The Impact of Birth Season and Sex on Motor Skills in 2-Year-Old Children: A Study in Jinhua, Eastern China.

BACKGROUND: This study investigates the effects of birth season and sex on the development of gross and fine motor skills in 2-year-old children in Jinhua, Eastern China. METHODS: Conducted in Jinhua, a city in central Zhejiang Province, Eastern China, this research involved 225 children, assessing their gross and fine motor skills using the Peabody Developmental Motor Scales, Second Edition. Scores were adjusted for age in months to avoid the relative age effect. Statistical analyses included MANOVA to evaluate the impacts of season and sex. RESULTS: Sex had no significant impact on overall motor development scores (p > 0.05). However, the season of birth significantly affected fine motor quotient (FMQ) and total motor quotient (TMQ) (p < 0.05). Boys' motor skills were generally unaffected by season, whereas girls born in winter exhibited superior fine motor skills compared to those born in summer. CONCLUSIONS: Seasonal environmental factors significantly influence early motor development, particularly fine motor skills in girls. These findings highlight the importance of considering seasonal variations in early childhood interventions aimed at enhancing exercise physiology and sports performance.

Twisted Structure and Multiple Charge-Transfer Channels Endow Thermally Activated Delayed Fluorescence Devices with Small Efficiency Roll-Off and Low Concentration Dependence.

Despite the rapid development of thermally activated delayed fluorescent (TADF) materials, developing organic light-emitting diodes (OLEDs) with small efficiency roll-off remains a formidable challenge. Herein, we have designed a TADF molecule (mClSFO) based on the spiro fluorene skeleton. The highly twisted structure and multiple charge-transfer channels effectively suppress aggregation-caused quenching (ACQ) and endow mClSFO with excellent exciton dynamic properties to reduce efficiency roll-off. Fast radiative rate (kr) and rapid reverse intersystem crossing (RISC) rate (kRISC) of 1.6 × 107 s-1 and 1.07 × 106 s-1, respectively, are obtained in mClSFO. As a result, OLEDs based on mClSFO obtain impressive maximum external quantum efficiency (EQEmax) exceeding 20% across a wide doping concentration range of 10-60 wt%. 30 wt% doped OLED exhibits an EQEmax of 23.1% with a small efficiency roll-off, maintaining an EQE of 18.6% at 1000 cd m-2. The small efficiency roll-off and low concentration dependence observed in the TADF emitter underscore its significant potential.

Assessment of the measurement properties of the Peabody Developmental Motor Scales-2 by applying the COSMIN methodology.

The Peabody Developmental Motor Scales-2 (PDMS-2) has been used to assess the gross and fine motor skills of children (0-6 years); however, the measurement properties of the PDMS-2 are inconclusive. Here, we aimed to systematically review the measurement properties of PDMS-2, and synthesize the quality of evidence using the Consensus-based Standards for the Selection of Health Measurements Instruments (COSMIN) methodology. Electronic databases, including PubMed, EMBASE, Web of Science, CINAHL and MEDLINE, were searched for relevant studies through January 2023; these studies used PDMS-2. The methodological quality of each study was assessed by the COSMIN risk-of-bias checklist, and the measurement properties of PDMS-2 were evaluated by the COSMIN quality criteria. Modified GRADE was used to evaluate the quality of the evidence. We included a total of 22 articles in the assessment. Among the assessed measurement properties, the content validity of PDMS-2 was found to be sufficient with moderate-quality evidence. The structural validity, internal consistency, test-retest reliability and interrater reliability of the PDMS-2 were sufficient for high-quality evidence, while the intrarater reliability was sufficient for moderate-quality evidence. Sufficient high-quality evidence was also found for the measurement error of PDMS-2. The overall construct validity of the PDMS-2 was sufficient but showed inconsistent quality of evidence. The responsiveness of PDMS-2 appears to be sufficient with low-quality evidence. Our findings demonstrate that the PDMS-2 has sufficient content validity, structural validity, internal consistency, reliability and measurement error with moderate to high-quality evidence. Therefore, PDMS-2 is graded as 'A' and can be used in motor development research and clinical settings.

