Wheat Bax Inhibitor-1 interacts with TaFKBP62 and mediates response to heat stress.

BACKGROUND: Heat stress is a severe environmental stress that affects plant growth and reduces yield. Bax inhibitor-1 (BI-1) is a cytoprotective protein that is involved in the response to biotic and abiotic stresses. The Arabidopsis (Arabidopsis thaliana) BI-1 mutants atbi1-1 and atbi1-2 are hypersensitive to heat stress, and AtBI-1 overexpression rescues thermotolerance deficiency in atbi1 plants. Nevertheless, the mechanism of BI-1 in plant thermotolerance is still unclear. RESULTS: We identified a wheat (Triticum aestivum L.) BI-1 gene, TaBI-1.1, which was highly upregulated in an RNA sequencing (RNA-seq) analysis of heat-treated wheat. The upregulation of TaBI-1.1 under heat stress was further demonstrated by real time quantitative PCR (qRT-PCR) and ß-glucuronidase (GUS) staining. Compared with the wild type Col-0, the atbi1-2 mutant is hypersensitive to heat stress, and constitutive expression of TaBI-1.1 in atbi1-2 (35S::TaBI-1.1/ atbi1-2) rescued the deficiency of atbi1-2 under heat stress. Furthermore, we identified TaFKBP62 as a TaBI-1.1-interacting protein that co-localized with TaBI-1.1 on the endoplasmic reticulum (ER) membrane and enhanced heat stress tolerance. Additionally, HSFA2, HSFB1, ROF1, HSP17.4B, HSP17.6A, HSP17.8, HSP70B, and HSP90.1 expression levels were suppressed in atbi1-2 plants under heat stress. In contrast, 35S::TaBI-1.1/atbi1-2 relieved the inhibitory effect of AtBI-1 loss of function. CONCLUSIONS: TaBI-1.1 interacted with TaFKBP62 and co-localized with TaFKBP62 on the ER membrane. Both TaBI-1.1 and AtBI-1 regulated the expression of heat-responsive genes and were conserved in plant thermotolerance.

Wheat CBL-interacting protein kinase 23 positively regulates drought stress and ABA responses.

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.

Identification and characterization of GmMYB118 responses to drought and salt 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.

The Maize WRKY Transcription Factor ZmWRKY40 Confers Drought Resistance in Transgenic Arabidopsis.

Abiotic stresses restrict the growth and yield of crops. Plants have developed a number of regulatory mechanisms to respond to these stresses. WRKY transcription factors (TFs) are plant-specific transcription factors that play essential roles in multiple plant processes, including abiotic stress response. At present, little information regarding drought-related WRKY genes in maize is available. In this study, we identified a WRKY transcription factor gene from maize, named ZmWRKY40. ZmWRKY40 is a member of WRKY group II, localized in the nucleus of mesophyll protoplasts. Several stress-related transcriptional regulatory elements existed in the promoter region of ZmWRKY40. ZmWRKY40 was induced by drought, high salinity, high temperature, and abscisic acid (ABA). ZmWRKY40 could rapidly respond to drought with peak levels (more than 10-fold) at 1 h after treatment. Overexpression of ZmWRKY40 improved drought tolerance in transgenic Arabidopsis by regulating stress-related genes, and the reactive oxygen species (ROS) content in transgenic lines was reduced by enhancing the activities of peroxide dismutase (POD) and catalase (CAT) under drought stress. According to the results, the present study may provide a candidate gene involved in the drought stress response and a theoretical basis to understand the mechanisms of ZmWRKY40 in response to abiotic stresses in maize.

Maize WRKY Transcription Factor ZmWRKY106 Confers Drought and Heat Tolerance in Transgenic Plants.

WRKY transcription factors constitute one of the largest transcription factor families in plants, and play crucial roles in plant growth and development, defense regulation and stress responses. However, knowledge about this family in maize is limited. In the present study, we identified a drought-induced WRKY gene, ZmWRKY106, based on the maize drought de novo transcriptome sequencing data. ZmWRKY106 was identified as part of the WRKYII group, and a phylogenetic tree analysis showed that ZmWRKY106 was closer to OsWRKY13. The subcellular localization of ZmWRKY106 was only observed in the nucleus. The promoter region of ZmWRKY106 included the C-repeat/dehydration responsive element (DRE), low-temperature responsive element (LTR), MBS, and TCA-elements, which possibly participate in drought, cold, and salicylic acid (SA) stress responses. The expression of ZmWRKY106 was induced significantly by drought, high temperature, and exogenous abscisic acid (ABA), but was weakly induced by salt. Overexpression of ZmWRKY106 improved the tolerance to drought and heat in transgenic Arabidopsis by regulating stress-related genes through the ABA-signaling pathway, and the reactive oxygen species (ROS) content in transgenic lines was reduced by enhancing the activities of superoxide dismutase (SOD), peroxide dismutase (POD), and catalase (CAT) under drought stress. This suggested that ZmWRKY106 was involved in multiple abiotic stress response pathways and acted as a positive factor under drought and heat stress.

Overexpression of ZmWRKY65 transcription factor from maize confers stress resistances in transgenic Arabidopsis.

