Genome-wide identification of Tomato Golden 2-Like transcription factors and abiotic stress related members screening

Regulatory network of flavonoids, phenolic acids and terpenoids biosynthesis in Zizyphus jujuba Mill. cv. Goutou jujube fruits

Flavonoids, phenolic acids and terpenoids are important active ingredients that are biomarkers for evaluating the quality of Zizyphus jujuba Mill. Cv. Goutou jujube fruit. Nevertheless, regulatory network of these active ingredients biosynthesis in jujube fruit is still unclear. Here, integrated metabolomics and transcriptomics analyses were conducted at four different stages during the ripening of jujube fruits. Cytochrome P450 enzymes (CYP450s) and uridine 5'-diphospho-glucuronosyltransferases (UGTs) are pivotal enzymes for flavonoids, phenolic acids and terpenoids biosynthesis in plants. Benzoylmalic acid, a phenolic acid, 4', 5, 7-trihydroxyflavanon and quercetin-3-O-(6″-p-coumaroyl), two flavonoid metabolites, and jujuboside B1, a triterpenoid metabolite were targeted as they were correlated with both CYP450s and UGTs. Furthermore, networks of TFs, CYP450s and UGTs involved in the target metabolites biosynthesis were elucidated. NAC_1 and bZIP2 up-regulated CYP71A7 expression, while G2-like2 and bHLH_1 positively regulated the CSE expression contributing to promoted benzoylmalic acid biosynthesis. G2-like2, bHLH_1 and bHLH_2 indicated a positive relationship with CYP93D1, CYP86C2/3 or UGT71A16 which were positively correlated with 4', 5, 7-trihydroxyflavanon biosynthesis. MYB1/2/3, C2H2_2 and WRKY positively regulated expression of CYP82A4 or UGT_1 resulted in increased quercetin-3-O-(6″-p-coumaroyl) galactoside biosynthesis. G2-like2 and bHLH_1 up-regulated 4 C L, CYP93D1 or UGT71A16 was the reason for an increase of jujuboside B1 biosynthesis. The findings provide new insight into molecular breeding of high-quality jujube fruits.

NAC61 regulates late- and post-ripening osmotic, oxidative, and biotic stress responses in grapevine

During late- and post-ripening stages, grape berry undergoes profound biochemical and physiological changes whose molecular control is poorly understood. Here, we report the role of NAC61, a grapevine NAC transcription factor, in regulating different processes involved in berry ripening progression. NAC61 is highly expressed during post-harvest berry dehydration and its expression pattern is closely related to sugar concentration. The ectopic expression of NAC61 in Nicotiana benthamiana leaves resulted in low stomatal conductance, high leaf temperature, tissue collapse and a higher relative water content. Transcriptome analysis of grapevine leaves transiently overexpressing NAC61 and DNA affinity purification and sequencing analyses allowed us to narrow down a list of NAC61-regulated genes. Direct regulation of the stilbene synthase regulator MYB14, the osmotic stress-related gene DHN1b, the Botrytis cinerea susceptibility gene WRKY52, and NAC61 itself was validated. We also demonstrate that NAC61 interacts with NAC60, a proposed master regulator of grapevine organ maturation, in the activation of MYB14 and NAC61 expression. Overall, our findings establish NAC61 as a key player in a regulatory network that governs stilbenoid metabolism and osmotic, oxidative, and biotic stress responses that are the hallmark of late- and post-ripening grape stages.

A GARP transcription factor SlGCC positively regulates lateral root development in tomato via auxin-ethylene interplay

MAIN CONCLUSION

SlGCC, a GARP transcription factor, functions as a root-related transcriptional repressor. SlGCC synchronizes auxin and ethylene signaling involving SlPIN3 and SlIAA3 as intermediate targets sketching a molecular map for lateral root development in tomato. The root system is crucial for growth and development of plants as it performs basic functions such as providing mechanical support, nutrients and water uptake, pathogen resistance and responds to various stresses. SlGCC, a GARP family transcription factor (TF), exhibited predominant expression in age-dependent (initial to mature stages) tomato root. SlGCC is a transcriptional repressor and is regulated at a transcriptional and translational level by auxin and ethylene. Auxin and ethylene mediated SlGCC protein stability is governed via proteasome degradation pathway during lateral root (LR) growth development. SlGCC over-expressor (OE) and under-expressed (UE) tomato transgenic lines demonstrate its role in LR development. This study is an attempt to unravel the vital role of SlGCC in regulating tomato LR architecture.

