Genome-wide identification of SIMILAR to RCD ONE (SRO) gene family in rapeseed (Brassica napus L.) reveals their role in drought stress response.

Rapeseed (Brassica napus L.) is an important oilseed crop widely cultivated worldwide, and drought is the main environmental factor limiting its yield enhancement and the expansion of planted areas. SIMILAR TO RCD ONE (SRO) is a plant-specific small gene family that plays a crucial role in plant growth, development, and responses to abiotic stresses such as drought. However, the functional role of SROs in rapeseed remains poorly understood. In this study, 19 BnaSROs were identified from the rapeseed genome, with 9, 10, 10, 18, and 20 members identified from the genomes of Brassica rapa, Brassica nigra, Brassica oleracea, Brassica juncea, and Brassica carinata, respectively. We then analyzed their sequence characteristics, phylogenetic relationships, gene structures, and conserved domains, and explored the collinearity relationships of the SRO members in Brassica napus and Brassica juncea. Next, we focused on the analysis of tissue expression and stress-responsive expression patterns of rapeseed SRO members and examined their expression profiles under ABA, MeJA and water-deficit drought treatments using qPCR. Transcriptome data analysis and qPCR detection indicated that BnaSROs exhibit multiple stress-responsive expression patterns. BnaSRO1 and BnaSRO11, which are likely to function through interactions with NAC transcription factors, were screened as major drought-regulated members. Our results provide a solid foundation for functional analysis of the role of the SRO gene family in abiotic stress responses, especially drought stress responses, in rapeseed.

A Genome-Wide Analysis of the Jasmonic Acid Biosynthesis Gene Families in Peanut Reveals Their Crucial Roles in Growth and Abiotic Stresses.

Abiotic stress is a limiting factor in peanut production. Peanut is an important oil crop and cash crop in China. Peanut yield is vulnerable to abiotic stress due to its seeds grown underground. Jasmonic acid (JA) is essential for plant growth and defense against adversity stresses. However, the regulation and mechanism of the jasmonic acid biosynthesis pathway on peanut defense against abiotic stresses are still limitedly understood. In this study, a total of 64 genes encoding key enzymes of JA biosynthesis were identified and classified into lipoxygenases (AhLOXs), alleno oxide synthases (AhAOSs), allene oxide cyclases (AhAOCs), and 12-oxo-phytodienoic acid reductases (AhOPRs) according to gene structure, conserved motif, and phylogenetic feature. A cis-regulatory element analysis indicated that some of the genes contained stress responsive and hormone responsive elements. In addition to proteins involved in JA biosynthesis and signaling, they also interacted with proteins involved in lipid biosynthesis and stress response. Sixteen putative Ah-miRNAs were identified from four families targeting 35 key genes of JA biosynthesis. A tissue expression pattern analysis revealed that AhLOX2 was the highest expressed in leaf tissues, and AhLOX32 was the highest expressed in shoot, root, and nodule tissues. AhLOX16, AhOPR1, and AhOPR3 were up-regulated under drought stress. AhLOX16, AhAOS3, AhOPR1, and AhAOC4 had elevated transcript levels in response to cold stress. AhLOX5, AhLOX16, AhAOC3, AhOPR1, and AhOPR3 were up-regulated for expression under salt stress. Our study could provide a reference for the study of the abiotic stress resistance mechanism in peanut.

A CAM-Related NF-YB Transcription Factor Enhances Multiple Abiotic Stress Tolerance in Arabidopsis.

