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A soybean elongation factor Tu family (EF-Tu) protein, GmEF8, was determined to interact with GmCBL1, and GmEF8 expression was found to be induced by various abiotic stresses such as drought and heat. An ortholog of GmEF8 was identified in Arabidopsis, a T-DNA knockout line for which exhibited hypersensitivity to drought and heat stresses. Complementation with GmEF8 rescued the sensitivity of the Arabidopsis mutant to drought and heat stresses, and GmEF8 overexpression conferred drought and heat tolerance to transgenic Arabidopsis plants. In soybean, plants with GmEF8-overexpressing hairy roots (OE-GmEF8) exhibited enhanced drought and heat tolerance and had higher proline levels compared to plants with RNAi GmEF8-knockdown hairy roots (MR-GmEF8) and control hairy roots (EV). A number of drought-responsive genes, such as GmRD22 and GmP5CS, were induced in the OE-GmEF8 line compared to MR-GmEF8 and EV under normal growth conditions. These results suggest that GmEF8 has a positive role in regulating drought and heat stresses in Arabidopsis and soybean. This study reveals a potential role of the soybean GmEF8 gene in response to abiotic stresses, providing a foundation for further investigation into the complexities of stress signal transduction pathways.

Salt tolerance during seed germination is essential for seedling establishment under salt stress. Sirtuin-like proteins, NAD

The implementation of scalable quantum networks requires photons at the telecom band and long-lived spin coherence. The single Er3+ in solid-state hosts is an important candidate that fulfills these critical requirements simultaneously. However, to entangle distant Er3+ ions through photonic connections, the emission frequency of individual Er3+ in solid-state matrix must be the same, which is challenging because the emission frequency of Er3+ depends on its local environment. In this study, we propose and experimentally demonstrate the Stark tuning of the emission frequency of a single Er3+ in a Y2SiO5 crystal by employing electrodes interfaced with a silicon photonic crystal cavity. We obtain a Stark shift of 182.9 ± 0.8 MHz which is approximately 27 times of the optical emission linewidth, demonstrating the promising applications in tuning the emission frequency of independent Er3+ into the same spectral channels. Our results provide a useful solution for the construction of scalable quantum networks based on single Er3+ and a universal tool for tuning the emission of individual rare-earth ions.

Summary Drought and salt stresses impose major constraints on soybean production worldwide. However, improving agronomically valuable soybean traits under drought conditions can be challenging due to trait complexity and multiple factors that influence yield. Here, we identified a nuclear factor Y C subunit (NF‐YC) family transcription factor member, GmNF‐YC14, which formed a heterotrimer with GmNF‐YA16 and GmNF‐YB2 to activate the GmPYR1‐mediated abscisic acid (ABA) signalling pathway to regulate stress tolerance in soybean. Notably, we found that CRISPR/Cas9‐generated GmNF‐YC14 knockout mutants were more sensitive to drought than wild‐type soybean plants. Furthermore, field trials showed that overexpression of GmNF‐YC14 or GmPYR1 could increase yield per plant, grain plumpness, and stem base circumference, thus indicating improved adaptation of soybean plants to drought conditions. Taken together, our findings expand the known functional scope of the NF‐Y transcription factor functions and raise important questions about the integration of ABA signalling pathways in plants. Moreover, GmNF‐YC14 and GmPYR1 have potential for application in the improvement of drought tolerance in soybean plants.

NAC family transcription factors (TFs) are important regulators in plant development and stress responses. However, the biological functions of NAC TFs in wheat are rarely studied. In this study, 43 putative drought-induced NAC genes were identified from de novo transcriptome sequencing data of wheat following drought treatment. Twelve wheat NACs along with ten known stress-related NACs from Arabidopsis and rice were clustered into Group II based on a phylogenetic analysis. TaNAC48, which showed a higher and constitutive expression level in Group II, was selected for further investigation. TaNAC48 transcript was up-regulated by drought, PEG, H2O2 and abscisic acid (ABA) treatment and encoded a nuclear localized protein. Overexpression of TaNAC48 significantly promoted drought tolerance with increased proline content, and decreased rates of water loss, malondialdehyde (MDA), H2O2 and O2− content. Root length and a stomatal aperture assay confirmed that TaNAC48-overexpression plants increased sensitivity to ABA. Electrophoretic mobility shift assay (EMSA) and luciferase reporter analysis indicated that TaAREB3 could bind to a cis-acting ABA-responsive element (ABRE) on TaNAC48 promoter and activate the expression of TaNAC48. These results suggest that TaNAC48 is essential in mediating crosstalk between the ABA signaling pathway and drought stress responses in wheat.

Drought is a critical abiotic stressor that modulates soybean yield. Drought stress drastically enhances reactive oxygen species (ROS) formation, and maintaining ROS content above a cytostatic level but below a cytotoxic level is essential for normal biology processes in plants. At present, most of the known ROS-scavenging systems are in the cytoplasm, and the mechanism of ROS regulation in the nucleus remains unclear. GmNTF2B-1 is a member of the IV subgroup in the nucleus transporter family. Its expression is localized to the roots and is stimulated by drought stress. In this study, the overexpression of GmNTF2B-1 was found to improve the drought tolerance of transgenic soybean by influencing the ROS content in plants. An oxidoreductase, GmOXR17, was identified to interact with GmNTF2B-1 in the nucleus through the yeast two-hybrid, coimmunoprecipitation and bimolecular fluorescence complementation assays. The drought tolerance of GmOXR17 transgenic soybean was similar to that of GmNTF2B-1. GmNTF2B-1 was expressed in both cytoplasm and nucleus, and GmOXR17 transferred from the cytoplasm to the nucleus under drought stress. The overexpression of GmNTF2B-1 enhanced the nuclear entry of GmOXR17, and the overexpression of GmNTF2B-1 or GmOXR17 could decrease the H2 O2 content and oxidation level in the nucleus. In conclusion, the interaction between GmNTF2B-1 and GmOXR17 may enhance the nuclear entry of GmOXR17, thereby enhancing nuclear ROS scavenging to improve the drought resistance of soybean.

Virus-derived small interference RNAs (vsiRNAs) not only suppress virus infection in plants via induction of RNA silencing but also enhance virus infection by regulating host defensive gene expression. However, the underlying mechanisms that control vsiRNA-mediated host immunity or susceptibility remain largely unknown. In this study, we generated several transgenic wheat lines using four artificial microRNA expression vectors carrying vsiRNAs from Wheat yellow mosaic virus (WYMV) RNA1. Laboratory and field tests showed that two transgenic wheat lines expressing amiRNA1 were highly resistant to WYMV infection. Further analyses showed that vsiRNA1 could modulate the expression of a wheat thioredoxin-like gene (TaAAED1), which encodes a negative regulator of reactive oxygen species (ROS) production in the chloroplast. The function of TaAAED1 in ROS scavenging could be suppressed by vsiRNA1 in a dose-dependent manner. Furthermore, transgenic expression of amiRNA1 in wheat resulted in broad-spectrum disease resistance to Chinese wheat mosaic virus, Barley stripe mosaic virus, and Puccinia striiformis f. sp. tritici infection, suggesting that vsiRNA1 is involved in wheat immunity via ROS signaling. Collectively, these findings reveal a previously unidentified mechanism underlying the arms race between viruses and plants.