Extended Conjugation Strategy Enabling Red-Shifted and Efficient Emission of Orange-Red Thermally Activated Delayed Fluorescence Materials.

In account of the energy gap law, the development of efficient narrow-band gap thermally activated delayed fluorescence (TADF) materials remains a major challenge for the application of organic light-emitting diodes (OLEDs). The orange-red TADF materials are commonly designed with either large π-conjugated systems or strong intramolecular donor-acceptor (D-A) interactions for red-shift emission and small singlet-triplet energy gap (ΔEST). There are rare reports on the simultaneous incorporation of these two strategies on the same material systems. Herein, two orange-red emitters named 1P2D-BP and 2P2D-DQ have been designed by extending the conjugation degree of the center acceptor DQ and increasing the number distribution of the peripheral donor PXZ units, respectively. The emission peak of 1P2D-BP is red-shifted to 615 nm compared to 580 nm for 2P2D-DQ, revealing the pronounced effect of the conjugation extension on the emission band gap. In addition, the distorted molecular structure yields a small ΔEST of 0.02 eV, favoring the acquisition of a high exciton utilization through an efficient reverse intersystem crossing process. As a result, orange-red OLEDs with both 1P2D-BP and 2P2D-DQ have achieved an external quantum efficiency (EQE) of more than 17%. In addition, the efficient white OLED based on 1P2D-BP is realized through precise exciton assignment and energy transport modulation, showing an EQE of 23.6% and a color rendering index of 82. The present work provides an important reference for the design of high-efficiency narrow-band gap materials in the field of solid-state lighting.

Functional Roles of Two ß-Tubulin Isotypes in Regulation of Sensitivity of Colletotrichum fructicola to Carbendazim.

Colletotrichum fructicola is the major pathogen of anthracnose in tea-oil trees in China. Control of anthracnose in tea-oil trees mainly depends on the application of chemical fungicides such as carbendazim. However, the current sensitivity of C. fructicola isolates in tea-oil trees to carbendazim has not been reported. Here, we tested the sensitivity of 121 C. fructicola isolates collected from Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangsu, and Jiangxi provinces in China to carbendazim. One hundred and ten isolates were sensitive to carbendazim, and 11 isolates were highly resistant to carbendazim. The growth rates, morphology, and pathogenicity of three resistant isolates were identical to those of three sensitive isolates, which indicates that these resistant isolates could form a resistant population under carbendazim application. These results suggest that carbendazim should not be the sole fungicide in control of anthracnose in tea-oil trees; other fungicides with different mechanisms of action or mixtures of fungicides could be considered. In addition, bioinformatics analysis identified two ß-tubulin isotypes in C. fructicola: Cfß1tub and Cfß2tub. E198A mutation was discovered in the Cfß2tub of three carbendazim-resistant isolates. We also investigated the functional roles of two ß-tubulin isotypes. CfΔß1tub exhibited slightly increased sensitivity to carbendazim and normal phenotypes. Surprisingly, CfΔß2tub was highly resistant to carbendazim and showed a seriously decreased growth rate, conidial production, pathogenicity, and abnormal hyphae morphology. Promoter replacement mutant CfΔß2-2×ß1 showed partly restored phenotypes, but it was still highly resistant to carbendazim, which suggests that Cfß1tub and Cfß2tub are functionally interchangeable to a certain degree.

Influence of different caregiving styles on fundamental movement skills among children.

Purpose: This study investigated the influence of parenting and grandparenting caregiving styles on fundamental motor skills (FMS) of preschool children. Method: A total of 1,326 preschool children (698 boys, 628 girls) aged 4-6 years were recruited from the kindergartens of Jinhua City, China. Locomotor skills (LM), ball skills (BS), and total fundamental movement skills (TS) of children were assessed by the Test of Gross Motor Development-3rd edition (TGMD-3). Results: There were 978 children in parenting and 348 children in grandparenting caregiving styles. The LM, BS and TS scores of children were considerably (p < 0.001) increased with age (irrespective of sex or caregiving style). For the sex comparisons, BS scores of boys were significantly higher than girls (p < 0.001), while LM and TS scores were not different between boys and girls. For the caregiving style comparison, parenting is superior to grandparenting in developing of children's FMS. Parenting boys of 4-, 5-, and 6-years old showed better BS compared to age-matched parenting girls, whereas boys of 5-years old in grandparenting only showed better BS compared to same-age grandparenting girls (p < 0.05). Furthermore, parenting boys of 6-years reported higher LM (p < 0.01), BS (p < 0.001), and TS (p < 0.001) scores compared to grandparenting boys, but girls' FMS at all ages were not significantly different between the caregiving styles. Conclusion: Parenting caregiving style is positively associated with proper development of FMS among children. Girl children with poor FMS in grandparenting may need a special care or intervention programs to promote their FMS.

