Genome-wide identification of the B3 gene family in soybean and the response to melatonin under cold stress

The members of zinc finger-homeodomain (ZF-HD) transcription factors are associated with abiotic stresses in soybean: insights from genomics and expression analysis

BACKGROUND

Zinc finger homeodomain (ZF-HD) belongs to the plant-specific transcription factor (TF) family and is widely involved in plant growth, development and stress responses. Despite their importance, a comprehensive identification and analysis of ZF-HD genes in the soybean (Glycine max) genome and their possible roles under abiotic stress remain unexplored.

RESULTS

In this study, 51 ZF-HD genes were identified in the soybean genome that were unevenly distributed on 17 chromosomes. All GmZF-HD genes contained a conserved ZF-HD_dimer domain and had diverse physicochemical features. Furthermore, the GmZF-HD gene structures exhibited 3 to 10 conserved motifs, and most of them showed intronless gene structures. Phylogenetic analysis categorized them into eight major groups with the highest closeness to dicots including Brassica rapa and Malus domestica. The cis-element analysis recognized plant growth and development (10%), phytohormones (31%) and stress-responsive (59%) elements. Synteny analysis identified 73 segmental and 1 tandem duplicated genes that underwent purifying selection. The collinearity analysis revealed that GmZF-HD genes showed higher homology with dicot species, indicating common ancestors with close evolutionary relationships. A total of 94 gma-miRNAs from 41 diverse miRNA families were identified, targeting 40 GmZF-HD genes, with GmZF-HD6 being most targeted by 7 miRNAs, and gma-miR4993 emerging as the dominant miRNA family. Different TFs including ERF, LBD, BBR-BPC and MYB, etc., were predicted in all 51 GmZF-HD genes upstream regions and visualized in the network. Expression profiling through RNA-Seq showed diverse expressions of GmZF-HD genes in different tissues including seeds, roots, shoots and leaves under diverse conditions. Further, the qRT-PCR analysis demonstrated that all tested GmZF-HD genes were significantly induced in soybean leaves, mainly the GmZF-HD5/6/13/39 and GmZF-HD45 genes were significantly upregulated (2.5 to 8.8 folds) under the tested stress treatments compared to control, highlighting their potential roles in response to stresses in soybean.

CONCLUSION

Overall, this study reveals comprehensive insights into the ZF-HD genes in soybeans and provides a valuable contribution towards functional studies for soybean improvement under stress conditions.

Multi-Omics Analysis Provides Insights into Green Soybean in Response to Cold Stress

Green soybean (Glycine max (L.) Merrill) is a highly nutritious food that is a good source of protein and fiber. However, it is sensitive to low temperatures during the growing season, and enhancing cold tolerance has become a research hotspot for breeding improvement. Background/Objectives: The underlying molecular mechanisms of cold tolerance in green soybean are not well understood. Methods: Here, a comprehensive analysis of transcriptome and metabolome was performed on a cold-tolerant cultivar treated at 10 °C for 24 h. Results: Compared to control groups, we identified 17,011 differentially expressed genes (DEGs) and 129 differentially expressed metabolites (DEMs). The DEGs and DEMs were further subjected to KEGG functional analysis. Finally, 11 metabolites (such as sucrose, lactose, melibiose, and dehydroascorbate) and 17 genes (such as GOLS, GLA, UGDH, and ALDH) were selected as candidates associated with cold tolerance. Notably, the identified metabolites and genes were enriched in two common pathways: 'galactose metabolism' and 'ascorbate and aldarate metabolism'. Conclusions: The findings suggest that green soybean modulates the galactose metabolism and ascorbate and aldarate metabolism pathways to cope with cold stress. This study contributes to a deeper understanding of the complex molecular mechanisms enabling green soybeans to better avoid low-temperature damage.

Characterization and expression analysis of the B3 gene family during seed development in Akebia trifoliata

BACKGROUND

B3 genes encode transcription factors that play key roles in plant growth and development. However, the specific B3 genes involved in the seed development of Akebia trifoliata remain unexplored.

