Improve the Prediction Accuracy of Apple Tree Canopy Nitrogen Content through Multiple Scattering Correction Using Spectroscopy

Method: Use Multiple Scattering Correction to eliminate the interference of scattering on spectrum in the process of field measurement so as to improve the accuracy of prediction model of tree canopy nitrogen content. Apple trees in Qixia of Yantai City were taken as the test material. The spectral reflectivity of apple tree canopy went through the First Derivative (FD) and Multiple Scattering Correction (MSC) plus first derivative, respectively. The correlation coefficients were calculated between spectral reflectivity and nitrogen content. The Support Vector Machine (SVM) method was used to establish the prediction model. The result indicates that the MSC pre-processing can improve the correlation between spectral reflectivity and nitrogen content. The SVM model with MSC + FD pre-processing was a good way to predict the nitrogen content. The calibration R2 of the model was 0.746;the validation R2 was 0.720;and its RMSE was 0.452 g·kgˉ1. MSC can commendably eliminate scattering error to improve the prediction accuracy of prediction model.

Oxygen Vacancy-induced Electron Density Tuning of Fe_(3)O_(4) for Enhanced Oxygen Evolution Catalysis

Despite the tremendous efforts devoted to enhancing the activity of oxygen evolution reaction(OER)catalysts,there is still a huge challenge to deeply understand the electronic structure characteristics of transition metal oxide to guide the design of more active catalysts.Herein,Fe_(3)O_(4)with oxygen vacancies(Fe_(3)O_(4)-Vac)was synthesized via Ar ion irradiation method and its OER activity was greatly improved by properly modulating the electron density around Fe atoms.The electron density of Fe_(3)O_(4)-Vac around Fe atoms increased compared to that of Fe_(3)O_(4)according to the characterization of synchrotron-based X-ray absorption near-edge structure(XANES),extended X-ray absorption fine structure(EXAFS)spectra,and density functional theory(DFT)calculation.Moreover,the DFT results indicate the enhancement of the desorption of HOO^(*)groups which significantly reduced the OER reaction barrier.Fe_(3)O_(4)-Vac catalyst shows an overpotential of 353 m V,lower than that of Fe OOH(853 m V)and Fe_(3)O_(4)(415 m V)at 10 m A cm^(-2),and a low Tafel slope of 50 m V dec^(-1)in 1 M KOH,which was even better than commercial RuO_(2)at high potential.This modulation approach provides us with valuable insights for exploring efficient and robust water-splitting electrocatalysts.

Estimating Canopy Nitrogen Contents of an Apple Tree Using Hyperspectral Remote Sensing

Estimating an apple tree canopy nitrogen contents using hyperspectral techniques is important in theoretical and realistic significance for fertilization and management.Taking 80 Fuji apple trees at the early fruiting stage as the research objects,the hyperspectral characteristics of the apple canopy were analyzed systematically.The apple canopy hyperspectral and the canopy nitrogen contents were measured respectively.The canopy hyperspectral characteristics under different nitrogen contents were analyzed and selected the sensitive wave bands.The apple canopy nitrogen content monitoring models were established by using multiple regression method,robust regression and BP neural network method.The results showed that the canopy hyperspectral reflectance had obvious differences under different nitrogen contents.The sensitive bands concentrate on 724~1136 nm.Estimation models based on hyperspectral indices are not ideal.Models based on robust regression(M regression)and BP neural network are better than multiple statistical model,and the accuracy of the BP neural network monitoring model is the best.The results of the study provide a certain reference for estimating apple nutrition using hyperspectral technology.

Activities of some defense proteins associated with age or plant family in larch needles of Larix olgensis and L. kaempferi× L. gmelinii

Defence proteins are a kind of chemical defence compounds. They play a key role in plant restraining biotic and abiotic harm. To illuminate activities of some defense proteins associated with age or plant family of larch, the larch needles were collected from two different families of Korean larch, Larix olgensis and a hybrid larch, L. kaempferi × L. gmelinii, respectively, and then the activities of defence proteins in those were tested using a UV spectrophotometry. The results showed that the activities of protective enzymes at thel6-/17- and 19-year-age groups were higher than those at the other age groups in the both larch species. While the activities of polyphenol oxidase （PPO） at the 16-/17-year-age group and phenylalanine ammonia-lyase （PAL） and protease inhibitors at the 19-year-age group were the highest among all age groups. Then, compared with L. olgensis, the hybrid larch had significant effects on the activities of protective enzymes. The effects of plant family on the activities of PAL and chymotrypsin inhibitor were significantly different, and then those on the activities of PPO were not significantly different. The effects of the two families in L. olgensis on the activities of trypsin inhibitor （TI） were significantly different, while those in the hybrid larch on the activities of TI were contrary. To conclusions showed that the different age and plant family significantly affected the activities of defence proteins in the needles of two larch species, and then enhanced the larch resistance to pests. These could play a key function in forestry tree genetic improvement and management in future.

