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Using light and scanning electron microscopy (SEM), comparative analyses of anatomical and micro‐morphological characteristics of the leaf, stem and peduncle have been carried out on five species of the family Asteraceae (Aster amellus, Galatella linosyris, G. cana, G. sedifolia and Tripolium pannonicum), previously included in Aster although more recent morphological and phylogenetic studies indicate that Galatella and Tripolium should be considered as separate genera. The aim of the present study was to establish whether these species could be differentiated by anatomical characters. Our results will further inform the decision to separate the four aforementioned species from the genus Aster, as well as indicate whether anatomical data confirm the proposed circumscription of the genera Galatella and Tripolium. The anatomical observations and data analyses using discriminant and correspondence analysis showed that the combination of selected qualitative and quantitative characters separated the species into three groups, corresponding to the three genera. The characters of the leaf blade, its epidermis in particular, proved to be of the highest significance for discrimination at generic rank. The specific qualitative features that characterize each of the species and the genera were emphasized. Our findings support the attribution of the examined species to three genera, which proved to be anatomically distinguishable and well defined.

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.

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The lamina, main vein and peduncle anatomical properties of Centaurea sadleriana Janka plants from two populations, were examined using light and scanning electron microscopy. The indumentum was comprised of glandular and non-glandular trichomes of two types. The leaves were amphistomatic, isolateral, with strongly developed palisade tissue. Secretory ducts were observed along the phloem or sclerenchyma of large vascular bundles. Collenchyma alternated with chlorenchyma in the main vein and peduncle. Large groups of strongly lignified sclerenchyma were present along the phloem of peduncle vascular bundles. These features, together with thickened walls of epidermal cells and cuticle, numerous trichomes and thick-walled parenchyma in the perimedullar zone, were perceived as a xeromorphic peduncle structural adaptation. Non-enzymatic antioxidant compounds of phenolic origin were detected in small amounts and their respective content was higher in leaves compared to inflorescences. Compounds of phenolic orgin showed positive correlation with total potenial of antioxidant activity indicated by the DPPH assay. Greater total quantity of polyphenols and tannins was detected in leaves of plants from Zobnatica locality, while leaves of plants from Rimski Sanac were characterized by higher content of total flavonoids and proantocyanidins. Phytochemical analysis showed that dominant secondary biomolecules in inflorescences were phenolic pigments including anthocyanins and leucoanthocyanins, and free quinones in leaves.