Evolutionary insights and expression dynamics of the CaNFYB transcription factor gene family in pepper (Capsicum annuum) under salinity stress

Introduction: The Capsicum annuum nuclear factor Y subunit B (CaNFYB) gene family plays a significant role in diverse biological processes, including plant responses to abiotic stressors such as salinity. Methods: In this study, we provide a comprehensive analysis of the CaNFYB gene family in pepper, encompassing their identification, structural details, evolutionary relationships, regulatory elements in promoter regions, and expression profiles under salinity stress. Results and discussion: A total of 19 CaNFYB genes were identified and subsequently characterized based on their secondary protein structures, revealing conserved domains essential for their functionality. Chromosomal distribution showed a non-random localization of these genes, suggesting potential clusters or hotspots for NFYB genes on specific chromosomes. The evolutionary analysis focused on pepper and comparison with other plant species indicated a complex tapestry of relationships with distinct evolutionary events, including gene duplication. Moreover, promoter cis-element analysis highlighted potential regulatory intricacies, with notable occurrences of light-responsive and stress-responsive binding sites. In response to salinity stress, several CaNFYB genes demonstrated significant temporal expression variations, particularly in the roots, elucidating their role in stress adaptation. Particularly CaNFYB01, CaNFYB18, and CaNFYB19, play a pivotal role in early salinity stress response, potentially through specific regulatory mechanisms elucidated by their cis-elements. Their evolutionary clustering with other Solanaceae family members suggests conserved ancestral functions vital for the family's survival under stress. This study provides foundational knowledge on the CaNFYB gene family in C. annuum, paving the way for further research to understand their functional implications in pepper plants and relative species and their potential utilization in breeding programs to enhance salinity tolerance.

Genome-wide identification of CaARR-Bs transcription factor gene family in pepper and their expression patterns under salinity stress

In plants, ARRs-B transcription factors play a crucial role in regulating cytokinin signal transduction, abiotic stress resistance, and plant development. A number of adverse environmental conditions have caused severe losses for the pepper (Capsicum annuum L.)-a significant and economically important vegetable. Among the transcription factors of the type B-ARRs family, multiple members have different functions. In pepper, only a few members of the ARRs-B family have been reported and characterized. The current study aimed to characterize ARRs-B transcription factors in C. annuum, including phylogenetic relationships, gene structures, protein motif arrangement, and RT-qPCR expression analyses and their role in salinity stress. In total, ten genes encode CaARRs-B transcription factors (CaARR1 to CaARR10) from the largest subfamily of type-B ARRs were identified in C. annum. The genome-wide analyses of the CaARRs-B family in C. annuum were performed based on the reported ARRs-B genes in Arabidopsis. An analysis of homologous alignments of candidate genes, including their phylogenetic relationships, gene structures, conserved domains, and qPCR expression profiles, was conducted. In comparison with other plant ARRs-B proteins, CaARRs-B proteins showed gene conservation and potentially specialized functions. In addition, tissue-specific expression profiles showed that CaARRs-B genes were differentially expressed, suggesting functionally divergent. CaARRs-B proteins had a typical conserved domain, including AAR-like (pfam: PF00072) and Myb DNA binding (pfam: PF00249) domains. Ten of the CaARRs-B genes were asymmetrically mapped on seven chromosomes in Pepper. Additionally, the phylogenetic tree of CaARRs-B genes from C. annuum and other plant species revealed that CaARRs-B genes were classified into four clusters, which may have evolved conservatively. Further, using quantitative real-time qRT-PCR, the study assessed the expression patterns of CaARRs-B genes in Capsicum annuum seedlings subjected to salt stress. The study used quantitative real-time qRT-PCR to examine CaARRs-B gene expression in Capsicum annuum seedlings under salt stress. Roots exhibited elevated expression of CaARR2 and CaARR9, while leaves showed decreased expression for CaARR3, CaARR4, CaARR7, and CaARR8. Notably, no amplification was observed for CaARR10. This research sheds light on the roles of CaARRs-B genes in pepper's response to salinity stress. These findings enrich our comprehension of the functional implications of CaARRs-B genes in pepper, especially in responding to salinity stress, laying a solid groundwork for subsequent in-depth studies and applications in the growth and development of Capsicum annuum.

