Project description:Ammonium transporters (AMTs) are responsible for ammonium absorption and utilization in plants. As a high-nitrogen-demand crop and a legume, soybean can also obtain ammonium from symbiotic root nodules in which nitrogen-fixing rhizobia convert atmospheric nitrogen (N2) into ammonium. Although increasing evidence implicates vital roles of ammonium transport in soybean, no systematic analyses of AMTs in soybean (named GmAMTs) or functional analyses of GmAMTs are available. In this study, we aimed to identify all GmAMT family genes and gain a better understanding of the characteristics of GmAMT genes in soybean. Here, due to the improved genome assembly and annotation of soybean, we tried to generate a phylogenetic tree of 16 GmAMTs based on new information. Consistent with reported data, GmAMT family members can be divided into two subfamilies of GmAMT1 (6 genes) and GmAMT2 (10 genes). Interestingly, unlike Arabidopsis, which has only one AMT2, soybean has substantially increased the number of GmAMT2s, suggesting enhanced demand for ammonium transport. These genes were distributed on nine chromosomes, of which GmAMT1.3, GmAMT1.4, and GmAMT1.5 were three tandem repeat genes. The gene structures and conserved protein motifs of the GmAMT1 and GmAMT2 subfamilies were different. All the GmAMTs were membrane proteins with varying numbers of transmembrane domains ranging from 4 to 11. Promoter analysis found that these GmAMT genes have phytohormone-, circadian control-, and organ expression-related cis-elements in their promoters, and notably, there were nodulation-specific and nitrogen-responsive elements in the promoters of the GmAMT1 and GmAMT2 genes. Further expression data showed that these GmAMT family genes exhibited different spatiotemporal expression patterns across tissues and organs. In addition, GmAMT1.1, GmAMT1.2, GmAMT2.2, and GmAMT2.3 were responsive to nitrogen treatment, while GmAMT1.2, GmAMT1.3, GmAMT1.4, GmAMT1.5, GmAMT1.6, GmAMT2.1, GmAMT2.2, GmAMT2.3, GmAMT3.1, and GmAMT4.6 showed circadian rhythms in transcription. RT-qPCR validated the expression patterns of GmAMTs in response to different forms of nitrogen and exogenous ABA treatments. Gene expression analysis also confirmed that GmAMTs are regulated by key nodulation gene GmNINa, indicating a role of GmAMTs in symbiosis. Together, these data indicate that GmAMTs may differentially and/or redundantly regulate ammonium transport during plant development and in response to environmental factors. These findings provide a basis for future research on the functions of GmAMTs and the mechanisms through which GmAMTs regulate ammonium metabolism and nodulation in soybean.
Project description:BackgroundSoybean is a major source of oil and protein in the human diet and in animal feed. However, as soybean is deficient in sulfur-containing amino acids, its nutritional value is limited. Increasing sulfate assimilation and utilization efficiency is a valuable approach to augment the concentration of sulfur-containing amino acids in soybean seeds, and sulfate transporters play important roles in both sulfate uptake and translocation within plants.ResultsIn this study, we isolated and characterized a soybean sulfate transporter gene: GmSULTR1;2b. The gene was found to be specifically expressed in root tissues and induced by low-sulfur stress. In addition, GmSULTR1;2b expression in yeast could complement deficiency in the sulfate transporter genes SUL1 and SUL2. Under +S conditions, GmSULTR1;2b-overexpressing tobacco plants accumulated higher levels of organic matter and exhibited enhanced biomass and seed weight compared to control plants. Under -S conditions, acclimation of GmSULTR1;2b-overexpressing plants was much better than control plants. GmSULTR1;2b-overexpressing tobacco seedlings showed better tolerance to drought stress than the control plants, but no significant difference was observed under salt stress. Transcriptome analysis revealed 515 genes with at least a 2-fold change in expression in the leaves of tobacco plants overexpressing GmSULTR1;2b. Of these, 227 gene annotations were classified into 12 functional categories associated with 123 relevant pathways, including biosynthesis and metabolism-related proteins, stress-related proteins, and transporters.ConclusionsThe findings reported here indicate that the increased biomass and seed yield observed in transgenic tobacco plants could have resulted from greater nutrient uptake and transport capability as well as enhanced development and accumulation of organic matter. Taken together, our results indicate that GmSULTR1;2b plays an important role in sulfur uptake and could alter the sulfur status of plants. Our study suggests that overexpressing GmSULTR1;2b may enhance plant yield under +S conditions, reduce plant production loss under -S conditions, and improve plant tolerance to sulfur deficiency stress.
