Genome-Wide Identification and Expression Patterns of the F-box Family in Poplar under Salt Stress

Comprehensive analysis of the stress associated protein (SAP) family and the function of PagSAP9 from Populus alba × P. glandulosa in salt stress

Poplar tree growth is frequently hindered by environmental stressors, particularly soil salinization. Enhancing salt tolerance is essential for improving their adaptability and biomass under these conditions. The Stress-Associated Protein (SAP) family, characterized by A20/AN1 zinc finger domains, plays a crucial role in plants' tolerance to abiotic stress. However, functional investigations on SAP proteins in poplar are limited. In our study, we identified 19 SAP members in poplar, distributed unevenly across ten chromosomes and classified them into two major groups based on phylogenetic relationship and structure characteristics. Notably, only three segmental duplications were found, while no tandem duplications were detected. The PagSAP9 gene from Populus alba x P. glandulosa, featured both A20 and AN1 domains, was successfully characterized and localized to both cytoplasm and nucleus. It was predominantly expressed in roots and leaves and showed significantly upregulation under salt stress. And the overexpressing PagSAP9 transgenic poplars enhanced the activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT), alongside reduced malondialdehyde (MDA) content. Additionally, DAB and NBT histological stainings further confirmed the positive effects of PagSAP9 gene. Collectively, these findings highlight the potential of the PagSAP9 gene to improve salt tolerance in poplar, emphasizing the broader applicability of SAP genes in plant stress resistance and providing valuable genetic resources for developing resilient plant varieties.

Genome-wide identification of bZIP transcription factors in 12 Rosaceae species and modeling of novel mechanisms of EjbZIPs response to salt stress

In plantae, basic leucine zipper (bZIP) transcription factors (TFs) are widespread and regulate a variety of biological processes under abiotic stress. However, it has not been extensively studied in Rosaceae, and the functional effects of bZIP on Eriobotrya japonica under salt stress are still unknown. Therefore, in this study, the bZIP TF family of 12 species of Rosaceae was analyzed by bioinformatics method, and the expression profile and quantitative real-time polymerase chain reaction of E. japonica under salt stress were analyzed. The results showed that a total of 869 bZIP TFs were identified in 12 species of Rosaceae and divided into nine subfamilies. Differences in promoter cis-elements between subfamilies vary depending on their role. Species belonging to the same subfamily have a similar number of chromosomes and the number of genes contained on each chromosome. Gene duplication analysis has found segmental duplication to be a prime force in the evolution of Rosaceae species. In addition, nine EjbZIPs were significantly different, including seven up-regulated and two down-regulated in E. japonica under salt stress. Especially, EjbZIP13 was involved in the expression of SA-responsive proteins by binding to the NPR1 gene. EjbZIP27, EjbZIP30, and EjbZIP38 were highly expressed in E. japonica under salt stress, thus improving the salt tolerance capacity of the plants. These results can provide a theoretical basis for exploring the characteristics and functions of the bZIP TF family in more species and breeding salt-tolerant E. japonica varieties. It also provides a reference for resolving the response mechanism of bZIP TF in 12 Rosaceae species under salt stress.

Identification of the sweet orange (Citrus sinensis) bHLH gene family and the role of CsbHLH55 and CsbHLH87 in regulating salt stress

Salt stress is one of the primary environmental stresses limiting plant growth and production and adversely affecting the growth, development, yield, and fruit quality of Citrus sinensis. bHLH (basic helix-loop-helix) genes are involved in many bioregulatory processes in plants, including growth and development, phytohormone signaling, defense responses, and biosynthesis of specific metabolites. In this study, by bioinformatics methods, 120 CsbHLHgenes were identified, and phylogenetic analysis classified them into 18 subfamilies that were unevenly distributed on nine chromosomes. The cis-acting elements of the CsbHLH genes were mainly hormone-related cis-acting elements. Seventeen CsbHLH genes exhibited significant differences in expression under salt stress. Six CsbHLH genes with significant differences in expression were randomly selected for quantitative real-time polymerase chain reaction (qRT-PCR) validation. The qRT-PCR results showed a strong correlation with the transcriptome data. Phytohormones such as jasmonic acid (JA) are essential for biotic and abiotic stress responses in plants, and CsbHLH55 and CsbHLH87 are considered candidate target genes for sweet orange MYC2 transcription factors involved in the JA signaling pathway. These genes are the main downstream effectors in the JA signaling pathway and can be activated to participate in the JA signaling pathway. Activation of the JA signaling pathway inhibits the production of reactive oxygen species and improves the salt tolerance of sweet orange plants. The CsbHLH55 and CsbHLH87 genes could be candidate genes for breeding new transgenic salt-resistant varieties of sweet orange.

