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Background: The endosperm serves as the primary source of nutrients for maize (Zea mays L.) kernel embryo development and germination. Positioned at the base of the endosperm, the transfer cells (TCs) of the basal endosperm transfer layer (BETL) generate cell wall ingrowths, which enhance the connectivity between the maternal plant and the developing kernels. These TCs play a crucial role in nutrient transport and defense against pathogens. The molecular mechanism underlying BETL development in maize remains unraveled. Results: This study demonstrated that the MYB-related transcription factor ZmMYBR29, exhibited specific expression in the basal cellularized endosperm, as evidenced by in situ hybridization analysis. Utilizing the CRISPR/Cas9 system, we successfully generated a loss-of-function homozygous zmmybr29 mutant, which presented with smaller kernel size. Observation of histological sections revealed abnormal development and disrupted morphology of the cell wall ingrowths in the BETL. The average grain filling rate decreased significantly by 26.7% in zmmybr29 mutant in comparison to the wild type, which impacted the dry matter accumulation within the kernels and ultimately led to a decrease in grain weight. Analysis of RNA-seq data revealed downregulated expression of genes associated with starch synthesis and carbohydrate metabolism in the mutant. Furthermore, transcriptomic profiling identified 23 genes that expressed specifically in BETL, and the majority of these genes exhibited altered expression patterns in zmmybr29 mutant. Conclusions: In summary, ZmMYBR29 encodes a MYB-related transcription factor that is expressed specifically in BETL, resulting in the downregulation of genes associated with kernel development. Furthermore, ZmMYBR29 influences kernels weight by affecting the grain filling rate, providing a new perspective for the complementation of the molecular regulatory network in maize endosperm development. [ABSTRACT FROM AUTHOR]

In many situations, the dual protection of image information transmission security and identity authentication is required. A quantum encryption and watermarking technique combining quantum Baker map (QBM) and quantum discrete cosine transform (QDCT) is presented to address this issue. Firstly, the watermark information used for identity authentication is scrambled by QBM, and the original image is decomposed by two-level quantum Haar wavelet transform (QHWT). To ensure the invisibility and robustness of the watermark, HL 1 obtained from LH is selected for further segmentation, and then QDCT is applied to HL 1 sub-block. The obtained matrix is used for watermark embedding. Special pre-processing is applied to the binary image before embedding the identity information, increasing embedding capacity while ensuring robustness and invisibility. Then the watermarked image is encrypted. In the encryption process, QBM is used for block scrambling. A quantum artificial image constructed with chaotic sequences manufactured from 3D Henon hyperchaotic system is utilized to diffuse pixel values. Quantum swap operation is used to achieve further bit-level scrambling, and the ciphertext image containing identity information is obtained. The encrypting security and the invisibility and robustness of watermarking are tested through numerical simulation. [ABSTRACT FROM AUTHOR]

Background: Iva xanthiifolia, native to North America, is now widely distributed in northeastern China and has become a vicious invasive plant. This article aims to probe the role of leaf extract in the invasion of I. xanthiifolia. Methods: We collected the rhizosphere soil of Amaranthus tricolor and Setaria viridis in the invasive zone, the noninvasive zone and the noninvasive zone treated with extract from I. xanthiifolia leaf, and obtained I. xanthiifolia rhizosphere soil in the invasive zone. All wild plants were identified by Xu Yongqing. I. xanthiifolia (collection number: RQSB04100), A. tricolor (collection number: 831,030) and S. viridis (collection number: CF-0002-034) are all included in Chinese Virtual Herbarium (https://www.cvh.ac.cn/index.php). The soil bacterial diversity was analyzed based on the Illumina HiSeq sequencing platform. Subsequently, taxonomic analysis and Faprotax functional prediction were performed. Results: The results showed that the leaf extract significantly reduced the diversity of indigenous plant rhizosphere bacteria. A. tricolor and S. viridis rhizobacterial phylum and genus abundances were significantly reduced under the influence of I. xanthiifolia or its leaf extract. The results of functional prediction showed that bacterial abundance changes induced by leaf extracts could potentially hinder nutrient cycling in native plants and increased bacterial abundance in the A. tricolor rhizosphere related to aromatic compound degradation. In addition, the greatest number of sensitive Operational Taxonomic Units (OTUs) appeared in the rhizosphere when S. viridis was in response to the invasion of I. xanthiifolia. It can be seen that A. tricolor and S. viridis have different mechanisms in response to the invasion of I. xanthiifolia. Conclusion: I. xanthiifolia leaves material has potential role in invasion by altering indigenous plant rhizosphere bacteria. [ABSTRACT FROM AUTHOR]

