Investigation of the AQP Family in Soybean and the Promoter Activity of TIP2;6 in Heat Stress and Hormone Responses.

Aquaporins (AQPs) are one diverse family of membrane channel proteins that play crucial regulatory roles in plant stress physiology. However, the heat stress responsiveness of AQP genes in soybean remains poorly understood. In this study, 75 non-redundant AQP encoding genes were identified in soybean. Multiple sequence alignments showed that all GmAQP proteins possessed the conserved regions, which contained 6 trans-membrane domains (TM1 to TM6). Different GmAQP members consisted of distinct Asn-Pro-Ala (NPA) motifs, aromatic/arginine (ar/R) selectivity filters and Froger's positions (FPs). Phylogenetic analyses distinguished five sub-families within these GmAQPs: 24 GmPIPs, 24 GmTIPs, 17 GmNIPs, 8 GmSIPs, and 2 GmXIPs. Promoter cis-acting elements analyses revealed that distinct number and composition of heat stress and hormone responsive elements existed in different promoter regions of GmAQPs. QRT-PCR assays demonstrated that 12 candidate GmAQPs with relatively extensive expression in various tissues or high expression levels in root or leaf exhibited different expression changes under heat stress and hormone cues (abscisic acid (ABA), l-aminocyclopropane-l-carboxylic acid (ACC), salicylic acid (SA) and methyl jasmonate (MeJA)). Furthermore, the promoter activity of one previously functionally unknown AQP gene-GmTIP2;6 was investigated in transgenic Arabidopsis plants. The beta-glucuronidase (GUS) activity driven by the promoter of GmTIP2;6 was strongly induced in the heat- and ACC-treated transgenic plants and tended to be accumulated in the hypocotyls, vascular bundles, and leaf trichomes. These results will contribute to uncovering the potential functions and molecular mechanisms of soybean GmAQPs in mediating heat stress and hormone signal responses.

Investigation of the ASR family in foxtail millet and the role of ASR1 in drought/oxidative stress tolerance.

KEY MESSAGE: Six foxtail millet ASR genes were regulated by various stress-related signals. Overexpression of ASR1 increased drought and oxidative tolerance by controlling ROS homeostasis and regulating oxidation-related genes in tobacco plants. Abscisic acid stress ripening (ASR) proteins with ABA/WDS domains constituted a class of plant-specific transcription factors, playing important roles in plant development, growth and abiotic stress responses. However, only a few ASRs genes have been characterized in crop plants and none was reported so far in foxtail millet (Setaria italic), an important drought-tolerant crop and model bioenergy grain crop. In the present study, we identified six foxtail millet ASR genes. Gene structure, protein alignments and phylogenetic relationships were analyzed. Transcript expression patterns of ASR genes revealed that ASRs might play important roles in stress-related signaling and abiotic stress responses in diverse tissues in foxtail millet. Subcellular localization assays showed that SiASR1 localized in the nucleus. Overexpression of SiASR1 in tobacco remarkably increased tolerance to drought and oxidative stresses, as determined through developmental and physiological analyses of germination rate, root growth, survival rate, relative water content, ion leakage, chlorophyll content and antioxidant enzyme activities. Furthermore, expression of SiASR1 modulated the transcript levels of oxidation-related genes, including NtSOD, NtAPX, NtCAT, NtRbohA and NtRbohB, under drought and oxidative stress conditions. These results provide a foundation for evolutionary and functional characterization of the ASR gene family in foxtail millet.

Acute methanol poisoning with bilateral diffuse cerebral hemorrhage: A case report.

BACKGROUND: Acute methanol poisoning (AMP) is a systemic disease that mainly affects the central nervous system and is characterized by ocular damage and metabolic acidosis. If appropriate treatments are inadequate or delayed, the mortality can exceed 40%. As the most serious complication, cerebral hemorrhage is rare with reported prevalence of 7%-19%. CASE SUMMARY: A 62-year-old man drank liquor mixed with 45% methanol and 35% alcohol. His vision blurred 10 h later and he fell into coma in another 9 h. Serum toxicological tests were performed immediately, and continuous renal replacement therapy (CRRT) was carried out as the lactic acid exceeded 15 mmol/L and blood pH was 6.78. In addition, the toxicological report revealed 1300.5 µg/mL of methanol in serum and 1500.2 µg/mL in urine. After 59 h of CRRT, the methanol level decreased to 126.0 µg/mL in serum and 151.0 µg/mL in urine. However, the patient was still unconscious and his pupillary light reflex was slow. Computed tomography showed hemorrhage in the left putamen. After 16 d of life support treatment, putamen hemorrhage developed into diffuse symmetric intracerebral hemorrhage. In the end, his family gave up and the patient was discharged, and died in a local hospital. CONCLUSION: Cerebral hemorrhage requires constant vigilance during the full course of treatment for severe cases of AMP.