Abiotic stresses often occur simultaneously, and the tolerance mechanisms of plants to combined multiple abiotic stresses remain poorly studied. Extremophytes, adapted to abiotic stressors, might possess stress-adaptive or -responsive regulators that could enhance multiple abiotic stress resistance in crop plants. We identified an NF-YB transcription factor (TF) from the heat-tolerant obligate Crassulacean acid metabolism (CAM) plant, Kalanchoe fedtschenkoi, as a potential regulator of multiple abiotic stresses. The KfNF-YB3 gene was overexpressed in Arabidopsis to determine its role in multiple abiotic stress responses. Transgenic lines exhibited accelerated flowering time, increased biomass, larger rosette size, higher seed yield, and more leaves. Transgenic lines had higher germination rates under combined NaCl, osmotic, and water-deficit stress treatments compared to control plants. They also showed enhanced root growth and survival under simultaneous NaCl, osmotic, water-deficit, and heat stress conditions in vitro. Interestingly, potted transgenic lines had higher survival rates, yield, and biomass under simultaneous heat, water-deficit, and light stresses compared to control plants. Altogether, these results provide initial insights into the functions of a CAM-related TF and its potential roles in regulating multiple abiotic stress responses. The CAM abiotic stress-responsive TF-based approach appears to be an ideal strategy to enhance multi-stress resilience in crop plants.

Investigation on the Potential Functions of ZmEPF/EPFL Family Members in Response to Abiotic Stress in Maize.

Maize is an important crop used for food, feed, and fuel. Abiotic stress is an important factor affecting maize yield. The EPF/EPFL gene family encodes class-specific secretory proteins that play an important role in the response to abiotic stress in plants. In order to explore and utilize the EPF/EPFL family in maize, the family members were systematically identified, and their chromosomal localization, physicochemical properties, cis-acting element prediction in promoters, phylogenetic tree construction, and expression pattern analysis were carried out using bioinformatics techniques. A total of 18 ZmEPF/EPFL proteins were identified in maize, which are mostly alkaline and a small portion acidic. Subcellular localization results showed that ZmEPF6, ZmEPF12, and ZmEPFL2 are localized in the nucleus and cytoplasm. Analysis of cis-acting elements revealed that members of the ZmEPF/EPFL family contain regulatory elements such as light response, anoxic, low temperature, and hormone response regulatory elements. RT-qPCR results showed that these family members are indeed responding to cold stress and hormone treatments. These results of this study provide a theoretical basis for improving the abiotic stress resistance of maize in future research.

Nutritional management and physiological responses of Atriplex nummularia Lindl. on the improvement of phytoextraction in salt-affected soil.

Soil salinity is a significant abiotic stress and poses risks to environmental sustainability. Thus, the improvement of the time for recovering the salt-affect soil is crucial for the phytoextraction process using halophytes plants, especially regarding on nutritional management. We evaluated the responses of Atriplex nummularia Lindl. to nitrogen (N) and phosphorus (P) under different salinity levels. The treatments comprised doses of N (N1 = 80 kg ha-1) and P (P1 = 60 kg ha-1): (1) without N and P (N0P0) (control); (2) with N and without P (N1P0); (3) without N and with P (N0P1); and (4) with N and P (N1P1) and five levels of electrical conductivity from irrigation water: 0.08, 1.7, 4.8, 8.6, and 12.5 dS m-1. The. We evaluated dry biomass of leaves, stems, and roots 93 days after transplantation. We also assessed the leaf and osmotic water potential, the osmotic adjustment, and the nutrient contents (N, P, Na, and K). N application increased 22.3, 17.8, and 32.8% the leaf biomass, stem biomass, and osmotic adjustment, respectively; and consequently, boosts Na extraction in 27.8%. Thus, the time of the phytoextraction process can be improved with N fertilizer at a rate of 80 kg ha-1.

Very few studies have investigated the nutrient dynamics responses in Atriplex species in salt-affected soils; thus, this study represents a novelty. We tested the management of nitrogen (N) and phosphate (P) fertilizers to increase crop yield and optimize the phytoextraction process in salt-affected soils. We believe our results contribute to the improvement of the knowledge of this relevant topic, mainly in terms of the recovery of areas degraded by salinity. There is a paucity of studies associating salinity and nutritional management of soils worldwide.

Data from collection and analysis of RNA sequencing data from pearl millet.

