Analysis of salt resistance conferred by salt overly sensitive 3 protein from mulberry (Morus notabilis)
Year: 2026
Type: article
Abstract: Introduction Soil salinization severely threatens crop productivity and agricultural sustainability. Mulberry ( Morus notabilis ) is an economically important woody crop, but the molecular mechanisms of its salt tolerance remain unclear. The conserved Salt Overly Sensitive 3 ( SOS3 ) gene regulates ion homeostasis under salt stress, making it a key target for exploring mulberry’s salt adaptation. Methods We cloned MnSOS3 from M. notabilis , constructed a prokaryotic expression vector (pCold-TF- MnSOS3 ) for transformation into Escherichia coli BL21, and generated MnSOS3 -overexpressing transgenic tobacco ( Nicotiana benthamiana ) via Agrobacterium -mediated transformation. Salt tolerance was evaluated in E. coli (0.6 M NaCl) and tobacco (300 mM NaCl), with Na⁺/K⁺ content quantification in tobacco leaves (250 mM NaCl, 24 h) and verification of MnSOS3-MnSOS2 interaction via yeast two-hybrid assay. Results and discussion Recombinant E. coli expressing MnSOS3 showed enhanced growth (maximum OD₆₀₀ = 0.338) vs. near-zero growth in the control. Transgenic tobacco line MnSOS3 -2 (highest expression) exhibited 33.3% survival under 300 mM NaCl, 2.5-fold higher than wild-type (WT, 13.3%). Transgenic leaves accumulated 54.8% less Na⁺ (0.95 ± 0.02 vs. 2.10 ± 0.07 mmol/g FW) and 45.8% more K⁺ (1.75 ± 0.02 vs. 1.20 ± 0.02 mmol/g FW) than WT, leading to a 67.8% lower Na⁺/K⁺ ratio (0.55 ± 0.01 vs. 1.71 ± 0.08). The yeast two-hybrid assay confirmed MnSOS3-MnSOS2 interaction. These findings show MnSOS3 boosts salt tolerance via Na⁺/K⁺ homeostasis and SOS pathway activation, a key resource for salt-tolerant mulberry breeding.
Source: Frontiers in Plant Science
Authors: Dan Liu, Changyu Qiu, Sheng Huang, Xiaomei Lu, Yanrong Zeng, Guangshu Zhu, Chaohua Zhang, Qiang Lin
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7126218787