Transcriptome analysis of Clematis lanuginosa: Novel features of the molecular events occurring under heat-shock stress

The weak heat tolerance of Clematis ornamental varieties negatively affects their ornamental qualities in the summer.To elucidate heat resistance mechanisms,Clematis lanuginosa,which is an important original parent of the Clematis large-flowered group of ornamental varieties,was selected for use in this study.Here,six libraries,including three biological replicates each of control and heat-shock stress samples,were determined using RNA-sequencing technology.In total,62,050 unigenes were obtained,and 6,439 unigenes exceeded 1 kb in length.A total of 42,377 unigenes were annotated using six databases.Between the two treatments,2,165 differentially expressed genes were identified,with 1,565 being up-regulated and 600 down-regulated.In addition,51 heat-shock protein-encoding genes were identified,among which the small heat-shock proteins accounted for 68.63%.In total,two heat-shock factors and 12 ribosomal proteins were significantly up-regulated under heatstress conditions.The differential expressions of ethylene-responsive transcription factor,chalcone synthase,cysteine-rich receptor-like kinase and aspartic protease unigenes in guard cells were induced by heat-shock.The data obtained will assist the elucidation of the molecular events underlying heat-stress responses in C.lanuginosa.

Inhibiting oxygen vacancies and twisting NbO_(6) octahedron in erbium modified KNN-based multifunctional ceramics

It is a challenge to obtain highly tunable multifunctional performances in one ferroelectric system by a simple approach to meet the miniaturization,integration,and functionalization requirements of advanced electronic components.Herein,rare earth erbium(Er)modulated 0.9K_(0.5)Na_(0.5)NbO_(3)-0.1Sr(1-x)Er_(x)Ti_((1-x/4))O_(3),(0.9KNN-0.1ST:xEr)transparent-photoluminescent-ferroelectric energy storage multifunctional ceramics are prepared to solve this problem.The effect of lattice distortion and oxygen vacancies by Er doping on the optical and electrical properties is systematically investigated.The Er^(3+)ions can introduce a large distortion of the NbO_(6) octahedron by replacing the A-site in KNN-based ceramics.Thanks to the higher c/a ratio and lower oxygen vacancy content are simultaneously obtained in 0.9KNN-0.1ST:0.1Er ceramics.The effective energy storage density(Wrec)of 0.86 J/cm^(3),excellent near-infrared transmittance of 51.7%(1100 nm)and strong green upconversion photoluminescence are achieved in this multifunctional ceramic.This study provides a solid basis for rare earth ions doped ferroelectric ceramics with tunable multifunctional properties and has significant potential for applications in optoelectronic devices.

Positional cloning and characterization reveal the role of a miRNA precursor gene ZmLRT in the regulation of lateral root number and drought tolerance in maize

Lateral roots play essential roles in drought tolerance in maize(Zea mays L.). However, the genetic basis for the variation in the number of lateral roots in maize remains elusive. Here, we identified a major quantitative trait locus(QTL),q LRT5-1, controlling lateral root number using a recombinant inbred population from a cross between the maize lines Zong3(with many lateral roots) and 87-1(with few lateral roots).Fine-mapping and functional analysis determined that the candidate gene for qLRT5-1,ZmLRT, expresses the primary transcript for the microRNA miR166a. ZmLRT was highly expressed in root tips and lateral root primordia,and knockout and overexpression of ZmLRT increased and decreased lateral root number,respectively. Compared with 87-1, the ZmLRT gene model of Zong3 lacked the second and third exons and contained a 14 bp deletion at the junction between the first exon and intron,which altered the splicing site. In addition,ZmLRT expression was significantly lower in Zong3 than in 87-1, which might be attributed to the insertions of a transposon and over large DNA fragments in the Zong3 ZmLRT promoter region. These mutations decreased the abundance of mature miR166a in Zong3, resulting in increased lateral roots at the seedling stage.Furthermore, miR166a post-transcriptionally repressed five development-related class-Ⅲ homeodomain-leucine zipper genes. Moreover,knockout of ZmLRT enhanced drought tolerance of maize seedlings. Our study furthers our understanding of the genetic basis of lateral root number variation in maize and highlights ZmLRT as a target for improving drought tolerance in maize.

Paternally imprinted LATE-FLOWERING2 transcription factor contributes to paternal-excess interploidy hybridization barriers in wheat∞

Interploidy hybridization between hexaploid and tetraploid genotypes occurred repeatedly during genomic introgression events throughout wheat evolution,and is commonly employed in wheat breeding programs.Hexaploid wheat usually serves as maternal parent because the reciprocal cross generates progeny with severe defects and poor seed germination,but the underlying mechanism is poorly understood.Here,we performed detailed analysis of phenotypic variation in endosperm between two interploidy reciprocal crosses arising from tetraploid(Triticum durum,AABB)and hexaploid wheat(Triticum aestivum,AABBDD).In the paternal‐versus the maternal‐excess cross,the timing of endosperm cellularization was delayed and starch granule accumulation in the endosperm was repressed,causing reduced germination percentage.The expression profiles of genes involved in nutrient metabolism differed strongly between these endosperm types.Furthermore,expression patterns of parental alleles were dramatically disturbed in interploidy versus intraploidy crosses,leading to increased number of imprinted genes.The endosperm‐specific TaLFL2 showed a paternally imprinted expression pattern in interploidy crosses partially due to allele‐specific DNA methylation.Paternal TaLFL2 binds to and represses a nutrient accumulation regulator TaNAC019,leading to reduced storage protein and starch accumulation during endosperm development in paternal‐excess cross,as confirmed by interploidy crosses between tetraploid wild‐type and clustered regularly interspaced palindromic repeats(CRISPR)–CRISPR‐associated protein 9 generated hexaploid mutants.These findings reveal a contribution of genomic imprinting to paternal‐excess interploidy hybridization barriers during wheat evolution history and explains why experienced breeders preferentially exploit maternal‐excess interploidy crosses in wheat breeding programs.