Genome-Wide Identification and Expression Analysis of Cysteine-Rich Polycomb-like Protein (CPP) Gene Family in Tomato

The cysteine-rich polycomb-like protein (CPP) gene family is a class of transcription factors containing conserved cysteine-rich CRC structural domains that is involved in the regulation of plant growth and stress tolerance to adversity. Relative to other gene families, the CPP gene family has not received sufficient attention. In this study, six SlCPPs were identified for the first time using the most recent genome-wide identification data of tomato. Subsequently, a phylogenetic analysis classified SlCPPs into four subfamilies. The analysis of cis-acting elements in the promoter indicates that SlCPPs are involved in plant growth and development and also stress response. We present for the first time the prediction of the tertiary structure of these SlCPPs proteins using the AlphaFold2 artificial intelligence system developed by the DeepMind team. Transcriptome data analysis showed that SlCPPs were differentially expressed in different tissues. Gene expression profiling showed that all SlCPPs except SlCPP5 were up-regulated under drought stress; SlCPP2, SlCPP3 and SlCPP4 were up-regulated under cold stress; SlCPP2 and SlCPP5 were up-regulated under salt stress; all SlCPPs were up-regulated under inoculation with Cladosporium fulvum; and SlCPP1, SlCPP3, and SlCPP4 were up-regulated under inoculation with Stemphylium lycopersici. We performed a virus-induced gene silencing experiment on SlCPP3, and the results indicated that SlCPP3 was involved in the response to drought stress. Finally, we predicted the interaction network of the key gene SlCPP3, and there was an interaction relationship between SlCPP3 and 10 genes, such as RBR1 and MSI1. The positive outcome showed that SlCPPs responded to environmental stress. This study provides a theoretical and empirical basis for the response mechanisms of tomato in abiotic stresses.

Genomics, Proteomics, and Metabolomics Approaches to Improve Abiotic Stress Tolerance in Tomato Plant

To explore changes in proteins and metabolites under stress circumstances, genomics, proteomics, and metabolomics methods are used. In-depth research over the previous ten years has gradually revealed the fundamental processes of plants' responses to environmental stress. Abiotic stresses, which include temperature extremes, water scarcity, and metal toxicity brought on by human activity and urbanization, are a major cause for concern, since they can result in unsustainable warming trends and drastically lower crop yields. Furthermore, there is an emerging reliance on agrochemicals. Stress is responsible for physiological transformations such as the formation of reactive oxygen, stomatal opening and closure, cytosolic calcium ion concentrations, metabolite profiles and their dynamic changes, expression of stress-responsive genes, activation of potassium channels, etc. Research regarding abiotic stresses is lacking because defense feedbacks to abiotic factors necessitate regulating the changes that activate multiple genes and pathways that are not properly explored. It is clear from the involvement of these genes that plant stress response and adaptation are complicated processes. Targeting the multigenicity of plant abiotic stress responses caused by genomic sequences, transcripts, protein organization and interactions, stress-specific and cellular transcriptome collections, and mutant screens can be the first step in an integrative approach. Therefore, in this review, we focused on the genomes, proteomics, and metabolomics of tomatoes under abiotic stress.

Identification of GOLDEN2-like transcription factor genes in soybeans and their role in regulating plant development and metal ion stresses

The Golden 2-Like (G2-like or GLK) transcription factors are essential for plant growth, development, and many stress responses as well as heavy metal stress. However, G2-like regulatory genes have not been studied in soybean. This study identified the genes for 130 G2-Like candidates' in the genome of Glycine max (soybean). These GLK genes were located on all 20 chromosomes, and several of them were segmentally duplicated. Most GLK family proteins are highly conserved in Arabidopsis and soybean and were classified into five major groups based on phylogenetic analysis. These GmGLK gene promoters share cis-acting elements involved in plant responses to abscisic acid, methyl jasmonate, auxin signaling, low temperature, and biotic and abiotic stresses. RNA-seq expression data revealed that the GLK genes were classified into 12 major groups and differentially expressed in different tissues or organs. The co-expression network complex revealed that the GmGLK genes encode proteins involved in the interaction of genes related to chlorophyll biosynthesis, circadian rhythms, and flowering regulation. Real-time quantitative PCR analysis confirmed the expression profiles of eight GLK genes in response to cadmium (Cd) and copper (Cu) stress, with some GLK genes significantly induced by both Cd and Cu stress treatments, implying a functional role in defense responsiveness. Thus, we present a comprehensive perspective of the GLK genes in soybean and emphasize their important role in crop development and metal ion stresses.

