Soybean PI 675847 A as a new source of salt tolerance

Abstract

Soil salinity is a major limitation to legume production in many areas of the world. Identification of the genetic source of salt tolerance is critical in soybean breeding for improving soybean production in salt-affected regions. Vietnam has unique sources of soybean germplasm and varieties are grown in the area where exposure to salinity is frequent. However, there is little research on the identification of salt tolerant sources in the Vietnamese gene pool. The present study compared 18 Vietnamese soybean cultivars for their differences in salt tolerance. Under a range of NaCl stress from 0 to 200 mM NaCl, there was a large variation in salt tolerance among the 18 soybean lines evaluated. The soybean accession PI 675847 A (Vietnamese variety DT2008), was identified as a useful source of salt tolerance. During vegetative growth, PI 675847 A had lower leaf scorch scores, higher cell membrane stability, better photosynthesis and biomass accumulation under NaCl stress than the other 17 strains evaluated. In addition, PI 675847 A maintained better growth and seed yield in salt-affected soils compared with the sensitive lines. Analyses of ion contents in plant leaves under saline conditions showed that PI 675847 A was able to limit uptake and transport of Na+ and Cl−. Because of its higher productivity under saline conditions, PI 675847 A will be a useful germplasm source in soybean improvement programs for salt tolerance.

Co‐expression of Arabidopsis AtAVP1 and AtNHX1 to Improve Salt Tolerance in Soybean

“…Together, these studies suggest that it is possible to improve salt tolerance in soybean by genetic engineering. In addition, salt tolerance in soybean is primarily determined by NaCl exclusion from uptake and transport to the shoot and leaves (Phang et al, 2008;Guan et al, 2014;Quach et al, 2018). In the present study, our data showed that under 100 mM NaCl (?10.0 dS m −1 ), the transgenic plants had better growth than the WT, but the better performance did not last long and all genotypes died after 6 wk of salt treatment.…”

“…In this study, the Arabidopsis AtAVP1 and AtNHX1 were expressed individually or in combination in DT26 (Quach et al, 2018). We found that the transgenic plants showed improvement of salt tolerance to moderate stress (100 mM NaCl) and severe stress (200 mM NaCl).…”

“…This observation is not unexpected in soybean, since salt tolerance at different growth stages are not well correlated; the plants with tolerance at emergence stages may not tolerate salt stress at vegetative growth stages (Phang et al, 2008). In addition, salt tolerance in soybean is primarily determined by NaCl exclusion from uptake and transport to the shoot and leaves (Phang et al, 2008;Guan et al, 2014;Quach et al, 2018). Co-expression of AVP1 and NHX1 in a low-Na + -uptake soybean genetic background might be an option for long-term salt exposure.…”

“…The final binary vectors, designated as pSalt10 and pSalt11, were delivered into Agrobacterium strain EHA101. Soybean transformation was performed on the variety DT26, which was recently introduced for winter and spring crops in northern Vietnam (Quach et al, 2018). Twenty-five transgenic events of the two gene constructs were generated.…”