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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]

Highlights • Phenotypic plasticity is exceptionally high in A. adscensionis. • Survival in environmental heterogeneity is due to specific anatomical modifications. • Sclerification protects plants organs from collapse and desiccation. • Water conservation is a prime strategy in A. adscensionis for survival. Abstract Aristida adscensionis L. is a widely distributed grass species that particularly invades Potohar region (arid/semi-arid conditions) of the country. Exploration of adaptive components in this grass in relation to altitudinal gradient is the first attempt. Plant samples were collected from 6 different altitudinal ranges, viz. 400, 600, 800, 1000, 1200 and 1400 m a.s.l. Morpho-anatomical and physiological features along altitudinal gradient varied significantly that showed phenotypic plasticity in this species to inhabit a variety of environmental conditions. Stomata at 400 m altitude were larger and rhomboid-shaped, which changed to narrowly elliptic at moderate elevations and circular at high elevations. Growth and biomass production were maximum at 800–1000 m a.s.l. along with most of the morpho-anatomical and physiological features like proportion of vascular tissue, nutrient uptake, and chlorophyll pigments. Xeromorphy was high in plants colonisng at 1200 m elevations, which was indicated by an intensive sclerification, increased amount of storage parenchyma, increased vascular bundle number, deeply grooved bulliform cells, and dense pubescence on adaxial leaf surface. Leaf succulence was the unique feature in plants inhabiting 1400 m elevation. Another prominent feature was the development of chlorenchyma inner to stem epidermis. All these features reflect the tolerance capacity of A. adsecnsionis against environmental adversaries like salinity, aridity and low temperatures of the Potohar region. [ABSTRACT FROM AUTHOR]

• Grasses dominated diverse habitats, due to their specific adaptive strategies. • Root morpho-anatomical characteristics are more developed at lower elevations. • Anatomical modifications were specific and related to water conservation. • Structural and functional attributes contribute to widespread distribution of grasses. The adaptability potential of plants enables them to colonize diverse habitats along elevation gradients. Studying these adaptive traits and linking them to environmental attributes provide useful information to understand limitations imposed by elevation gradients on distribution of plant species. To meet these objectives, six most dominant perennial grass species with broad distributional ranges along an elevation gradient from 300–1400 m a.s.l in northern Punjab (Pakistan) were selected for the present study. Dominance of different grass species were linked to proportion of parenchyma, sclerification of aerial plant parts, size of vascular tissue, leaf thickness, and size and density of trichomes. Chrysopogon serrulatus dominated all elevations except the highest one, which was directly linked to increased root area and high proportion of storage parenchyma, vascular region, large metaxylem vessels, increased sclerification in aerial parts, and size and density of trichomes. Cymbopogon jwarancusa dominated lower and middle elevations (300–1000 m) and exhibited increased sclerification in stem and leaves, higher vascular bundle area, and, increased leaf sheath thickness. Lognormal distribution exhibited a non-linear response for eco-morphological and physiological characteristics with decreasing pattern along increase in elevation. Physiological traits responded negatively in response to climatic variables. Root anatomical traits exhibited nonlinear response at lower elevation, while stem traits responded positively at medium elevational gradients (700–1000 m). Leaf sheath showed positive response with elevation and temperature. In conclusion, morpho-physiological and anatomical modifications were specific to grasses studied, which contributed differently towards growth and survival along elevation gradient. [ABSTRACT FROM AUTHOR]