Photon echo is a fundamental tool for the manipulation of electromagnetic fields. Unavoidable spontaneous emission noise is generated in this process due to the strong rephasing pulse, which limits the achievable signal-to-noise ratio and represents a fundamental obstacle towards their applications in the quantum regime. Here we propose a noiseless photon-echo protocol based on a four-level atomic system. We implement this protocol in a Eu3+:Y2SiO5 crystal to serve as an optical quantum memory. A storage fidelity of 0.952 ± 0.018 is obtained for time-bin qubits encoded with single-photon-level coherent pulses, which is far beyond the maximal fidelity achievable using the classical measure-and-prepare strategy. In this work, the demonstrated noiseless photon-echo quantum memory features spin-wave storage, easy operation and high storage fidelity, which should be easily extended to other physical systems., Photon echo techniques are difficult to implement in the quantum regime due to coherent and spontaneous emission noise. Here, the authors propose a low-noise photon-echo quantum memory approach based on all-optical control in a four-level system, and demonstrate it using a Eu3+:Y2SiO5 crystal.

Tubby-like proteins (TLPs) are transcription factors that are widely present in eukaryotes and generally participate in growth and developmental processes. Using genome databases, a total of 22 putative TLP genes were identified in the soybean genome, and unevenly distributed across 13 chromosomes. Phylogenetic analysis demonstrated that the predicted GmTLP proteins were divided into five groups (I-V). Gene structure, protein motifs, and conserved domains were analyzed to identify differences and common features among the GmTLPs. A three-dimensional protein model was built to show the typical structure of TLPs. Analysis of publicly available gene expression data showed that GmTLP genes were differentially expressed in response to abiotic stresses. Based on those data, GmTLP8 was selected to further explore the role of TLPs in soybean drought and salt stress responses. GmTLP8 overexpressors had improved tolerance to drought and salt stresses, whereas the opposite was true of GmTLP8-RNAi lines. 3,3-diaminobenzidine and nitro blue tetrazolium staining and physiological indexes also showed that overexpression of GmTLP8 enhanced the tolerance of soybean to drought and salt stresses; in addition, downstream stress-responsive genes were upregulated in response to drought and salt stresses. This study provides new insights into the function of GmTLPs in response to abiotic stresses.

Abiotic stresses induce the accumulation of reactive oxygen species (ROS) and significantly affect plant growth. Protein phosphatase 2A (PP2A) plays an important role in controlling intracellular and extracellular ROS signals. However, the interaction between PP2A, ROS, and stress tolerance remains largely unclear. In this study, we found that the B′′ subunit of PP2A (PP2A-B′′) can be significantly induced and was analyzed using drought- and salt-induced soybean transcriptome data. Eighty-three soybean PP2A-B′′ genes were identified from the soybean genome via homologous sequence alignment, which was distributed across 20 soybean chromosomes. Among soybean PP2A-B′′ family genes, 26 GmPP2A-B′′ members were found to be responsive to drought and salt stresses in soybean transcriptome data. Quantitative PCR (qPCR) analysis demonstrated that GmPP2A-B′′71 had the highest expression levels under salt and drought stresses. Functional analysis demonstrated that overexpression of GmPP2A-B′′71 in soybeans can improve plant tolerance to drought and salt stresses; however, the interference of GmPP2A-B′′71 in soybean increased the sensibility to drought and salt stresses. Further analysis demonstrated that overexpression of GmPP2A-B′′71 in soybean could enhance the expression levels of stress-responsive genes, particularly genes associated with ROS elimination. These results indicate that PP2A-B′′ can promote plant stress tolerance by regulating the ROS signaling, which will contribute to improving the drought resistance of crops.

TIFY proteins play crucial roles in plant abiotic and biotic stress responses. Our transcriptome data revealed several

Tubby-like proteins (TLPs) are transcription factors that are widely present in eukaryotes and generally participate in growth and developmental processes. Using genome databases, a total of 22 putative

Abscisic acid (ABA) receptors are considered as the targeted manipulation of ABA sensitivity and water productivity in plants. Regulation of their stability or activity will directly affect ABA signalling. Mitogen-activated protein kinase (MAPK) cascades link multiple environmental and plant developmental cues. However, the molecular mechanism of ABA signalling and MAPK cascade interaction remains largely elusive. TaMPK3 overexpression decreases drought tolerance and wheat sensitivity to ABA, significantly weakening ABA's inhibitory effects on growth. Under drought stress, overexpression lines show lower survival rates, shoot fresh weight and proline content, but higher malondialdehyde levels at seedling stage, as well as decreased grain width and 1000 grain weight in both glasshouse and field conditions at the adult stage. TaMPK3-RNAi increases drought tolerance. TaMPK3 interaction with TaPYL4 leads to decreased TaPYL4 levels by promoting its ubiquitin-mediated degradation, whereas ABA treatment diminishes TaMPK3-TaPYL interactions. In addition, the expression of ABA signalling proteins is impaired in TaMPK3-overexpressing wheat plants under ABA treatment. The MPK3-PYL interaction module was found to be conserved across monocots and dicots. Our results suggest that the MPK3-PYL module could serve as a negative regulatory mechanism for balancing appropriate drought stress response with normal plant growth signalling in wheat.

Calmodulin-binding protein 60 (CBP60) members constitute a plant-specific protein family that plays an important role in plant growth and development. In the soybean genome, nineteen CBP60 members were identified and analyzed for their corresponding sequences and structures to explore their functions. Among GmCBP60A-1, which primarily locates in the cytomembrane, was significantly induced by drought and salt stresses. The overexpression of GmCBP60A-1 enhanced drought and salt tolerance in Arabidopsis, which showed better state in the germination of seeds and the root growth of seedlings. In the soybean hairy roots experiment, the overexpression of GmCBP60A-1 increased proline content, lowered water loss rate and malondialdehyde (MDA) content, all of which likely enhanced the drought and salt tolerance of soybean seedlings. Under stress conditions, drought and salt response-related genes showed significant differences in expression in hairy root soybean plants of GmCBP60A-1-overexpressing and hairy root soybean plants of RNAi. The present study identified GmCBP60A-1 as an important gene in response to salt and drought stresses based on the functional analysis of this gene and its potential underlying mechanisms in soybean stress-tolerance.

