Overexpression of StNF-YB3.1 reduces photosynthetic capacity and tuber production, and promotes ABA-mediated stomatal closure in potato (Solanum tuberosum L.)

Genome-wide investigation of the nuclear factor Y gene family in Ginger (Zingiber officinale Roscoe): evolution and expression profiling during development and abiotic stresses

BACKGROUND

Nuclear factor Y (NF-Y) plays a vital role in numerous biological processes as well as responses to biotic and abiotic stresses. However, its function in ginger (Zingiber officinale Roscoe), a significant medicinal and dietary vegetable, remains largely unexplored. Although the NF-Y family has been thoroughly identified in many plant species, and the function of individual NF-Y TFs has been characterized, there is a paucity of knowledge concerning this family in ginger.

METHODS

We identified the largest number of NF-Y genes in the ginger genome using two BLASTP methods as part of our ginger genome research project. The conserved motifs of NF-Y proteins were analyzed through this process. To examine gene duplication events, we employed the Multiple Collinearity Scan toolkit (MCScanX). Syntenic relationships of NF-Y genes were mapped using the Dual Synteny Plotter software. Multiple sequence alignments were performed with MUSCLE under default parameters, and the resulting alignments were used to generate a maximum likelihood (ML) phylogenetic tree with the MEGA X program. RNA-seq analysis was conducted on collected samples, and statistical analyses were performed using Sigma Plot v14.0 (SYSTAT Software, USA).

RESULTS

In this study, the ginger genome was utilized to identify 36 NF-Y genes (10 ZoNF-YAs, 16 ZoNF-YBs, and 10 ZoNF-YCs), which were renamed based on their chromosomal distribution. Ten distinct motifs were identified within the ZoNF-Y genes, with certain unique motifs being vital for gene function. By analyzing their chromosomal location, gene structure, conserved protein motifs, and gene duplication events, we gained a deeper understanding of the evolutionary characteristics of these ZoNF-Y genes. Detailed analysis of ZoNF-Y gene expression patterns across various tissues, performed through RNA-seq and qRT-PCR, revealed their significant role in regulating ginger rhizome and flower growth and development. Additionally, we identified the ZoNF-Y family genes that responded to abiotic stresses.

CONCLUSION

This study represents the first identification of the ZoNF-Y family in ginger. Our findings contribute to research on evolutionary characteristics and provide a better understanding of the molecular basis for development and abiotic stress response. Furthermore, it lays the foundation for further functional characterization of ZoNF-Y genes with an aim of ginger crop improvement.

Potato: from functional genomics to genetic improvement

Potato is the most widely grown non-grain crop and ranks as the third most significant global food crop following rice and wheat. Despite its long history of cultivation over vast areas, slow breeding progress and environmental stress have led to a scarcity of high-yielding potato varieties. Enhancing the quality and yield of potato tubers remains the ultimate objective of potato breeding. However, conventional breeding has faced challenges due to tetrasomic inheritance, high genomic heterozygosity, and inbreeding depression. Recent advancements in molecular biology and functional genomic studies of potato have provided valuable insights into the regulatory network of physiological processes and facilitated trait improvement. In this review, we present a summary of identified factors and genes governing potato growth and development, along with progress in potato genomics and the adoption of new breeding technologies for improvement. Additionally, we explore the opportunities and challenges in potato improvement, offering insights into future avenues for potato research.

Genome-Wide Identification, Characterization and Expression Analysis of Plant Nuclear Factor (NF-Y) Gene Family Transcription Factors in Saccharum spp