The Identification and Analysis of the Self-Incompatibility Pollen Determinant Factor SLF in Lycium barbarum

Self-incompatibility is a widespread genetic mechanism found in flowering plants. It plays a crucial role in preventing inbreeding and promoting outcrossing. The genes that control self-incompatibility in plants are typically determined by the S-locus female determinant factor and the S-locus male determinant factor. In the Solanaceae family, the male determinant factor is often the SLF gene. In this research, we cloned and analyzed 13 S2-LbSLF genes from the L. barbarum genome, which are located on chromosome 2 and close to the physical location of the S-locus female determinant factor S-RNase, covering a region of approximately 90.4 Mb. The amino acid sequence identity of the 13 S2-LbSLFs is 58.46%, and they all possess relatively conserved motifs and typical F-box domains, without introns. A co-linearity analysis revealed that there are no tandemly repeated genes in the S2-LbSLF genes, and that there are two pairs of co-linear genes between S2-LbSLF and the tomato, which also belongs to the Solanaceae family. A phylogenetic analysis indicates that the S2-LbSLF members can be divided into six groups, and it was found that the 13 S2-LbSLFs are clustered with the SLF genes of tobacco and Petunia inflata to varying degrees, potentially serving as pollen determinant factors regulating self-incompatibility in L. barbarum. The results for the gene expression patterns suggest that S2-LbSLF is only expressed in pollen tissue. The results of the yeast two-hybrid assay showed that the C-terminal region of S2-LbSLFs lacking the F-box domain can interact with S-RNase. This study provides theoretical data for further investigation into the functions of S2-LbSLF members, particularly for the identification of pollen determinant factors regulating self-incompatibility in L. barbarum.

Genome-wide identification and expression pattern analysis of the kiwifruit GRAS transcription factor family in response to salt stress

BACKGROUND

GRAS is a family of plant-specific transcription factors (TFs) that play a vital role in plant growth and development and response to adversity stress. However, systematic studies of the GRAS TF family in kiwifruit have not been reported.

RESULTS

In this study, we used a bioinformatics approach to identify eighty-six AcGRAS TFs located on twenty-six chromosomes and phylogenetic analysis classified them into ten subfamilies. It was found that the gene structure is relatively conserved for these genes and that fragmental duplication is the prime force for the evolution of AcGRAS genes. However, the promoter region of the AcGRAS genes mainly contains cis-acting elements related to hormones and environmental stresses, similar to the results of GO and KEGG enrichment analysis, suggesting that hormone signaling pathways of the AcGRAS family play a vital role in regulating plant growth and development and adversity stress. Protein interaction network analysis showed that the AcGRAS51 protein is a relational protein linking DELLA, SCR, and SHR subfamily proteins. The results demonstrated that 81 genes were expressed in kiwifruit AcGRAS under salt stress, including 17 differentially expressed genes, 13 upregulated, and four downregulated. This indicates that the upregulated AcGRAS55, AcGRAS69, AcGRAS86 and other GRAS genes can reduce the salt damage caused by kiwifruit plants by positively regulating salt stress, thus improving the salt tolerance of the plants.

CONCLUSIONS

These results provide a theoretical basis for future exploration of the characteristics and functions of more AcGRAS genes. This study provides a basis for further research on kiwifruit breeding for resistance to salt stress. RT-qPCR analysis showed that the expression of 3 AcGRAS genes was elevated under salt stress, indicating that AcGRAS exhibited a specific expression pattern under salt stress conditions.

Genome-wide identification of the TIFY family reveals JAZ subfamily function in response to hormone treatment in Betula platyphylla

BACKGROUND

The TIFY family is a plant-specific gene family and plays an important role in plant growth and development. But few reports have been reported on the phylogenetic analysis and gene expression profiling of TIFY family genes in birch (Betula platyphylla).

RESULTS

In this study, we characterized TIFY family and identified 12 TIFY genes and using phylogeny and chromosome mapping analysis in birch. TIFY family members were divided into JAZ, ZML, PPD and TIFY subfamilies. Phylogenetic analysis revealed that 12 TIFY genes were clustered into six evolutionary branches. The chromosome distribution showed that 12 TIFY genes were unevenly distributed on 5 chromosomes. Some TIFY family members were derived from gene duplication in birch. We found that six JAZ genes from JAZ subfamily played essential roles in response to Methyl jasmonate (MeJA), the JAZ genes were correlated with COI1 under MeJA. Co-expression and GO enrichment analysis further revealed that JAZ genes were related to hormone. JAZ proteins involved in the ABA and SA pathways. Subcellular localization experiments confirmed that the JAZ proteins were localized in the nucleus. Yeast two-hybrid assay showed that the JAZ proteins may form homologous or heterodimers to regulate hormones.

CONCLUSION

Our results provided novel insights into biological function of TIFY family and JAZ subfamily in birch. It provides the theoretical reference for in-depth analysis of plant hormone and molecular breeding design for resistance.