Assembly of JAZ-JAZ and JAZ-NINJA complexes in jasmonate signaling.

Jasmonates (JAs) are plant hormones with crucial roles in development and stress resilience. They activate MYC transcription factors by mediating the proteolysis of MYC inhibitors called JAZ proteins. In the absence of JA, JAZ proteins bind and inhibit MYC through the assembly of MYC-JAZ-Novel Interactor of JAZ (NINJA)-TPL repressor complexes. However, JAZ and NINJA are predicted to be largely intrinsically unstructured, which has precluded their experimental structure determination. Through a combination of biochemical, mutational, and biophysical analyses and AlphaFold-derived ColabFold modeling, we characterized JAZ-JAZ and JAZ-NINJA interactions and generated models with detailed, high-confidence domain interfaces. We demonstrate that JAZ, NINJA, and MYC interface domains are dynamic in isolation and become stabilized in a stepwise order upon complex assembly. By contrast, most JAZ and NINJA regions outside of the interfaces remain highly dynamic and cannot be modeled in a single conformation. Our data indicate that the small JAZ Zinc finger expressed in Inflorescence Meristem (ZIM) motif mediates JAZ-JAZ and JAZ-NINJA interactions through separate surfaces, and our data further suggest that NINJA modulates JAZ dimerization. This study advances our understanding of JA signaling by providing insights into the dynamics, interactions, and structure of the JAZ-NINJA core of the JA repressor complex.

Baseline Sensitivity and Resistance Mechanism of Colletotrichum Isolates on Tea-Oil Trees of China to Tebuconazole.

Colletotrichum fungi could cause anthracnose, a destructive disease in tea-oil trees. The sterol demethylation inhibitor (DMI) tebuconazole has been widely used in controlling plant diseases for many years. However, the baseline sensitivity of Colletotrichum isolates on tea-oil trees to tebuconazole has not been determined. In this study, the sensitivity to tebuconazole of 117 Colletotrichum isolates from tea-oil trees of seven provinces in southern China was tested. The mean effective concentration resulted in 50% mycelial growth inhibition (EC50), 0.7625 µg/ml. The EC50 values of 100 isolates (83%) were lower than 1 µg/ml, and those of 20 isolates (17%) were higher than 1 µg/ml, which implied that resistance has already occurred in Colletotrichum isolates on tea-oil trees. The EC50 values of the most resistant and sensitive isolates (named Ca-R and Cc-S1, respectively) were 1.8848 and 0.1561 µg/ml, respectively. The resistance mechanism was also investigated in this study. A gene replacement experiment indicated that the CYP51A/B gene of resistant isolates Ca-R and Cf-R1 cannot confer Cc-S1 full resistance to DMI fungicides, although three single point mutants, Cc-S1CYP51A-T306A and Cc-S1CYP51A-R478K, exhibited decreased sensitivity to DMI fungicides. This result suggested that resistance of Colletotrichum isolates was partly caused by mutations in CYP51A. Moreover, the expression level of CYP51A/B was almost identical among Ca-R, Cf-R1, Cc-S1, and Cc-S1CYP51A point mutants, which indicated that the resistance was irrelevant to the expression level of CYP51A, and other nontarget-based resistance mechanisms may exist. Our results could help to guide the application of DMI fungicides and be useful for investigating the mechanism of resistance.

Quantum-Solving Algorithm for d'Alembert Solutions of the Wave Equation.