Plant nuclear factor (NF-Y) is a transcriptional activating factor composed of three subfamilies: NF-YA, NF-YB, and NF-YC. These transcriptional factors are reported to function as activators, suppressors, and regulators under different developmental and stress conditions in plants. However, there is a lack of systematic research on the NF-Y gene subfamily in sugarcane. In this study, 51 NF-Y genes (ShNF-Y), composed of 9 NF-YA, 18 NF-YB, and 24 NF-YC genes, were identified in sugarcane (Saccharum spp.). Chromosomal distribution analysis of ShNF-Ys in a Saccharum hybrid located the NF-Y genes on all 10 chromosomes. Multiple sequence alignment (MSA) of ShNF-Y proteins revealed conservation of core functional domains. Sixteen orthologous gene pairs were identified between sugarcane and sorghum. Phylogenetic analysis of NF-Y subunits of sugarcane, sorghum, and Arabidopsis showed that ShNF-YA subunits were equidistant while ShNF-YB and ShNF-YC subunits clustered distinctly, forming closely related and divergent groups. Expression profiling under drought treatment showed that NF-Y gene members were involved in drought tolerance in a Saccharum hybrid and its drought-tolerant wild relative, Erianthus arundinaceus. ShNF-YA5 and ShNF-YB2 genes had significantly higher expression in the root and leaf tissues of both plant species. Similarly, ShNF-YC9 had elevated expression in the leaf and root of E. arundinaceus and in the leaf of a Saccharum hybrid. These results provide valuable genetic resources for further sugarcane crop improvement programs.

Crucial Abiotic Stress Regulatory Network of NF-Y Transcription Factor in Plants

Nuclear Factor-Y (NF-Y), composed of three subunits NF-YA, NF-YB and NF-YC, exists in most of the eukaryotes and is relatively conservative in evolution. As compared to animals and fungi, the number of NF-Y subunits has significantly expanded in higher plants. The NF-Y complex regulates the expression of target genes by directly binding the promoter CCAAT box or by physical interaction and mediating the binding of a transcriptional activator or inhibitor. NF-Y plays an important role at various stages of plant growth and development, especially in response to stress, which attracted many researchers to explore. Herein, we have reviewed the structural characteristics and mechanism of function of NF-Y subunits, summarized the latest research on NF-Y involved in the response to abiotic stresses, including drought, salt, nutrient and temperature, and elaborated the critical role of NF-Y in these different abiotic stresses. Based on the summary above, we have prospected the potential research on NF-Y in response to plant abiotic stresses and discussed the difficulties that may be faced in order to provide a reference for the in-depth analysis of the function of NF-Y transcription factors and an in-depth study of plant responses to abiotic stress.

Drought stress tolerance mechanisms and their potential common indicators to salinity, insights from the wild watermelon (Citrullus lanatus): A review

Climate change has escalated the effect of drought on crop production as it has negatively altered the environmental condition. Wild watermelon grows abundantly in the Kgalagadi desert even though the environment is characterized by minimal rainfall, high temperatures and intense sunshine during growing season. This area is also characterized by sandy soils with low water holding capacity, thus bringing about drought stress. Drought stress affects crop productivity through its effects on development and physiological functions as dictated by molecular responses. Not only one or two physiological process or genes are responsible for drought tolerance, but a combination of various factors do work together to aid crop tolerance mechanism. Various studies have shown that wild watermelon possess superior qualities that aid its survival in unfavorable conditions. These mechanisms include resilient root growth, timely stomatal closure, chlorophyll fluorescence quenching under water deficit as key physiological responses. At biochemical and molecular level, the crop responds through citrulline accumulation and expression of genes associated with drought tolerance in this species and other plants. Previous salinity stress studies involving other plants have identified citrulline accumulation and expression of some of these genes (chloroplast APX, Type-2 metallothionein), to be associated with tolerance. Emerging evidence indicates that the upstream of functional genes are the transcription factor that regulates drought and salinity stress responses as well as adaptation. In this review we discuss the drought tolerance mechanisms in watermelons and some of its common indicators to salinity at physiological, biochemical and molecular level.

NF-YB family transcription factors in Arabidopsis: Structure, phylogeny, and expression analysis in biotic and abiotic stresses

