Characterization of alkaline stress tolerance mechanisms inLotusforage species modulated byPantoea eucalypti

Abstract

2This study was designed to elucidate the physiological responses of three Lotus forage 1 3 accessions to alkaline stress and the influence of the inoculation of a Pantoea eucalypti 1 4 endophyte strain on its mitigation. One-month-old diploid accessions of Lotus 1 5 3 1addition, under alkaline conditions, Lc dissipated more energy than control plants. 3 2 Expression of the metal-transporting gene NRAMP1 increased in the inoculated Lc 3 3 accession under stress, while remaining unmodified in Lt and LtxLc hybrid.3 4 [ 2 ]Altogether, the results obtained make clear the importance of inoculation with P.1 eucalypti, which contributed significantly to the mitigation of alkaline stress. Thus, all 2 the results provide useful information for improving alkaline tolerance traits in Lotus 3 forage species and their interspecific hybrids. 4 5 tolerance 7 8 Abbreviations 9 NPQ, non-photochemical fluorescence quenching; PSII, photosystem II; q P , 1 0 photochemical fluorescence quenching coefficients; ROS, reactive oxygen species; 1 1 PSII , quantum efficiency of PSII in light; Lt, Lotus tenuis; Lc: Lotus corniculatus; Lt x 1 2

Lotus tenuis biological nitrogen fixation and performance contribute to defining its strategic role in the Salado River Basin lowlands (Argentina)

“…In this study, Conyza bonariensis and Lythrum sp were tested as reference species because of their similarity to the legume in terms of phenology and rooting pro le with soil depth, closeness to the legume in the site, and accompaniment throughout the growth cycle. Shoot reference materials were harvested at the same time and at the same three phenological stages as the legume, and were processed in the same way for total N and δ 15 N determination, and 13 C estimation. The results of δ 13 C and δ 15 N were expressed as parts per thousand (‰) deviations, in the ratio of the heavy to the light isotope of each element, based on international standards (Vienna Pee Dee Belemnite, V-PDB for 13 C, and atmospheric N 2 for 15 N).…”

“…Shoot reference materials were harvested at the same time and at the same three phenological stages as the legume, and were processed in the same way for total N and δ 15 N determination, and 13 C estimation. The results of δ 13 C and δ 15 N were expressed as parts per thousand (‰) deviations, in the ratio of the heavy to the light isotope of each element, based on international standards (Vienna Pee Dee Belemnite, V-PDB for 13 C, and atmospheric N 2 for 15 N). The 'B' value is the δ 15 N of shoots of legumes that are fully dependent upon N 2 xation and sampled at the same growth stage and with the same rhizobia strains as the eld plants ( Unkovich and Baldock 2008).…”

“…Aliquots were loaded in a Thermo Delta Advantage isotope ratio mass spectrometer couple with a Flash 2000 Elemental Analyser at the Laboratorio de Isótopos Estables en Ciencias Ambientales (LIECA, Argentina) to obtain the N and C isotope ratio and the total N and C content. Natural abundances of 15 N and 13 C were expressed using 'delta' notation (‰):…”

“…L. tenuis not only contributes to forage production and in uences the growth of associated plant species in this area, but also contributes to restoration and phytoremediation of degraded environments (Vignolio et al 1999). This major bene cious effect on the plant community structure and ecosystem function warrants including it among the keystone species (González-Robles et al 2020; Campestre et al 2020). This effect is large relative to abundance of forage supply (i.e., high fodder community importance) (Bailleres et al 2020).…”

Biological Nitrogen Fixation, Carbon assimilation and plant performance of Lotus tenuis, contribute to define a strategic role in the lowlands in the Salado River Basin (Argentina)

“…This bene cious effect on the vegetal community observed justify its inclusion within the keystone species because of the large effects on community structure and ecosystem function (González-Robles et al 2020;Campestre et al 2020). This effect is large relative to abundance of forage supply (i.e., high fodder community importance) (Bailleres et al 2020).…”