DEAD-box RNA helicases constitute the largest subfamily of RNA helicase superfamily 2 (SF2), and play crucial roles in plant growth, development, and abiotic stress responses. Wheat is one of the most important cereal crops in worldwide, and abiotic stresses greatly restrict its production. So far, the DEAD-box RNA helicase family has yet to be characterized in wheat. Here, we performed a comprehensive genome-wide analysis of the DEAD-box RNA helicase family in wheat, including phylogenetic relationships, chromosomal distribution, duplication events, and protein motifs. A total of 141 TaDEAD-box genes were identified and found to be unevenly distributed across all 21 chromosomes. Whole genome/segmental duplication was identified as the likely main driving factor for expansion of the TaDEAD-box family. Expression patterns of the 141 TaDEAD-box genes were compared across different tissues and under abiotic stresses to identify genes to be important in growth or stress responses. TaDEAD-box57-3B was significantly up-regulated under multiple abiotic stresses, and was therefore selected for further analysis. TaDEAD-box57-3B was localized to the cytoplasm and plasma membrane. Ectopic expression of TaDEAD-box57-3B in Arabidopsis improved tolerance to drought and salt stress as measured by germination rates, root lengths, fresh weights, and survival rates. Transgenic lines also showed higher levels of proline and chlorophyll and lower levels of malonaldehyde (MDA) than WT plants in response to drought or salt stress. In response to cold stress, the transgenic lines showed significantly better growth and higher survival rates than WT plants. These results indicate that TaDEAD-box57-3B may increase tolerance to drought, salt, and cold stress in transgenic plants through regulating the degree of membrane lipid peroxidation. This study provides new insights for understanding evolution and function in the TaDEAD-box gene family.

Nitrogen plays a crucial role in wheat growth and development. Here, we analyzed the tolerance of wheat strains XM26 and LM23 to low-nitrogen stress using a chlorate sensitivity experiment. Subsequently, we performed transcriptome analyses of both varieties exposed to low-nitrogen (LN) and normal (CK) treatments. Compared with those under CK treatment, 3534 differentially expressed genes (DEGs) were detected in XM26 in roots and shoots under LN treatment (p &lt, 0.05, and |log2FC| &gt, 1). A total of 3584 DEGs were detected in LM23. A total of 3306 DEGs, including 863 DEGs in roots and 2443 DEGs in shoots, were specifically expressed in XM26 or showed huge differences between XM26 and LM23 (log2FC ratio &gt, 3). These were selected for gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. The calcium-mediated plant–pathogen interaction, MAPK signaling, and phosphatidylinositol signaling pathways were enriched in XM26 but not in LM23. We also verified the expression of important genes involved in these pathways in the two varieties using qRT-PCR. A total of 156 transcription factors were identified among the DEGs, and their expression patterns were different between the two varieties. Our findings suggest that calcium-related pathways play different roles in the two varieties, eliciting different tolerances to low-nitrogen stress.

DEAD-box RNA helicases constitute the largest subfamily of RNA helicase superfamily 2 (SF2), and play crucial roles in plant growth, development, and abiotic stress responses. Wheat is one of the most important cereal crops in worldwide, and abiotic stresses greatly restrict its production. So far, the DEAD-box RNA helicase family has yet to be characterized in wheat. Here, we performed a comprehensive genome-wide analysis of the DEAD-box RNA helicase family in wheat, including phylogenetic relationships, chromosomal distribution, duplication events, and protein motifs. A total of 141 TaDEAD-box genes were identified and found to be unevenly distributed across all 21 chromosomes. Whole genome/segmental duplication was identified as the likely main driving factor for expansion of the TaDEAD-box family. Expression patterns of the 141 TaDEAD-box genes were compared across different tissues and under abiotic stresses to identify genes to be important in growth or stress responses. TaDEAD-box57-3B was significantly up-regulated under multiple abiotic stresses, and was therefore selected for further analysis. TaDEAD-box57-3B was localized to the cytoplasm and plasma membrane. Ectopic expression of TaDEAD-box57-3B in Arabidopsis improved tolerance to drought and salt stress as measured by germination rates, root lengths, fresh weights, and survival rates. Transgenic lines also showed higher levels of proline and chlorophyll and lower levels of malonaldehyde (MDA) than WT plants in response to drought or salt stress. In response to cold stress, the transgenic lines showed significantly better growth and higher survival rates than WT plants. These results indicate that TaDEAD-box57-3B may increase tolerance to drought, salt, and cold stress in transgenic plants through regulating the degree of membrane lipid peroxidation. This study provides new insights for understanding evolution and function in the TaDEAD-box gene family.

Abiotic stresses induce the accumulation of reactive oxygen species (ROS) and significantly affect plant growth. Protein phosphatase 2A (PP2A) plays an important role in controlling intracellular and extracellular ROS signals. However, the interaction between PP2A, ROS, and stress tolerance remains largely unclear. In this study, we found that the B

BRI1-EMS suppressor (BES)/brassinazole-resistant (BZR) family transcription factors are involved in a variety of physiological processes, but the biological functions of some BES/BZR transcription factors remain unknown; moreover, it is not clear if any of these proteins function in the regulation of plant stress responses. Here, wheat (Triticum aestivum) brassinazole-resistant 2 (TaBZR2)-overexpressing plants exhibited drought tolerant phenotypes, whereas downregulation of TaBZR2 in wheat by RNA interference resulted in elevated drought sensitivity. electrophoretic mobility shift assay and luciferase reporter analysis illustrate that TaBZR2 directly interacts with the gene promoter to activate the expression of T. aestivum glutathione s-transferase-1 (TaGST1), which functions positively in scavenging drought-induced superoxide anions (O2−). Moreover, TaBZR2 acts as a positive regulator in brassinosteroid (BR) signaling. Exogenous BR treatment enhanced TaBZR2-mediated O2− scavenging and antioxidant enzyme gene expression. Taken together, we demonstrate that a BES/BZR family transcription factor, TaBZR2, functions positively in drought responses by activating TaGST1 and mediates the crosstalk between BR and drought signaling pathways. Our results thus provide new insights into the mechanisms underlying how BES/BZR family transcription factors contribute to drought tolerance in wheat.