Plant-specific WRKY transcription factors play important roles in regulating the expression of defense-responsive genes against pathogen attack. A multiple stress-responsive WRKY gene, ZmWRKY65, was identified in maize by screening salicylic acid (SA)-induced de novo transcriptomic sequences. The ZmWRKY65 protein was localized in the nucleus of mesophyll protoplasts. The analysis of the ZmWRKY65 promoter sequence indicated that it contains several stress-related transcriptional regulatory elements. Many environmental factors affecting the transcription of ZmWRKY65 gene, such as drought, salinity, high temperature and low temperature stress. Moreover, the transcription of ZmWRKY65 gene was also affected by the induction of defense related plant hormones such as SA and exogenous ABA. The results of seed germination and stomatal aperture assays indicated that transgenic Arabidopsis plants exhibit enhanced sensitivity to ABA and high concentrations of SA. Overexpression of ZmWRKY65 improved tolerance to both pathogen attack and abiotic stress in transgenic Arabidopsis plants and activated several stress-related genes such as RD29A, ERD10, and STZ as well as pathogenesis-related (PR) genes such as PR1, PR2 and PR5; these genes are involved in resistance to abiotic and biotic stresses in Arabidopsis. Together, this evidence implies that the ZmWRKY65 gene is involved in multiple stress signal transduction pathways.

Conformational Mobility of GOx Coenzyme Complex on Single-Wall Carbon Nanotubes.

A critical issue in bioelectrochemical applications that use electrodes modified by Single Wall Carbon Nanotubes (SWCNTs) is to ensure high activity of the catalytic site of an immobilized enzyme protein interacting with nanomaterials. Since Flavin Adenine Dinucleotide (FAD), a coenzyme of glucose oxidase (GOx), is the active center of the catalytic site, conformation of which could determine the activity of enzyme, it is important to understand the dynamic mechanism of its conformational mobility while GOx is adsorbed on SWCNTs with multiple orientations. However, this dynamic mechanism still remains unclear at the atomic level due to the coenzyme being embedded in the apo-GOx and the limitations of appropriate experimental methods. In this study, a molecular dynamics (MD) simulation was performed to investigate the conformational mobility mechanism of the coenzyme. The trajectory and the interaction energy clearly indicate that the adsorption of GOx onto SWCNTs plays an important role in the conformational mobility of the coenzyme, and its mobility is greatly affected by the distribution of water molecules due to it being hydrophobic.

Alcohol-related Injuries at an emergency department in Eastern Taiwan.

BACKGROUND/PURPOSE: Injuries are major causes of mortality and morbidity in Taiwan. Alcohol involvement often plays a role in injuries. The purpose of this study was to determine the prevalence of alcohol-related injuries at an emergency department in Eastern Taiwan and their associated factors. METHODS: All injured patients who made emergency visits between October 2002 and September 2003 were enrolled. For each patient, the attending nurse completed an injury-coding sheet, which included the results of an assessment of whether the patient had an alcohol odor or alcohol consumption related behavior. Nurses recorded suspicion of alcohol consumption based on possible categories of "no alcohol odor", "alcohol odor", "intoxicated", "suspected" or "unknown". Blood alcohol testing was also performed based on the decision of the attending physician. Injuries were defined as alcohol-related based on the report of "alcohol odor" or "intoxicated" by the nurse or a positive blood alcohol test. Logistic regression was used to assess the significance of the association of possible related factors with alcohol-related injury. RESULTS: A total of 8822 eligible visits were studied and 14% were classified as alcohol-related. The proportion of alcohol-related injuries was 14.9% for vehicle-related injuries, and 51.3% for assaults. Male, young to middle aged, aboriginal ethnicity and visits after midnight were factors associated with increased likelihood of alcohol-related injuries. Multiple logistic regression analysis revealed that the three factors most significantly associated with alcohol-related injuries were visits after midnight (odds ratio, OR, 7.5; 95% confidence interval, CI, 6.4-8.9], assaults (OR, 3.4; 95% CI, 2.3-4.8), and head injuries (OR, 2.7; 95% CI, 2.3-3.2). CONCLUSION: Injuries were alcohol related in one out of seven patients this study from an emergency department in eastern Taiwan. Ongoing epidemiologic monitoring of the prevalence and nature of alcohol abuse among patients visiting the ED are urgently needed.

Generation of a sub-diffraction hollow ring by shaping an azimuthally polarized wave.

The generation of a sub-diffraction optical hollow ring is of great interest in various applications, such as optical microscopy, optical tweezers, and nanolithography. Azimuthally polarized light is a good candidate for creating an optical hollow ring structure. Various of methods have been proposed theoretically for generation of sub-wavelength hollow ring by focusing azimuthally polarized light, but without experimental demonstrations, especially for sub-diffraction focusing. Super-oscillation is a promising approach for shaping sub-diffraction optical focusing. In this paper, a planar sub-diffraction diffractive lens is proposed, which has an ultra-long focal length of 600 λ and small numerical aperture of 0.64. A sub-diffraction hollow ring is experimentally created by shaping an azimuthally polarized wave. The full-width-at-half-maximum of the hollow ring is 0.61 λ, which is smaller than the lens diffraction limit 0.78 λ, and the observed largest sidelobe intensity is only 10% of the peak intensity.

Creation of Sub-diffraction Longitudinally Polarized Spot by Focusing Radially Polarized Light with Binary Phase Lens.

The generation of a sub-diffraction longitudinally polarized spot is of great interest in various applications, such as optical tweezers, super-resolution microscopy, high-resolution Raman spectroscopy, and high-density optical data storage. Many theoretical investigations have been conducted into the tight focusing of a longitudinally polarized spot with high-numerical-aperture aplanatic lenses in combination with optical filters. Optical super-oscillation provides a new approach to focusing light beyond the diffraction limit. Here, we propose a planar binary phase lens and experimentally demonstrate the generation of a longitudinally polarized sub-diffraction focal spot by focusing radially polarized light. The lens has a numerical aperture of 0.93 and a long focal length of 200λ for wavelength λ = 632.8 nm, and the generated focal spot has a full-width-at-half-maximum of about 0.456λ, which is smaller than the diffraction limit, 0.54λ. A 5λ-long longitudinally polarized optical needle with sub-diffraction size is also observed near the designed focal point.