When faced with a quantum-solving problem for partial differential equations, people usually transform such problems into Hamiltonian simulation problems or quantum-solving problems for linear equation systems. In this paper, we propose a third approach to solving partial differential equations that differs from the two approaches. By using the duality quantum algorithm, we construct a quantum-solving algorithm for solving the first-order wave equation, which represents a typical class of partial differential equations. Numerical results of the quantum circuit have high precision consistency with the theoretical d'Alembert solution. Then the routine is applied to the wave equation with either a dissipation or dispersion term. As shown by complexity analysis for all these cases of the wave equation, our algorithm has a quadratic acceleration for each iteration compared to the classical algorithm.

Validamycin A Enhances the Interaction Between Neutral Trehalase and 14-3-3 Protein Bmh1 in Fusarium graminearum.

In agriculture, Trehalase is considered the main target of the biological fungicide validamycin A, and the toxicology mechanism of validamycin A is unknown. 14-3-3 proteins, highly conserved proteins, participate in diverse cellular processes, including enzyme activation, protein localization, and acting as a molecular chaperone. In Saccharomyces cerevisiae, the 14-3-3 protein Bmh1could interact with Nth1 to respond to specific external stimuli. Here, we characterized FgNth, FgBmh1, and FgBmh2 in Fusarium graminearum. ΔFgNth, ΔFgBmh1, and ΔFgBmh2 displayed great growth defects and their peripheral tips hyphae generated more branches when compared with wild-type (WT) PH-1. When exposed to validamycin A as well as high osmotic and high temperature stresses, ΔFgNth, ΔFgBmh1, and ΔFgBmh2 showed more tolerance than WT. Both ΔFgNth and ΔFgBmh1 displayed reduced deoxynivalenol production but opposite for ΔFgBmh2, and all three deletion mutants showed reduced virulence on wheat coleoptiles. In addition, coimmunoprecipitation (Co-IP) experiments suggested that FgBmh1 and FgBmh2 both interact with FgNth, but no interaction was detected between FgBmh1 and FgBmh2 in our experiments. Further, validamycin A enhances the interaction between FgBmh1 and FgNth in a positive correlation under concentrations of 1 to 100 µg/ml. In addition, both high osmotic and high temperature stresses promote the interaction between FgBmh1 and FgNth. Co-IP assay also showed that neither FgBmh1 nor FgBmh2 could interact with FgPbs2, a MAPKK kinase in the high-osmolarity glycerol pathway. However, FgBmh2 but not FgBmh1 binds to the heat shock protein FgHsp70 in F. graminearum. Taken together, our results demonstrate that FgNth and FgBmh proteins are involved in growth and responses to external stresses and virulence; and validamycin enhanced the interaction between FgNth and FgBmh1in F. graminearum.

Robust Quantum Search with Uncertain Number of Target States.

The quantum search algorithm is one of the milestones of quantum algorithms. Compared with classical algorithms, it shows quadratic speed-up when searching marked states in an unsorted database. However, the success rates of quantum search algorithms are sensitive to the number of marked states. In this paper, we study the relation between the success rate and the number of iterations in a quantum search algorithm of given λ=M/N, where M is the number of marked state and N is the number of items in the dataset. We develop a robust quantum search algorithm based on Grover-Long algorithm with some uncertainty in the number of marked states. The proposed algorithm has the same query complexity ON as the Grover's algorithm, and shows high tolerance of the uncertainty in the ratio M/N. In particular, for a database with an uncertainty in the ratio M±MN, our algorithm will find the target states with a success rate no less than 96%.

S-adenosyl-L-homocysteine hydrolase FgSah1 is required for fungal development and virulence in Fusarium graminearum.

