Chronic ionising radiation exposure is a main consequence of radioactive pollution of the environment. The development of functional genomics approaches coupled with morphological and physiological studies allows new insights into plant adaptation to life under chronic irradiation. Using morphological, reproductive, physiological, and transcriptomic experiments, we evaluated the way in which Arabidopsis thaliana natural accessions from the Chernobyl exclusion zone recover from chronic low-dose and acute high-dose γ-irradiation of seeds. Plants from radioactively contaminated areas were characterized by lower germination efficiency, suppressed growth, decreased chlorophyll fluorescence, and phytohormonal changes. The transcriptomes of plants chronically exposed to low-dose radiation indicated the repression of mobile genetic elements and deregulation of genes related to abiotic stress tolerance. Furthermore, these chronically irradiated natural accessions showed higher tolerance to acute 150 Gy γ-irradiation of seeds, according to transcriptome and phytohormonal profiles. Overall, the lower sensitivity of the accessions from radioactively contaminated areas to acute high-dose irradiation may come at the cost of their growth performance under normal conditions.

The development of adaptation strategies for crops under ever-changing climate conditions is a critically important food security issue. Studies of barley responses to ionising radiation showed that this evolutionarily ancient stress factor can be successfully used to identify molecular pathways involved in adaptation to a range of abiotic stressors. In order to identify potential molecular contributors to abiotic stress resilience, we examined the transcriptomic profiles of barley seedlings after exposure to γ-rays, electrons, and protons. A total of 553 unique differentially expressed genes with increased expression and 124 with decreased expression were detected. Among all types of radiation, the highest number of differentially expressed genes was observed in electron-irradiated samples (428 upregulated and 56 downregulated genes). Significant upregulation after exposure to the three types of radiation was shown by a set of ROS-responsive genes, genes involved in DNA repair, cell wall metabolism, auxin biosynthesis and signalling, as well as photosynthesis-related genes. Most of these genes are known to be involved in plant ROS-mediated responses to other abiotic stressors, especially with genotoxic components, such as heavy metals and drought. Ultimately, the modulation of molecular pathways of plant responses to ionising radiation may be a prospective tool for stress tolerance programmes.

The stimulation of growth and development of crops using ionising radiation (radiation hormesis) has been reported by many research groups. However, specific genes contributing to the radiation stimulation of plant growth are largely unknown. In this work, we studied the impact of the low-dose γ-irradiation of barley seeds on the growth dynamics and gene expression of eight barley cultivars in a greenhouse experiment. Our findings confirmed that candidate genes of the radiation growth stimulation, previously established in barley seedlings (PM19L-like, CML31-like, and AOS2-like), are significant in radiation hormesis throughout ontogeny. In γ-stimulated cultivars, the expression of these genes was aligned with the growth dynamics, yield parameters, and physiological conditions of plants. We identified contrasting cultivars for future gene editing and found that the γ-stimulated cultivar possessed some specific abiotic stress-responsive elements in the promotors of candidate genes, possibly revealing a new level of radiation hormesis effect execution. These results can be used in creating new productive barley cultivars, ecological toxicology of radionuclides, and eustress biology studies.

Relevance. The modern direction of bean breeding is focused on increasing the protein content in seeds and green beans, as well as vitamins, folic acid, biologically active substances and antioxidants, improving organoleptic properties and reducing the content of anti-nutritional substances. When creating the initial material for breeding, the following traits are important: resistance to biotic and abiotic factors, stable high yield, technological effectiveness, bush type and upright form, high symbiotic activity. An effective approach to increasing the genetic diversity of the initial material is radiation mutagenesis.Purpose of research. To study the effect of γ-irradiation of seeds on germination, morphometric parameters and duration of phenophases of Russian bean varieties and to determine the optimal dose of γ-radiation for the radiation mutagenesis protocol.Materials and Methods. Objects of the study – 3 bean varieties bred by Omsk State Agrarian University. The seeds were γ-irradiated (source – ⁶⁰Co) at doses of 50–200 Gy (dose rate 60 Gy/hour). The seeds were germinated under controlled conditions; germination energy and germination were assessed. The hypocotyl length, number and length of roots were measured in seedlings. The duration of development phases and productivity of plants were assessed. Statistical analysis was performed in R (ver. 4.3.3) and MS Office Excel 2019.Results. Hormesis effect was noted for 50 Gy γ-irradiation dose, which was manifested in higher values of germination energy and seed germination (variety Pamyati Ryzhkova), hypocotyl length (variety Marusya and Pamyati Ryzhkova) and in a decrease in the phenophases duration (variety Omskiy Rubin). Gamma irradiation at all applicable doses statistically significantly inhibited root development. Root length, as the most sensitive parameter to radiation, was chosen to calculate the dose causing a 50% growth reduction (RD50). For the Marusya variety, RD50 was 40 Gy, for the Pamyati Ryzhkova and Omsky Rubin varieties - 60 Gy.Conclusion. Variety specificity was established in the reaction to seed irradiation. Doses of 50 Gy or less (10-50 Gy) can be used to study the hormetic effects of γ-irradiation of bean seeds. Doses of 100 and 200 Gy turned out to be lethal. Starting doses of 40-60 Gy are recommended for the radiation mutagenesis protocols of Russian bean varieties.

Anthracnose stands as the primary obstacle to lupin cultivation, impeding development despite the considerable agronomic, ecological, and economic potential of such legume crops. This review explores recent efforts to unravel the complexities of anthracnose in domesticated lupins, focusing on both the plant perspective and the causative pathogenic agent, Colletotrichum lupini. Leveraging cutting-edge technologies has yielded crucial insights into various facets of this devastating disease, encompassing plant and pathogen biology, genetic and molecular regulations of the interaction, fungal diversity and population dynamics, and screening of plant genetic resources for anthracnose resistance. The lack of effective disease control measures, relying primarily on the use of disease-free seeds, highlights the need to develop anthracnose-resistant varieties. However, challenges arise from the intricacy of lupin's response to the disease, influenced by polygenic inheritance, in spite of loci with major effects, and environmental factors. The slow pace of genetic improvement underscores the need for more efficient breeding processes, including biotechnological approaches. This review offers a comprehensive overview of current progress and knowledge gaps, stressing the urgent need to further enhance understanding of C. lupini pathogenic mechanisms and lupin‘s resistance. Integrating advanced technologies and accelerated research efforts is paramount for achieving efficient disease management and sustainable lupin cultivation in the face of anthracnose challenges.