Nuclear factor-Y (NF-Y) transcription factors (TFs) are conserved heterotrimeric complexes present and widespread across eukaryotes. Three main subunits make up the structural and functional aspect of the NF-Y TFs: NF-YA, NF-YB and NF-YC, which bind to the conserved CCAAT- box of the promoter region of specific genes, while also interacting with each other, thereby forming myriad combinations. The NF-YBs are expressed differentially in various tissues and plant development stages, likely impacting many of the cellular processes constitutively and under stress conditions. In this study, ten members of NF-YB family from Arabidopsis thaliana were identified and expression profiles were mined from microarray data under different biotic and abiotic conditions, revealing key insights into the involvement of this class of proteins in the cellular and biological processes in Arabidopsis. Analysis of cis-acting regulatory elements (CAREs) indicated the presence of abiotic and biotic stress-related transcription factor binding sites (TFBs), shedding light on the multifaceted roles of these TFs. Microarray data analysis inferred distinct patterns of expression in various tissues under differing treatments such as drought, cold and heat stress as well as bacterial, fungal, and viral stress, indicating their likelihood of having an expansive range of regulatory functions under native and stressed conditions; while quantitative real-time PCR (qRT-PCR) based expression analysis revealed that these TFs get real-time-modulated in a stress dependent manner. This study, overall, provides an understanding of the AtNF-YB family of TFs in their regulation and participation in various morphogenetic and defense- related pathways and can provide insights for development of transgenic plants for trait dependent studies.

Transcriptome-wide characterization, evolutionary analysis, and expression pattern analysis of the NF-Y transcription factor gene family and salt stress response in Panax ginseng

Jilin ginseng (Panax ginseng C. A. Meyer) has a long history of medicinal use worldwide. The quality of ginseng is governed by a variety of internal and external factors. Nuclear factor Y (NF-Y), an important transcription factor in eukaryotes, plays a crucial role in the plant response to abiotic stresses by binding to a specific promoter, the CCAAT box. However, the NF-Y gene family has not been reported in Panax ginseng. In this study, 115 PgNF-Y transcripts with 40 gene IDs were identified from the Jilin ginseng transcriptome database. These genes were classified into the PgNF-YA (13), PgNF-YB (14), and PgNF-YC (13) subgroups according to their subunit types, and their nucleotide sequence lengths, structural domain information, and amino acid sequence lengths were analyzed. The phylogenetic analysis showed that the 79 PgNF-Y transcripts with complete ORFs were divided into three subfamilies, NF-YA, NF-YB, and NF-YC. PgNF-Y was annotated to eight subclasses under three major functions (BP, MF, and CC) by GO annotation, indicating that these transcripts perform different functions in ginseng growth and development. Expression pattern analysis of the roots of 42 farm cultivars, 14 different tissues of 4-year-old ginseng plants, and the roots of 4 different-ages of ginseng plants showed that PgNF-Y gene expression differed across lineages and had spatiotemporal specificity. Coexpression network analysis showed that PgNF-Ys acted synergistically with each other in Jilin ginseng. In addition, the analysis of the response of PgNF-YB09, PgNF-YC02, and PgNF-YC07-04 genes to salt stress treatment was investigated by fluorescence quantitative PCR. The expression of these genes increased after salt stress treatment, indicating that they may be involved in the regulation of the response to salt stresses in ginseng. These results provide important functional genetic resources for the improvement and gene breeding of ginseng in the future.Conclusions: This study fills a knowledge gap regarding the NF-Y gene family in ginseng, provides systematic theoretical support for subsequent research on PgNF-Y genes, and provides data resources for resistance to salt stress in ginseng.

CmNF-YB8 affects drought resistance in chrysanthemum by altering stomatal status and leaf cuticle thickness

Drought is a major abiotic stress that limits plant growth and development. Adaptive mechanisms have evolved to mitigate drought stress, including the capacity to adjust water loss rate and to modify the morphology and structure of the epidermis. Here, we show that the expression of CmNF-YB8, encoding a nuclear factor Y (NF-Y) B-type subunit, is lower under drought conditions in chrysanthemum (Chrysanthemum morifolium). Transgenic chrysanthemum lines in which transcript levels of CmNF-YB8 were reduced by RNA interference (CmNF-YB8-RNAi) exhibited enhanced drought resistance relative to control lines, whereas lines overexpressing CmNF-YB8 (CmNF-YB8-OX) were less tolerant to drought. Compared to wild type (WT), CmNF-YB8-RNAi plants showed reduced stomatal opening and a thicker epidermal cuticle that correlated with their water loss rate. We also identified genes involved in stomatal adjustment (CBL-interacting protein kinase 6, CmCIPK6) and cuticle biosynthesis (CmSHN3) that are more highly expressed in CmNF-YB8-RNAi lines than in WT, CmCIPK6 being a direct downstream target of CmNF-YB8. Virus-induced gene silencing of CmCIPK6 or CmSHN3 in the CmNF-YB8-RNAi background abolished the effects of CmNF-YB8-RNAi on stomatal closure and cuticle deposition, respectively. CmNF-YB8 thus regulates CmCIPK6 and CmSHN3 expression to alter stomatal movement and cuticle thickness in the leaf epidermis, thereby affecting drought resistance.