Plant G proteins are versatile components of transmembrane signaling transduction pathways. The deficient mutant of heterotrimeric G protein leads to defects in plant growth and development, suggesting that it regulates the GA pathway in Arabidopsis. However, the molecular mechanism of G protein regulation of the GA pathway is not understood in plants. In this study, two G protein β subunit (AGB1) mutants, agb1-2 and N692967, were dwarfed after exogenous application of GA3. AGB1 interacts with the DNA-binding domain MYB62, a GA pathway suppressor. Transgenic plants were obtained through overexpression of MYB62 in two backgrounds including the wild-type (MYB62/WT&nbsp, Col-0) and agb1 mutants (MYB62/agb1) in Arabidopsis. Genetic analysis showed that under GA3 treatment, the height of the transgenic plants MYB62/WT and MYB62/agb1 was lower than that of WT. The height of MYB62/agb1 plants was closer to MYB62/WT plants and higher than that of mutants agb1-2 and N692967, suggesting that MYB62 is downstream of AGB1 in the GA pathway. qRT-PCR and competitive DNA binding assays indicated that MYB62 can bind MYB elements in the promoter of GA2ox7, a GA degradation gene, to activate GA2ox7 transcription. AGB1 affected binding of MYB62 on the promoter of GA2ox7, thereby negatively regulating th eactivity of MYB62.

MADS-box transcription factors play vital roles in multiple biological processes in plants. At present, a comprehensive investigation into the genome-wide identification and classification of MADS-box genes in foxtail millet (Setaria italica L.) has not been reported. In this study, we identified 72 MADS-box genes in the foxtail millet genome and give an overview of the phylogeny, chromosomal location, gene structures, and potential functions of the proteins encoded by these genes. We also found that the expression of 10 MIKC-type MADS-box genes was induced by abiotic stresses (PEG-6000 and NaCl) and exogenous hormones (ABA and GA), which suggests that these genes may play important regulatory roles in response to different stresses. Further studies showed that transgenic Arabidopsis and rice (Oryza sativa L.) plants overexpressing SiMADS51 had reduced drought stress tolerance as revealed by lower survival rates and poorer growth performance under drought stress conditions, which demonstrated that SiMADS51 is a negative regulator of drought stress tolerance in plants. Moreover, expression of some stress-related genes were down-regulated in the SiMADS51-overexpressing plants. The results of our study provide an overall picture of the MADS-box gene family in foxtail millet and establish a foundation for further research on the mechanisms of action of MADS-box proteins with respect to abiotic stresses.

Domain of unknown function 4228 (DUF4228) proteins are a class of proteins widely found in plants, playing an important role in response to abiotic stresses. However, studies on the DUF4228 family in soybean (Glycine max L.) are sparse. In this study, we identified a total of 81 DUF4228 genes in soybean genome, named systematically based on their chromosome distributions. Results showed that these genes were unevenly distributed on the 20 chromosomes of soybean. The predicted soybean DUF4228 proteins were identified in three groups (Groups I–III) based on a maximum likelihood phylogenetic tree. Genetic structure analysis showed that most of the GmDUF4228 genes contained no introns. Expression profiling showed that GmDUF4228 genes were widely expressed in different organs and tissues in soybean. RNA-seq data were used to characterize the expression profiles of GmDUF4228 genes under the treatments of drought and salt stresses, with nine genes showing significant up-regulation under both drought and salt stress further functionally verified by promoter (cis-acting elements) analysis and quantitative real-time PCR (qRT-PCR). Due to its upregulation under drought and salt stresses based on both RNA-seq and qRT-PCR analyses, GmDUF4228-70 was selected for further functional analysis in transgenic plants. Under drought stress, the degree of leaf curling and wilting of the GmDUF4228-70-overexpressing (GmDUF4228-70-OE) line was lower than that of the empty vector (EV) line. GmDUF4228-70-OE lines also showed increased proline content, relative water content (RWC), and chlorophyll content, and decreased contents of malondialdehyde (MDA), H2O2, and O2–. Under salt stress, the changes in phenotypic and physiological indicators of transgenic plants were the same as those under drought stress. In addition, overexpression of the GmDUF4228-70 gene promoted the expression of marker genes under both drought and salt stresses. Taken together, the results indicated that GmDUF4228 genes play important roles in response to abiotic stresses in soybean.

Abiotic stresses, such as drought and salinity, severely affects the growth, development and productivity of the plants. The Catharanthus roseus RLK1-like (CrRLK1L) protein kinase family is involved in several processes in the plant life cycle. However, there have been few studies addressing the functions of CrRLK1L proteins in soybean. In this study, 38 CrRLK1L genes were identified in the soybean genome (Glycine max Wm82.a2.v1). Phylogenetic analysis demonstrated that soybean CrRLK1L genes were grouped into clusters, cluster I, II, III. The chromosomal mapping demonstrated that 38 CrRLK1L genes were located in 14 of 20 soybean chromosomes. None were discovered on chromosomes 1, 4, 6, 7, 11, and 14. Gene structure analysis indicated that 73.6% soybean CrRLK1L genes were characterized by a lack of introns.15.7% soybean CrRLK1L genes only had one intron and 10.5% soybean CrRLK1L genes had more than one intron. Five genes were obtained from soybean drought- and salt-induced transcriptome databases and were found to be highly up-regulated. GmCrRLK1L20 was notably up-regulated under drought and salinity stresses, and was therefore studied further. Subcellular localization analysis revealed that the GmCrRLK1L20 protein was located in the cell membrane. The overexpression of the GmCrRLK1L20 gene in soybean hairy roots improved both drought tolerance and salt stresses and enhanced the expression of the stress-responsive genes GmMYB84, GmWRKY40, GmDREB-like, GmGST15, GmNAC29, and GmbZIP78. These results indicated that GmCrRLK1L20 could play a vital role in defending against drought and salinity stresses in soybean.

Phospholipase C (PLC) performs significant functions in a variety of biological processes, including plant growth and development. The PLC family of enzymes principally catalyze the hydrolysis of phospholipids in organisms. This exhaustive exploration of soybean GmPLC members using genome databases resulted in the identification of 15 phosphatidylinositol-specific PLC (GmPI-PLC) and 9 phosphatidylcholine-hydrolyzing PLC (GmNPC) genes. Chromosomal location analysis indicated that GmPLC genes mapped to 10 of the 20 soybean chromosomes. Phylogenetic relationship analysis revealed that GmPLC genes distributed into two groups in soybean, the PI-PLC and NPC groups. The expression patterns and tissue expression analysis showed that GmPLCs were differentially expressed in response to abiotic stresses. GmPI-PLC7 was selected to further explore the role of PLC in soybean response to drought and salt stresses by a series of experiments. Compared with the transgenic empty vector (EV) control lines, over-expression of GmPI-PLC7 (OE) conferred higher drought and salt tolerance in soybean, while the GmPI-PLC7-RNAi (RNAi) lines exhibited the opposite phenotypes. Plant tissue staining and physiological parameters observed from drought- and salt-stressed plants showed that stress increased the contents of chlorophyll, oxygen free radical (O2–), hydrogen peroxide (H2O2) and NADH oxidase (NOX) to amounts higher than those observed in non-stressed plants. This study provides new insights in the functional analysis of GmPLC genes in response to abiotic stresses.