Project description:Pectin Methylesterase Inhibitors (PMEI) gene family is widely spread in plants and plays crucial roles in plant development as well as biotic and abiotic stress response. However, little information was known about the function of PMEI genes in soybean. Herein, we identified 170 PMEI genes in soybean. These PMEI genes were divided into four groups (I-IV) based on phylogenetic analysis, and they were unevenly distributed in 18 soybean chromosomes. Gene structures and motif pattern analyses revealed that the PMEI genes in the same group showed the same characteristics. For the GmPMEI genes, gene duplication events occurred broadly, 52 pairs tandem duplication events and 55 pairs segmental duplication events suggested that the GmPMEI genes had high homology. Besides, the PMEI genes presented different expression patterns in different tissues, while several of these genes were expressed only in flowers. Under the biotic and abiotic stresses, PMEI genes had significant positive impact on the tolerance ability of soybean, and the ABA-responsive elements and SA-responsive elements played vital roles in responding to a variety of stresses. This study provides insights into the evolution and potential functions of GmPMEIs.
Project description:The family of phosphate transporters (PHTs) mediates the uptake and translocation of Pi inside the plants. However, little is known about transporters in soybean. Therefore, Searched the Genome Database for Soybean, 57 GmPHTs family members were identified in soybean, Phylogenetic analysis suggested that members of the PHTs gene family can be divided into six clades. Collinearity analysis revealed that most of the GmPHT genes shared syntenic relationships with PHTs members in Arabidopsis thaliana and that large segment duplication played a major driving force for GmPHTs evolution in addition to tandem duplication. Further analysis of the promoter revealed that light-responsive elements and abiotic stress-responsive elements were widely distributed within the promoter regions of GmPHT genes. Based on RNA-seq data, GmPHTs showed different expression patterns in roots and leaves of soybean treated with long-term low phosphorus and short-term low phosphorus, in addition, the expression levels of GmPHT genes can be regulated by drought stresses, it was implied that the induced expression of GmPHTs could promote phosphorus uptake and transport in soybean and thus adapt to low phosphorus and drought stress, which is the first step dissection of Pi transport system and probably refers to new roles of PHTs genes in soybean.
Project description:The glabrous-enhancer-binding protein (GeBP) family is a family of plant-specific transcription factors, whose members share a central DNA-binding domain. Previous studies have already proven that GeBP genes are involved in the control of cell expansion but not cell proliferation in Arabidopsis. However, there has not yet been a versatile analysis of the GeBP genes’ function in soybean (Glycine max L.). Here, we identified and named 9 GmGeBP genes in the soybean genome. These genes were distributed on 7 of the 20 chromosomes and the intron numbers ranged from zero to one. According to the phylogenetic tree, 52 GeBP genes obtained from four plant species were clustered into major four groups. Through the RNA-seq analysis of the nine GmGeBP genes, 8 of 9 GmGeBP genes were be found to expressed differentially across the 14 tissues. Additionally, among nine GmGeBP genes, only GeBP4 were highly expressed in abnormal trichome soybeans, which was predicted to be involved in trichome development. This genome-wide analysis of GmGeBP genes helps to provide an overview of the evolution and functions of two kinds of soybean plants. These results will help to clarify the potential functions and characteristics of GmGeBP genes in the soybean life cycle.
Project description:The NRAMP (natural resistance-associated macrophage protein) family of genes has been widely characterized in organisms ranging from bacteria to yeast, plants, mice, and humans. This gene family plays vital roles in divalent metal ion transport across cellular membranes. As yet, comprehensive analysis of NRAMP family genes has not been reported for soybean. In this study, bioinformatics analysis was conducted to identify 13 soybean NRAMP genes, along with their gene structures, phylogenetic relationships, and transmembrane domains. Expression analysis suggests that GmNRAMP genes function in numerous tissues and development stages. Moreover, soybean NRAMP genes were differentially regulated by deficiencies of N, P, K, Fe, and S, along with toxicities of Fe, Cu, Cd, and Mn. These results indicate that GmNRAMP genes function in many nutrient stress pathways, and might be involved in crosstalk among nutrient stress pathways. Subcellular localization analysis in Arabidopsis protoplasts confirmed the tonoplast or plasma membrane localization of selected soybean NRMAP proteins. Protein-protein interaction analysis found that the networks of three GmNRAMP proteins which putatively interact with nodulin-like proteins, almost distinct from the network that is common to the other 10 soybean NRAMP proteins. Subsequent qRT-PCR results confirmed that these three GmNRMAP genes exhibited enhanced expression in soybean nodules, suggesting potential functions in the transport of Fe or other metal ions in soybean nodules. Overall, the systematic analysis of the GmNRAMP gene family reported herein provides valuable information for further studies on the biological roles of GmNRAMPs in divalent metal ion transport in various soybean tissues under numerous nutrient stresses and soybean-rhizobia symbiosis.