Genome-wide screening and identification of nuclear Factor-Y family genes and exploration their function on regulating abiotic and biotic stress in potato (Solanum tuberosum L.)

The Nuclear Factor-Y (NF-Y) transcription factor (TF), which includes three distinct subunits (NF-YA, NF-YB and NF-YC), is known to manipulate various aspects of plant growth, development, and stress responses. Although the NF-Y gene family was well studied in many species, little is known about their functions in potato. In this study, a total of 37 potato NF-Y genes were identified, including 11 StNF-YAs, 20 StNF-YBs, and 6 StNF-YCs. The genetic features of these StNF-Y genes were investigated by comparing their evolutionary relationship, intron/exon organization and motif distribution pattern. Multiple alignments showed that all StNF-Y proteins possessed clearly conserved core regions that were flanked by non-conserved sequences. Gene duplication analysis indicated that nine StNF-Y genes were subjected to tandem duplication and eight StNF-Ys arose from segmental duplication events. Synteny analysis suggested that most StNF-Y genes (33 of 37) were orthologous to potato's close relative tomato (Solanum lycopersicum L.). Tissue-specific expression of the StNF-Y genes suggested their potential roles in controlling potato growth and development. The role of StNF-Ys in regulating potato responses to abiotic stress (ABA, drought and salinity) was also confirmed: twelve StNF-Y genes were up-regulated and another two were down-regulated under different abiotic treatments. In addition, genes responded differently to pathogen challenges, suggesting that StNF-Y genes may play distinct roles under certain biotic stress. In summary, insights into the evolution of NF-Y family members and their functions in potato development and stress responses are provided.

Genome-Wide Analysis of NF-Y Genes in Potato and Functional Identification of StNF-YC9 in Drought Tolerance

The nuclear factor Y (NF-Y) family is comprised of transcription factors that have been implicated in multiple plant biological processes. However, little is known about this family in potato. In the present study, a total of 41 StNF-Y genes were identified in the potato genome. In addition, the phylogenetic, gene structure, motif, and chromosomal location of this family were analyzed. The tissue expression profiles based on RNA-seq data showed that 27 StNF-Y genes had tissue-specific expression, while the remaining 14 had low expression in all tissues. Publicly available transcriptomics data from various abiotic stresses revealed several stress-responsive StNF-Y genes, which were further verified via quantitative real-time polymerase chain reaction experiments. Furthermore, the StNF-YC9 gene was highly induced by dehydration and drought treatments. StNF-YC9 protein was mainly localized in the nucleus and cytoplasmic membrane. Overexpressing StNF-YC9 potato lines (OxStNF-YC9) had significantly increased in root length and exhibited stronger stomatal closure in potato treated by polyethylene-glycol and abscisic acid. In addition, OxStNF-YC9 lines had higher photosynthetic rates and decreased water loss under short-term drought stress compared to wild-type plants. During long-term drought stress, OxStNF-YC9 lines had higher proline levels, lower malondialdehyde content, and increased activity of several antioxidant enzymes, including superoxide dismutase, catalase, and peroxidase. This study increased our understanding of the StNF-Y gene and suggested that StNF-YC9 played an important role in drought tolerance by increased the photosynthesis rate, antioxidant enzyme activity, and proline accumulation coupled to lowered malondialdehyde accumulation in potato.

