Evaluating salinity effects on transgenic soybean harboring a cytokinin dehydrogenase gene at early growth stage

Abstract

Soil salinization, along with drought, is a natural threat that has a great impact on agricultural production in many locations throughout the world. The cytokinin oxidases/dehydrogenases(CKXs) playan essential role in determiningplant CK levels and several of which havebeen modulated to improve abiotic stress tolerance. In this study, theaimwasto investigate whether there were differential effects of salinity on wild-type (WT) soybean (Glycine max L.) plantsand a transgenic soybean line harboring GmCKX13, which had previously been identified as a responsive gene to osmotic stress. The effects of salt stress were monitored by deploying different concentrations of NaCl. According to the obtained results, the transgenic plants could maintain a better germination rateand radicle growththan the WT plants after a 4-day treatment of200 mM NaCl. In addition, the transgenic seedlings also displayed a more vigorous shoot and root growth with a larger biomass production under the adverse condition. The analytic data revealed that advantages acquired by the transformed plants at least came from the better capacity to reserve water in the tissue and lower stress damage, as indicated by a lower malondialdehyde content. Taking these findings together, it is suggested that modulating the expression of CKX13could contribute to better salt tolerance in soybeans, providing the foundation for conducting more elaborate studies in the futureand paving the pathway for the development of elitesalinity-tolerant varieties.