The genus Arachis: an excellent resource for studies on differential gene expression for stress tolerance

Physiological and transcriptomic analyses revealed the alleviating effects of exogenous Ca2+ and NO compound treatment on high salt stress in Reaumuria soongorica

BACKGROUND

Soil salinization represents the most prevalent abiotic stress, severely impacting a severe impact on plant growth and crop yield. Consequently, delving into the mechanism through which exogenous substances enhance plant salt tolerance holds significant importance for the stabilization and augmentation of crop yield.

RESULT

In this study, within the context of salt stress, the seedlings of R. soongorica were subjected to exogenous Ca2+ and NO treatments. The aim was to comprehensively explore the alleviation effects of exogenous Ca2+ and NO on the high salt stress endured by R. soongorica from the perspectives of physiology and transcriptomics. The experimental results demonstrated that the combined treatment of exogenous Ca2+ and NO increased the relative water content and free water content of R. soongorica seedlings during salt stress conditions. Simultaneously, it induced a reduction in the leaf sap concentration, leaf water potential, water saturation deficit, and the ratio of bound water to free water. These modifications effectively regulated water metabolism and mitigated physiological drought induced by salt stress. In addition, the concurrent treatment of exogenous Ca2+ and NO could diminish Na+ and Cl- levels in R. soongorica seedlings under salt stress. At the same time, it was effective in elevating the contents of K+ and Ca2+, thereby facilitating the adjustment of the ion equilibrium. As a result, this treatment served to relieve the ion toxicity precipitated by salt stress, which is crucial for maintaining the physiological homeostasis and viability of the seedlings. Transcriptional analysis revealed that 65 differentially expressed genes (DEGs) were observable at three distinct stress time points in the context of high salt stress. Additionally, 154 DEGs were detected at three stress time points during the combined treatment. KEGG enrichment analysis revealed that phenylpropanoids biosynthesis, plant hormone signal transduction, MAPK signalling pathway, brassinosteroid biosynthesis and zeatin biosynthesis were significantly enriched under high salt stress and exogenous Ca2+ and NO compound treatment. Furthermore, WGCNA uncovered that multiple genes, including ADK, SBT, F-box protein, MYB, ZIP, PAL, METTL, and LRR, were implicated in the adaptive and mitigating mechanisms associated with the combined treatment of exogenous Ca2+ and NO in modulating high salt stress within R. soongorica seedlings.

CONCLUSION

The outcomes of this study are highly conducive to disclosing the mechanism through which the combined treatment of exogenous Ca2+ and NO ameliorates the salt tolerance of R. soongorica from both physiological and transcriptional aspects. It also paves a solid theoretical groundwork for the employment of biotechnology in the breeding of R. soongorica, thereby offering valuable insights and a scientific basis for further research and practical applications in enhancing the plant's ability to withstand salt stress and for the development of more salt-tolerant varieties of R. soongorica.

Transcription factors as molecular switches regulating plant responses to drought stress

Plants often experience abiotic stress, which severely affects their growth. With the advent of global warming, drought stress has become a pivotal factor affecting crop yield and quality. Increasing numbers of studies have focused on elucidating the molecular mechanisms underlying plant responses to drought stress. As molecular switches, transcription factors (TFs) are key participants in drought-resistance regulatory networks in crops. TFs regulate the transcription of downstream genes and are regulated by various upstream regulatory factors. Therefore, understanding the mechanisms of action of TFs in regulating drought stress can help enhance the adaptive capacity of crops under drought conditions. In this review, we summarize the structural characteristics of several common TFs, their multiple drought-response pathways, and recently employed research strategies. We describe the application of new technologies such as analysis of stress granule dynamics and function, multi-omics data, gene editing, and molecular crosstalk between TFs in drought resistance. This review aims to familiarize readers with the regulatory network of TFs in drought resistance and to provide a reference for examining the molecular mechanisms of drought resistance in plants and improving agronomic traits.

Thaumatin-like Proteins in Legumes: Functions and Potential Applications-A Review

Thaumatin-like proteins (TLPs) comprise a complex and evolutionarily conserved protein family that participates in host defense and several developmental processes in plants, fungi, and animals. Importantly, TLPs are plant host defense proteins that belong to pathogenesis-related family 5 (PR-5), and growing evidence has demonstrated that they are involved in resistance to a variety of fungal diseases in many crop plants, particularly legumes. Nonetheless, the roles and underlying mechanisms of the TLP family in legumes remain unclear. The present review summarizes recent advances related to the classification, structure, and host resistance of legume TLPs to biotic and abiotic stresses; analyzes and predicts possible protein-protein interactions; and presents their roles in phytohormone response, root nodule formation, and symbiosis. The characteristics of TLPs provide them with broad prospects for plant breeding and other uses. Searching for legume TLP genetic resources and functional genes, and further research on their precise function mechanisms are necessary.

Transcriptome-Wide N6-Methyladenosine (m6A) Methylation Analyses in a Compatible Wheat-Puccinia striiformis f. sp. tritici Interaction

N6-methyladenosine (m6A) is a prevalent internal modification in eukaryotic mRNA, tRNA, miRNA, and long non-coding RNA. It is also known for its role in plant responses to biotic and abiotic stresses. However, a comprehensive m6A transcriptome-wide map for Puccinia striiformis f. sp. tritici (Pst) infections in wheat (Triticum aestivum) is currently unavailable. Our study is the first to profile m6A modifications in wheat infected with a virulent Pst race. Analysis of RNA-seq and MeRIP-seq data revealed that the majority of differentially expressed genes are up-regulated and hyper-methylated. Some of these genes are enriched in the plant-pathogen interaction pathway. Notably, genes related to photosynthesis showed significant down-regulation and hypo-methylation, suggesting a potential mechanism facilitating successful Pst invasion by impairing photosynthetic function. The crucial genes, epitomizing the core molecular constituents that fortify plants against pathogenic assaults, were detected with varying expression and methylation levels, together with a newly identified methylation motif. Additionally, m6A regulator genes were also influenced by m6A modification, and their expression patterns varied at different time points of post-inoculation, with lower expression at early stages of infection. This study provides insights into the role of m6A modification regulation in wheat's response to Pst infection, establishing a foundation for understanding the potential function of m6A RNA methylation in plant resistance or susceptibility to pathogens.