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Salt excretory halophytes are the major sources of phytoremediation of salt-affected soils. Cressa cretica is a widely distributed halophyte in hypersaline lands in the Cholistan Desert. Therefore, identification of key physio-anatomical traits related to phytoremediation in differently adapted C. cretica populations was focused on. Four naturally adapted ecotypes of non-succulent halophyte Cressa cretica L. form hyper-arid and saline desert Cholistan. The selected ecotypes were: Derawar Fort (DWF, ECe 20.8 dS m−1) from least saline site, Traway Wala Toba (TWT, ECe 33.2 dS m−1) and Bailah Wala Dahar (BWD, ECe 45.4 dS m−1) ecotypes were from moderately saline sites, and Pati Sir (PAS, ECe 52.4 dS m−1) was collected from the highly saline site. The natural population of this species was collected and carefully brought to the laboratory for different structural and functional traits. As a result of high salinity, Na+, Cl–, K+, and Ca2+ content significantly increased at root and shoot level. At root level, some distinctive modifications such as increased sclerification in vascular bundles, enlarged vascular bundles, metaxylem vessels, phloem region, and storage parenchyma (cortex) are pivotal for water storage under extreme arid and osmotic condition. At the stem level, enhanced sclerification in outer cortex and vascular bundles, stem cellular area, cortical proportion, metaxylem and phloem area, and at the leaf level, very prominent structural adaptations were thicker and smaller leaves with increased density of salt glands and trichomes at surface, few and large stomata, reduced cortical and mesophyll parenchyma, and narrow xylem vessels and phloem area represent their non-succulent nature. The ecotype collected from hypersaline environments was better adapted regarding growth traits, ion uptake and excretion, succulence, and phytoremediation traits. More importantly, structural and functional traits such as root length and biomass, accumulation of toxic ions along with K+ in root and shoot, accumulation of Ca2+ in shoot and Mg2+ in root, excretion of toxic ions were the highest in this ecotype. In conclusion, all these alterations strongly favor water conservation, which certainly contributes to ecotypes survival under salt-induced physiological drought. Naturally adapted salt tolerant plants provide exceptional material for exploring adaptive mechanisms they use to confront high salt concentrations. Cressa cretica is a hypersaline hyperarid desert colonizer, which was previously underexplored. In the present study, we focused on the new insight on relationship among anatomical modifications, salt accumulation and excretion and phytoremediation potential of this rare species. [ABSTRACT FROM AUTHOR]

Micro and macro-morphological features contribute to plants' tolerance to a variety of environmental pollutants. The contribution of such structural modifications in the phytoremediation potential of Diplachne fusca populations collected from five saline habitats were explored when treated with 100 to 400 mM NaCl for 75 days along with control. Structural modifications in the populations from the highest salinity included development of aerenchyma in stem instead of chlorenchyma, absence of excretory hairs in stem, and exceptionally large trichomes on the leaf surface to help excretion of excess salt. Large parenchyma cells provided more space for water and solute storage, while broad metaxylem vessels were linked to better conduction water and nutrients, which ultimately excreted via glandular hairs, microhairs, and vesicular hairs. Broad metaxylem vessels and exceptionally long hairs observed in the populations collected from 52 dS m−1. In conclusion, large stem aerenchyma, exceptionally large trichomes on the leaf surface, and tightly packed outer cortical region in roots with intensive sclerification just inside the epidermis accompanied with salt excretion via glandular hairs, microhairs, and vesicular hairs were the main anatomical modifications involved in the phytoremediation potential of D. fusca in hyper-saline environments. Morpho-anatomical characteristics of the differently adapted populations of Diplachne fusca has never been reported. In particular, structural variation in their mechanism of adaptation for salinity tolerance was investigated for the first time in current study. [ABSTRACT FROM AUTHOR]