Overexpression of AtSZF2 from Arabidopsis Showed Enhanced Tolerance to Salt Stress in Soybean

Abstract

Plants have adapted to environmental challenges by expressing many plant genes in response to the stresses. Among those genes, CCCH zinc finger proteins are involved in abiotic and biotic stresses. Transgenic soybean plants overexpressing AtSZF2 were produced to investigate that its ectopic overexpression enhanced salt stress tolerance by Agrobacterium-mediated transformation using half-seed explants. Sixteen transgenic lines were chosen to analyze for T-DNA insertion and transcription levels, and most of them were confirmed as positive. In further analysis with Southern blot, stable transformation event and copy number were confirmed. Following high salinity stress on the detached leaf and whole plant of two transgenic lines (#4 and #6) revealed that the ectopic expression of AtSZF2 was correlated with stress tolerance in phenotype, ion leakage and chlorophyll content with statistical significance. In another test with 20% PEG treatment, similar tolerance of transgenic plants was observed with lower ion leakage and higher chlorophyll content, indicating that the damage of cell membrane was prevented in transgenic plants. Finally, expression of various abiotic stress-responding genes was detected by reverse transcriptase and quantitative real-time PCR analysis with the transgenic plants. It could be proposed that introduction of AtSZF2 resulted in the modulation of ABA/stress responsive gene expression in transgenic soybean plants and make them tolerant against salt stress. Considering soybean as a salt-sensitive crop and importance of salt stress tolerance in specific farming region, the introduction of AtSZF2 may provide an approach for crop improvement in soybean breeding.

Overexpression of a Chromatin Architecture-Controlling ATPG7 has Positive Effect on Yield Components in Transgenic Soybean

“…The biggest advantage of half-seed method is saving at least one week in the early procedure of transformation and no requirement for sophisticated wounding on explant. This modified protocol enabled us to produce the successful soybean transgenic plants with many genes (Kim et al 2012;Kim et al 2013, Kim et al 2016Kim et al 2017).…”

“…The desired destination vector, pCSEN (provided by Dr. D.H. Lee) was used for the vector construction. The plasmid, pCSEN-ATPG7 was constructed and transformed into Agrobacterium tumefaciens strain EHA105 (Karimi et al 2002), following the protocol described by Kim et al (2013Kim et al ( , 2016Kim et al ( , 2017.…”

“…Kwangankong) were utilized in Agrobacterium-mediated transformation experiments, following the protocol described by Kim et al (2013Kim et al ( , 2016Kim et al ( , 2017. T0 plants with two trifoliates were screened using an herbicide assay to determine the resistance and to identify putative transformants that express Bar gene.…”

“…1) was used for the soybean transformation with half-seeds of the Korean soybean cultivar Kwangankong (Fig. 2) described by Kim et al (2013Kim et al ( , 2016Kim et al ( , 2017. A total of 27 transgenic soybean plants were produced from about 400 explants.…”

“…This improvement has substantial implication as a big forward step to functional genomics of soybean via transgenic research. With this modified transformation protocol, many genes have been introduced to soybean in order to investigate their physiological change or improvement in crops (Kim et al 2013;Kim et al 2016;Kim et al 2017).…”