Pearl millet (Pennisetum glaucum, also known as Cenchrus americanus) is a cereal crop that has a C4 photosynthesis system and that can grow and develop seeds even under stressed conditions including drought-stressed, high temperature-stressed and nutrient-poor conditions. In previous studies, transcriptomes of pearl millet were studied by RNA sequencing (RNA-Seq) to understand mechanisms regulating its development and tolerance to such stressed conditions. Here, RNA-Seq reads from 565 pearl millet samples from 25 projects in the NCBI (National Center for Biotechnology Information) BioProject database were collected and mapped to the pearl millet reference genome to obtain read counts and transcripts per million (TPM) for each pearl millet gene. The count and TPM data for all the 565 samples as well as the attributes of those samples and projects were deposited in the figshare repository (https://doi.org/10.6084/m9.figshare.24902100).

Transgenic tobacco plants overexpressing a wheat salt stress root protein (TaSSRP) exhibit enhanced tolerance to heat stress.

BACKGROUND: Heat stress is a detrimental abiotic stress that limits the development of many plant species and is linked to a variety of cellular and physiological problems. Heat stress affects membrane fluidity, which leads to negative effects on cell permeability and ion transport. Research reveals that heat stress causes severe damage to cells and leads to rapid accumulation of reactive oxygen species (ROS), which could cause programmed cell death. METHODS AND RESULTS: This current study aimed to validate the role of Triticum aestivum Salt Stress Root Protein (TaSSRP) in plants' tolerance to heat stress by modulating its expression in tobacco plants. The Relative Water Content (RWC), total chlorophyll content, and Membrane Stability Index (MSI) of the seven distinct transgenic lines (T0 - 2, T0 - 3, T0 - 6, T0 - 8, T0 - 9, T0 - 11, and T0 - 13), increased in response to heat stress. Despite the fact that the same tendency was detected in wild-type (WT) plants, changes in physio-biochemical parameters were greater in transgenic lines than in WT plants. The expression analysis revealed that the transgene TaSSRP expressed from 1.00 to 1.809 folds in different lines in the transgenic tobacco plants. The gene TaSSRP offered resistance to heat stress in Nicotiana tabacum, according to the results of the study. CONCLUSION: These findings could help to improve our knowledge and understanding of the mechanism underlying thermotolerance in wheat, and the novel identified gene TaSSRP could be used in generating wheat varieties with enhanced tolerance to heat stress.

The Discovery of Highly Efficient and Promising ABA Receptor Antagonists for Agricultural Applications Based on APAn Modification.

Abscisic acid (ABA) is one of the many naturally occurring phytohormones widely found in plants. This study focused on refining APAn, a series of previously developed agonism/antagonism switching probes. Twelve novel APAn analogues were synthesized by introducing varied branched or oxygen-containing chains at the C-6' position, and these were screened. Through germination assays conducted on A. thaliana, colza, and rice seeds, as well as investigations into stomatal movement, several highly active ABA receptor antagonists were identified. Microscale thermophoresis (MST) assays, molecular docking, and molecular dynamics simulation showed that they had stronger receptor affinity than ABA, while PP2C phosphatase assays indicated that the C-6'-tail chain extending from the 3' channel effectively prevented the ligand-receptor binary complex from binding to PP2C phosphatase, demonstrating strong antagonistic activity. These antagonists showed effective potential in promoting seed germination and stomatal opening of plants exposed to abiotic stress, particularly cold and salt stress, offering advantages for cultivating crops under adverse conditions. Moreover, their combined application with fluridone and gibberellic acid could provide more practical agricultural solutions, presenting new insights and tools for overcoming agricultural challenges.

Genetic Engineering for Enhancing Sugarcane Tolerance to Biotic and Abiotic Stresses.