Background: Klebsiella pneumoniae capsular types K1, K2, K5, K20, K54, and K57 are prevalent hypervirulent types associated with community infections, and worrisomely, hypervirulent strains that acquired drug resistance have been found. In the search for alternative therapeutics, studies have been conducted on phages that infect K. pneumoniae K1, K2, K5, and K57-type strains and their phage-encoded depolymerases. However, phages targeting K. pneumoniae K20-type strains and capsule depolymerases capable of digesting K20-type capsules have rarely been reported. In this study, we characterized a phage that can infect K. pneumoniae K20-type strains, phage vB_KpnM‐20. Methods: A phage was isolated from sewage water in Taipei, Taiwan, its genome was analyzed, and its predicted capsule depolymerases were expressed and purified. The host specificity and capsule-digesting activity of the capsule depolymerases were determined. The therapeutic effect of the depolymerase targeting K. pneumoniae K20-type strains was analyzed in a mouse infection model. Results: The isolated Klebsiella phage, vB_KpnM‐20, infects K. pneumoniae K7, K20, and K27-type strains. Three capsule depolymerases, K7dep, K20dep, and K27dep, encoded by the phage were specific to K7, K20, and K27-type capsules, respectively. K20dep also recognized Escherichia coli K30-type capsule, which is highly similar to K. pneumoniae K20-type. The survival of K. pneumoniae K20-type-infected mice was increased following administration of K20dep. Conclusions: The potential of capsule depolymerase K20dep for the treatment of K. pneumoniae infections was revealed using an in vivo infection model. In addition, K7dep, K20dep, and K27dep capsule depolymerases could be used for K. pneumoniae capsular typing. [ABSTRACT FROM AUTHOR]

• First report of bla NDM-1 / bla NDM-4 and bla OXA-181 co-harbouring strains in Taiwan • Discovery of a novel bla NDM-1 + bla OXA-181 hybrid plasmid • An outbreak of bla NDM-4 + bla OXA-181 co-carriage with enhanced carbapenem resistance • The emergence of KL51 carbapenem-resistant Klebsiella pneumoniae The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) is related to the transmission of carbapenemase genes. Strains carrying more than one carbapenemase with a broadened spectrum of antibiotic resistance have been detected, which is concerning. Although bla KPC -encoding ST11-KL47/KL64 strains are dominant, other clones are emerging. This study investigated 137 CRKP from patients' blood samples in Taiwan. Polymerase chain reaction (PCR) was used to identify carbapenemase genes and capsular (KL) types. Most strains (56%, 77/137) possessed bla KPC alone; however, 12% (17/137) carried bla NDM + bla OXA-48-like and these strains showed high resistance to imipenem and meropenem. Strains carrying bla NDM + bla OXA-48-like predominantly belonged to KL51 (n =15), followed by KL64 (n =1) and KL47 (n =1). Whole-genome sequencing of one KL51 strain indicated that bla NDM-4 and bla OXA-181 are carried on two different plasmids. PCR was performed using specific primers located in these plasmids, and all bla NDM + bla OXA-48-like -encoding strains except the KL64 strain were considered to carry the two abovementioned plasmids. Genome analysis for the KL64 strain revealed that bla NDM-1 and bla OXA-181 are encoded in one plasmid. Notably, the KL51 bla OXA-181 plasmid shared high sequence similarity with the KL64 bla NDM-1 + bla OXA-181 plasmid, except the KL64 plasmid comprised a 15,040-bp insertion encoding bla NDM-1. The data revealed KL51 as a predominant KL type carrying bla NDM-4 + bla OXA-181 , and identified a novel plasmid carrying bla NDM-1 + bla OXA-181 , highlighting the spread of specific plasmids and clones of CRKP in Taiwan. [ABSTRACT FROM AUTHOR]