The S-adenosyl-L-homocysteine hydrolase (Sah1) plays a crucial role in methylation and lipid metabolism in yeast and mammals, yet its function remains elusive in filamentous fungi. In this study, we characterized Sah1 in the phytopathogenic fungus F. graminearum by generating knockout and knockout-complemented strains of FgSAH1. We found that the FgSah1-GFP fusion protein was localized to the cytoplasm, and that deletion of FgSAH1 resulted in defects in vegetative growth, asexual and sexual reproduction, stress responses, virulence, lipid metabolism, and tolerance against fungicides. Moreover, the accumulations of S-adenosyl-L-homocysteine (AdoHcy) and S-adenosyl-L-methionine (AdoMet) (the methyl group donor in most methyl transfer reactions) in ΔFgSah1 were seven- and ninefold higher than those in the wild-type strain, respectively. All of these defective phenotypes in ΔFgSah1 mutants were rescued by target gene complementation. Taken together, these results demonstrate that FgSah1 plays essential roles in methylation metabolism, fungal development, full virulence, multiple stress responses, lipid metabolism, and fungicide sensitivity in F. graminearum. To our knowledge, this is the first report on the systematic functional characterization of Sah1 in F. graminearum.

Functional Roles of α1-, α2-, ß1-, and ß2-Tubulins in Vegetative Growth, Microtubule Assembly, and Sexual Reproduction of Fusarium graminearum.

The plant pathogen Fusarium graminearum contains two α-tubulin isotypes (α1 and α2) and two ß-tubulin isotypes (ß1 and ß2). The functional roles of these tubulins in microtubule assembly are not clear. Previous studies reported that α1- and ß2-tubulin deletion mutants showed severe growth defects and hypersensitivity to carbendazim, which have not been well explained. Here, we investigated the interaction between α- and ß-tubulin of F. graminearum. Colocalization experiments demonstrated that ß1- and ß2-tubulin are colocalized. Coimmunoprecipitation experiments suggested that ß1-tubulin binds to both α1- and α2-tubulin and that ß2-tubulin can also bind to α1- or α2-tubulin. Interestingly, deletion of α1-tubulin increased the interaction between ß2-tubulin and α2-tubulin. Microtubule observation assays showed that deletion of α1-tubulin completely disrupted ß1-tubulin-containing microtubules and significantly decreased ß2-tubulin-containing microtubules. Deletion of α2-, ß1-, or ß2-tubulin had no obvious effect on the microtubule cytoskeleton. However, microtubules in α1- and ß2-tubulin deletion mutants were easily depolymerized in the presence of carbendazim. The sexual reproduction assay indicates that α1- and ß1-tubulin deletion mutants could not produce asci and ascospores. These results implied that α1-tubulin may be essential for the microtubule cytoskeleton. However, our Δα1-2×α2 mutant (α1-tubulin deletion mutant containing two copies of α2-tubulin) exhibited normal microtubule network, growth, and sexual reproduction. Interestingly, the Δα1-2×α2 mutant was still hypersensitive to carbendazim. In addition, both ß1-tubulin and ß2-tubulin were found to bind the mitochondrial outer membrane voltage-dependent anion channel (VDAC), indicating that they could regulate the function of VDAC. IMPORTANCE In this study, we found that F. graminearum contains four different α-/ß-tubulin heterodimers (α1-/ß1-, α1-/ß2-, α2-/ß1-, and α2-/ß2-tubulin heterodimers), and they assemble together into a single microtubule. Moreover, α1- and α2-tubulins are functionally interchangeable in microtubule assembly, vegetative growth, and sexual reproduction. These results provide more insights into the functional roles of different tubulins of F. graminearum, which could be helpful for purification of tubulin heterodimers and development of new tubulin-binding agents.

Microtubule-assisted mechanism for toxisome assembly in Fusarium graminearum.

In Fusarium graminearum, a trichothecene biosynthetic complex known as the toxisome forms ovoid and spherical structures in the remodelled endoplasmic reticulum (ER) under mycotoxin-inducing conditions. Previous studies also demonstrated that disruption of actin and tubulin results in a significant decrease in deoxynivalenol (DON) biosynthesis in F. graminearum. However, the functional association between the toxisome and microtubule components has not been clearly defined. In this study we tested the hypothesis that the microtubule network provides key support for toxisome assembly and thus facilitates DON biosynthesis. Through fluorescent live cell imaging, knockout mutant generation, and protein-protein interaction assays, we determined that two of the four F. graminearum tubulins, α1 and ß2 tubulins, are indispensable for DON production. We also showed that these two tubulins are directly associated. When the α1 -ß2 tubulin heterodimer is disrupted, the metabolic activity of the toxisome is significantly suppressed, which leads to significant DON biosynthesis impairment. Similar phenotypic outcomes were shown when F. graminearum wild type was treated with carbendazim, a fungicide that binds to microtubules and disrupts spindle formation. Based on our results, we propose a model where α1 -ß2 tubulin heterodimer serves as the scaffold for functional toxisome assembly in F. graminearum.