RESULTS

A total of 72 AktB3 genes were identified and classified into five subfamilies (ARF, LAV, RAV, HSI, and REM) based on phylogenetic analysis. These 72 AktB3 genes were unevenly distributed across 16 chromosomes. Collinear analysis indicated that segmental duplication has played a significant role in the evolution of AktB3 genes, and underwent purification selection. Expression profiling across seed development stages revealed that seven AktB3 genes, particularly from the LAV subfamily (AktABI3, AktFUS3, AktLEC2), were up-regulated at 70 days after flowering (DAF). Notably, the expression of oleosin exhibited a strong positive correlation with LAV subfamily genes, highlighting their potential roles as hub genes in lipid metabolism and seed development. Yeast two-hybrid (Y2H) and yeast one-hybrid (Y1H) experiments confirmed that AktFUS3-1, AktFUS3-2, and AktLEC2 form protein complexes and individually bind to the AktOLE1 promoter, thereby regulating downstream gene expression. These results provide direct evidence of the cooperative role these transcription factors play in controlling lipid metabolism, particularly related to oleosin proteins. Additionally, miRNA sequencing across three seed developmental stages identified 591 miRNAs and 1,673 target gene pairs. A total of 23 AktB3 genes were predicted to be targets of 20 miRNAs, with 11 miRNAs specifically targeting the ARF subfamily genes. Particularly, miR160-x, miR160-z, and miR167-z were predicted to target ARF subfamily genes, potentially influencing seed development. Moreover, the miRNA-B3 regulatory modules, especially involving ARF genes and miR160/167, require further study to clarify their roles in seed development.

CONCLUSIONS

These findings contribute valuable resources for future functional studies of the molecular regulatory networks governing seed development in A. trifoliata.

Transcriptome analysis unveiled the genetic basis of rapid seed germination strategies in alpine plant Rheum pumilum

Rheum pumilum stands as both a quintessential alpine plant and a significant traditional Chinese and Tibetan medicinal herb. Unraveling the molecular intricacies of seed germination in Rh. pumilum not only unveils the genetic foundations of plant seed germination strategies in high-altitude environments but also offers insights for cultivating Rh. pumilum medicinal materials. Employing transcriptome sequencing and the Weighted Gene Co-expression Network Analysis, this study delved into the shifts in gene expression levels across various stages of seed germination in Rh. pumilum. The process of seed germination in Rh. pumilum entails a cascade of complex physiological events. Six hormones (ABA, IAA, ETH, GA, BR, CK) emerged as pivotal players in seeds breaking in shells and the facilitation of rapid seed germination in Rh. pumilum. Fourteen transcription factor families (LOB, GRAS, B3, bHLH, bZIP, EIL, MYB, MYB related, NAC, TCP, WRKY, HSF, PLATZ, and SBP) along with four key genes (E2.4.1.13, EIN3, BZR, and BIN2) were identified that may be associated with both biotic and abiotic environmental stress. The ETR, ACACA and ATPeV0C genes were linked with energy accumulation during the initial stages of seed germination, CYP707A may play an important role in breaking seed dormancy, while the BRI1 gene may be correlated with swift seed germination. Additionally, several unidentified genes were recognized to play key roles in seed germination of Rh. pumilum, warranting further investigation. Moreover, Rh. pumilum demonstrates full activation of crucial physiological functions such as energy metabolism, signal transduction, and responses to biological and abiotic stresses during the seed breaking in shells. This study provides molecular evidence elucidating the swift seed germination strategies adopted by alpine plants to thrive in high-altitude environments. Furthermore, it serves as a foundational reference for enhancing seed germination rates and breeding practices to promote the sustainable development of Rh. pumilum medicinal materials.

Comprehensive analysis of B3 family genes in pearl millet (Pennisetum glaucum) and the negative regulator role of PgRAV-04 in drought tolerance

Introduction

Members of the plant-specific B3 transcription factor superfamily play crucial roles in various plant growth and developmental processes. Despite numerous valuable studies on B3 genes in other species, little is known about the B3 superfamily in pearl millet.

Methods and results

Here, through comparative genomic analysis, we identified 70 B3 proteins in pearl millet and categorized them into four subfamilies based on phylogenetic affiliations: ARF, RAV, LAV, and REM. We also mapped the chromosomal locations of these proteins and analyzed their gene structures, conserved motifs, and gene duplication events, providing new insights into their potential functional interactions. Using transcriptomic sequencing and real-time quantitative PCR, we determined that most PgB3 genes exhibit upregulated expression under drought and high-temperature stresses, indicating their involvement in stress response regulation. To delve deeper into the abiotic stress roles of the B3 family, we focused on a specific gene within the RAV subfamily, PgRAV-04, cloning it and overexpressing it in tobacco. PgRAV-04 overexpression led to increased drought sensitivity in the transgenic plants due to decreased proline levels and peroxidase activity.

