Two lysin motif extracellular (LysMe) proteins are deployed in rice to facilitate arbuscular mycorrhizal symbiosis.

During arbuscular mycorrhizal (AM) symbiosis, plant innate immunity is modulated to a prime state to allow for fungal colonization. The underlying mechanisms remain to be further explored. In this study, two rice genes encoding LysM extracellular (LysMe) proteins were investigated. By obtaining OsLysMepro:GUS transgenic plants and generating oslysme1, oslysme2 and oslysme1oslysme2 mutants via CRISPR/Cas9 technique, OsLysMe genes were revealed to be specifically induced in the arbusculated cells and mutations in either gene caused significantly reduced root colonization rate by AM fungus Rhizophagus irregularis. Overexpression of OsLysMe1 or OsLysMe2 dramatically increased the colonization rates in rice and Medicago truncatula. The electrophoretic mobility shift assay and dual-luciferase reporter assay supported that OsLysMe genes are regulated by OsWRI5a. Either OsLysMe1 or OsLysMe2 can efficiently rescue the impaired AM phenotype of the mtlysme2 mutant, supporting a conserved function of LysMe across monocotyledonous and dicotyledonous plants. The co-localization of OsLysMe proteins with the apoplast marker SP-OsRAmy3A implies their probable localization to the periarbuscular space (PAS) during symbiosis. Relative to the fungal biomass marker RiTEF, some defense-related genes showed disproportionately high expression levels in the oslysme mutants. These data support that rice plants deploy two OsLysMe proteins to facilitate AM symbiosis, likely by diminishing plant defense responses.

Rapid assessment of cosmic radiation exposure in aviation based on BP neural network method.

Cosmic radiation exposure is one of the important health concerns for aircrews. In this work, we constructed a back propagation neural network model for the real-time and rapid assessment of cosmic radiation exposure to the public in aviation. The multi-dimensional dataset for this neural network was created from modeling the process of cosmic ray transportation in magnetic field by geomagnetic cutoff rigidity method and air shower simulation by a Monte Carlo based Geant4 code. The dataset was characterized by parameters including cosmic ray energy spectrum, Kp-index, coordinated universal time, altitude, latitude, and longitude. The effective dose and dose rate was finally converted from the particle fluxes at flight position by the neural network. This work shows a good agreement with other models from International Civil Aviation Organization. It is also illustrated that the effective dose rate by galactic cosmic ray is <10 µSv h-1 and the value during ground level enhancement (GLE) 42 is 4 ~ 10 times larger on the routes calculated in this work. In GLE 69, the effective dose rate reaches several mSv h-1 in the polar region. Based on this model, a real-time warning system is achieved.

The Rice Qa-SNAREs in SYP13 Subfamily Are Involved in Regulating Arbuscular Mycorrhizal Symbiosis and Seed Fertility.

Qa-SNARE gene SYP132 (isoform α) was previously reported to affect arbuscular mycorrhizal (AM) symbiosis in the legume species Medicago truncatula. In non-legumes especially monocots, it remains unknown whether certain SNARE genes are also involved in AM symbiosis. In this work, we studied a rice orthologous gene OsSYP132, which showed induced expression in mycorrhizal roots and two paralogous genes OsSYP131a and OsSYP131b, which were not induced by the AM fungus Rhizophagus irregularis. After employing CRISPR/Cas9 technique to generate their mutants, the Ossyp131a homozygous mutant T0 plants exhibited a dwarf phenotype and produced no fertile seeds, indicating a required role of this gene in seed fertility. Unlike the case in legume, the Ossyp132 mutants exhibited normal mycorrhizal phenotype, so did the Ossyp131b mutants. In the Ossyp131b Ossyp132 double mutants, however, the colonization rate and arbuscule abundance level decreased markedly, indicating an impaired fungal proliferation ability in rice roots. Such a defect was further confirmed by the reduced expression levels of AM marker genes. Our results in rice therefore demonstrated that while SYP13II members showed evolutionary and induction patterns specific to symbiosis, AM symbiosis is in fact controlled by the combined action of both SYP13I and SYP13II clades, revealing a functional redundancy among SYNTAXIN genes in mutualism.

Dual Roles of OsGH3.2 in Modulating Rice Root Morphology and Affecting Arbuscular Mycorrhizal Symbiosis.