The Dis1/Stu2/XMAP215 Family Gene FgStu2 Is Involved in Vegetative Growth, Morphology, Sexual and Asexual Reproduction, Pathogenicity and DON Production of Fusarium graminearum.

The conserved Dis1/Stu2/XMAP215 microtubule association proteins (MAPs) family plays an important role in microtubule dynamics, nucleation, and kinetochore-microtubule attachments. However, function of Dis1/Stu2/XMAP215 homolog in plant pathogenic fungi has not been determined. Here, we identified and investigated the Dis1/Stu2/XMAP215 homolog (FGSG_10528) in Fusarium graminearum (FgStu2p). Co-localization experiment and co-immunoprecipitation (Co-IP) assay demonstrated that FgStu2p is a microtubule associated protein. Besides, FgStu2 could also interact with Fgγ-tubulin and presumed FgNdc80, which suggested that the FgStu2 gene might associate with microtubule nucleation and kinetochore-microtubule attachments like Dis1/Stu2/XMAP215 homologs in other species. Moreover, the FgStu2 promoter replacement mutants (FgStu2-Si mutants) produced twisted hyphae and decreased growth rate. Microscope examination further showed that the microtubule polymerization was reduced in FgStu2-Si mutants, which could account for the aberrant morphology. Although the microtubule polymerization was affected in FgStu2-Si mutants, the FgStu2-Si mutants didn't show highly increased sensitivity to anti-microtubule fungicide carbendazim (methyl benzimidazol-2-ylcarbamate [MBC]). In addition, the FgStu2-Si mutants exhibited curved conidia, decreased number of conidial production, blocked ability of perithecia production, decreased pathogenicity and deoxynivalenol (DON) production. Taken together, these results indicate that the FgStu2 gene plays a crucial role in vegetative growth, morphology, sexual reproduction, asexual reproduction, virulence and deoxynivalenol (DON) production of F. graminearum, which brings new insights into the functions of Dis1/Stu2/XMAP215 homolog in plant pathogenic fungi.

Detrimental Effects of Multiple Mutations in Position 240 of Fusarium graminearum ß2-Tubulin.

Fusarium graminearum causes Fusarium head blight (FHB), a destructive disease of cereal crops worldwide. Carbendazim (methylbenzimidazol-2-ylcarbamate [MBC]) is widely used for controlling FHB. A previous study showed that the F240L mutation in the ß2-tubulin of F. graminearum (Fgß2-tubulin) confers hypersensitivity to MBC. Whether the substitution of phenylalanine by other amino acids in position 240 of the Fgß2-tubulin gene also confers hypersensitivity to MBC is unknown. Moreover, the biological fitness of these mutants is poorly understood. In this study, we substituted position 240 of Fgß2-tubulin with other amino acids. We found that the F240A, F240E, F240I, and F240Y mutations in Fgß2-tubulin could also confer F. graminearum hypersensitivity to MBC, although the effective concentration resulting in 50% inhibition (EC50) differed among the mutations. The F240G mutation, in contrast, decreased the sensitivity to MBC. In addition, a molecular docking assay indicated that the binding affinity between Fgß2-tubulin and MBC were increased by the F240A, F240E, F240I, and F240Y mutations but decreased by the F240G mutation. All mutants had normal conidial morphology, but the growth rates and pathogenicity of the F240A, F240E, F240G, F240I, and F240Y mutants were significantly decreased. Moreover, the F240A and F240G mutants produced twisted hyphae. In addition, microtubules were sparse and rarely observed in ß2F240A-EGFP, ß2F240E-EGFP, and ß2F240G-EGFP. These results indicate that position 240 (phenylalanine) is not only vital to the function of Fgß2-tubulin but also plays an important role in regulating the sensitivity of F. graminearum to MBC. Any mutation in this site would be detrimental to survival.

