Arbuscular mycorrhizal fungi (AMF) play an important role in nutrient cycling processes and plant stress resistance. To evaluate the effect of Rhizophagus irregularis CD1 on plant growth promotion (PGP) and Verticillium wilt disease, the symbiotic efficiency of AMF (SEA) was first investigated over a range of 3% to 94% in 17 cotton varieties. The high-SEA subgroup had significant PGP effects in a greenhouse. From these results, the highest-SEA variety of Lumian 1 was selected for a two-year field assay. Consistent with the performance from the greenhouse, the AMF-mediated PGP of Lumian 1 also produced significant results, including an increased plant height, stem diameter, number of petioles, and phosphorus content. Compared with the mock treatment, AMF colonization obviously inhibited the symptom development of Verticillium dahliae and more strongly elevated the expression of pathogenesis-related genes and lignin synthesis-related genes. These results suggest that AMF colonization could lead to the mycorrhiza-induced resistance (MIR) of Lumian 1 to V. dahliae. Interestingly, our results indicated that the AMF endosymbiont could directly inhibit the growth of phytopathogenic fungi including V. dahliae by releasing undefined volatiles. In summary, our results suggest that stronger effects of AMF application result from the high-SEA.

Cu ions are required by all living organisms and play important roles in many bactericides and fungicides. We previously reported that Cu can elicit defense responses, which are dependent on the ethylene signaling pathway in However, the mechanism by which Cu elicits the biosynthesis of ethylene remains unclear. Here, we show that CuSO treatment rapidly increases the production of ethylene. In addition, it upregulates the expression of several defense-related genes and ethylene biosynthesis genes, including genes encoding -adenosylmethionine synthase, 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS) and ACC oxidase. Among these genes, () was identified as essential for the defense response and early ethylene biosynthesis induced by Cu Furthermore, Cu-induced expression depended on the copper-response-element (CuRE) in the promoter of Our study indicates that Cu specifically activates the expression of to promote the early biosynthesis of ethylene that elicits plant immunity in plants.

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The formation of ZrB2 particles in Al–Si alloys not only improves the properties of the Al–Si alloy but also helps remove B from Si for the preparation of solar-grade Si. A thermodynamic study was performed to identify the mechanism of ZrB2 formation in Al–Si alloys. The precipitated B-bearing particles, i.e., ZrB x , were determined to be ZrB2 via electron probe microanalysis. The composition of the Al–Si alloy, which could form stable ZrB2 particles, was determined by measuring and calculating the equilibrium concentrations of Zr and B and the solubility products of ZrB2 in a Si-saturated Al–Si alloy at different temperatures. Thereafter, the segregation coefficients of B between solid Si crystals and the Si-saturated Al–Si melt with and without Zr addition were estimated thermodynamically. The mechanism whereby the B removal from Si was enhanced with Zr addition was as follows: the Zr not only reduced the concentration of B in the molten Al–Si but also significantly reduced the segregation coefficient of B between the solid Si and Si-saturated Al–Si melt.

WSe 2 has been widely used in NO 2 gas sensors in recent years, but it still suffers from low responsiveness and slow reaction kinetics. Herein, we used the chemical vapor deposition method to synthesize a vertically grown few-layer WSe 2 (3D-WSe 2 ) nanosheet film. Three-dimensional-WSe 2 is transformed into vertical growth by introducing a TiO 2 buffer layer and exposes much more edge active sites to improve gas sensitivity. As a result, it has not only high crystallinity and few defects but also a high response to NO 2 (34.6% at 1 ppm), a fast response time (66 s), a short recovery time (17 min), a low limit of detection (4 ppb), excellent stability, and gas selectivity at room temperature.