Several angiosperm GRETCHEN HAGEN 3 (GH3) genes, including tomato SlGH3.4 and rice OsGH3.2 are induced during arbuscular mycorrhizal (AM) symbiosis, but their functions remain largely unclear. Recently, tomato SlGH3.4 was suggested to negatively regulate arbuscule incidence via decreasing auxin levels in colonized cells. In this study, by acquiring rice OsGH3.2pro:ß-glucuronidase (GUS) transgenic plants and generating Osgh3.2 mutants via CRISPR/Cas9 technique, the roles of OsGH3.2 in modulating rice root morphology and affecting AM symbiosis were investigated through time course experiments. Unlike SlGH3.4, OsGH3.2 showed asymbiotic expression in rice young lateral roots, and its mutation resulted in a "shallow" root architecture. Such root morphological change was also observed under symbiotic condition and it likely promoted AM fungal colonization, as the mutants exhibited higher colonization levels and arbuscule incidence than wild-type at early stages. Similar to SlGH3.4, OsGH3.2 showed symbiotic expression in cortical cells that have formed mature arbuscules. At late stages of symbiosis, Osgh3.2 mutants showed elongated cortical cells and larger arbuscules than wild-type, indicating elevated auxin level in the colonized cells. Together, these results revealed both asymbiotic and symbiotic roles of OsGH3.2 in modulating rice root architecture and controlling auxin levels in arbusculated cells, which further affected colonization rate and arbuscule phenotype.

OsADK1, a novel kinase regulating arbuscular mycorrhizal symbiosis in rice.

Arbuscular mycorrhizal (AM) symbiosis relies on the formation of arbuscules for efficient nutrient exchange between plants and AM fungi. In this study, we identified a novel kinase gene in rice named OsADK1 (Arbuscule Development Kinase 1) that is required for arbuscule development. By obtaining OsADK1pro::GUS transgenic rice plants and also generating Osadk1 mutants via CRISPR/Cas9 technique, OsADK1 was revealed to be specifically induced in the arbusculated cortical cells and mutations in OsADK1 resulted in an extremely low colonisation rate (c. 3%) of rice roots by AM fungus Rhizophagus irregularis. In the mutant roots, the very few observed arbuscules nearly all arrested at an early 'trunk-forming' phase without forming any branches. Increasing the inoculum strength of AM fungus or cocultivation with a wild-type nurse plant did not result in the rescue of the arbuscule phenotype. Transcriptome sequencing of both nursed and un-nursed Osadk1 mutants then revealed that the mutation of OsADK1 could greatly affect the AM symbiotic programme, including many key transcription factors such as RAM1 and WRI5. OsADK1 therefore represents a new rice kinase that is required for arbuscule branching. Its identification opens a new window to explore the elaborate signal transduction pathway that determines arbuscule development during plant-fungus symbiosis.

Effect of L3MBTL3/PTPN9 polymorphisms on risk to alcohol-induced ONFH in Chinese Han population.

PURPOSE: Alcohol-induced osteonecrosis femoral head necrosis (ONFH) is a disease that seriously affects human health. Abnormal expression of L3MBTL3/PTPN9 gene can cause a variety of human diseases. The purpose of this study is to investigate the effect of L3MBTL3/PTPN9 gene polymorphism on the susceptibility of alcohol-induced ONFH in Chinese Han population. METHODS: A total of 308 alcohol-induced ONFH patients and 425 healthy controls were enrolled in this case-control study. Alleles, genotypes, genetic models, haplotypes, and multifactor dimensionality reduction analyses (MDR) based on age-corrected by using odds ratio (OR) and 95% confidence interval (CI) were performed. RESULTS: Our result revealed rs2068957 in the L3MBTL3 gene increased the risk of alcohol ONFH under the recessive model after correction. Besides, we also found that rs75393192 in the PTPN9 gene was a protective site in stratification over 40 years of age and stage. In stratified analysis of necrotic sites, we only found that rs2068957 was associated with increased susceptibility of alcohol-induced ONFH under the co-dominant model and recessive model. Haplotype "GC" in the block (rs76107647|rs10851882 in PTPN9 gene) significantly decreased the susceptibility of alcoholic ONFH. CONCLUSIONS: Our results provide evidence that L3MBTL3/PTPN9 polymorphisms are associated with alcohol-induced ONFH risk in Chinese Han population.

Step consistency active control method for inertial piezoelectric actuator using embedded strain gauges.

Inertial piezoelectric actuators (IPAs) are widely used in micro-nano manipulation, biomedicine, and other fields as the simple structure and excitation signal. However, the step consistency is difficult to guarantee in a large stroke range due to the limited machining accuracy of the mover and inherent roll back, which limits the practical application in these precision fields. Therefore, a step consistency active control method for IPAs is proposed based on bending hybrid motions, which uses embedded strain gauges as the force sensors to acquire the pressure between the mover and the actuator. The IPA is driven by horizontal bending motion, and the pressure can be dynamically adjusted by vertical bending motion to ensure the constant pressure and achieve a constant step. Experiments results show that the maximum standard deviation of the step is 0.41 µm under the active control of 350 Vp-p and 1 Hz driving voltage within 2 mm stroke range in 500 driving cycles, and the maximum standard deviation of the step is 1.14 µm under the non-active control with the same conditions, which show that the proposed method evidently improves the step consistency of IPA in a large stroke range.