Sugarcane, a vital cash crop, contributes significantly to the world's sugar supply and raw materials for biofuel production, playing a significant role in the global sugar industry. However, sustainable productivity is severely hampered by biotic and abiotic stressors. Genetic engineering has been used to transfer useful genes into sugarcane plants to improve desirable traits and has emerged as a basic and applied research method to maintain growth and productivity under different adverse environmental conditions. However, the use of transgenic approaches remains contentious and requires rigorous experimental methods to address biosafety challenges. Clustered regularly interspaced short palindromic repeat (CRISPR) mediated genome editing technology is growing rapidly and may revolutionize sugarcane production. This review aims to explore innovative genetic engineering techniques and their successful application in developing sugarcane cultivars with enhanced resistance to biotic and abiotic stresses to produce superior sugarcane cultivars.

Metabolism-Based Herbicide Resistance to Mesosulfuron-methyl and Identification of Candidate Genes in Bromus japonicus.

The evolved resistance of Bromus japonicus Houtt. to ALS-inhibiting herbicides is well established. Previous studies have primarily focused on target-site resistance; however, non-target-site resistance has not been well characterized. This investigation demonstrated that ALS gene sequencing did not detect any previously known resistance mutations in a mesosulfuron-methyl-resistant (MR) population, and notably, treatment with the P450 monooxygenase (P450) inhibitor malathion markedly heightened susceptibility to mesosulfuron-methyl. Utilizing UPLC-MS/MS analysis confirmed elevated mesosulfuron-methyl metabolism in MR plants. The integration of Isoform Sequencing (Iso-Seq) and RNA Sequencing (RNA-Seq) facilitated the identification of candidate genes associated with non-target sites in a subpopulation with two generations of herbicide selection. Through qRT-PCR analysis, 21 differentially expressed genes were characterized, and among these, 10 genes (comprising three P450s, two glutathione S-transferases, one glycosyltransferase, two ATP-binding cassette transporters, one oxidase, and one hydrolase) exhibited constitutive upregulation in resistant plants. Our findings substantiated that increased herbicide metabolism is a driving force behind mesosulfuron-methyl resistance in this B. japonicus population.

Overexpression of AcWRKY31 Increases Sensitivity to Salt and Drought and Improves Tolerance to Mealybugs in Pineapple.

Pineapple is a globally significant tropical fruit, but its cultivation faces numerous challenges due to abiotic and biotic stresses, affecting its quality and quantity. WRKY transcription factors are known regulators of stress responses, however, their specific functions in pineapple are not fully understood. This study investigates the role of AcWRKY31 by overexpressing it in pineapple and Arabidopsis. Transgenic pineapple lines were obtained using Agrobacterium-mediated transformation methods and abiotic and biotic stress treatments. Transgenic AcWRKY31-OE pineapple plants showed an increased sensitivity to salt and drought stress and an increased resistance to biotic stress from pineapple mealybugs compared to that of WT plants. Similar experiments in AcWRKY31-OE, AtWRKY53-OE, and the Arabidopsis Atwrky53 mutant were performed and consistently confirmed these findings. A comparative transcriptomic analysis revealed 5357 upregulated genes in AcWRKY31-OE pineapple, with 30 genes related to disease and pathogen response. Notably, 18 of these genes contained a W-box sequence in their promoter region. A KEGG analysis of RNA-Seq data showed that upregulated DEG genes are mostly involved in translation, protein kinases, peptidases and inhibitors, membrane trafficking, folding, sorting, and degradation, while the downregulated genes are involved in metabolism, protein families, signaling, and cellular processes. RT-qPCR assays of selected genes confirmed the transcriptomic results. In summary, the AcWRKY31 gene is promising for the improvement of stress responses in pineapple, and it could be a valuable tool for plant breeders to develop stress-tolerant crops in the future.

WRKY Transcription Factor Responses and Tolerance to Abiotic Stresses in Plants.

