Phenotypic Investigation and RNA-seq of KN1 Involved in Leaf Angle Formation in Maize (Zea mays L.).

Leaf angle (LA) is one of the core agronomic traits of maize, which controls maize yield by affecting planting density. Previous studies have shown that the KN1 gene is closely related to the formation of maize LA, but its specific mechanism has not been fully studied. In this study, phenotype investigation and transcriptomic sequencing were combined to explore the mechanism of LA changes in wild type maize B73 and mutant kn1 under exogenous auxin (IAA) and abscisic acid (ABA) treatment. The results showed that the effect of exogenous phytohormones had a greater impact on the LA of kn1 compared to B73. Transcriptome sequencing showed that genes involved in IAA, gibberellins (GAs) and brassinosteroids (BRs) showed different differential expression patterns in kn1 and B73. This study provides new insights into the mechanism of KN1 involved in the formation of maize LA, and provides a theoretical basis for breeding maize varieties with suitable LA.

Characteristics of the atmospheric boundary layer height: A perspective on turbulent motion.

Turbulent motion is the essential difference between the atmospheric boundary layer and the free atmosphere. Due to the lack of detection methods for vertical turbulent structures, commonly used methods usually focus on material distribution, thermal effects, or dynamic effects, and they fail to reflect the boundary layer objectively in terms of turbulence. Therefore, to date, the acquisition and characteristic analysis of the atmospheric boundary layer height under turbulent angles have not been achieved. This study proposes a method for obtaining the height of the boundary layer based on the power-law exponent of atmospheric turbulence. The proposed method is validated and analyzed with data from radiosondes obtained under sunny, cloudy, and light rain weather conditions, demonstrating its advantages. With the proposed method, the first published acquisition of boundary layer height characteristics based on turbulent motion is achieved, including a statistical analysis of the daily and monthly variation characteristics of the boundary layer height over the Shenzhen area in China. Moreover, different oscillation frequencies of the boundary layer height under different wind directions are revealed. The results of this study break the traditional bottleneck of not being able to obtain the height of the boundary layer based on turbulence, and provide a new perspective for the acquisition and research of the boundary layer height.

Corrigendum: Morphological characterization and transcriptome analysis of leaf angle mutant bhlh112 in maize [Zea mays L.].

[This corrects the article DOI: 10.3389/fpls.2022.995815.].

Morphological characterization and transcriptome analysis of leaf angle mutant bhlh112 in maize [Zea mays L.].

Leaf angle is an important agronomic trait in maize [Zea mays L.]. The compact plant phenotype, with a smaller leaf angle, is suited for high-density planting and thus for increasing crop yields. Here, we studied the ethyl methane sulfonate (EMS)-induced mutant bhlh112. Leaf angle and plant height were significantly decreased in bhlh112 compared to the wild-type plants. After treatment of seedlings with exogenous IAA and ABA respectively, under the optimal concentration of exogenous hormones, the variation of leaf angle of the mutant was more obvious than that of the wild-type, which indicated that the mutant was more sensitive to exogenous hormones. Transcriptome analysis showed that the ZmbHLH112 gene was related to the biosynthesis of auxin and brassinosteroids, and involved in the activation of genes related to the auxin and brassinosteroid signal pathways as well as cell elongation. Among the GO enrichment terms, we found many differentially expressed genes (DEGs) enriched in the cell membrane and ribosomal biosynthesis, hormone biosynthesis and signaling pathways, and flavonoid biosynthesis, which could influence cell growth and the level of endogenous hormones affecting leaf angle. Therefore, ZmbHLH112 might regulate leaf angle development through the auxin signaling and the brassinosteroid biosynthesis pathways. 12 genes related to the development of leaf were screened by WGCNA; In GO enrichment and KEGG pathways, the genes were mainly enriched in rRNA binding, ribosome biogenesis, Structural constituent of ribosome; Arabidopsis ribosome RNA methyltransferase CMAL is involved in plant development, likely by modulating auxin derived signaling pathways; The free 60s ribosomes and polysomes in the functional defective mutant rice minute-like1 (rml1) were significantly reduced, resulting in plant phenotypic diminution, narrow leaves, and growth retardation; Hence, ribosomal subunits may play an important role in leaf development. These results provide a foundation for further elucidation of the molecular mechanism of the regulation of leaf angle in maize.

