Morfo-anatomía e histoquímica de órganos vegetativos de Lycium humile (Solanaceae): rasgos adaptativos a humedales salinos de altura

LEAL, MARIANA; MERCADO, M. INÉS; CUELLO, A. SOLEDAD; ZAMPINI, I. CATIANA; PONESSA, GRACIELA I.; ISLA, M. INÉS

DARWINIANA

INSTITUTO DE BOTÁNICA DARWINION

Año: 2023 vol. 11 p. 466 - 484

0011-6793

Lycium humile Phil., is an extreme halophyte plant, endemic to Argentina, Bolivia, and Chile,which grows between 2000 and 4000 m a.s.l. in saline wetlands environments. The aim of thiswork is to identify morpho-anatomical and histochemical adaptive characteristics of the vegetativeorgans of L. humile linked to its tolerance to extreme environments of high altitude saline wetlands,in order to evaluate its potential as source of metabolites with commercial value or as source ofresistance genes related to abiotic stress tolerance. To carry out the analysis, during the period ofFebruary 2018, samples were obtained from plants belonging to 4 populations of the species (5individuals per population) located at the departments of Antofagasta de la Sierra, Santa María andAmbato, province of Catamarca, Argentina. Leaf and stems were studied using histochemical tests,conventional histological preparations and optical microscopy. Different foliar tissues were analyzedby scanning electron microscopy coupled to elemental X-ray diffraction spectroscopy (EDS). Theleaves and stems of the analyzed populations showed uniform anatomical and histochemical features.It was stated for the first time that the succulence of the leaf is reached by the folding of the tissuesevidenced in a tridimensional venation pattern. The presence of isolateral-radial mesophyll and aquiferparenchyma is highlighted as a unique feature characteristic for the species. The glandular trichomesand palisade parenchyma revealed complex contents of phenols, flavonoids, proteins, lipids, terpenes,and alkaloids; while the outer layer of the cuticles presented phenolic, terpenic and lipidic deposits.The EDS analysis showed crystalliferous idioblasts with high contents of Ca2+ and Na+. The stemsexhibited hypodermis and air chambers formed in the cortical and medullary layers. These anatomicaland histochemical characteristics of L. humile represent adaptive traits to saline high-altitude wetlandenvironments. Its functionality in relation to the environment and its potential as source of resistancegenes and metabolites interesting for the cosmetic and pharmaceutical industries are discussed.