Identification and Comprehensive Analysis of the Nuclear Factor-Y Family Genes Reveal Their Multiple Roles in Response to Nutrient Deficiencies in Brassica napus

Nuclear Factor-Y (NF-Y) transcription factors play vital roles in plant abiotic stress response. Here, the NF-Y family in Brassica napus, which is hyper-sensitive to nitrogen (N) deprivation, was comprehensively identified and systematically characterized. A total of 108 NF-Y family members were identified in B. napus and categorized into three subfamilies (38 NF-YA, 46 NF-YB and 24 NF-YC; part of the Arabidopsis NF-YC homologous genes had been lost during B. napus evolution). In addition, the expansion of the NF-Y family in B. napus was driven by whole-genome duplication and segmental duplication. Differed expression patterns of BnaNF-Ys were observed in response to multiple nutrient starvations. Thirty-four genes were regulated only in one nutrient deficient condition. Moreover, more BnaNF-YA genes were differentially expressed under nutrient limited environments compared to the BnaNF-YB and BnaNF-YC subfamilies. Sixteen hub genes responded diversely to N deprivation in five rapeseed tissues. In summary, our results laid a theoretical foundation for the follow-up functional study of the key NF-Y genes in B. napus in regulating nutrient homeostasis, especially N.

Expression of the Malus sieversii NF-YB21 Encoded Gene Confers Tolerance to Osmotic Stresses in Arabidopsis thaliana

Drought is the main environmental factor that limits the yield and quality of apples (Malus × domestica) grown in arid and semi-arid regions. Nuclear factor Ys (NF-Ys) are important transcription factors involved in the regulation of plant growth, development, and various stress responses. However, the function of NF-Y genes is poorly understood in apples. Here, we identified 43 NF-Y genes in the genome of apples and conducted an initial functional characterization of the apple NF-Y. Expression analysis of NF-Y members in M. sieversii revealed that a large number of NF-Ys were highly expressed in the roots compared with the leaves, and a large proportion of NF-Y genes responded to drought treatment. Furthermore, heterologous expression of MsNF-YB21, which was significantly upregulated by drought, led to a longer root length and, thus, conferred improved osmotic and salt tolerance in Arabidopsis. Moreover, the physiological analysis of MsNF-YB21 overexpression revealed enhanced antioxidant systems, including antioxidant enzymes and compatible solutes. In addition, genes encoding catalase (AtCAT2, AtCAT3), superoxide dismutase (AtFSD1, AtFSD3, AtCSD1), and peroxidase (AtPER12, AtPER42, AtPER47, AtPER51) showed upregulated expression in the MsNF-YB21 overexpression lines. These results for the MsNF-Y gene family provide useful information for future studies on NF-Ys in apples, and the functional analysis of MsNF-YB21 supports it as a potential target in the improvement of apple drought tolerance via biotechnological strategies.

Genomic Organization, Phylogenetic Comparison, and Differential Expression of the Nuclear Factor-Y Gene Family in Apple (Malus Domestica)

The nuclear factor Y (NF-Y) as a transcription factor plays an important role in plants growth and development, and response to stress. However, few genome-wide analyzes and functional research of the NF-Y family has been undertaken in apple (Malus domestica Borkh.) so far. In this study, we comprehensively identified the 43 MdNF-Y genes in apple, which dispersedly distributed among the three subgroups based on their sequence alignment analysis, including 11 MdNF-YAs, 22 MdNF-YBs and 10 MdNF-YCs. The members in the same subgroups had similar evolution relationships, gene structures, and conserved motifs. The gene duplication analysis suggested that all the genes were dispersed followed by 27 segmental duplication. Moreover, based on synteny analysis of MdNF-Ys with eight plant species results suggested that some ortholog genes were preserved during the evolution of these species. Cis-element analysis showed potential functions of MdNF-Ys in apple growth and development and responded to abiotic stress. Furthermore, the interaction among MdNF-Ys protein were investigated in yeast two-hybrid assays. The expression patterns of MdNF-Ys in tissue-specific response reveled divergence and might play important role in apple growth and development. Subsequently, whole MdNF-Y genes family was carried out for RT-PCR in response to five abiotic stress (ABA, drought, heat, cold, and salinity) to identify their expression patterns. Taken together, our study will provide a foundation for the further study to the molecular mechanism of apple in growing development and response to abiotic stresses.