Structural basis of Fusarium myosin I inhibition by phenamacril.

Fusarium is a genus of filamentous fungi that includes species that cause devastating diseases in major staple crops, such as wheat, maize, rice, and barley, resulting in severe yield losses and mycotoxin contamination of infected grains. Phenamacril is a novel fungicide that is considered environmentally benign due to its exceptional specificity; it inhibits the ATPase activity of the sole class I myosin of only a subset of Fusarium species including the major plant pathogens F. graminearum, F. asiaticum and F. fujikuroi. To understand the underlying mechanisms of inhibition, species specificity, and resistance mutations, we have determined the crystal structure of phenamacril-bound F. graminearum myosin I. Phenamacril binds in the actin-binding cleft in a new allosteric pocket that contains the central residue of the regulatory Switch 2 loop and that is collapsed in the structure of a myosin with closed actin-binding cleft, suggesting that pocket occupancy blocks cleft closure. We have further identified a single, transferable phenamacril-binding residue found exclusively in phenamacril-sensitive myosins to confer phenamacril selectivity.

Intron-mediated regulation of ß-tubulin genes expression affects the sensitivity to carbendazim in Fusarium graminearum.

The plant pathogenic fungus, Fusarium graminearum, is known to have two ß-tubulin genes (named Fg-ß1tub and Fg-ß2tub). Mutations in Fg-ß2tub rather than in Fg-ß1tub have been shown to confer resistance to carbendazim (MBC), even though Fg-ß1tub has higher homology than Fg-ß2tub to the ß-tubulin isotypes related to benzimidazole resistance in other fungi. However, sequence alignment of ß-tubulin isotypes related to benzimidazole resistance showed that the number and position of introns in Fg-ß2tub are more consistent than Fg-ß1tub to those in other ß-tubulin genes. In detail, Fg-ß1tub lacks three introns, i.e., intron i3, i4, and i6 corresponding to positions in Fg-ß2tub of F. graminearum. To investigate the effects of the divergence introns on the function of ß-tubulins in F. graminearum, a strategy of intron deletion and insertion was used. Our results showed that deletion of the second intron from Fg-ß1tub gene increased Fg-ß1tub expression levels leading to increased sensitivity to MBC. Besides, inserting the divergence introns into Fg-ß1tub can increase Fg-ß1tub expression leading to increased sensitivity to MBC. In addition, intron-mediated Fg-ß1tub gene expression requires a splicing-competent intron within the body of the host gene. Furthermore, the insertion and deletion of introns in Fg-ß1tub gene have no significant effect on hyphal growth, conidiation and virulence in F. graminearum. Thus, we proposed that introns may be among the factors contributing to the evolution and functional divergence of two ß-tubulin genes and also significantly regulate the expression of ß-tubulin genes, which, in turn, affects sensitivity to MBC fungicides in F. graminearum.

A new point mutation in ß2-tubulin confers resistance to carbendazim in Fusarium asiaticum.

Resistance to benzimidazole fungicides in many phytopathogenic fungi is caused by specific point mutations in the ß-tubulin gene (ß-tubulin). However, the mutated locus and genotype of ß-tubulin differ among phytopathogenic fungi. To validate the point mutation in Fusarium asiaticum ß2-tubulin that confers resistance to carbendazim and to analyze the molecular interaction between carbendazim and F. asiaticum ß2-tubulin. In this study, a new point mutation (GAG→GCG, E198A) at codon 198 of ß2-tubulin in a wild-type F. asiaticum strain was constructed by site-directed mutagenesis followed by a split marker strategy. The site-directed mutants were verified and exhibited a high level of resistance to carbendazim. In the absence of fungicide treatment, the biological characteristics did not differ between the site-directed mutants and the wild-type strain. Molecular docking between carbendazim and ß2-tubulin was carried out using the Surflex-Dock program in Sybyl X-2.0 version and the results indicated that the E198A mutation altered the configuration of ß2-tubulin, resulting in the change of the bonding sites and docking scores. We concluded that the point mutation of F. asiaticum ß2-tubulin conferring carbendazim resistance may not always be the bonding site for carbendazim.