Foliar applied 24-epibrassinolide alleviates salt stress in rice (Oryza sativa L.) by suppression of ABA levels and upregulation of secondary metabolites

Salt stress hinders plant growth and disrupts many physio-biochemical and molecular processes. The present study evaluated the potential role of foliar applied 24-epibrassinolide (EBR) for mitigating the adverse effects of salinity in rice plants. Our findings showed that salt stress reduced several growth and physiological parameters, and substantially increased oxidative stress in rice seedlings. The foliar application of EBR replenished the negative effects of salt stress by improving plant growth and physiological attributes in rice plants. Moreover, application of EBR substantially reduced oxidative injuries by enhancing antioxidant enzymes and phenolic compounds in rice plants during salt stress. Interestingly, the endogenous ABA levels were declined in stressed plants by EBR treatment, also validated by expression analysis of ABA-related genes. In addition, application of EBR upregulated carotenoids and flavonoids pathway genes, thus showing its function to activate secondary metabolism in rice plants during salt stress. The principal component analysis (PCA) indicated that, under salt stress, the response of EBR-treated rice plants was strongly correlated with the accumulation of phenolic compounds and flavonoids. Collectively, this study presents useful insight into the distinct role of EBR by activating underlying enzymatic and non-enzymatic defense mechanisms to mitigate salinity in rice plants.National Natural Science Foundation of China | Ref. 31901558China Postdoctoral Science Foundation | Ref. 2019M65017

A Novel Vision-Based Pose Measurement Method Considering the Refraction of Light

Nowadays, due to the advantages of non-contact and high-speed, vision-based pose measurements have been widely used for aircraft performance testing in a wind tunnel. However, usually glass ports are used to protect cameras against the high-speed airflow influence, which will lead to a big measurement error. In this paper, to further improve the vision-based pose measurement accuracy, an imaging model which considers the refraction light of the observation window was proposed. In this method, a nonlinear camera calibration model considering the refraction brought by the wind tunnel observation window, was established first. What’s more, a new method for the linear calibration of the normal vector of the glass observation window was presented. Then, combining with the proposed matching method based on coplanarity constraint, the six pose parameters of the falling target could be calculated. Finally, the experimental setup was established to conduct the pose measurement study in the laboratory, and the results satisfied the application requirements. Besides, experiments for verifying the vision measurement accuracy were also performed, and the results indicated that the displacement and angle measurement accuracy approximately increased by 57% and 33.6%, respectively, which showed the high accuracy of the proposed method

A Mitochondrial Transcription Termination Factor, ZmSmk3, Is Required for nad1 Intron4 and nad4 Intron1 Splicing and Kernel Development in Maize

The expression systems of the mitochondrial genes are derived from their bacterial ancestors, but have evolved many new features in their eukaryotic hosts. Mitochondrial RNA splicing is a complex process regulated by families of nucleus-encoded RNA-binding proteins, few of which have been characterized in maize (Zea mays L.). Here, we identified the Zea mays small kernel 3 (Zmsmk3) candidate gene, which encodes a mitochondrial transcription termination factor (mTERF) containing two mTERF motifs, which is conserved in monocotyledon; and the target introns were also quite conserved during evolution between monocotyledons and dicotyledons. The mutations of Zmsmk3 led to arrested embryo and endosperm development, resulting in small kernels. A transcriptome of 12 days after pollination endosperm analysis revealed that the starch biosynthetic pathway and the zein gene family were down-regulated in the Zmsmk3 mutant kernels. ZmSMK3 is localized in mitochondria. The reduced expression of ZmSmk3 in the mutant resulted in the splicing deficiency of mitochondrial nad4 intron1 and nad1 intron4, causing a reduction in complex I assembly and activity, impairing mitochondria structure and activating the alternative respiratory pathway. So, the results suggest that ZmSMK3 is required for the splicing of nad4 intron 1 and nad1 intron 4, complex I assembly and kernel development in maize

Combined DFT and XPS Investigation of Cysteine Adsorption on the Pyrite (1 0 0) Surface

The adsorption of cysteine on the pyrite (1 0 0) surface was evaluated by using first-principles-based density functional theory (DFT) and X-ray photoelectron spectroscopy (XPS) measurements. The frontier orbitals analyses indicate that the interaction of cysteine and pyrite mainly occurs between HOMO of cysteine and LUMO of pyrite. The adsorption energy calculation shows that the configuration of the -OH of -COOH adsorbed on the Fe site is the thermodynamically preferred adsorption configuration, and it is the strongest ionic bond according to the Mulliken bond populations. As for Fe site mode, the electrons are found transferred from cysteine to Fe of pyrite (1 0 0) surface, while there is little or no electron transfer for S site mode. Projected density of states (PDOS) is analyzed further in order to clarify the interaction mechanism between cysteine and the pyrite (1 0 0) surface. After that, the presence of cysteine adsorption on the pyrite (1 0 0) surface is indicated by the qualitative results of the XPS spectra. This study provides an alternative way to enhance the knowledge of microbe–mineral interactions and find a route to improve the rate of bioleaching