Project description:The CHYR (CHY ZINC-FINGER AND RING FINGER PROTEIN) proteins have been functionally characterized in iron regulation and stress response in Arabidopsis, rice and Populus. However, their roles in soybean have not yet been systematically investigated. Here, in this study, 16 GmCHYR genes with conserved Zinc_ribbon, CHY zinc finger and Ring finger domains were obtained and divided into three groups. Moreover, additional 2-3 hemerythrin domains could be found in the N terminus of Group III. Phylogenetic and homology analysis of CHYRs in green plants indicated that three groups might originate from different ancestors. Expectedly, GmCHYR genes shared similar conserved domains/motifs distribution within the same group. Gene expression analysis uncovered their special expression patterns in different soybean tissues/organs and under various abiotic stresses. Group I and II members were mainly involved in salt and alkaline stresses. The expression of Group III members was induced/repressed by dehydration, salt and alkaline stresses, indicating their diverse roles in response to abiotic stress. In conclusion, our work will benefit for further revealing the biological roles of GmCHYRs.
Project description:WNK kinases are a unique class of serine/threonine protein kinases that lack a conserved catalytic lysine residue in the kinase domain, hence the name WNK (with no K, i.e., lysine). WNK kinases are involved in various physiological processes in plants, such as circadian rhythm, flowering time, and stress responses. In this study, we identified 26 WNK genes in soybean and analyzed their phylogenetic relationships, gene structures, chromosomal distribution, cis-regulatory elements, expression patterns, and conserved protein motifs. The soybean WNK genes were unevenly distributed on 15 chromosomes and underwent 21 segmental duplication events during evolution. We detected 14 types of cis-regulatory elements in the promoters of the WNK genes, indicating their potential involvement in different signaling pathways. The transcriptome database revealed tissue-specific and salt stress-responsive expression of WNK genes in soybean, the second of which was confirmed by salt treatments and qRT-PCR analysis. We found that most WNK genes were significantly up-regulated by salt stress within 3 h in both roots and leaves, except for WNK5, which showed a distinct expression pattern. Our findings provide valuable insights into the molecular characteristics and evolutionary history of the soybean WNK gene family and lay a foundation for further analysis of WNK gene functions in soybean.Supplementary informationThe online version contains supplementary material available at 10.1007/s11032-024-01440-5.
Project description:Inorganic phosphate is one of key macronutrients essential for plant growth. The acquisition and distribution of phosphate are mediated by phosphate transporters functioning in various physiological and biochemical processes. In the present study, we comprehensively evaluated the phosphate transporter (PHT) gene family in the latest release of the Populus trichocarpa genome (version 3.0; Phytozome 11.0) and a total of 42 PHT genes were identified which formed five clusters: PHT1, PHT2, PHT3, PHT4, and PHO. Among the 42 PHT genes, 41 were localized to 15 Populus chromosomes. Analysis of these genes led to identification of 5-14 transmembrane segments, most of which were conserved within the same cluster. We identified 234 putative cis elements in the 2-kb upstream regions of the 42 PHT genes, many of which are related to development, stress, or hormone. Tissue-specific expression analysis of the 42 PtPHT genes revealed that 25 were highly expressed in the roots of P. tremula, suggesting that most of them might be involved in Pi uptake. Some PtPHT genes were highly expressed in more than six of the twelve investigated tissues of P. tremula, while the expression of a few of them was very low in all investigated tissues. In addition, the expression of the PtPHT genes was verified by quantitative real-time PCR in four tissues of P. simonii. Transcripts of 7 PtPHT genes were detected in all four tested tissues of P. simonii. Most PtPHT genes were expressed in the roots of P. simonii at high levels. Further, PtPHT1.2 and PtPHO9 expression was increased under drought conditions, irrespective of the phosphate levels. In particular, PtPHT1.2 expression was significantly induced by approximately 90-fold. However, the transcriptional changes of some PtPHT genes under drought stress were highly dependent on the phosphate levels. These results will aid in elucidation of the functions of PtPHT in the growth, development, and stress response of the poplar plant.
Project description:WRKY proteins are a superfamily of plant transcription factors with important roles in plants. WRKY proteins have been extensively analyzed in plant species including Arabidopsis and rice. Here we report characterization of soybean WRKY gene family and their functional analysis in resistance to soybean cyst nematode (SCN), the most important soybean pathogen. Through search of the soybean genome, we identified 174 genes encoding WRKY proteins that can be classified into seven groups as established in other plants. WRKY variants including a WRKY-related protein unique to legumes have also been identified. Expression analysis reveals both diverse expression patterns in different soybean tissues and preferential expression of specific WRKY groups in certain tissues. Furthermore, a large number of soybean WRKY genes were responsive to salicylic acid. To identify soybean WRKY genes that promote soybean resistance to SCN, we first screened soybean WRKY genes for enhancing SCN resistance when over-expressed in transgenic soybean hairy roots. To confirm the results, we transformed five WRKY genes into a SCN-susceptible soybean cultivar and generated transgenic soybean lines. Transgenic soybean lines overexpressing three WRKY transgenes displayed increased resistance to SCN. Thus, WRKY genes could be explored to develop new soybean cultivars with enhanced resistance to SCN.