Seven local landraces of common and durum wheat (Triticum aestivumL. andT. durumL.) from the arid and semi-arid areas of the Sultanate of Oman were examined for specific leaf and stem structural features for water conservation. On the basis of shoot fresh and dry weights (g plant−1), degree of tolerance to drought and salt stresses in these wheat landraces/cultivars can be ranked as S-24 > J-305 > Sarraya > Senain > Cooley > MH-97 > Missani>Hamira > Shwairaa. Modifications related to water conservation were found to be high degree of sclerification, succulence in leaf and stem, low resistance to water conductance in vascular tissue, and pubescence on leaf surface. The salt and drought tolerant cultivar S-24 showed high proportion of chlorenchyma and intensive sclerification in stem structure, and well-developed bulliform cells and dense pubescence on the leaves. These modified features were poorly developed in lesser stress tolerant Omani wheat landraces like Hamira and Shwairaa. Accession Senain also showed stem succulence (solid stem), an important xeromorphic feature. Structural modifications in landrace Missani were found to be increased sclerification in vascular tissue and high number of metaxylem vessels and high proportion of parenchyma in stem, and highly developed bulliform cells in leaf. Overall, the promising anatomical traits in highly stress tolerant landraces/cultivars were chlorenchyma in stem, rigorous sclerification in parenchyma and around vascular tissue, stem and leaf succulence, and enhanced ratio of major conducting tissue. [ABSTRACT FROM PUBLISHER]

Morpho-anatomical and physiological response of Cyperus alopecuroides Rottb. (Family Cyperaceae), occurring in industrial-polluted water near Sheikhupura, Pakistan, to metal (Ni and Cd) stress were examined. Two levels (30 and 60 mg L-1) of each of Ni and Cd were maintained during the experiment. Growth and development were severely affected by both metals, however, Cd was more toxic than Ni, although Ni was absorbed readily by the roots and its considerable amount was translocated to aerial plant parts due to its mobile nature. In contrast, high amount of Cd were retained in the roots. Specific root physio-anatomical modifications for Ni tolerance were found result from leaf turgor potential, high accumulation of organic osmolytes, enhanced sclerification, and aerenchyma formation, while leaves were more developed bulliform cells and stellate parenchyma. Cd tolerance was found to be related to accumulation of organic osmolytes, thick epidermis and endodermis, enhanced sclerification, and stellate cell formation in stem, and well developed bulliform cells in leaves. The structural and functional response of metal toxicity were very specific in C. alopecuroides depending on the type of metal which enabled this species to survive successfully in metal-polluted wetlands. [ABSTRACT FROM AUTHOR]

Two ecotypes of Cenchrus setigerus Vahl (birdwood grass) were collected from dry mountains surrounding hyper-saline Kalar Kahar Lake and Gatwala artificial forest plantation. The ramets of the two ecotypes were established in pots for 15 days and then subjected to 100% FC (control) or 75% and 50% FC (field capacity) levels. Growth attributes such as plant height, tillers per plant, leaves per plant, shoot fresh and dry weights were severely affected while root length was the only attribute that increased in both ecotypes under moisture stress. Root anatomical attributes like cortical and pith parenchyma, and vascular region thickness increased in both ecotypes under water stress. Root radius increased in the Faisalabad ecotype at 75% FC, while increased in Salt Range ecotype only at 50% FC. Stem cellular region, sclerenchymatous cell area, vascular bundle area and metaxylem area increased significantly under moderate and severe water deficit only in the Faisalabad ecotype. The Salt Range ecotype exhibited intensive sclerification and large vascular tissue at 50% FC. Leaf anatomical attributes like epidermal cell area, bundle sheath thickness, sclerenchyma thickness and its cell area, and, vascular bundles area significantly increased in the Salt Range ecotype with increasing water deficit. The Faisalabad ecotype showed significant increase in vascular bundle area, metaxylem area and adaxial stomatal area. These findings indicated that both C. setigerus ecotypes mainly relied on water conservation and survival rather than maintaining growth and biomass production. The anatomical modifications at root, stem and leaf levels ensured survival of C. setigerus ecotypes in extreme arid conditions. • Growth attributes were severely affected while root length increased under stress • Root radius increased in the Faisalabad ecotype at 75% FC, while at 50% FC in Salt Range ecotype • Stem area, sclerification and vascular bundle area increased only in Faisalabad ecotype • The Salt Range ecotype exhibited intensive sclerification in leaves and large vascular tissue at 50% FC • The Faisalabad ecotype showed an increase in vascular bundle area, metaxylem area and adaxial stomatal area [ABSTRACT FROM AUTHOR]