• An all-few-mode fiber spatiotemporal mode-locked figure-8 laser at 1.55 µm is constructed. • The switchable generation of femtosecond and picosecond spatiotemporal mode-locked pulses is achieved for the first time. • Both in the femtosecond and picosecond pulse regimes, the pulse-pattern-tunable operation can be achieved. • The switching principle between the femtosecond and picosecond pulses is theoretically analyzed. We report, for the first time to the best of our knowledge, the switchable generation of versatile femtosecond and picosecond spatiotemporal mode-locked (STML) pulses in an all-few-mode fiber figure-8 laser at 1.55 µm. Both in the femtosecond and picosecond pulse regimes, the laser has pulse-pattern-tunable function, namely, the pulse patterns can be tuned from single-pulse, multiple pulses to soliton molecules. Particularly, the femtosecond soliton molecules operate at the loosely bound states while the picosecond soliton molecules can operate both at the loosely and tightly bound states. The theoretical analyses are carried out to give the further insight in the switchable generation of the femtosecond and picosecond pulses. It is found that the filtering effect of the nonlinear amplifying loop mirror (NALM) plays the major role in the generation of the femtosecond pulses while the multimode interference filtering effect induced by the active few-mode fiber-passive few-mode fiber structure plays the role in the generation of the picosecond pulses. The obtained results contribute to further exploring the characteristics of the STML fiber laser and such a laser with tunable output of versatile femtosecond and picosecond pulses has potential applications in optical communications, laser processing and measuring. [ABSTRACT FROM AUTHOR]

Maize (Zea mays) smut is a common biotrophic fungal disease caused by Ustilago maydis and leads to low maize yield. Maize resistance to U. maydis is a quantitative trait. However, the molecular mechanism underlying the resistance of maize to U. maydis is poorly understood. Here, we reported that a maize mutant caused by a single gene mutation exhibited defects in both fungal resistance and plant development. maize mutant highly susceptible to U. maydis (mmsu) with a dwarf phenotype forms tumors in the ear. A map-based cloning and allelism test demonstrated that 1 gene encoding a putative arogenate dehydratase/prephenate dehydratase (ADT/PDT) is responsible for the phenotypes of the mmsu and was designated as ZmADT2. Combined transcriptomic and metabolomic analyses revealed that mmsu had substantial differences in multiple metabolic pathways in response to U. maydis infection compared with the wild type. Disruption of ZmADT2 caused damage to the chloroplast ultrastructure and function, metabolic flux redirection, and reduced the amounts of salicylic acid (SA) and lignin, leading to susceptibility to U. maydis and dwarf phenotype. These results suggested that ZmADT2 is required for maintaining metabolic flux, as well as resistance to U. maydis and plant development in maize. Meanwhile, our findings provided insights into the maize response mechanism to U. maydis infection. A gene encoding a putative arogenate dehydratase/prephenate dehydratase is essential for resistance to Ustilago maydis and plant development by maintaining metabolic flux in maize. [ABSTRACT FROM AUTHOR]

Object detection is one of the most challenging tasks in computer vision. With the advances in semiconductor devices and chip technology, hardware accelerators have been widely used. Field-programmable gate arrays (FPGAs) are a highly flexible hardware platform that allows customized reconfiguration of the integrated circuit, which has the potential to improve the efficiency of object detection accelerators. However, few reviews summarize FPGA-based object detection accelerators. Also, there is no general principle for realizing object detection according to FPGA characteristics. In this paper, the current hardware accelerators are introduced and compared. Then, the typical deep learning-based object detectors are summarized. Next, the questions of "Why choose FPGA," "The design goals of FPGA accelerators" and "The design methods for FPGA accelerators" are discussed in detail. Finally, the challenges of object detection algorithms, hardware, and co-design are presented. In addition, an online platform (https://github.com/vivian13maker/) is constructed to provide specific information on all advanced works. [ABSTRACT FROM AUTHOR]

