Rapid industrialization, urbanization, and mine tailings runoff are the main sources of heavy metal contamination of agricultural land, which has become one of the major constraints to crop growth and productivity. Finding appropriate solutions to protect plants and agricultural land from heavy metal pollution/harmful effects is important for sustainable development. Phytoremediation and plant growth-promoting rhizobacteria (PGPR) are promising methods for this purpose, which both heavily rely on an appropriate understanding of the anatomical structure of plants. Specialized anatomical features, such as those of epidermis and endodermis and changes in the root vascular tissue, are often associated with heavy metal tolerance in legumes. This review emphasizes the uptake and transport of heavy metals by legume plants that can be used to enhance soil detoxification by phytoremediation processes. Moreover, the review also focuses on the role of rhizospheric organisms in the facilitation of heavy metal uptake, the various mechanisms of enhancing the availability of heavy metals in the rhizosphere, the genetic diversity, and the microbial genera involved in these processes. The information presented here can be exploited for improving the growth and productivity of legume plants in metal-prone soils.

The concentration of Na+, K+, Ca2+ and Mg2+ in the root and aboveground organs of three halophyte species (Salicornia europaea, Suaeda maritima and Salsola soda) as well as in the soil where they grew from maritime and inland saline areas were investigated. The aim of our research was to evaluate the capability of some halophyte species to absorb different cations and to find if there exists differentiation of salt accumulation between populations from inland and maritime saline areas. In five analyzed localities (Tivatska solila, Ulcinj salina, Slano Kopovo, Melenci, Okanj), external Na+ concentrations exceeded other investigated cations. Our investigated halophytes accumulate more Na+ than the Mg2+, Ca2+ and K+ and more cations were recorded in aboveground organs than in the root. Populations from maritime saline area generally had higher cation concentrations than plants from inland saline area.

Anatomical and Random Amplified Polymorphic DNA (RAPD) analysis of two typical populations of Salicornia europaea from Montenegro and Greece (Lesvos), one typical population of S. ramosissima from Spain and one population that belongs to the Salicornia genus from Serbia, was undertaken to develop a new strategy for identifying Salicornia plants. Anatomical variability and differentiation were examined using Principal Component Analysis (PCA) and Multivariate Discriminant Function Analysis (MDA). On the basis of the anatomical measurements, the four populations were classified into three groups: one joining the plants from Serbia and Spain, one comprising the Montenegrin group and one comprising the Lesvos group. RAPD analysis indicated that populations from Spain and Serbia were closely related to each other and the Lesvos group was quite different from all the other investigated populations. These results opened up the possibility that the specimens from Serbia belonged to S. ramosissima and not to S. europaea, as reported previously.

Limonium gmelinii (Willd.) O. Kuntze 1891 subsp. hungaricum (Klokov) So? is Pannonian endemic subspecies that inhabits continental halobiomes, while Limonium anfractum (Salmon) Salmon 1924 is one of the indicators of halophyte vegetation of marine rocks and its distribution is restricted to the southern parts of Mediterranean Sea coast. In this work, micromorphological and anatomical characters of leaves of these two Limonium taxa were analyzed, in order to examine their adaptations to specific environmental conditions on saline habitats. The results showed that both taxa exhibited strong xeromorphic adaptations that reflected in flat cell walls of epidermal cells, thick cuticle, high palisade/spongy tissue ratio, high index of palisade cells, the presence of sclereid idioblasts in leaf mesophyll and mechanical tissue by phloem and xylem. Both taxa are crynohalophytes and have salt glands on adaxial and abaxial epidermis for excretion of surplus salt. Relatively high dimensions of mesophyll cells, absence of non-glandular hairs and unprotected stomata slightly increased above the level of epidermal cells, are also adaptations to increased salinity.