Lidar system with a fast scanning speed for sea fog detection.

Sea fog changes widely and rapidly, and existing Lidar scanning speeds are insufficient to detect such changes. Therefore, we developed a Lidar system with a fast scanning speed and long detection distance. Experimental results show that at high scanning speeds, the maximum correlation between the Lidar's visibility results and those from two forward scattering visibility meters reaches 0.9537, with a minimum relative error less than 15.31%. The results also show that the visibility of the proposed Lidar system has high accuracy when fast scanning. During the tests, the Lidar system successfully captured sea fog many times and closely tracked the changes of sea visibility, which verifies the feasibility and reliability of the developed Lidar system for obtaining visibility measurements and sea fog detection.

Correction: Significant field enhancements in an individual silver nanoparticle near a substrate covered with a thin gain film.

Correction for 'Significant field enhancements in an individual silver nanoparticle near a substrate covered with a thin gain film' by Jinhong Xian et al., Nanoscale, 2014, 6, 13994-14001, DOI: 10.1039/C4NR03678F.

Early forest-fire detection using scanning polarization lidar.

As forest terrain is complex, containing leaves and other obstacles, it is difficult to distinguish the signal of forest-fire smoke when using single-channel lidar. To address this difficulty, a scanning micropulse polarization lidar system is developed, and a new method to detect forest fires is proposed in this study. Based on the characteristics of the depolarization ratio of in-scene obstacles, a matrix is constructed to remove obstacle signals, which in turn reduces the misidentification rate. Artificial forest-fire tests are carried out to verify the correctness of the proposed method and the feasibility of early forest-fire detection using the scanning polarization lidar system. In the working mode, the developed polarizing lidar system can locate a forest fire within three minutes with the proposed method. The experimental results show that forest fires can be accurately detected in real time when using scanning polarization lidar.

Parameter optimization of a visibility LiDAR for sea-fog early warnings.

Sea fog represents a significant risk for safe navigation of sea vessels. Visibility LiDAR systems might offer a striking way to reduce the risks associated with sea fog, but they should be appropriately designed to provide a proper level of detection for reliable forewarning of sea fog. Here we analyze the performances of a visibility LiDAR system with the aim of achieving optimal detection operation. A series of echo signals are simulated under different visibility conditions addressing the influence of the various hardware parameters on the final system performances and defining an optimal visibility LiDAR configuration. Using the optimized parameters, a visibility LiDAR system was realized and tested in a field campaign on Hengsha Island (Shanghai). The experimental findings obtained by the visibility LiDAR are compared with results of a forward scattering visibility meter showing good consistency in homogeneous atmosphere, while even superior performances are observed for inhomogeneous atmospheric conditions. Our experimental results indicate that an optimized visibility LiDAR can provide an early warning for light fog located at a distance of 5 km, i.e. about 3.5 hours in advance to the spreading of the fog to the shore. These findings demonstrate the good performances of the visibility LiDAR developed in the present study in performing visibility measurements and its capability of providing sea-fog warning.

Urban air pollution monitoring using scanning Lidar.

We have developed a scanning Lidar system in this work to detect urban air pollution changes in real time and locate the sources of urban air pollution. We first proposed an algorithm to retrieve atmospheric extinction coefficients, which we used to create Lidar maps. Using Lidar map of the average extinction coefficients, we identified the locations of the local maximum values, and hence, the positions of the urban air pollution sources. Experimental results indicate that this method is effective for urban air pollution monitoring.

Novel Lidar algorithm for horizontal visibility measurement and sea fog monitoring.