Plant C2 domain proteins play essential biological functions in numerous plants. In this study, 180 soybean C2 domain genes were identified by screening. Phylogenetic relationship analysis revealed that C2 domain genes fell into three distinct groups with diverged gene structure and conserved functional domain. Chromosomal location analysis indicated that C2 domain genes mapped to 20 chromosomes. The transcript profiles based on RNA-seq data showed that GmC2-58, GmC2-88, and GmC2-148 had higher levels of expression under salt, drought, and abscisic acid (ABA) treatments. GmC2-148, encoding a cell membrane-localized protein, had the highest level of response to various treatments according to real-time quantitative polymerase chain reaction (RT-qPCR) analysis. Under salt and drought stresses, the soybean plants with GmC2-148 transgenic hairy roots showed delayed leaf rolling, a higher content of proline (Pro), and lower contents of H2O2, O2– and malondialdehyde (MDA) compared to those of the empty vector (EV) plants. The results of transgenic Arabidopsis in salt and drought treatments were consistent with those in soybean treatments. In addition, the soybean plants with GmC2-148 transgenic hairy roots increased transcript levels of several abiotic stress-related marker genes, including COR47, NCDE3, NAC11, WRKY13, DREB2A, MYB84, bZIP44, and KIN1 which resulted in enhanced abiotic stress tolerance in soybean. These results indicate that C2 domain genes are involved in response to salt and drought stresses, and this study provides a genome-wide analysis of the C2 domain family in soybean.

MADS-box transcription factors play vital roles in multiple biological processes in plants. At present, a comprehensive investigation into the genome-wide identification and classification of MADS-box genes in foxtail millet (Setaria italica L.) has not been reported. In this study, we identified 72 MADS-box genes in the foxtail millet genome and give an overview of the phylogeny, chromosomal location, gene structures, and potential functions of the proteins encoded by these genes. We also found that the expression of 10 MIKC-type MADS-box genes was induced by abiotic stresses (PEG-6000 and NaCl) and exogenous hormones (ABA and GA), which suggests that these genes may play important regulatory roles in response to different stresses. Further studies showed that transgenic Arabidopsis and rice (Oryza sativa L.) plants overexpressing SiMADS51 had reduced drought stress tolerance as revealed by lower survival rates and poorer growth performance under drought stress conditions, which demonstrated that SiMADS51 is a negative regulator of drought stress tolerance in plants. Moreover, expression of some stress-related genes were down-regulated in the SiMADS51-overexpressing plants. The results of our study provide an overall picture of the MADS-box gene family in foxtail millet and establish a foundation for further research on the mechanisms of action of MADS-box proteins with respect to abiotic stresses.

GRAS genes, which form a plant-specific transcription factor family, play an important role in plant growth and development and stress responses. However, the functions of GRAS genes in soybean (Glycine max) remain largely unknown. Here, 117 GRAS genes distributed on 20 chromosomes were identified in the soybean genome and were classified into 11 subfamilies. Of the soybean GRAS genes, 80.34% did not have intron insertions, and 54 pairs of genes accounted for 88.52% of duplication events (61 pairs). RNA-seq analysis demonstrated that most GmGRASs were expressed in 14 different soybean tissues examined and responded to multiple abiotic stresses. Results from quantitative real-time PCR analysis of six selected GmGRASs suggested that GmGRAS37 was significantly upregulated under drought and salt stress conditions and abscisic acid and brassinosteroid treatment; therefore, this gene was selected for further study. Subcellular localization analysis revealed that the GmGRAS37 protein was located in the plasma membrane, nucleus, and cytosol. Soybean hairy roots overexpressing GmGRAS37 had improved resistance to drought and salt stresses. In addition, these roots showed increased transcript levels of several drought‐ and salt-related genes. The results of this study provide the basis for comprehensive analysis of GRAS genes and insight into the abiotic stress response mechanism in soybean.

NF-YA transcription factors function in modulating tolerance to abiotic stresses that are serious threats to crop yields. In this study, GmNFYA13, an NF-YA gene in soybean, was strongly induced by salt, drought, ABA, and H2O2, and suppressed by tungstate, an ABA synthesis inhibitor. The GmNFYA13 transcripts were detected in different tissues in seedling and flowering stages, and the expression levels in roots were highest. GmNFYA13 is a nuclear localization protein with self-activating activity. Transgenic Arabidopsis plants overexpressing GmNFYA13 with higher transcript levels of stress-related genes showed ABA hypersensitivity and enhanced tolerance to salt and drought stresses compared with WT plants. Moreover, overexpression of GmNFYA13 resulted in higher salt and drought tolerance in OE soybean plants, while suppressing it produced the opposite results. In addition, GmNFYA13 could bind to the promoters of GmSALT3, GmMYB84, GmNCED3, and GmRbohB to regulate their expression abundance in vivo. The data in this study suggested that GmNFYA13 enhanced salt and drought tolerance in soybean plants.

Ankyrin repeat (ANK) proteins are essential in cell growth, development, and response to hormones and environmental stresses. In the present study, 226 ANK genes were identified and classified into nine subfamilies according to conserved domains in the soybean genome (Glycine max L.). Among them, the GmANK114 was highly induced by drought, salt, and abscisic acid. The GmANK114 encodes a protein that belongs to the ANK-RF subfamily containing a RING finger (RF) domain in addition to the ankyrin repeats. Heterologous overexpression of GmANK114 in transgenic Arabidopsis improved the germination rate under drought and salt treatments compared to wild-type. Homologous overexpression of GmANK114 improved the survival rate under drought and salt stresses in transgenic soybean hairy roots. In response to drought or salt stress, GmANK114 overexpression in soybean hairy root showed higher proline and lower malondialdehyde contents, and lower H2O2 and O2- contents compared control plants. Besides, GmANK114 activated transcription of several abiotic stress-related genes, including WRKY13, NAC11, DREB2, MYB84, and bZIP44 under drought and salt stresses in soybean. These results provide new insights for functional analysis of soybean ANK proteins and will be helpful for further understanding how ANK proteins in plants adapt to abiotic stress.

