Editing Metabolism, Sex, and Microbiome: How Can We Help Poplar Resist Pathogens?

Poplar (Populus) is a genus of woody plants of great economic value. Due to the growing economic importance of poplar, there is a need to ensure its stable growth by increasing its resistance to pathogens. Genetic engineering can create organisms with improved traits faster than traditional methods, and with the development of CRISPR/Cas-based genome editing systems, scientists have a new highly effective tool for creating valuable genotypes. In this review, we summarize the latest research data on poplar diseases, the biology of their pathogens and how these plants resist pathogens. In the final section, we propose to plant male or mixed poplar populations; consider the genes of the MLO group, transcription factors of the WRKY and MYB families and defensive proteins BbChit1, LJAMP2, MsrA2 and PtDef as the most promising targets for genetic engineering; and also pay attention to the possibility of microbiome engineering.

Culturable Bacterial Endophytes of Wild White Poplar (Populus alba L.) Roots: A First Insight into Their Plant Growth-Stimulating and Bioaugmentation Potential.

The white poplar (Populus alba L.) has good potential for a green economy and phytoremediation. Bioaugmentation using endophytic bacteria can be considered as a safe strategy to increase poplar productivity and its resistance to toxic urban conditions. The aim of our work was to find the most promising strains of bacterial endophytes to enhance the growth of white poplar in unfavorable environmental conditions. To this end, for the first time, we performed whole-genome sequencing of 14 bacterial strains isolated from the tissues of the roots of white poplar in different geographical locations. We then performed a bioinformatics search to identify genes that may be useful for poplar growth and resistance to environmental pollutants and pathogens. Almost all endophytic bacteria obtained from white poplar roots are new strains of known species belonging to the genera Bacillus, Corynebacterium, Kocuria, Micrococcus, Peribacillus, Pseudomonas, and Staphylococcus. The genomes of the strains contain genes involved in the enhanced metabolism of nitrogen, phosphorus, and metals, the synthesis of valuable secondary metabolites, and the detoxification of heavy metals and organic pollutants. All the strains are able to grow on media without nitrogen sources, which indicates their ability to fix atmospheric nitrogen. It is concluded that the strains belonging to the genus Pseudomonas and bacteria of the species Kocuria rosea have the best poplar growth-stimulating and bioaugmentation potential, and the roots of white poplar are a valuable source for isolation of endophytic bacteria for possible application in ecobiotechnology.

Impact of pathogen reduction methods on immunological properties of the COVID-19 convalescent plasma.

BACKGROUND AND OBJECTIVES: COVID-19 convalescent plasma is an experimental treatment against SARS-CoV-2. The aim of this study is to assess the impact of different pathogen reduction methods on the levels and virus neutralizing activity of the specific antibodies against SARS-CoV2 in convalescent plasma. MATERIALS AND METHODS: A total of 140 plasma doses collected by plasmapheresis from COVID-19 convalescent donors were subjected to pathogen reduction by three methods: methylene blue (M)/visible light, riboflavin (R)/UVB and amotosalen (A)/UVA. To conduct a paired comparison, individual plasma doses were divided into 2 samples that were subjected to one of these methods. The titres of SARS-CoV2 neutralizing antibodies (NtAbs) and levels of specific immunoglobulins to RBD, S- and N-proteins of SARS-CoV-2 were measured before and after pathogen reduction. RESULTS: The methods reduced NtAbs titres differently: among units with the initial titre 80 or above, 81% of units remained unchanged and 19% decreased by one step after methylene blue; 60% were unchanged and 40% decreased by one step after amotosalen; after riboflavin 43% were unchanged and 50% (7%, respectively) had a one-step (two-step, respectively) decrease. Paired two-sample comparisons (M vs. A, M vs. R and A vs. R) revealed that the largest statistically significant decrease in quantity and activity of the specific antibodies resulted from the riboflavin treatment. CONCLUSION: Pathogen reduction with methylene blue or with amotosalen provides the greater likelihood of preserving the immunological properties of the COVID-19 convalescent plasma compared to riboflavin.