Plants are subjected to abiotic stresses throughout their developmental period. Abiotic stresses include drought, salt, heat, cold, heavy metals, nutritional elements, and oxidative stresses. Improving plant responses to various environmental stresses is critical for plant survival and perpetuation. WRKY transcription factors have special structures (WRKY structural domains), which enable the WRKY transcription factors to have different transcriptional regulatory functions. WRKY transcription factors can not only regulate abiotic stress responses and plant growth and development by regulating phytohormone signalling pathways but also promote or suppress the expression of downstream genes by binding to the W-box [TGACCA/TGACCT] in the promoters of their target genes. In addition, WRKY transcription factors not only interact with other families of transcription factors to regulate plant defence responses to abiotic stresses but also self-regulate by recognising and binding to W-boxes in their own target genes to regulate their defence responses to abiotic stresses. However, in recent years, research reviews on the regulatory roles of WRKY transcription factors in higher plants have been scarce and shallow. In this review, we focus on the structure and classification of WRKY transcription factors, as well as the identification of their downstream target genes and molecular mechanisms involved in the response to abiotic stresses, which can improve the tolerance ability of plants under abiotic stress, and we also look forward to their future research directions, with a view of providing theoretical support for the genetic improvement of crop abiotic stress tolerance.

Passion fruit HD-ZIP genes: Characterization, expression variance, and overexpression PeHB31 enhanced drought tolerance via lignin pathway.

The HD-ZIP (homeodomain-leucine zipper) genes hold significant importance in transcriptional regulation, especially in plant development and responses to abiotic stresses. However, a comprehensive study targeting HD-ZIP family members in passion fruit has been absent. In our current research, 34 HD-ZIP family members (PeHBs) were identified by bioinformatics analysis. Transcriptome analysis revealed that PeHBs exhibited distinct expression patterns when subjected to the four different abiotic stresses, and significant differential expression of PeHBs was also found among the three developmental stages of the fruit and between the purple and yellow genotype passion fruit leaves. An integrated metabolome and transcriptome analysis further revealed that the HD-ZIP III class gene PeHB31 (homologous to ATHB8), was co-upexpressed with lignans in yellow fruit P. edulis (commonly used as a resistance rootstock) when compared to purple fruit P. edulis. The transformation of Arabidopsis and yeast with the PeHB31 gene showed an enhancement in their capacity to withstand drought conditions. Notably, the transgenic Arabidopsis plants exhibited an increase in lignin content within the vascular tissues of their stems. This research lays the groundwork for future studies on the control mechanisms of lignin biosynthesis by HD-ZIP genes (especially HD-ZIP classes III and I) involved in drought tolerance.

A review on Ubiquitin ligases: Orchestrators of plant resilience in adversity.

Ubiquitin- proteasome system (UPS) is universally present in plants and animals, mediating many cellular processes needed for growth and development. Plants constantly defend themselves against endogenous and exogenous stimuli such as hormonal signaling, biotic stresses such as viruses, fungi, nematodes, and abiotic stresses like drought, heat, and salinity by developing complex regulatory mechanisms. Ubiquitination is a regulatory mechanism involving selective elimination and stabilization of regulatory proteins through the UPS system where E3 ligases play a central role; they can bind to the targets in a substrate-specific manner, followed by poly-ubiquitylation, and subsequent protein degradation by 26S proteasome. Increasing evidence suggests different types of E3 ligases play important roles in plant development and stress adaptation. Herein, we summarize recent advances in understanding the regulatory roles of different E3 ligases and primarily focus on protein ubiquitination in plant-environment interactions. It also highlights the diversity and complexity of these metabolic pathways that enable plant to survive under challenging conditions. This reader-friendly review provides a comprehensive overview of E3 ligases and their substrates associated with abiotic and biotic stresses that could be utilized for future crop improvement.

Characterization of the GGP gene family in potato (Solanum tuberosum L.) and Pepper (Capsicum annuum L.) and its expression analysis under hormonal and abiotic stresses.

