Functional characterization and intracellular localization of a Lotus tenuis NHX antiporter

AFFINITO AGOSTINA; ESPASANDIN FABIANA DANIELA; MARIANA DEL VAS; ALVAREZ MAYRA YANET; ADRIANA N ANDRES; SANSBERRO PEDRO ALFONSO; DÍAZ PALEO ANTONIO

Plant Cell, Tissue and Organ Culture

Springer

Año: 2021 vol. 146 p. 565 - 576

1573-5044

AbstractLotus tenuis is a perennial forage legume widely scattered in the flooding Pampa region of Argentina. Even when it is considereda salt-tolerant species, the molecular basis underlying this trait still remains unknown. Intracellular compartmentation ofNa+into vacuoles by NHX antiporters is an important and well known strategy to reduce ion toxicity during salt stress. In thisstudy, the subcellular localization of Lotus tenuis NHX1 was determined by the transient expression of a LtNHX1-GFP fusionprotein in Nicotiana benthamiana agroinfiltrated leaves, confirming that it is a tonoplast-located NHX antiporter. To studyLtNHX1 contribution to salinity tolerance, a transgenic Lotus tenuis line was obtained by Agrobacterium-mediated transformation.Overexpression of the transgene was confirmed by PCR and RT-PCR analyses. Compared to wild-type, transgenic plantsdisplayed less sensitivity and grew better under high salt stress, with higher survival rates, shoot length, and dry weight. Theseresults suggest that the activity of the tonoplast-located LtNHX1 antiporter contributes to Lotus tenuis salt tolerance.