Effect of microcrystalline cellulose under different hydrolysis durations on the stability of thyme oil emulsion.

The thyme oil emulsion was prepared using a novel type of nanocellulose obtained under different hydrolysis durations. The effect of different cellulose structures on interfacial adsorption properties of emulsion and loading efficiency of thyme oil were analyzed. The results showed that the cellulose particles became more homogeneous and hydrophilic after hydrolysis duration for 10 h. The loading efficiency of thyme oil for all emulsions reached about 80%. The retention rate of thyme oil decreased during the storage period, and rising temperatures will exacerbate the loss of thyme oil. Compared to Hd2, emulsions stabilized by Hd10 exhibited better stability and higher retention at all storage conditions. Cellulose emulsion can increase the dispersion and improve the stability of thyme oil. A smaller cellulose particle could make the emulsion become more stable. The experimental results confirmed that cellulose can be used as a stabilizer to encapsulate and transport hydrophobic active ingredient. PRACTICAL APPLICATION: The study results demonstrated that the emulsion transport system was developed using cellulose nanoparticles prepared by hydrolysis. The system can be used to load hydrophobic active substances (active peptides, curcumin, ß-carotene, essential oils, etc.). It can protect the active substance from environmental damage, enhance water solubility and stability, and improve the bioavailability of the active substance.

Characterization of structure and stability of emulsions stabilized with cellulose macro/nano particles.

The characterization of emulsions covered with cellulose particles prepared under varying hydrolysis durations investigated. The results showed that with the increasing hydrolysis durations, the particle size distribution profiles of emulsion stabilized cellulose particles shifted to a lower particle size. This was primarily because at longer hydrolysis durations, a larger number of particles per interfacial area were expected to be adsorbed at the interface of oil droplets. At hydrolysis durations of 6 and 10 h, the mean particle diameter of emulsion had an increase of 20-30 nm after 7 days and showed good stability with storage time, which can be attributed to a relatively thick interface layer. Emulsions stabilized by cellulose particles prepared at hydrolysis durations of 6 and 10 h showed good stability against changes in pH and NaCl concentration. These results can be useful for designing food and beverage Pickering emulsions with the improved bioavailability of functional nutrients.

Structural characteristics and rheological properties of ovalbumin-gum arabic complex coacervates.

After formation of the ovalbumin (OVA)-gum arabic (GA) complex coacervates, a more ordered crystal structure was obtained, and the protein denaturation temperature increased from 72 to 96 °C. GA can reduce the pH-induced conformational perturbations of ovalbumin. The presence of GA improved the stability of the α-helix and ß-turn regions against pH, but showed less influence on the random coil and ß-sheet domains. The complex coacervates showed the highest viscosity value at pH 3.7 compared with the other pH values tested (4.0, 3.4, 3.0, 2.7) due to the stronger interactions of OVA and GA. A large thixotropic loop was observed for the coacervate obtained at pH 3.7 compared with that obtained at pH 4.0. Moreover, the salt concentration and OVA:GA ratio influenced the rheological properties by affecting the structure and composition of the complexes. A stronger interaction between OVA and GA led to greater viscoelastic properties.

Soybean TCP transcription factors: Evolution, classification, protein interaction and stress and hormone responsiveness.

TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors, a family of plant-specific proteins, play crucial roles in plant growth and development and stress response. However, systematical information is unknown regarding the TCP gene family in soybean. In the present study, a total of 54 GmTCPs were identified in soybean, which were grouped into 11 groups with the typical TCP conserved domains. Phylogenetic relationship, protein motif and gene structure analyses distinguished the GmTCPs into two homology classes: Class I and Class II. Class II was then differentiated into two subclasses: CIN and CYC/TB1. Unique cis-element number and composition existed in the promoter regions which might be involved in the gene transcriptional regulation of different GmTCPs. Tissue expression analysis demonstrated the diverse spatiotemporal expression profiles of GmTCPs. Furthermore, the interaction protein of one previously functionally unknown TCP protein-GmTCP8 was investigated. Yeast two-hybrid assay showed the interaction between GmTCP8 and an abscisic acid receptor (GmPYL10). QRT-PCR assays indicated the distinct expression profiles of GmTCPs in response to abiotic stresses (heat, drought and salt) and stress-related signals (abscisic acid, brassinolide, salicylicacid and methyl jasmonate). These results will facilitate to uncover the possible roles of GmTCPs under abiotic stress and hormone signal responses in soybean.