GDP-L-galactose phosphorylase (GGP) is a key rate-limiting enzyme in plant ascorbic acid synthesis, which plays an important role in plant growth and development as well as stress response. However, the presence of GGP and its function in potato and pepper are not known. In this study, we first identified two GGP genes in each potato and pepper genomes using a genome-wide search approach. We then analyzed their physicochemical properties, conserved domains, protein structures and phylogenetic relationships. Phylogenetic tree analysis revealed that members of the potato and pepper GGP gene families are related to eggplant (Solanum melongena L.), Arabidopsis (Arabidopsis thaliana L.), tobacco (Nicotiana tabacum L.) and tomato (Solanum lycopersicum L.), with tomato being the most closely related. The promoter sequences mainly contain homeopathic elements such as light-responsive, hormone-responsive and stress-responsive, with light-responsive elements being the most abundant. By analyzing the structure of the genes, it was found that there is no transmembrane structure or signal peptide in the GGP gene family of potatoes and peppers, and that all of its members are hydrophilic proteins. The expression profiles of different tissues show that StGGP1 has the highest expression levels in leaves, StGGP2 has the highest expression levels in stamens, and CaGGPs have the highest expression levels in the early stages of fruit development (Dev1). It was found that StGGPs and CaGGPs genes showed different response to phytohormones and abiotic stresses. Abscisic acid (ABA) treatment induced the most significant change in the expression of StGGPs, while the expression of CaGGPs showed the most pronounced change under methyl jasmonate (MeJA) treatment. StGGPs responded mainly to dark treatment, whereas CaGGPs responded mainly to NaCl stress. These results provide an important basis for a detailed study about the functions of GGP homologous genes in potato and pepper in response to abiotic stresses.

Cell death in bryophytes: emerging models to study core regulatory modules and conserved pathways.

Regulated cell death (RCD) plays key roles during essential processes along the plant life cycle. It takes part of specific developmental programs and maintains the organism homeostasis in response to unfavourable environments. Bryophytes could provide with valuable models to study developmental RCD processes as well as those triggered by biotic and abiotic stresses. Some pathways analogous to the ones present in angiosperms occur in the gametophytic haploid generation of bryophytes, allowing direct genetic studies. In this review, we focus on such RCD programs, identifying core conserved mechanisms and raising new key questions to analyse RCD from an evolutionary perspective.

Silicon improves the drought tolerance in pepper plants through the induction of secondary metabolites, GA biosynthesis pathway, and suppression of chlorophyll degradation.

Drought stress caused by the global climate considerably disturbs plant yield and growth. Here, we explored the putative roles of silicon in repressing drought mechanisms in pepper and the prominent involvement of secondary metabolites, GA pathway, and photosystem II. Our research revealed that the transcript level of the flavonoid biosynthesis-associated genes, including the PAL, 4-CL, CHS, FLS-1, F3H and DFR, progressively induced in the pepper leaves treated with silicon during the drought stress duration. Moreover, the phenolic and flavonoid compounds extensively induced in the pepper plants. Furthermore, the pepper plants markedly inhibited chlorophyll catabolic-allied genes, senescence-related marker gene, and the Rbohs gene. Silicon application also sustained the membrane stability, supported via fewer electrolyte leakage processes and minor, O2- H2O2 and MDA levels during drought. Apart from this, the pepper plants significantly induced the expression level of the photosystem II-related genes, osmoprotectants pathway-associated genes, and antioxidant defense genes. Moreover, the GA biosynthesis genes were prompted, while the ABA signaling and biosynthesis genes were suppressed in the silicon-supplemented plants. These consequences infer that the role of Si supplementation on enhancing drought tolerance could be elucidated through the activation of secondary metabolites, flavonoid biosynthesis, osmoprotectants, GA pathway, the efficiency of PSII, and the suppression of chlorophyll degradation. Our research outcomes unveil new and remarkable characteristics of silicon supplementation and offer a series of candidate targets for improving the tolerance of pepper plants to drought stress.

Unboxing PGPR-mediated management of abiotic stress and environmental cleanup: what lies inside?