Isolation, characterization and expression analysis of stress responsive plant nuclear transcriptional factor subunit (NF-YB2) from commercial Saccharum hybrid and wild relative Erianthus arundinaceus

Plant nuclear factor (NF-Y) is a transcription activating factor, consisting of three subunits, and plays a key regulatory role in many stress-responsive mechanisms including drought and salinity stresses. NF-Ys function both as complex and individual subunits. Considering the importance of sugarcane as a commercial crop with high socio-economic importance and the crop being affected mostly by water deficit stress and salinity stress causing significant yield loss, nuclear transcriptional factor NF-YB2 was focused in this study. Plant nuclear factor subunit B2 from Erianthus arundinaceus (EaNF-YB2), a wild relative of sugarcane which is known for its drought and salinity stress tolerance, and commercial Saccharum hybrid Co 86032 (ShNF-YB2) was isolated and characterized. Both EaNF-YB2 and ShNF-YB2 genes are 543 bp long that encodes for a polypeptide of 180 amino acid residues. Comparison of EaNF-YB2 and ShNF-YB2 gene sequences revealed nucleotide substitutions at nine positions corresponding to three synonymous and six nonsynonymous amino acid substitutions that resulted in variations in physiochemical properties. However, multiple sequence alignment (MSA) of NF-YB2 proteins showed conservation of functionally important amino acid residues. In silico analysis revealed NF-YB2 to be a hydrophilic and intracellular protein, and EaNF-YB2 is thermally more stable than that of ShNF-YB2. Phylogenetic analysis suggested the lower rate of evolution of NF-YB2. Subcellular localization in sugarcane callus revealed NF-YB2 localization at nucleus that further evidenced it to be a transcription activation factor. Comparative RT-qPCR experiments showed a significantly higher level of NF-YB2 expression in E. arundinaceus when compared to that in the commercial Saccharum hybrid Co 86032 under drought and salinity stresses. Hence, EaNF-YB2 could be an ideal candidate gene, and its overexpression in sugarcane through genetic engineering approach might enhance tolerance to drought and salinity stresses.

Arabidopsis CK2 family gene CKB3 involved in abscisic acid signaling

CKB3 is a regulatory (beta) subunit of CK2. In this study Arabidopsis thaliana homozygous T-DNA mutant ckb3 was studied to understand the role of CKB3 in abscisic acid (ABA) signaling. The results shown: CKB3 was expressed in all organs and the highest expression in the seeds, followed by the root. During seed germination and root growth the ckb3 mutant showed reduced sensitivity to ABA. The ckb3 mutant had more stomatal opening and increased proline accumulation and leaf water loss. The expression levels of number of genes in the ABA regulatory network had changed. This study demonstrates that CKB3 is an ABA signaling-related gene and may play a positive role in ABA signaling.

Identification, expression, and putative target gene analysis of nuclear factor-Y (NF-Y) transcription factors in tea plant (Camellia sinensis)

Genome-wide identification and characterization of nuclear factor-Y family in tea plants, and their expression profiles and putative targets provide the basis for further elucidation of their biological functions. The nuclear factor-Y (NF-Y) transcription factors (TFs) are crucial regulators of plant growth and physiology. However, the NF-Y TFs in tea plant (Camellia sinensis) have not yet been elucidated, and its biological functions, especially the putative target genes within the genome range, are still unclear. In this study, we identified 35 CsNF-Y encoding genes in the tea plant genome, including 10 CsNF-YAs, 15 CsNF-YBs and 10 CsNF-YCs. Their conserved domains and motifs, phylogeny, duplication event, gene structure, and promoter were subsequently analyzed. Tissue expression analysis revealed that CsNF-Ys exhibited three distinct expression patterns in eight tea tree tissues, among which CsNF-YAs were moderately expressed. Drought and abscisic acid (ABA) treatment indicated that CsNF-YAs may have a greater impact than other subunit members. Furthermore, through the genome-wide investigation of the presence of the CCAAT box, we found that CsNF-Ys may participate in the development of tea plants by regulating target genes of multiple physiological pathways, including photosynthesis, chlorophyll metabolism, fatty acid biosynthesis, and amino acid metabolism pathways. Our findings will contribute to the functional analysis of NF-Y genes in woody plants and the cultivation of high-quality tea plant cultivars.