Discussion

This study not only adds to the existing body of knowledge on the B3 family's characteristics but also advances our functional understanding of the PgB3 genes in pearl millet, reinforcing the significance of these factors in stress adaptation mechanisms.

Genome-wide analysis of the common bean (Phaseolus vulgaris) laccase gene family and its functions in response to abiotic stress

BACKGROUND

Laccase (LAC) gene family plays a pivotal role in plant lignin biosynthesis and adaptation to various stresses. Limited research has been conducted on laccase genes in common beans.

RESULTS

29 LAC gene family members were identified within the common bean genome, distributed unevenly in 9 chromosomes. These members were divided into 6 distinct subclades by phylogenetic analysis. Further phylogenetic analyses and synteny analyses indicated that considerable gene duplication and loss presented throughout the evolution of the laccase gene family. Purified selection was shown to be the major evolutionary force through Ka / Ks. Transcriptional changes of PvLAC genes under low temperature and salt stress were observed, emphasizing the regulatory function of these genes in such conditions. Regulation by abscisic acid and gibberellins appears to be the case for PvLAC3, PvLAC4, PvLAC7, PvLAC13, PvLAC14, PvLAC18, PvLAC23, and PvLAC26, as indicated by hormone induction experiments. Additionally, the regulation of PvLAC3, PvLAC4, PvLAC7, and PvLAC14 in response to nicosulfuron and low-temperature stress were identified by virus-induced gene silence, which demonstrated inhibition on growth and development in common beans.

CONCLUSIONS

The research provides valuable genetic resources for improving the resistance of common beans to abiotic stresses and enhance the understanding of the functional roles of the LAC gene family.

The silicon regulates microbiome diversity and plant defenses during cold stress in Glycine max L

Introduction

With climate change, frequent exposure of bioenergy and food crops, specifically soybean (Glycine max L.), to low-temperature episodes is a major obstacle in maintaining sustainable plant growth at early growth stages. Silicon (Si) is a quasi-essential nutrient that can help to improve stress tolerance; however, how Si and a combination of cold stress episodes influence plant growth, plant physiology, and microbiome diversity has yet to be fully discovered.

Methods

The soybean plants were exposed to cold stress (8-10°C) with or without applying Si, and the different plant organs (shoot and root) and rhizospheric soil were subjected to microbiome analysis. The plant growth, physiology, and gene expression analysis of plant defenses during stress and Si were investigated.

Results and discussion

We showed that cold stress significantly retarded soybean plants' growth and biomass, whereas, Si-treated plants showed ameliorated negative impacts on plant growth at early seedling stages. The beneficial effects of Si were also evident from significantly reduced antioxidant activities - suggesting lower cold-induced oxidative stress. Interestingly, Si also downregulated critical genes of the abscisic acid pathway and osmotic regulation (9-cis-epoxy carotenoid dioxygenase and dehydration-responsive element binding protein) during cold stress. Si positively influenced alpha and beta diversities of bacterial and fungal microbiomes with or without cold stress. Results showed significant variation in microbiome composition in the rhizosphere (root and soil) and phyllosphere (shoot) in Si-treated plants with or without cold stress exposures. Among microbiome phyla, Proteobacteria, Bacteroidota, and Ascomycota were significantly more abundant in Si treatments in cold stress than in control conditions. For the core microbiome, we identified 179 taxa, including 88 unique bacterial genera in which Edaphobacter, Haliangium, and Streptomyces were highly abundant. Enhanced extracellular enzyme activities in the cold and Si+cold treatments, specifically phosphatase and glucosidases, also reflected the microbiome abundance. In conclusion, this work elucidates cold-mediated changes in microbiome diversity and plant growth, including the positive impact Si can have on cold tolerance at early soybean growth stages - a step toward understanding crop productivity and stress tolerance.