Ubiquitylation is a form of post-translational modification of proteins that can alter localization, functionality, degradation, or transcriptional activity within a cell. E2 ubiquitin-conjugating enzyme (UBC) and E3 ubiquitin ligases are the primary determinants of substrate specificity in the context of ubiquitin conjugation. Multiubiquitination modifies target proteins for 26S proteasome degradation, while monoubiquitination controls protein activation and localization. At present, research on the monoubiquitination, especially histone monoubiquitination, has mostly focused on model plants with relatively few on crop species. In this study, we identified 91 UBC-like genes in soybean. The chromosomal localization, phylogenetic relationships, gene structures, and putative cis-acting elements were evaluated. Furthermore, the tissue-specific expression patterns of UBC Class I genes under drought stress were also investigated. Among Class I genes, GmUBC9 induction in response to drought stress was evident, and so this gene was selected for further analysis. GmUBC9 localized to the nucleus and endoplasmic reticulum. The overexpression of GmUBC9 in Arabidopsis led to enhanced tolerance for drought conditions across a range of stages of development, while overexpression in soybean hairy roots similarly led to improvements in tolerance for drought conditions, increased proline content, and reduced MDA content in soybean seedlings compared to wild type plants. HISTONE MONOUBIQUITINATION 2 (HUB2), an E3-like protein involved in histone H2B ubiquitylation (H2Bub1), was found to interact with GmUBC9 through Y2H analysis and BiFC assays in Arabidopsis and soybean. Under drought conditions, the level of H2Bub1 increased, and transcription of drought response genes was activated in GmUBC9 transgenic Arabidopsis and soybean. In addition, GmUBC9 transgenic Arabidopsis and soybean showed a late-flowering phenotype and had increased expression levels of the flowering related genes FLC and MAF4. These findings indicate that GmUBC9 is important for drought stress response and regulation of flowering time in soybean.

Photonic quantum memory is the core element in quantum information processing (QIP). For the scalable and convenient practical applications, great efforts have been devoted to the integrated quantum memory based on various waveguides fabricated in solids. However, on-demand storage of qubits, which is an essential requirement for QIP, is still challenging to be implemented using such integrated quantum memory. Here we report the on-demand storage of time-bin qubits in an on-chip waveguide memory on the surface of a $^{151}$Eu$^{3+}$:Y$_2$SiO$_5$ crystal, utilizing the Stark modulated atomic frequency comb protocol. A qubit storage fidelity of $99.3\%\pm0.2\%$ is obtained with a input of 0.5 photons per pulse, far beyond the highest fidelity achievable using the classical measure-and-prepare strategy. The developed integrated quantum memory with the on-demand retrieval capability, represents an important step towards practical applications of integrated quantum nodes in quantum networks., 6 pages, 4 figures and 1 table

Foxtail millet (Setaria italica) originated in China and is generally cultivated in arid and barren soil. Through long-term harsh environmental selection, foxtail millet has acquired significant drought resistance. However, the molecular mechanism of foxtail millet drought resistance is still unknown. Here, we identified a drought-induced R2R3-MYB transcription factor SiMYB56 in foxtail millet. Overexpression of SiMYB56 significantly enhances tolerance to drought stress in transgenic rice plants at both the vegetative and the reproductive stage and has no adverse effect on its normal growth. Compared with wild-type controls, SiMYB56-overexpressing rice plants had lower MDA content and higher lignin content under drought conditions. Quantitative real-time PCR and Transcriptional activity assays demonstrated that SiMYB56 could activate expression of lignin biosynthesis genes under drought conditions. Also, we found that overexpression of SiMYB56 can led to ABA accumulation in the seeds transgenic rice plants. Further experiments showed that Overexpression of SiMYB56 can upregulate the expression of ABA synthesis and response related genes under drought conditions. In conclusion, SiMYB56 may enhance the drought resistance of transgenic rice plants by regulating lignin biosynthesis and ABA signaling pathway, making SiMYB56 a candidate gene for drought resistance improvement in gramineous crops.

GDSL-type esterase/lipase proteins (GELPs) belong to the SGNH hydrolase superfamily and contain a conserved GDSL motif at their N-terminus. GELPs are widely distributed in nature, from microbes to plants, and play crucial roles in growth and development, stress responses and pathogen defense. However, the identification and functional analysis of GELP genes are hardly explored in soybean. This study describes the identification of 194 GELP genes in the soybean genome and their phylogenetic classification into 11 subfamilies (A-K). GmGELP genes are disproportionally distributed on 20 soybean chromosomes. Large-scale WGD/segmental duplication events contribute greatly to the expansion of the soybean GDSL gene family. The Ka/Ks ratios of more than 70% of duplicated gene pairs ranged from 0.1-0.3, indicating that most GmGELP genes were under purifying selection pressure. Gene structure analysis indicate that more than 74% of GmGELP genes are interrupted by 4 introns and composed of 5 exons in their coding regions, and closer homologous genes in the phylogenetic tree often have similar exon-intron organization. Further statistics revealed that approximately 56% of subfamily K members contain more than 4 introns, and about 28% of subfamily I members consist of less than 4 introns. For this reason, the two subfamilies were used to simulate intron gain and loss events, respectively. Furthermore, a new model of intron position distribution was established in current study to explore whether the evolution of multi-gene families resulted from the diversity of gene structure. Finally, RNA-seq data were used to investigate the expression profiles of GmGELP gene under different tissues and multiple abiotic stress treatments. Subsequently, 7 stress-responsive GmGELP genes were selected to verify their expression levels by RT-qPCR, the results were consistent with RNA-seq data. Among 7 GmGELP genes, GmGELP28 was selected for further study owing to clear responses to drought, salt and ABA treatments. Transgenic Arabidopsis thaliana and soybean plants showed drought and salt tolerant phenotype. Overexpression of GmGELP28 resulted in the changes of several physiological indicators, which allowed plants to adapt adverse conditions. In all, GmGELP28 is a potential candidate gene for improving the salinity and drought tolerance of soybean.

Ubiquitylation is a form of post-translational modification of proteins that can alter localization, functionality, degradation, or transcriptional activity within a cell. E2 ubiquitin-conjugating enzyme (UBC) and E3 ubiquitin ligases are the primary determinants of substrate specificity in the context of ubiquitin conjugation. Multiubiquitination modifies target proteins for 26S proteasome degradation, while monoubiquitination controls protein activation and localization. At present, research on the monoubiquitination, especially histone monoubiquitination, has mostly focused on model plants with relatively few on crop species. In this study, we identified 91

Lack of potassium in soil limits crop yield. Increasing yield and conserving potassium ore requires improving K use efficiency (KUE). Many genes influence KUE in plants, but it is not clear how these genes function in the field. We identified the V-type H+-pyrophosphatase gene EdVP1 from Elymus dahurica. Gene expression analysis showed that EdVP1 was induced by low potassium stress. Protein subcellular localization analysis demonstrated that EdVP1 localized on the plasma membrane. We overexpressed EdVP1 in two wheat varieties and conducted K tolerance experiments across years. Yield per plant, grain number per spike, plant height, and K uptake of four transgenic wheat lines increased significantly compared with WT; results from two consecutive years showed that EdVP1 significantly increased yield and KUE of transgenic wheat. Pot experiments showed that transgenic plants had significantly longer shoots and roots, and higher K accumulation in shoots and roots and H+-PPase activity in shoots than WT under low K. A fluidity assay of potassium ion in EdVP1 transgenic plant roots showed that potassium ion influx and H+ outflow in transgenic plants were higher than WT. Overexpressing EdVP1 significantly improved yield and KUE of transgenic wheat and was related to higher K uptake capacity in root.