Traditionally, Klett and Fernald inversion estimates an initial value using the slope method for horizontal visibility, which causes inversion uncertainty. We proposed an algorithm to retrieve the extinction coefficient and visibility distribution information from scanning Lidar to overcome instability due to initial atmospheric extinction coefficient choice and assuming the Lidar ratio. Numerical simulations showed that extinction coefficient maximum relative was much larger for inhomogeneous atmosphere using the Klett method, reaching 0.31. In contrast, it is only 0.049 using the proposed algorithm. Experimental showed that the proposed algorithm and scanning Lidar system provide very high stability and accuracy, can work in different weather conditions and monitor sea fog evolution over real time, and is suitable for various situations with different visibility.

Characteristic analysis of broadband plasmonic emitting devices based on transformation optics.

The crescent nanostructure with gain medium inside is theoretically studied to analyze the characteristic of plasmonic emitting with wide bandwidth. An accurate analytical model is built based on the transformation optics. In this model, the poles of the electrostatic potential function are in the second and the fourth quadrant of the complex plane if the imaginary part of the relative permittivity of the gain medium is larger than the loss compensation threshold, and then the extinction cross section is to be negative by integrating the electrostatic potential over the half complex plane via an inverse Fourier transform. The positive extinction cross section corresponds to absorption, and the negative corresponds to emission. The proposed analytical model agrees well with the numerical simulation results based on the finite element method, to give a physical insight into the loss compensation property of the plasmonic nanostuctures. Results show that the negative extinction cross section is realizable by introducing the gain medium into a plasmonic crescent nanowire, which is equivalent to an emitting device with wide bandwidth.

Significant field enhancements in an individual silver nanoparticle near a substrate covered with a thin gain film.

In this paper, we propose a method to significantly enhance the local-field of a gap plasmonic system by placing a metallic nanoparticle in close proximity to a substrate covered with a thin film using a gain material (∼100 nm thickness). Compared with a conventional dielectric substrate, the thin gain film can contribute to several, or dozens, of times more intense local electric fields in the gap between the particle and the substrate. We use the finite difference time domain method to numerically analyze the influences of the gain coefficient of the film and of the other parameters on the field enhancement. The numerical results show that there is an optimal refractive index of the gain film that enables us to achieve a maximal field enhancement for a given NP radius. Moreover, the optimal refractive index of the gain film can be incorporated into any available materials using metal nanoparticles with an appropriate radius.

The protective effect of SCR(15-18) on cerebral ischemia-reperfusion injury.

OBJECTIVES: Soluble complement receptor type 1 (sCR1), a potent inhibitor of complement activation, has been shown to protect brain cells against cerebral ischemic/reperfusion (CI/R) injury due to its decay-accelerating activity for C3/C5 convertase and co-factor activity for C3b/C4b degradation. However, the effect of short consensus repeats (SCRs) 15-18, one of active domains of sCR1 with high C3b/C4b degradability, has not been demonstrated. Here, we investigated the protective effect of recombinant SCR(15-18) protein in middle cerebral artery occlusion (MCAO)-induced focal CI/R injury. METHODS: Recombinant SCR(15-18) protein was successfully expressed in Escherichia coli and refolded to its optimal bioactivity. Seventy-five Sprague-Dawley rats were randomly assigned into three groups: sham-operated group, CI/R group, and SCR(15-18)+CI/R group pretreated with 20 mg/kg SCR(15-18) protein. After 2 hours of MCAO and subsequent 24 hours of reperfusion, rats were evaluated for neurological deficits and cerebral infarction. Polymorphonuclear leukocyte accumulation, C3b deposition, and morphological changes in cerebral tissue were also estimated. RESULTS: SCR(15-18) pretreatment induced a 20% reduction of infarct size and an improvement of neurological function with 22·2% decrease of neurological deficit scores. Inhibition of cerebral neutrophils infiltration by SCR(15-18) was indicated from the reduction of myeloperoxidase activity in SCR(15-18)+CI/R rats. Decreased C3b deposition and improved morphological changes were also found in cerebral tissue of SCR(15-18)-treated rats. DISCUSSION: Our studies suggest a definitive moderately protective effect of SCR(15-18) against CI/R damage and provide preclinical experimental evidence supporting the possibility of using it as a small anti-complement therapeutic agent for CI/R injury therapy.