Genome-Wide Identification and Characterization of G2-Like Transcription Factor Genes in Moso Bamboo (Phyllostachys edulis)

G2-like (GLK) transcription factors contribute significantly and extensively in regulating chloroplast growth and development in plants. This study investigated the genome-wide identification, phylogenetic relationships, conserved motifs, promoter cis-elements, MCScanX, divergence times, and expression profile analysis of PeGLK genes in moso bamboo (Phyllostachys edulis). Overall, 78 putative PeGLKs (PeGLK1–PeGLK78) were identified and divided into 13 distinct subfamilies. Each subfamily contains members displaying similar gene structure and motif composition. By synteny analysis, 42 orthologous pairs and highly conserved microsynteny between regions of GLK genes across moso bamboo and maize were found. Furthermore, an analysis of the divergence times indicated that PeGLK genes had a duplication event around 15 million years ago (MYA) and a divergence happened around 38 MYA between PeGLK and ZmGLK. Tissue-specific expression analysis showed that PeGLK genes presented distinct expression profiles in various tissues, and many members were highly expressed in leaves. Additionally, several PeGLKs were significantly up-regulated under cold stress, osmotic stress, and MeJA and GA treatment, implying that they have a likelihood of affecting abiotic stress and phytohormone responses in plants. The results of this study provide a comprehensive understanding of the moso bamboo GLK gene family, as well as elucidating the potential functional characterization of PeGLK genes.

Identification and expression analysis of GARP superfamily genes in response to nitrogen and phosphorus stress in Spirodela polyrhiza

BACKGROUND

GARP transcription factors perform critical roles in plant development and response to environmental stimulus, especially in the phosphorus (P) and nitrogen (N) sensing and uptake. Spirodela polyrhiza (giant duckweed) is widely used for phytoremediation and biomass production due to its rapid growth and efficient N and P removal capacities. However, there has not yet been a comprehensive analysis of the GRAP gene family in S. polyrhiza.

RESULTS

We conducted a comprehensive study of GRAP superfamily genes in S. polyrhiza. First, we investigated 35 SpGARP genes which have been classified into three groups based on their gene structures, conserved motifs, and phylogenetic relationship. Then, we identified the duplication events, performed the synteny analysis, and calculated the K_a/K_s ratio in these SpGARP genes. The regulatory and co-expression networks of SpGARPs were further constructed using cis-acting element analysis and weighted correlation network analysis (WGCNA). Finally, the expression pattern of SpGARP genes were analyzed using RNA-seq data and qRT-PCR, and several NIGT1 transcription factors were found to be involved in both N and P starvation responses.

CONCLUSIONS

The study provides insight into the evolution and function of GARP superfamily in S. polyrhiza, and lays the foundation for the further functional verification of SpGARP genes.

Genome-wide characterization and analysis of Golden 2-Like transcription factors related to leaf chlorophyll synthesis in diploid and triploid Eucalyptus urophylla

Golden 2-Like (GLK) transcription factors play a crucial role in chloroplast development and chlorophyll synthesis in many plant taxa. To date, no systematic analysis of GLK transcription factors in tree species has been conducted. In this study, 40 EgrGLK genes in the Eucalyptus grandis genome were identified and divided into seven groups based on the gene structure and motif composition. The EgrGLK genes were mapped to 11 chromosomes and the distribution of genes on chromosome was uneven. Phylogenetic analysis of GLK proteins between E. grandis and other species provided information for the high evolutionary conservation of GLK genes among different species. Prediction of cis-regulatory elements indicated that the EgrGLK genes were involved in development, light response, and hormone response. Based on the finding that the content of chlorophyll in mature leaves was the highest, and leaf chlorophyll content of triploid Eucalyptus urophylla was higher than that of the diploid control, EgrGLK expression pattern in leaves of triploid and diploid E. urophylla was examined by means of transcriptome analysis. Differential expression of EgrGLK genes in leaves of E. urophylla of different ploidies was consistent with the trend in chlorophyll content. To further explore the relationship between EgrGLK expression and chlorophyll synthesis, co-expression networks were generated, which indicated that EgrGLK genes may have a positive regulatory relationship with chlorophyll synthesis. In addition, three EgrGLK genes that may play an important role in chlorophyll synthesis were identified in the co-expression networks. And the prediction of miRNAs targeting EgrGLK genes showed that miRNAs might play an important role in the regulation of EgrGLK gene expression. This research provides valuable information for further functional characterization of GLK genes in Eucalyptus.