, 25130, Pakistan.
Department of Plant Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, 44000, Pakistan.
Environ Sci Pollut Res Int. 2024 Apr;31(17):24836-24850. doi: 10.1007/s11356-024-32755-7. Epub 2024 Mar 8.
Chromium (Cr) contamination in soil-plant systems poses a pressing environmental challenge due to its detrimental impacts on plant growth and human health. Results exhibited that Cr stress decreased shoot biomass, root biomass, leaf relative water content, and plant height. However, single and co-application of Bacillus subtilis (BS) and arbuscular mycorrhizal fungi (AMF) considerably enhanced shoot biomass (+ 21%), root biomass (+ 2%), leaf relative water content (+ 26%), and plant height (+ 13) under Cr stress. The frequency of mycorrhizal (F) association (+ 5%), mycorrhizal colonization (+ 13%), and abundance of arbuscules (+ 5%) in the non-stressed soil was enhanced when inoculated with combined BS and AMF as compared to Cr-stressed soil. The co-inoculation with BS and AMF considerably enhanced total chlorophyll, carotenoids, and proline content in Cr-stressed plants. Cr-stressed plants resulted in attenuated response in SOD, POD, CAT, and GR activities when inoculated with BS and AMF consortia by altering oxidative stress biomarkers (HO and MDA). In Cr-stressed plants, the combined application of BS and AMF considerably enhanced proline metabolism, for instance, P5CR (+ 17%), P5CS (+ 28%), OAT (- 22%), and ProDH (- 113%) as compared to control. Sole inoculation with AMF downregulated the expression of SIPIP2;1, SIPIP2;5, and SIPIP2;7 in Cr-stressed plants. However, the expression of NCED1 was downregulated with the application of sole AMF. In contrast, the relative expression of Le4 was upregulated in the presence of AMF and BS combination in Cr-stressed plants. Therefore, it is concluded that co-application of BS and AMF enhanced Cr tolerance by enhancing proline metabolism, antioxidant enzymes, and aquaporin gene expression. Future study might concentrate on elucidating the molecular processes behind the synergistic benefits of BS and AMF, as well as affirming their effectiveness in field experiments under a variety of environmental situations. Long-term research on the effect of microbial inoculation on soil health and plant production might also help to design sustainable chromium remediation solutions.
土壤-植物系统中的铬污染是一个紧迫的环境挑战，因为它对植物生长和人类健康有不利影响。结果表明，铬胁迫降低了地上部生物量、根生物量、叶片相对含水量和株高。然而，枯草芽孢杆菌（BS）和丛枝菌根真菌（AMF）的单一和共同应用在铬胁迫下显著提高了地上部生物量（+21%）、根生物量（+2%）、叶片相对含水量（+26%）和株高（+13%）。与铬胁迫土壤相比，在非胁迫土壤中接种 BS 和 AMF 后，菌根（F）关联（+5%）、菌根定殖（+13%）和丛枝（+5%）的丰度增加。BS 和 AMF 的共同接种显著提高了铬胁迫下植物的总叶绿素、类胡萝卜素和脯氨酸含量。BS 和 AMF 接种后，铬胁迫下植物的 SOD、POD、CAT 和 GR 活性的响应减弱，通过改变氧化应激生物标志物（HO 和 MDA）。在铬胁迫下植物中，BS 和 AMF 的联合应用显著增强了脯氨酸代谢，例如 P5CR（+17%）、P5CS（+28%）、OAT（-22%）和 ProDH（-113%）与对照相比。单独接种 AMF 下调了铬胁迫下植物中 SIPIP2;1、SIPIP2;5 和 SIPIP2;7 的表达。然而，单独接种 AMF 时 NCED1 的表达下调。相反，在 Cr 胁迫下植物中，AMF 和 BS 组合的存在上调了 Le4 的相对表达。因此，结论是 BS 和 AMF 的共同应用通过增强脯氨酸代谢、抗氧化酶和水通道蛋白基因表达来提高 Cr 耐受性。未来的研究可能集中在阐明 BS 和 AMF 协同效益的分子过程上，并在各种环境条件下的田间试验中证实其有效性。关于微生物接种对土壤健康和植物生产影响的长期研究也可能有助于设计可持续的铬修复解决方案。