Vascular plant one-zinc-finger (VOZ) transcription factor, a plant specific one-zinc-finger-type transcriptional activator, is involved in regulating numerous biological processes such as floral induction and development, defense against pathogens, and response to multiple types of abiotic stress. Six VOZ transcription factor-encoding genes (GmVOZs) have been reported to exist in the soybean (Glycine max) genome. In spite of this, little information is currently available regarding GmVOZs. In this study, GmVOZs were cloned and characterized. GmVOZ genes encode proteins possessing transcriptional activation activity in yeast cells. GmVOZ1E, GmVOZ2B, and GmVOZ2D gene products were widely dispersed in the cytosol, while GmVOZ1G was primarily located in the nucleus. GmVOZs displayed a differential expression profile under dehydration, salt, and salicylic acid (SA) stress conditions. Among them, GmVOZ1G showed a significantly induced expression in response to all stress treatments. Overexpression of GmVOZ1G in soybean hairy roots resulted in a greater tolerance to drought and salt stress. In contrast, RNA interference (RNAi) soybean hairy roots suppressing GmVOZ1G were more sensitive to both of these stresses. Under drought treatment, soybean composite plants with an overexpression of hairy roots had higher relative water content (RWC). In response to drought and salt stress, lower malondialdehyde (MDA) accumulation and higher peroxidase (POD) and superoxide dismutase (SOD) activities were observed in soybean composite seedlings with an overexpression of hairy roots. The opposite results for each physiological parameter were obtained in RNAi lines. In conclusion, GmVOZ1G positively regulates drought and salt stress tolerance in soybean hairy roots. Our results will be valuable for the functional characterization of soybean VOZ transcription factors under abiotic stress.

Background Abiotic stress severely influences plant growth and development. MYB transcription factors (TFs), which compose one of the largest TF families, play an important role in abiotic stress responses. Result We identified 139 soybean MYB-related genes; these genes were divided into six groups based on their conserved domain and were distributed among 20 chromosomes (Chrs). Quantitative real-time PCR (qRT-PCR) indicated that GmMYB118 highly responsive to drought, salt and high temperature stress; thus, this gene was selected for further analysis. Subcellular localization revealed that the GmMYB118 protein located in the nucleus. Ectopic expression (EX) of GmMYB118 increased tolerance to drought and salt stress and regulated the expression of several stress-associated genes in transgenic Arabidopsis plants. Similarly, GmMYB118-overexpressing (OE) soybean plants generated via Agrobacterium rhizogenes (A. rhizogenes)-mediated transformation of the hairy roots showed improved drought and salt tolerance. Furthermore, compared with the control (CK) plants, the clustered, regularly interspaced, short palindromic repeat (CRISPR)-transformed plants exhibited reduced drought and salt tolerance. The contents of proline and chlorophyll in the OE plants were significantly greater than those in the CK plants, whose contents were greater than those in the CRISPR plants under drought and salt stress conditions. In contrast, the reactive oxygen species (ROS) and malondialdehyde (MDA) contents were significantly lower in the OE plants than in the CK plants, whose contents were lower than those in the CRISPR plants under stress conditions. Conclusions These results indicated that GmMYB118 could improve tolerance to drought and salt stress by promoting expression of stress-associated genes and regulating osmotic and oxidizing substances to maintain cell homeostasis. Electronic supplementary material The online version of this article (10.1186/s12870-018-1551-7) contains supplementary material, which is available to authorized users.

Background The calcineurin B-like protein (CBL)-interacting protein kinase (CIPK) signaling pathway responds to various abiotic stresses in plants. Results Wheat CIPK23, isolated from wheat drought transcriptome data set, was induced by multiple abiotic stresses, including drought, salt, and abscisic acid (ABA). Compared with wild-type plants, TaCIPK23-overexpression wheat and Arabidopsis showed an higher survival rate under drought conditions with enhanced germination rate, developed root system, increased accumulation of osmolytes, and reduced water loss rate. Over-expression of TaCIPK23 rendered transgenic plants ABA sensitivity, as evidenced by delayed seed germination and the induction of stomatal closure. Consistent with the ABA-sensitive phenotype, the expression level of drought- and ABA-responsive genes were increased under drought conditions in the transgenic plants. In addition, using yeast two-hybrid system, pull-down and bimolecular fluorescence complementation (BiFc) assays, TaCIPK23 was found to interact with TaCBL1 on the plasma membrane. Conclusions These results suggest that TaCIPK23 plays important roles in ABA and drought stress responses, and mediates crosstalk between the ABA signaling pathway and drought stress responses in wheat. Electronic supplementary material The online version of this article (10.1186/s12870-018-1306-5) contains supplementary material, which is available to authorized users.

Foxtail millet (Setaria italica (L.) P. Beauv) is a naturally stress tolerant crop. Compared to other gramineous crops, it has relatively stronger drought and lower nutrition stress tolerance traits. To date, the scope of functional genomics research in foxtail millet (S. italic L.) has been quite limited. NAC (NAM, ATAF1/2 and CUC2)-like transcription factors are known to be involved in various biological processes, including abiotic stress responses. In our previous foxtail millet (S. italic L.) RNA seq analysis, we found that the expression of a NAC-like transcription factor, S1NAC110 could be induced by drought stress; additionally, other references have reported that SiNAC110 expression could be induced by abiotic stress. So, we here selected SiNAC110 for further characterization and functional analysis. First, the predicted SiNAC110 protein encoded indicated SiNAC110 has a conserved NAM (no apical meristem) domain between the 11–139 amino acid positions. Phylogenetic analysis then indicated that SiNAC110 belongs to subfamily III of the NAC gene family. Subcellular localization analysis revealed that the SiNAC110-GFP fusion protein was localized to the nucleus in Arabidopsis protoplasts. Gene expression profiling analysis indicated that expression of SiNAC110 was induced by dehydration, high salinity and other abiotic stresses. Gene functional analysis using SiNAC110 overexpressed Arabidopsis plants indicated that, under drought and high salt stress conditions, the seed germination rate, root length, root surface area, fresh weight, and dry weight of the SiNAC110 overexpressed lines were significantly higher than the wild type (WT), suggesting that the SiNAC110 overex-pressed lines had enhanced tolerance to drought and high salt stresses. However, overexpression of S1NAC110 did not affect the sensitivity of SiNAC110 overexpressed lines to abscisic acid (ABA) treatment. Expression analysis of genes involved in proline synthesis, Na+/K+ transport, drought responses, and aqueous transport proteins were higher in the SiNAC110 overexpressed lines than in the WT, whereas expression of ABA-dependent pathway genes did not change. These results indicated that overexpression of SiNAC110 conferred tolerance to drought and high salt stresses, likely through influencing the regulation of proline biosynthesis, ion homeostasis and osmotic balance. Therefore, SiNAC110 appears to function in the ABA-independent abiotic stress response pathway in plants.

