Ectopic expression of Glycine max NHX3 and NHX1 genes enhance Arabidopsis drought tolerance

PEREZ BORROTO LS; WELIN B; PARDO EM; FLEITAS BELAMENDIA A L; TOUM L; GALLINO MALCUORI JP

Congreso; Congreso Internacional de Biotecnología de las Plantas y Agricultura. Bioveg 2019.; 2019

The important roleplayed by Na H antiporters in salt tolerance has been demonstrated inmany plant species, but there are relatively few studies providinginformation of their protective role during drought stress. To studythe possible contribution to stress tolerance under water-limitinggrowth conditions in plants, two closely related soybean Na Hantiporters, GmNHX3 and GmNHX1 isolated from cultivar MUNASQA, wereexpressed in Arabidopsis thaliana. Transgenic A. thaliana plantsoverexpressing GmNHX3 and GmNHX1displayed a higher visually droughttolerant phenotype than non-transformed plants, and this visualeffect was accompanied by an increase in relative water andchlorophyll content in transgenic lines under low water availability,as compared to non-transformed reference plants. Furthermore, anincreased sensitivity to abscisic acid was observed through stomatalclosure and seed germination inhibition studies in transgenic plantsexpressing GmNHX3, but not GmNHX1. Biochemical profiling revealedthat both GmNHX3 and GmNHX1 transgenic lines displayed increasedantioxidant enzyme activity, accumulated a higher concentration offree proline and showed less membrane damage due to lipidperoxidation under water deficit, as compared to wild-type plants.Finally, a significantly more rapid up-regulation of abioticstress-related genes was observed in transgenic lines as compared towild-type plants in response to both abscisic acid and mannitoltreatments. Altogether, the physiological, biochemical and molecularresults demonstrated that both GmNHX3 and GmNHX1 antiporters conferimproved protection during drought stress in higher plants and henceare potential genetic targets to improve drought tolerance in soybeanand other crops.p { margin-bottom: 0.25cm; line-height: 115%; }