Genome-wide analysis of poplar NF-YB gene family and identified PtNF-YB1 important in regulate flowering timing in transgenic plants

BACKGROUND

Compared with annual herbaceous plants, woody perennials require a longer period of juvenile phase to flowering, and many traits can be only expressed in adulthood, which seriously makes the breeding efficiency of new varieties slower. For the study of poplar early flowering, the main focus is on the study Arabidopsis homologue gene CO/FT. Based on studies of Arabidopsis, rice and other plant species, some important research progress has been made on the regulation of flowering time by NF-Y subunits. However, little is known about the function of NF-Y regulating flowering in poplar.

RESULTS

In the present study, we have identified PtNF-YB family members in poplar and focus on the function of the PtNF-YB1 regulate flowering timing using transgenic Arabidopsis and tomato. To understand this mechanisms, the expression levels of three known flowering genes (CO, FT and SOC1) were examined with RT-PCR in transgenic Arabidopsis. We used the Y2H and BiFC to assay the interactions between PtNF-YB1 and PtCO (PtCO1 and PtCO2) proteins. Finally, the potential molecular mechanism model in which PtNF-YB1 play a role in regulating flowering in poplar was discussed.

CONCLUSIONS

In this study, we have characterized the poplar NF-YB gene family and confirmed the function of the PtNF-YB1 regulate flowering timing. At the same time, we found that the function of PtNF-YB1 to improve early flowering can overcome species barriers. Therefore, PtNF-YB1 can be used as a potential candidate gene to improve early flowering by genetic transformation in poplar and other crops.

NUCLEAR FACTOR-Y: still complex after all these years?

The NUCLEAR FACTOR-Y (NF-Y) families of transcription factors are important regulators of plant development and physiology. Though NF-Y regulatory roles have recently been suggested for numerous aspects of plant biology, their roles in flowering time, early seedling development, stress responses, hormone signaling, and nodulation are the best characterized. The past few years have also seen significant advances in our understanding of the mechanistic function of the NF-Y, and as such, increasingly complex and interesting questions are now more approachable. This review will primarily focus on these developmental, physiological, and mechanistic roles of the NF-Y in recent research.

Genes Encoding Transcription Factors TaDREB5 and TaNFYC-A7 Are Differentially Expressed in Leaves of Bread Wheat in Response to Drought, Dehydration and ABA

Two groups of six spring bread wheat varieties with either high or low grain yield under the dry conditions of Central and Northern Kazakhstan were selected for analysis. Experiments were set up with the selected wheat varieties in controlled environments as follows: (1) slowly progressing drought imposed on plants in soil, (2) rapid dehydration of whole plants grown in hydroponics, (3) dehydration of detached leaves, and (4) ABA treatment of whole plants grown in hydroponics. Representatives of two different families of transcription factors (TFs), TaDREB5 and TaNFYC-A7, were found to be linked to yield-under-drought using polymorphic Amplifluor-like SNP marker assays. qRT-PCR revealed differing patterns of expression of these genes in the leaves of plants subjected to the above treatments. Under drought, TaDREB5 was significantly up-regulated in leaves of all high-yielding varieties tested and down-regulated in all low-yielding varieties, and the level of expression was independent of treatment type. In contrast, TaNFYC-A7 expression levels showed different responses in the high- and low-yield groups of wheat varieties. TaNFYC-A7 expression under dehydration (treatments 2 and 3) was higher than under drought (treatment 1) in all high-yielding varieties tested, while in all low-yielding varieties the opposite pattern was observed: the expression levels of this gene under drought were higher than under dehydration. Rapid dehydration of detached leaves and intact wheat plants grown in hydroponics produced similar changes in gene expression. ABA treatment of whole plants caused rapid stomatal closure and a rise in the transcript level of both genes during the first 30 min, which decreased 6 h after treatment. At this time-point, expression of TaNFYC-A7 was again significantly up-regulated compared to untreated controls, while TaDREB5 returned to its initial level of expression. These findings reveal significant differences in the transcriptional regulation of two drought-responsive and ABA-dependent TFs under slowly developing drought and rapid dehydration of wheat plants. The results obtained suggest that correlation between grain yield in dry conditions and TaNFYC-A7 expression levels in the examined wheat varieties is dependent on the length of drought development and/or strength of drought; while in the case of TaDREB5, no such dependence is observed.