BackgroundCrop productivity is challenged by abiotic stresses, among which drought stress is the most common.NF-Ygenes, especiallyNF-YAgenes, regulate tolerance to abiotic stress.ResultsSoybean NF-Y geneGmNFYA5was identified to have the highest transcript level among all 21NF-YAgenes in soybean (Glycine maxL.) under drought stress. Drought-induced transcript ofGmNFYA5was suppressed by the ABA synthesis inhibitor naproxen (NAP).GmNFYA5transcript was detected in various tissues at vegetative and reproductive growth stages with higher levels in roots and leaves than in other tissues, which was consist with theGmNFYA5promoter: GUS fusion assay. Overexpression ofGmNFYA5in transgenic Arabidopsis plants caused enhanced drought tolerance in seedlings by decreasing stomatal aperture and water loss from leaves. Overexpression and suppression ofGmNFYA5in soybean resulted in increased and decreased drought tolerance, respectively, relative to plants with an empty vector (EV). Transcript levels of ABA-dependent genes (ABI2,ABI3,NCED3,LEA3,RD29A,P5CS1,GmWRKY46,GmNCED2andGmbZIP1) and ABA-independent genes (DREB1A,DREB2A,DREB2B,GmDREB1,GmDREB2andGmDREB3) in transgenic plants overexpressingGmNFYA5were higher than those of wild-type plants under drought stress; suppression ofGmNFYA5transcript produced opposite results. GmNFYA5 probably regulated the transcript abundance ofGmDREB2andGmbZIP1by binding to the promoters in vivo.ConclusionsOur results suggested that overexpression ofGmNFYA5improved drought tolerance in soybean via both ABA-dependent and ABA-independent pathways.

Photon loss in optical fibers prevents long-distance distribution of quantum information on the ground. Quantum repeater is proposed to overcome this problem, but the communication distance is still limited so far because of the system complexity of the quantum repeater scheme. Alternative solutions include transportable quantum memory and quantum-memory-equipped satellites, where long-lived optical quantum memories are the key components to realize global quantum communication. However, the longest storage time of the optical memories demonstrated so far is approximately 1 minute. Here, by employing a zero-first-order-Zeeman magnetic field and dynamical decoupling to protect the spin coherence in a solid, we demonstrate coherent storage of light in an atomic frequency comb memory over 1 hour, leading to a promising future for large-scale quantum communication based on long-lived solid-state quantum memories., Quantum memories are key components for quantum communication, but current storage times are still too short. Here, the authors use the atomic frequency comb protocol in a zero-first-order-Zeeman field to coherently store an optical pulse for an hour in a cryogenically cooled rare-earth doped crystal.

Abiotic stresses, such as drought and salt, are major environmental stresses, affecting plant growth and crop productivity. Plant bZIP transcription factors (bZIPs) confer stress resistances in harsh environments and play important roles in each phase of plant growth processes. In this research, 15 soybean bZIP family members were identified from drought-induced de novo transcriptomic sequences of soybean, which were unevenly distributed across 12 soybean chromosomes. Promoter analysis showed that these 15 genes were rich in ABRE, MYB and MYC cis-acting elements which were reported to be involved in abiotic stress responses. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that 15 GmbZIP genes could be induced by drought and salt stress. GmbZIP2 was significantly upregulated under stress conditions and thus was selected for further study. Subcellular localization analysis revealed that the GmbZIP2 protein was located in the cell nucleus. qRT-PCR results show that GmbZIP2 can be induced by multiple stresses. The overexpression of GmbZIP2 in Arabidopsis and soybean hairy roots could improve plant resistance to drought and salt stresses. The result of differential expression gene analysis shows that the overexpression of GmbZIP2 in soybean hairy roots could enhance the expression of the stress responsive genes GmMYB48, GmWD40, GmDHN15, GmGST1 and GmLEA. These results indicate that soybean bZIPs played pivotal roles in plant resistance to abiotic stresses.

Foxtail millet (Setaria italica), which originated in China, has a strong tolerance to low nutrition stresses. However, the mechanism of foxtail millet tolerance to low-nitrogen stress is still unknown. In this study, the transcriptome of foxtail millet under low-nitrogen stress was systematically analyzed. Expression of 1891 genes was altered, including 1318 up-regulated genes and 573 down-regulated genes. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis revealed that 3% of these genes were involved in membrane transport and 5% were involved in redox processes. There were 74 total transcription factor (TF) genes in the DEGs (differentially expressed genes), and MYB-like transcription factors accounted for one-third (25) of the TF genes. We systematically analyzed the characteristics, expression patterns, chromosome locations, and protein structures of 25 MYB-like genes. The analysis of gene function showed that Arabidopsis and rice overexpressing SiMYB3 had better root development than WT under low-nitrogen stress. Moreover, EMSA results showed that SiMYB3 protein could specifically bind MYB elements in the promoter region of TAR2, an auxin synthesis related gene and MYB3-TAR2 regulate pair conserved in rice and foxtail millet. These results suggested that SiMYB3 can regulate root development by regulating plant root auxin synthesis under low-nitrogen conditions.

Pentatricopeptide-repeat (PPR) proteins were identified as a type of nucleus coding protein that is composed of multiple tandem repeats. It has been reported that PPR genes play an important role in RNA editing, plant growth and development, and abiotic stresses in plants. However, the functions of PPR proteins remain largely unknown in soybean. In this study, 179 DYW subgroup PPR genes were identified in soybean genome (Glycine max Wm82.a2.v1). Chromosomal location analysis indicated that DYW subgroup PPR genes were mapped to all 20 chromosomes. Phylogenetic relationship analysis revealed that DYW subgroup PPR genes were categorized into three distinct Clusters (I to III). Gene structure analysis showed that most PPR genes were featured by a lack of intron. Gene duplication analysis demonstrated 30 PPR genes (15 pairs, ~35.7%) were segmentally duplicated among Cluster I PPR genes. Furthermore, we validated the mRNA expression of three genes that were highly up-regulated in soybean drought- and salt-induced transcriptome database and found that the expression levels of GmPPR4 were induced under salt and drought stresses. Under drought stress condition, GmPPR4-overexpressing (GmPPR4-OE) plants showed delayed leaf rolling, higher content of proline (Pro), and lower contents of H2O2, O2&minus, and malondialdehyde (MDA) compared with the empty vector (EV)-control plants. GmPPR4-OE plants exhibited increased transcripts of several drought-inducible genes compared with EV-control plants. Our results provided a comprehensive analysis of the DYW subgroup PPR genes and an insight for improving the drought tolerance in soybean.