Synergistic Interaction between Symbiotic N2 Fixing Bacteria and Bacillus strains to Improve Growth, Physiological Parameters, Antioxidant Enzymes and Ni Accumulation in Faba Bean Plants (Vicia faba) under Nickel Stress

Abstract

Several activities in the agriculture sector lead to the accumulation of Nickel (Ni) in soil. Therefore, effective and economical ways to reduce soil bioavailability of Ni must be identified. Five isolates of Rhizobium leguminosarum biovar Viceae (ICARDA 441, ICARDA 36, ICARDA 39, TAL–1148, and ARC–207) and three bacterial strains (Bacillus subtilis, B. circulance, and B. coagulans) were evaluated for tolerance and biosorption of different levels of Ni (0, 20, 40, 60, and 80 mg L−1). Pot experiments were conducted during the 2019/2020 and 2020/2021 seasons using four inoculation treatments (inoculation with the most tolerant Rhizobium (TAL–1148), inoculation with the most tolerant Rhizobium (TAL–1148) + B. subtilis, inoculation with the most tolerant Rhizobium (TAL–1148) + B. circulance, and inoculation with the most tolerant Rhizobium (TAL–1148) + B. coagulans) under different levels of Ni (0, 200, 400, and 600 mg kg−1), and their effects on growth, physiological characteristics, antioxidant enzymes, and Ni accumulation in faba bean plants (Vicia faba C.V. Nobaria 1) were determined. The results showed that Rhizobium (TAL–1148) and B. subtilis were the most tolerant of Ni. In pot trials, inoculation with the most tolerant Rhizobium TAL–1148 + B. subtilis treatment was shown to be more effective in terms of growth parameters (dry weight of plant, plant height, number of nodules, and N2 content), and this was reflected in physiological characteristics and antioxidant enzymes under 600 mg kg−1 Ni compared to the other treatments in the 2019/2020 season. In the second season, 2020/2021, a similar pattern was observed. Additionally, lower concentrations of Ni were found in faba bean plants (roots and shoots). Therefore, a combination of the most tolerant Rhizobium (TAL–1148) + B. subtilis treatment might be used to reduce Ni toxicity.

Evaluation of Legume–Rhizobial Symbiotic Interactions Beyond Nitrogen Fixation That Help the Host Survival and Diversification in Hostile Environments

“…The presence of an efflux system, which reduces accumulation, has been a common strategy used by the rhizobia against several heavy metals. Some rhizobial symbionts have high Ni biosorption and storage capabilities, limiting their mobility in the plant [ 31 , 32 ]. A strong positive relationship between low concentrations of As in the shoots of Medicago truncatula and reduced expression of the plant’s NRT3.1-like gene, which is a nitrate transporter, has been reported [ 33 ].…”

“…Such collaborations have been successfully used to improve the stress tolerance capacity of rhizobia and leguminous plants. A substantial increase in Ni tolerance (600 mg Ni kg −1 ) was observed in faba bean plants when the Rhizobium TAL–1148 strain was co-inoculated with Ni-tolerant Bacillus subtilis [ 31 ]. A similar effect of metal toxicity mitigation was noticed in the Pongamia pinnata plant with the combined interaction of certain R. pisi and Ochrobacterium pseudogrignonense strains [ 46 , 47 ].…”

Respon Pertumbuhan Dan Hasil Kentang Var. Cingkariang Dan Populasi Gulma Terhadap Isolat Rizobakteri Indigen

“…Rizobakteria telah banyak dimanfaatkan dalam budidaya tanaman pertanian terutama dalam meningkatkan ketahanan tanaman terhadap cekaman air (Bouremani et al 2023;Fadiji et al 2022) pada tanaman alfalfa (Han et al 2022) dan bibit walnut (Liu et al 2023). Peranan PGPR juga telah terbukti mningkatkan ketahanan tanaman dan mitigasi terhadap cekaman salinitas pada tanaman gandum (Ayaz et al 2022;Gul et al 2023), tanaman tomat dan melon (Gopalakrishnan et al 2022), lettuce (Ouhaddou et al 2022) dan beberapa tanaman obat (Kumar et al 2022), perlindungan terhadap penyakit layu Fusarium pada tanaman tomat (Heo et al 2022) dan penyakit busuk akar pada cabai yang disebabkan oleh jamur Fusarium solani (Qiao et al 2023), serta peningkatan mekanisme ketahanan terhadap cekaman logam berat Nickel pada tanaman Vicia faba (Elbagory et al 2022) dan jenis tanaman legum lainnya (Pandey et al 2022).…”