Chenopodium quinoa Willd. is an annual facultative halophytic pseudocereal widely studied for its physiology and grain yield owing to its great tolerance to unfavorable growing conditions. However, the morphophysiological and anatomical characteristics of plants’ photosynthetic organs under various and combined abiotic stresses during the early stages of development have not been thoroughly studied. Therefore, the current study compared the influence of osmotic, salt, and combined stress at different intensities on the morphology and anatomy of photosynthetic organs in young quinoa plants. The main findings demonstrate that salt stress at an intensity between 100 and 200 mM NaCl is not critical for the growth of young quinoa plants and that the young plants can withstand salt stress at an intensity of 300 mM NaCl. However, it can be concluded that some adaptation mechanisms of the plants were already violated at a salt stress intensity of 200 mM NaCl, while significant changes in the water balance of the plants were observed at an intensity of 300 mM NaCl, possibly caused by damage to the cell structures.

Rhodiola linearifolia Boriss., a perennial alpine plant from the Crassulaceae family, is renowned for its unique medicinal properties. However, existing research on this species is limited, particularly regarding the impact of altitude on its physiological and medicinal compounds. The current study employed morphophysiological and anatomical methods to explore the adaptive mechanisms of R. linearifolia across different altitudinal gradients, while also examining photosynthetic pigments and metabolomic changes. Our results indicate that despite the simultaneous effects of various mountain abiotic factors, significant correlations can be identified between altitude and trait variation. An optimal growth altitude of 2687 m above sea level was identified, which is pivotal for sustainable ecosystem management and potential species introduction strategies. It is noted that increasing altitude stress enhances the synthesis of secondary antioxidant metabolites in R. linearifolia, enhancing its pharmaceutical potential.

The current study investigated the impact of cold stress on the morphological, physiological, and phytochemical properties of Juglans regia L. (J. regia) using in vitro microclone cultures. The study revealed significant stress-induced changes in the production of secondary antioxidant metabolites. According to gas chromatography–mass spectrometry (GC–MS) analyses, the stress conditions profoundly altered the metabolism of J. regia microclones. Although the overall spectrum of metabolites was reduced, the production of key secondary antioxidant metabolites significantly increased. Notably, there was a sevenfold (7×) increase in juglone concentration. These findings are crucial for advancing walnut metabolomics and enhancing our understanding of plant responses to abiotic stress factors. Additionally, study results aid in identifying the role of individual metabolites in these processes, which is essential for developing strategies to improve plant resilience and tolerance to adverse conditions.

The adaptive potential and biochemical properties of the Amaranthaceae species make them promising for introduction into agriculture and markets, particularly in arid conditions. Molecular genetic polymorphism analysis is the most powerful tool for studying plant resources; therefore, the current study aimed to investigate the polymorphisms of allelic variations in the ARF and SOD gene families, as well as the genetic diversity of six Amaranthaceae species, using retrotransposon-based fingerprinting with the multi-locus EPIC-PCR profiling approach. Additionally, the iPBS PCR amplification was employed for genome profiling, revealing variations in genetic diversity among the studied Amaranthaceae samples. The observed genetic diversity in Amaranthaceae species contributes to their enhanced tolerance to adverse environmental conditions. The knowledge about the genetic diversity of genes crucial in plant development and stress resistance can be useful for the genetic improvement of cultivated Amaranthaceae species.

There are about 60 species of the genus Rheum L. (Polygonaceae) distributed mainly in temperate and subtropical Asia, with the largest number (38 species, including 19 endemics) recorded in China. All species of the genus are used as medicinal plants. According to modern pharmacology, the most important property of the rhubarb root is regulation of the stomach and intestine function, due to its laxative effect; rhubarb also has antipyretic properties and antioxidant activity. The high content of dietary fibers provides protection against cardiovascular diseases, and vitamin K is valuable for the prevention of osteoporosis. However, the active ingredients and their mechanism of action have not been sufficiently studied. Rheum tataricum L., known for its high resistance to drought, salinity, and lack of nutrients is the least studied species of wild rhubarb. The whole plant, and especially the leaves, contains several toxic compounds, in particular anthraquinone glycosides and calcium oxalate crystals. Here we present the results of a comparative analysis of the anatomical and morphological structure of Rh. tataricum plants from ecopopulations growing in the Balkhash and Karatal districts of the Almaty region. We identified the differences due to the weather and climatic conditions of the ecopopulations. It is important to note that many idioblasts containing calcium oxalate were found in the rhizomes of Rh. tataricum, which prevent animals from eating plants and getting poisoned. The number of idioblasts in the central circle of the Rh. tataricum rhizome was smaller in the Balkhash district than in the Karatal district, while the idioblasts were larger in size in the former district. The medicinal and nutritional value of Rh. tataricum growing in a semi-desert environment indicates a high potential of the species in plant breeding, medicine, and as a food source. Key words: Rheum tataricum, extract, pharmacology, antioxidant activity, ecopopulation, morphology.

Walnut (Juglans regia L.), a plant belonging to the genus Juglans of the family Juglandaceae, native to the region extending from the Balkans east to the Himalayas. Since ancient times, walnut has been widely used in both folk and traditional medicine for various diseases and is among the medicinal plants of interest due to its rich content of antioxidants such as flavonoids, phenolic acids, melatonin, folate, gamma-tocopherol, selenium and proanthocyanidins in various organs (kernels, shells, roots and leaves). However, until now there have been virtually no studies on how walnut can respond to abiotic stresses in vitro culture and what benefits such a study can provide, so our work is devoted to the analysis of the antioxidant activity of J. regia shoot microclones in vitro after exposure to low positive temperatures. The results of this work show that Juglans regia effigia microclones subjected to cold stress have greater antioxidant potential than microclones grown under more favorable temperature conditions.