Generation of Replication-Competent Recombinant Influenza A Viruses Carrying a Reporter Gene Harbored in the Neuraminidase Segment▿

Replication-competent influenza viruses carrying reporter genes are of great use for basic research, screening of antiviral drugs, and neutralizing of antibodies. In this study, two recombinant influenza A viruses with a neuraminidase (NA) segment harboring enhanced green fluorescent protein (EGFP) in the background of A/PR/8/34 (PR8) were generated. The viral RNA (vRNA)-specific packaging signals for NA were largely retained for efficient packaging. An “autocleave” 2A peptide sequence, which was inserted at the N terminus or the COOH terminus of NA to link with EGFP, enabled NA and EGFP to be expressed monocistronically. Further analysis demonstrated that both viruses, named rPR8-EGFP+NA and rPR8-NA+EGPF, although with some characteristic differences in growth and EGFP expression, could replicate in noncomplementary cells and propagate to large quantities while maintaining genome stability after multiple passages in embryonated eggs. These replication-competent influenza viruses carrying reporter genes are a great addition to the tool set for developing antiviral therapeutics and vaccines and for in vivo studies of viral dissemination and pathogenicity

Genome-Wide Identification and Analysis of the WNK Kinase Gene Family in Upland Cotton

With-No-Lysine (WNK) kinases are a subfamily of serine/threonine protein kinases. WNKs are involved in plant abiotic stress response and circadian rhythms. However, members of the WNK subfamily and their responses to abiotic and biotic stresses in Gossypium hirsutum have not been reported. In this study, 26 GhWNKs were identified in G. hirsutum. The gene structure, conserved motifs, and upstream open reading frames (uORFs) of GhWNKs were identified. Moreover, GhWNKs regulation is predicted to be regulated by cis-acting elements, such as ABA responsive element (ABRE), MBS, and MYC. Furthermore, transcription factors including MIKC_MADS, C2H2, TALE, bZIP, Dof, MYB, bHLH, and HD-ZIP are projected to play a regulatory role in GhWNKs. The expression patterns of GhWNKs under normal conditions and biotic and abiotic stresses were evaluated, and their expression was found to vary. The expression patterns of several GhWNKs were induced by infiltration with Verticillium dahliae, suggesting that several GhWNKs may play important roles in the response of cotton to V. dahliae. Interestingly, a homoeologous expression bias within the GhWNKs was uncovered in upland cotton. Homoeologous expression bias within GhWNKs provides a framework to assist researchers and breeders in developing strategies to improve cotton traits by manipulating individual or multiple homeologs

Optimal procurement strategy for off-site prefabricated components considering construction schedule and cost

The implementation of prefabricated buildings is hindered by the high construction cost. To address this problem, it is important to determine the efficient leverage of the supply capacity of local factories to assure just-in-time delivery to the construction site, as well as to accurately model the various types of cost to achieve a near-optimal procurement strategy. This paper describes a mathematical model to optimize the procurement of prefabricated components. A genetic algorithm is applied to efficiently obtain the minimum total cost that includes installation cost, business management cost and loan interest cost. Finally, a number of numerical experiments are conducted, showing that the procurement strategy generated from the proposed mathematical model is better than the traditional procurement strategy in terms of construction duration reductions and total cost savings. The component procurement method proposed in this paper improves the scientific management ability of decision-makers, and provides purchasing framework for other prefabricated structural forms

Dissection of Hyperspectral Reflectance to Estimate Photosynthetic Characteristics in Upland Cotton (Gossypium hirsutum L.) under Different Nitrogen Fertilizer Application Based on Machine Learning Algorithms

Hyperspectral technology has enabled rapid and efficient nitrogen monitoring in crops. However, most approaches involve direct monitoring of nitrogen content or physiological and biochemical indicators directly related to nitrogen, which cannot reflect the overall plant nutritional status. Two important photosynthetic traits, the fraction of absorbed photosynthetically active radiation (FAPAR) and the net photosynthetic rate (Pn), were previously shown to respond positively to nitrogen changes. Here, Pn and FAPAR were used for correlation analysis with hyperspectral data to establish a relationship between nitrogen status and hyperspectral characteristics through photosynthetic traits. Using principal component and band autocorrelation analyses of the original spectral reflectance, two band positions (350–450 and 600–750 nm) sensitive to nitrogen changes were obtained. The performances of four machine learning algorithm models based on six forms of hyperspectral transformations showed that the light gradient boosting machine (LightGBM) model based on the hyperspectral first derivative could better invert the Pn of function–leaves in cotton, and the random forest (RF) model based on hyperspectral first derivative could better invert the FAPAR of the cotton canopy. These results provide advanced metrics for non–destructive tracking of cotton nitrogen status, which can be used to diagnose nitrogen nutrition and cotton growth status in large farms