The B3 gene family in Medicago truncatula: Genome-wide identification and the response to salt stress

The B3 family genes constitute a pivotal group of transcription factors that assume diverse roles in the growth, development, and response to both biotic and abiotic stresses in plants. Medicago truncatula is a diploid plant with a relatively small genome, adopted as a model species for legumes genetics and functional genomic research. In this study, 173 B3 genes were identified in the M. truncatula genome, and classified into seven subgroups by phylogenetic analysis. Collinearity analysis revealed that 18 MtB3 gene pairs arose from segmented replication events. Analysis of expression patterns disclosed that 61 MtB3s exhibited a spectrum of expression profiles across various tissues and in the response to salt stress, indicating their potential involvement in salt stress signaling response. Among these genes, MtB3-53 exhibited tissue-specific differential expression and demonstrated a rapid response to salt stress induction. Overexpression of MtB3-53 gene in Arabidopsis improves salt stress tolerance by increasing plant biomass and chlorophyll content, while reducing leaf cell membrane damage. Moreover, salt treatment resulted in more up-regulation of AtABF1, AtABI3, AtHKT1, AtKIN1, AtNHX1, and AtRD29A in MtB3-53 transgenic Arabidopsis plants compared to the wild type, providing evidences that MtB3-53 enhances plant salt tolerance not only by modulating ion homeostasis but also by stimulating the production of antioxidants, which leads to the alleviation of cellular damage caused by salt stress. In conclusion, this study provides a fundamental basis for future investigations into the B3 gene family and its capacity to regulate plant responses to environmental stressors.

Genome-Wide Identification and Expression Analysis Reveals the B3 Superfamily Involved in Embryogenesis and Hormone Responses in Dimocarpus longan Lour

B3 family transcription factors play an essential regulatory role in plant growth and development processes. This study performed a comprehensive analysis of the B3 family transcription factor in longan (Dimocarpus longan Lour.), and a total of 75 DlB3 genes were identified. DlB3 genes were unevenly distributed on the 15 chromosomes of longan. Based on the protein domain similarities and functional diversities, the DlB3 family was further clustered into four subgroups (ARF, RAV, LAV, and REM). Bioinformatics and comparative analyses of B3 superfamily expression were conducted in different light and with different temperatures and tissues, and early somatic embryogenesis (SE) revealed its specific expression profile and potential biological functions during longan early SE. The qRT-PCR results indicated that DlB3 family members played a crucial role in longan SE and zygotic embryo development. Exogenous treatments of 2,4-D (2,4-dichlorophenoxyacetic acid), NPA (N-1-naphthylphthalamic acid), and PP333 (paclobutrazol) could significantly inhibit the expression of the DlB3 family. Supplementary ABA (abscisic acid), IAA (indole-3-acetic acid), and GA3 (gibberellin) suppressed the expressions of DlLEC2, DlARF16, DlTEM1, DlVAL2, and DlREM40, but DlFUS3, DlARF5, and DlREM9 showed an opposite trend. Furthermore, subcellular localization indicated that DlLEC2 and DlFUS3 were located in the nucleus, suggesting that they played a role in the nucleus. Therefore, DlB3s might be involved in complex plant hormone signal transduction pathways during longan SE and zygotic embryo development.

Genome-wide identification of the PFK gene family and their expression analysis in Quercus rubra

The glycolytic pathway involves phosphofructokinase (PFK), a rate-limiting enzyme that catalyzes the phosphorylation of fructose-6-phosphate. In plants, the two PFK members are ATP-dependent phosphofructokinase (PFK) and pyrophosphate-fructose-6-phosphate phosphotransferase (PFP). However, the functions of the PFK family members in Quercus rubra are not well understood. The purpose of this study was to investigate the genome-wide distribution of the PFK family members and their roles in Q. rubra by performing a systematic study of the phylogenetic relationships, molecular characteristics, motifs, chromosomal and subcellular locations, and cis-elements of QrPFKs. We identified 14 QrPFK genes in the genome of Q. rubra, followed by examining their expression in different tissues, including the roots, stems, and leaves. The phylogenetic tree divided the 14 QrPFK genes into two groups: 11 belonging to PFK and three belonging to PFP. The expression profiles of all 14 proteins were relatively the same in leaves but differed between stems and roots. Four genes (Qurub.02G189400.1, Qurub.02G189400.2, Qurub.09G134300.1, and Qurub.09G134300.2) were expressed at very low levels in both stems and roots, while two (Qurub.05G235500.1 and Qurub.05G235500.1) were expressed at low levels and the others showed relatively high expression in all tissues.