Genome-Wide Identification and Characterization of SET Domain Family Genes in Brassica napus L

Impact of biotic stresses on the Brassicaceae family and opportunities for crop improvement by exploiting genotyping traits

MAIN CONCLUSION

Utilizing RNAi, miRNA, siRNA, lncRNA and exploiting genotyping traits can help safeguard the food supply from illnesses and pest damage to Brassicas, as well as reduce yield losses caused by plant pathogens and insect pests. In the natural environment, plants face significant challenges in the form of biotic stress, due to various living organisms, leading to biological stress and a sharp decline in crop yields. To cope with these effects, plants have evolved specialized mechanisms to mitigate these challenges. Plant stress tolerance and resistance are influenced by genes associated with stress-responsive pathogens that interact with various stress-related signaling pathway components. Plants employ diverse strategies and mechanisms to combat biological stress, involving a complex network of transcription factors that interact with specific cis-elements to regulate gene expression. Understanding both plant developmental and pathogenic disease resistance mechanisms can allow us to develop stress-tolerant and -resistant crops. Brassica genus includes commercially important crops, e.g., broccoli, cabbage, cauliflower, kale, and rapeseed, cultivated worldwide, with several applications, e.g., oil production, consumption, condiments, fodder, as well as medicinal ones. Indeed, in 2020, global production of vegetable Brassica reached 96.4 million tones, a 10.6% rise from the previous decade. Taking into account their commercial importance, coupled to the impact that pathogens can have in Brassica productivity, yield losses up to 60%, this work complies the major diseases caused due to fungal, bacterial, viral, and insects in Brassica species. The review is structured into three parts. In the first part, an overview is provided of the various pathogens affecting Brassica species, including fungi, bacteria, viruses, and insects. The second part delves into the exploration of defense mechanisms that Brassica plants encounter against these pathogens including secondary metabolites, duplicated genes, RNA interference (RNAi), miRNA (micro-RNA), siRNA (small interfering RNA), and lncRNA (long non-coding RNA). The final part comprehensively outlines the current applications of CRISPR/Cas9 technology aimed at enhancing crop quality. Taken collectively, this review will contribute to our enhanced understanding of these mechanisms and their role in the development of resistance in Brassica plants, thus supporting strategies to protect this crucial crop.

Genome-wide analysis of SET domain genes and the function of GhSDG51 during salt stress in upland cotton (Gossypium hirsutum L.)

BACKGROUND

Cotton, being extensively cultivated, holds immense economic significance as one of the most prominent crops globally. The SET (Su(var), E, and Trithorax) domain-containing protein is of significant importance in plant development, growth, and response to abiotic stress by modifying the lysine methylation status of histone. However, the comprehensive identification of SET domain genes (SDG) have not been conducted in upland cotton (Gossypium hirsutum L.).

RESULTS

A total of 229 SDGs were identified in four Gossypium species, including G. arboretum, G. raimondii, G. hirsutum, and G. barbadense. These genes could distinctly be divided into eight groups. The analysis of gene structure and protein motif revealed a high degree of conservation among the SDGs within the same group. Collinearity analysis suggested that the SDGs of Gossypium species and most of the other selected plants were mainly expanded by dispersed duplication events and whole genome duplication (WGD) events. The allopolyploidization event also has a significant impact on the expansion of SDGs in tetraploid Gossypium species. Furthermore, the characteristics of these genes have been relatively conserved during the evolution. Cis-element analysis revealed that GhSDGs play a role in resistance to abiotic stresses and growth development. Furthermore, the qRT-PCR results have indicated the ability of GhSDGs to respond to salt stress. Co-expression analysis revealed that GhSDG51 might co-express with genes associated with salt stress. In addition, the silencing of GhSDG51 in cotton by the virus-induced gene silencing (VIGS) method suggested a potential positive regulatory role of GhSDG51 in salt stress.

CONCLUSIONS

The results of this study comprehensively analyze the SDGs in cotton and provide a basis for understanding the biological role of SDGs in the stress resistance in upland cotton.

Dynamics of epigenetic control in plants via SET domain containing proteins: Structural and functional insights

Plants control expression of their genes in a way that involves manipulating the chromatin structural dynamics in order to adapt to environmental changes and carry out developmental processes. Histone modifications like histone methylation are significant epigenetic marks which profoundly and globally modify chromatin, potentially affecting the expression of several genes. Methylation of histones is catalyzed by histone lysine methyltransferases (HKMTs), that features an evolutionary conserved domain known as SET [Su(var)3-9, E(Z), Trithorax]. This methylation is directed at particular lysine (K) residues on H3 or H4 histone. Plant SET domain group (SDG) proteins are categorized into different classes that have been conserved through evolution, and each class have specificity that influences how the chromatin structure operates. The domains discovered in plant SET domain proteins have typically been linked to protein-protein interactions, suggesting that majority of the SDGs function in complexes. Additionally, SDG-mediated histone mark deposition also affects alternative splicing events. In present review, we discussed the diversity of SDGs in plants including their structural properties. Additionally, we have provided comprehensive summary of the functions of the SDG-domain containing proteins in plant developmental processes and response to environmental stimuli have also been highlighted.