Identification of the AQP members involved in abiotic stress responses from Arabidopsis.

Aquaporins (AQPs) constitute a highly diverse family of water channel proteins that play crucial biological functions in plant growth and development and stress physiology. In Arabidopsis, 35 AQPs are classified into four subfamilies (PIPs, TIPs, NIPs and SIPs). However, knowledge about the roles of different subfamily AQPs remains limited. Here, we explored the chromosomal location, gene structure and expression patterns of all AQPs in different tissues or under different abiotic stresses based on available microarray data. Tissue expression analysis showed that different AQPs had various expression patterns in tissues (root, leaf, flower and seed). Expression profiles under stress conditions revealed that most AQPs were responsive to osmotic, salt and drought stresses. Phenotypic and physiological identification showed that Tip2;2 loss-of-function mutant exhibited less sensitive to abiotic stresses (mannitol, NaCl and PEG) compared with wild-type, as evident by analysis of germination rate, root growth, survival rate, ion leakage, malondialdehyde (MDA) and proline contents. Mutant of TIP2;2 modulated the transcript levels of SOS1, SOS2, SOS3, DREB1A, DREB2A and P5CS1, under abiotic stress conditions. This study provides a basis for further functional identification of stress-related candidate AQPs in Arabidopsis.

The soybean GmDi19-5 interacts with GmLEA3.1 and increases sensitivity of transgenic plants to abiotic stresses.

Drought-induced (Di19) proteins played important roles in plant growth, development, and abiotic stress responses. In the present study, a total of seven Di19 genes were identified in soybean. Each soybean Di19 gene showed specific responses to salt, drought, oxidative, and ABA stresses based on expression profiles. With a relatively higher transcript level among Di19 members under four stress treatments, GmDi19-5 was selected for detailed analysis. Inhibitor assays revealed that ABA inhibitor (Fluridone) or H2O2 inhibitor (DMTU) was involved in the drought- or salt-induced transcription of GmDi19-5. The GUS activity driven by the GmDi19-5 promoter was induced by salt, PEG, ABA, and MV treatments and tended to be accumulated in the vascular bundles and young leaves. A subcellular localization assay showed that GmDi19-5 protein localized in the nucleus. Further investigation showed that GmDi19-5 protein was involved in the interaction with GmLEA3.1. Overexpression of GmDi19-5 increased sensitivity of transgenic Arabidopsis plants to salt, drought, oxidative, and ABA stresses and regulated expression of several ABA/stress-associated genes. This present investigation showed that GmDi19-5 functioned as a negative factor under abiotic stresses and was involved in ABA and SOS signaling pathway by altering transcription of stress-associated genes.

Foxtail Millet NF-Y Families: Genome-Wide Survey and Evolution Analyses Identified Two Functional Genes Important in Abiotic Stresses.

It was reported that Nuclear Factor Y (NF-Y) genes were involved in abiotic stress in plants. Foxtail millet (Setaria italica), an elite stress tolerant crop, provided an impetus for the investigation of the NF-Y families in abiotic responses. In the present study, a total of 39 NF-Y genes were identified in foxtail millet. Synteny analyses suggested that foxtail millet NF-Y genes had experienced rapid expansion and strong purifying selection during the process of plant evolution. De novo transcriptome assembly of foxtail millet revealed 11 drought up-regulated NF-Y genes. SiNF-YA1 and SiNF-YB8 were highly activated in leaves and/or roots by drought and salt stresses. Abscisic acid (ABA) and H2O2 played positive roles in the induction of SiNF-YA1 and SiNF-YB8 under stress treatments. Transient luciferase (LUC) expression assays revealed that SiNF-YA1 and SiNF-YB8 could activate the LUC gene driven by the tobacco (Nicotiana tobacam) NtERD10, NtLEA5, NtCAT, NtSOD, or NtPOD promoter under normal or stress conditions. Overexpression of SiNF-YA1 enhanced drought and salt tolerance by activating stress-related genes NtERD10 and NtCAT1 and by maintaining relatively stable relative water content (RWC) and contents of chlorophyll, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and malondialdehyde (MDA) in transgenic lines under stresses. SiNF-YB8 regulated expression of NtSOD, NtPOD, NtLEA5, and NtERD10 and conferred relatively high RWC and chlorophyll contents and low MDA content, resulting in drought and osmotic tolerance in transgenic lines under stresses. Therefore, SiNF-YA1 and SiNF-YB8 could activate stress-related genes and improve physiological traits, resulting in tolerance to abiotic stresses in plants. All these results will facilitate functional characterization of foxtail millet NF-Ys in future studies.