Abiotic stresses including heavy metal toxicity, drought, salt and temperature extremes disrupt the plant growth and development and lowers crop output. Presence of environmental pollutants further causes plants suffering and restrict their ability to thrive. Overuse of chemical fertilizers to reduce the negative impact of these stresses is deteriorating the environment and induces various secondary stresses to plants. Therefore, an environmentally friendly strategy like utilizing plant growth-promoting rhizobacteria (PGPR) is a promising way to lessen the negative effects of stressors and to boost plant growth in stressful conditions. These are naturally occurring inhabitants of various environments, an essential component of the natural ecosystem and have remarkable abilities to promote plant growth. Furthermore, multifarious role of PGPR has recently been widely exploited to restore natural soil against a range of contaminants and to mitigate abiotic stress. For instance, PGPR may mitigate metal phytotoxicity by boosting metal translocation inside the plant and changing the metal bioavailability in the soil. PGPR have been also reported to mitigate other abiotic stress and to degrade environmental contaminants remarkably. Nevertheless, despite the substantial quantity of information that has been produced in the meantime, there has not been much advancement in either the knowledge of the processes behind the alleged positive benefits or in effective yield improvements by PGPR inoculation. This review focuses on addressing the progress accomplished in understanding various mechanisms behind the protective benefits of PGPR against a variety of abiotic stressors and in environmental cleanups and identifying the cause of the restricted applicability in real-world.

Genome-wide identification, structural and gene expression analysis of BTB gene family in soybean.

BACKGROUND: The Bric-a-Brac/Tramtrack/Broad Complex (BTB) gene family plays essential roles in various biological processes in plants. These genes encode proteins that contain a conserved BTB domain, which is involved in protein-protein interactions and regulation of gene expression. However, there is no systematic reports on the BTB gene family in G.max. RESULTS: In total, 122 soybean BTB genes were identified, which were classified into four groups based on the phylogenetic analysis. Gene structures analysis indicated that the number of exon-intron in GmBTBs ranges from 0 to18. Cis-element analysis revealed that most GmBTB genes contained cis-elements related to an abiotic stress response. In addition, qRT-PCR analyses indicated that most GmBTBs are significantly up-regulated under salinity, drought, and nitrate stresses. They suggested their potential for targeted improvement of soybean response to multiple abiotic stresses and nitrate availability. CONCLUSION: These results provide valuable information for identifying the members of the GmBTB gene family in soybean and could provide a functional characterization of GmBTB genes in further research.

Genome-wide analysis of the SWEET gene family in Hemerocallis citrina and functional characterization of HcSWEET4a in response to salt stress.

Sugars will be eventually effluxed transporters (SWEETs) have been confirmed to play diverse physiological roles in plant growth, development and stress response. However, the characteristics and functions of the SWEET genes in Hemerocallis citrina remain unclear and poorly elucidated. In this study, the whole genome of Hemerocallis citrina was utilized to conduct bioinformatics analysis and a total of 19 HcSWEET genes were successfully identified. Analysis of the physicochemical properties indicated dominant differences among these HcSWEETs. A phylogenetic analysis revealed that HcSWEET proteins can be divided into 4 clades ranging from Clade I to IV, where proteins within the same clade exhibited shared conserved motifs and gene structures. Five to six exons were contained in the majority of HcSWEET genes, which were unevenly distributed across 11 chromosomes. The gene duplication analysis showed the presence of 4 gene pairs. Comparative syntenic maps revealed that the HcSWEET gene family might present more closed homology in monocotyledons than dicotyledons. Cis-acting element analysis of HcSWEET genes indicated key responsiveness to various hormones, light, and stresses. Additionally, transcriptome sequencing analysis suggested that most HcSWEET genes had a relatively higher expression in roots, and HcSWEET4a was significantly up-regulated under salt stress. Overexpression further verified the possibility that HcSWEET4a was involved in response to salt stress, which provides novel insights and facilitates in-depth studies of the functional analysis of HcSWEETs in resistance to abiotic stress.