Harnessing Knowledge from Plant Functional Genomics and Multi-Omics for Genetic Improvement

Plant biology research has currently entered the post-genomics era with the advances in genomic technologies [...].

Molecular Evolution of Histone Methylation Modification Families in the Plant Kingdom and Their Genome-Wide Analysis in Barley

In this study, based on the OneKP database and through comparative genetic analysis, we found that HMT and HDM may originate from Chromista and are highly conserved in green plants, and that during the evolution from algae to land plants, histone methylation modifications gradually became complex and diverse, which is more conducive to the adaptation of plants to complex and variable environments. We also characterized the number of members, genetic similarity, and phylogeny of HMT and HDM families in barley using the barley pangenome and the Tibetan Lasa Goumang genome. The results showed that HMT and HDM were highly conserved in the domestication of barley, but there were some differences in the Lasa Goumang SDG subfamily. Expression analysis showed that HvHMTs and HvHDMs were highly expressed in specific tissues and had complex expression patterns under multiple stress treatments. In summary, the amplification and variation of HMT and HDM facilitate plant adaptation to complex terrestrial environments, while they are highly conserved in barley and play an important role in barley growth and development with abiotic stresses. In brief, our findings provide a novel perspective on the origin and evolutionary history of plant HvHMTs and HvHDMs, and lay a foundation for further investigation of their functions in barley.

Genome-Wide Identification and Salt Stress Response Analysis of the bZIP Transcription Factor Family in Sugar Beet

As one of the largest transcription factor families in plants, bZIP transcription factors play important regulatory roles in different biological processes, especially in the process of stress response. Salt stress inhibits the growth and yield of sugar beet. However, bZIP-related studies in sugar beet (Beta vulgaris L.) have not been reported. This study aimed to identify the bZIP transcription factors in sugar beet and analyze their biological functions and response patterns to salt stress. Using bioinformatics, 48 BvbZIP genes were identified in the genome of sugar beet, encoding 77 proteins with large structural differences. Collinearity analysis showed that three pairs of BvbZIP genes were fragment replication genes. The BvbZIP genes were grouped according to the phylogenetic tree topology and conserved structures, and the results are consistent with those reported in Arabidopsis. Under salt stress, the expression levels of most BvbZIP genes were decreased, and only eight genes were up-regulated. GO analysis showed that the BvbZIP genes were mainly negatively regulated in stress response. Protein interaction prediction showed that the BvbZIP genes were mainly involved in light signaling and ABA signal transduction, and also played a certain role in stress responses. In this study, the structures and biological functions of the BvbZIP genes were analyzed to provide foundational data for further mechanistic studies and for facilitating the efforts toward the molecular breeding of stress-resilient sugar beet.

Research Advances and Prospects of Orphan Genes in Plants

Orphan genes (OGs) are defined as genes having no sequence similarity with genes present in other lineages. OGs have been regarded to play a key role in the development of lineage-specific adaptations and can also serve as a constant source of evolutionary novelty. These genes have often been found related to various stress responses, species-specific traits, special expression regulation, and also participate in primary substance metabolism. The advancement in sequencing tools and genome analysis methods has made the identification and characterization of OGs comparatively easier. In the study of OG functions in plants, significant progress has been made. We review recent advances in the fast evolving characteristics, expression modulation, and functional analysis of OGs with a focus on their role in plant biology. We also emphasize current challenges, adoptable strategies and discuss possible future directions of functional study of OGs.

Genome-Wide Identification and Analysis of Ariadne Gene Family Reveal Its Genetic Effects on Agronomic Traits of Brassica napus

E3 ligases promote protein ubiquitination and degradation, which regulate every aspect of eukaryotic life. The Ariadne (ARI) proteins of RBR (ring between ring fingers) protein subfamily has been discovered as a group of potential E3 ubiquitin ligases. Only a few available research studies show their role in plant adaptations processes against the external environment. Presently, the functions of ARI proteins are largely unknown in plants. Therefore, in this study, we performed genome-wide analysis to identify the ARI gene family and explore their potential importance in B. napus. A total of 39 ARI genes were identified in the B. napus genome and were classified into three subfamilies (A, B and C) based on phylogenetic analysis. The protein–protein interaction networks and enrichment analysis indicated that BnARI genes could be involved in endoreduplication, DNA repair, proteasome assembly, ubiquitination, protein kinase activity and stress adaptation. The transcriptome data analysis in various tissues provided us an indication of some BnARI genes’ functional importance in tissue development. We also identified potential BnARI genes that were significantly responsive towards the abiotic stresses. Furthermore, eight BnARI genes were identified as candidate genes for multiple agronomic traits through association mapping analysis in B. napus; among them, BnaA02g12100D, which is the ortholog of AtARI8, was significantly associated with ten agronomic traits. This study provided useful information on BnARI genes, which could aid targeted functional research and genetic improvement for breeding in B. napus.