TY - JOUR

T1 - New insights into the salt tolerance of the extreme halophytic species Lycium humile (Lycieae, Solanaceae)

AU - Palchetti, M. Virginia

AU - Reginato, Mariana

AU - Llanes, Analía

AU - Hornbacher, Johann

AU - Papenbrock, Jutta

AU - Barboza, Gloria E.

AU - Luna, Virginia

AU - Cantero, Juan José

N1 - Funding Information: This work was supported by Secretaría de Ciencia y Tecnología-UNC (Res. 411-18) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina (PIP number 11220170100147CO). M.V.P. thanks Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) for a doctoral fellowship. M.R. thanks German Academic Exchange Service (DAAD) for the short-term research stay scholarship.

PY - 2021/6

Y1 - 2021/6

N2 - Knowledge about Solanaceae species naturally adapted to salinity is scarce, despite the fact that a considerable number of Solanaceae has been reported growing in saline environments. Lycium humile Phil. inhabits extreme saline soils in the Altiplano-Puna region (Central Andes, South America) and represents a promising experimental model to study salt tolerance in Solanaceae plants. Seeds, leaves and roots were collected from a saline environment (Salar del Diablo, Argentina). Seeds were scarified and 30 days after germination salt treatments were applied by adding NaCl salt pulses (up to 750 or 1000 mM). Different growth parameters were evaluated, and leaf spectral reflectance, endogenous phytohormone levels, antioxidant capacity, proline and elemental content, and morpho-anatomical characteristics in L. humile under salinity were analyzed both in controlled and natural conditions. The multiple salt tolerance mechanisms found in this species are mainly the accumulation of the phytohormone abscisic acid, the increase of the antioxidant capacity and proline content, together with the development of a large leaf water-storage parenchyma that allows Na+ accumulation and an efficient osmotic adjustment. Lycium humile is probably one of the most salt-tolerant Solanaceae species in the world, and, in controlled conditions, can effectively grow at high NaCl concentrations (at least, up to 750 mM NaCl) but also, in the absence of salts in the medium. Therefore, we propose that natural distribution of L. humile is more related to water availability, as a limiting factor of growth in Altiplano-Puna saline habitats, than to high salt concentrations in the soils.

AB - Knowledge about Solanaceae species naturally adapted to salinity is scarce, despite the fact that a considerable number of Solanaceae has been reported growing in saline environments. Lycium humile Phil. inhabits extreme saline soils in the Altiplano-Puna region (Central Andes, South America) and represents a promising experimental model to study salt tolerance in Solanaceae plants. Seeds, leaves and roots were collected from a saline environment (Salar del Diablo, Argentina). Seeds were scarified and 30 days after germination salt treatments were applied by adding NaCl salt pulses (up to 750 or 1000 mM). Different growth parameters were evaluated, and leaf spectral reflectance, endogenous phytohormone levels, antioxidant capacity, proline and elemental content, and morpho-anatomical characteristics in L. humile under salinity were analyzed both in controlled and natural conditions. The multiple salt tolerance mechanisms found in this species are mainly the accumulation of the phytohormone abscisic acid, the increase of the antioxidant capacity and proline content, together with the development of a large leaf water-storage parenchyma that allows Na+ accumulation and an efficient osmotic adjustment. Lycium humile is probably one of the most salt-tolerant Solanaceae species in the world, and, in controlled conditions, can effectively grow at high NaCl concentrations (at least, up to 750 mM NaCl) but also, in the absence of salts in the medium. Therefore, we propose that natural distribution of L. humile is more related to water availability, as a limiting factor of growth in Altiplano-Puna saline habitats, than to high salt concentrations in the soils.

KW - Antioxidant

KW - Halophyte

KW - Mineral profile

KW - Morpho-anatomical responses

KW - Phytohormones

KW - Proline

KW - Salinity

UR - http://www.scopus.com/inward/record.url?scp=85103932946&partnerID=8YFLogxK

U2 - 10.1016/j.plaphy.2021.03.054

DO - 10.1016/j.plaphy.2021.03.054

M3 - Article

C2 - 33848929

AN - SCOPUS:85103932946

VL - 163

SP - 166

EP - 177

JO - Plant physiology and biochemistry

JF - Plant physiology and biochemistry

SN - 0981-9428

ER -