• The spatiotemporal mode-locked (STML) fiber laser, emerging as a novel pulsed light source, provides a unique platform for exploring nonlinear phenomena. In STML fiber lasers, the involvement of various transverse modes in soliton pulsations introduces complex spatiotemporal characteristics distinct from single-mode soliton pulsations. • In this paper, we firstly observe the dual-periodic dual-pulse synchronous pulsation (DDSP) and dual-periodic dual-pulse asynchronous pulsation (DDAP) in an STML fiber laser, to the best of our knowledge, and explore the characteristics of the DDSP and DDAP. These dual-periodic pulsations are composed of a short-period pulsation (SPP) lasting for tens of round-trip times (RTs) and a long-period pulsation (LPP) lasting for hundreds of RTs. The DDSP is characterized by the temporal synchronous evolution of both LPPs and SPPs between the two pulses. The DDAP is defined by the temporal synchronous evolution of LPPs but the asynchronization of SPPs between the two pulses. Notably, the study reveals consistent pulsation periods across various transverse modes whether in the DDSP or DDAP, and the LPPs exhibit synchronization for different transverse modes, while the SPPs are asynchronous. These findings illustrate that transverse modes do not influence the periodic modulation between two pulses. The obtained results not only enhance our understanding of the spatiotemporal characteristics of multi-pulse multi-periodic pulsation, but also lay the foundation for exploring novel nonlinear phenomena in fiber lasers. We report the firstly experimental observation of dual-periodic dual-pulse synchronous pulsation (DDSP) and dual-periodic dual-pulse asynchronous pulsation (DDAP) in a spatiotemporal mode-locked fiber laser, composed of a short-period pulsation (SPP) lasting for tens of round-trip times (RTs) and a long-period pulsation (LPP) lasting for hundreds of RTs. It is found that the DDSP displays in-phase modulations between two pulses during the dual-periodic pulsation, while the DDAP demonstrates out-phase modulations in the SPP. Notably, the study reveals consistent pulsation periods across various transverse modes whether in the DDSP or DDAP, and the LPPs exhibit synchronization for different transverse modes, while the SPPs are asynchronous. Our findings illustrate that transverse modes do not influence the periodic modulation between two pulses. This exploration enhances the comprehension of multi-period pulsations in spatiotemporal mode-locked fiber lasers, and contributes to investigating high-dimensional nonlinear phenomena. [ABSTRACT FROM AUTHOR]

Sir, We read the paper by Morlando et al1 regarding reproductive outcome after cesarean scar pregnancy (CSP) with great interest. Obviously, uterine curettage and hysteroscopy in the surgical group did not resect and repair the cesarean scar. [Extracted from the article]

The mitochondrion is a semi-autonomous organelle that provides energy for cell activities through oxidative phosphorylation. In this study, we identified a defective kernel 66 (dek66)-mutant maize with defective kernels. We characterized a candidate gene, DEK66 , encoding a ribosomal assembly factor located in mitochondria and possessing GTPase activity (which belongs to the ribosome biogenesis GTPase A family). In the dek66 mutant, impairment of mitochondrial structure and function led to the accumulation of reactive oxygen species and promoted programmed cell death in endosperm cells. Furthermore, the transcript levels of most of the key genes associated with nutrient storage, mitochondrial respiratory chain complex, and mitochondrial ribosomes in the dek66 mutant were significantly altered. Collectively, the results suggest that DEK66 is essential for the development of maize kernels by affecting mitochondrial function. This study provides a reference for understanding the impact of a mitochondrial ribosomal assembly factor in maize kernel development. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii is the main cause of nosocomial infections, which are increasingly difficult to treat due to the emergence of carbapenem resistance. This study focused on major carbapenemase genes and explored the association between carbapenemase genes, sequence types (ST types), and capsular types (K types). A total of 98 carbapenem-resistant A. baumannii (CRAB) strains were collected from two hospitals, the Chang Gung Memorial Hospital-Lin Kou branch (LCGMH) in northern Taiwan and the CGMH-Kaohsiung branch (KCGMH) in southern Taiwan, from 2015 to 2017. Major carbapenemase genes of class A, B, and D β-lactamases were detected by polymerase chain reaction. All strains except 1 were positive for bla OXA-51-like , 76 strains (77.6%) carried bla OXA-23-like , and 25 strains (25.5%) carried bla OXA-24-like. The regional distribution showed that bla OXA-23-like was more common than bla OXA-24-like in both hospitals (85.3% and 60% in LCGMH and KCGMH, respectively); however, the percentage of bla OXA-24-like was much higher in KCGMH (46.7%) than in LCGMH (16.2%). Oxford multilocus sequence typing and global optimal eBURST analysis were conducted for 59 strains. The results of this study showed the association between bla OXA gene patterns, ST types, and K types and demonstrated that four major K types, KL2, KL10, KL22, and KL52, which were associated with specific ST types, were mainly clustered into clonal complexes CC208 and CC549 (a unique clonal complex found in Taiwan). These findings provide important information for monitoring the epidemiology and dissemination of this pathogen. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to explore the risk of hemorrhage associated with co-prescriptions for Ginkgo biloba extract (GBE) and antiplatelet or anticoagulant agents, and evaluate the trends of co-prescriptions. Methods: A retrospective population based study was performed by using claim data of the Taiwan National Health Insurance Research Database from 2000 to 2008. Prescriptions for GBE alone and in combination with antiplatelet/anticoagulant drugs were retrieved and the odds ratio for co-prescriptions after the first prescription of GBE was explored. Results: The total number of prescriptions for GBE alone or in combination with antiplatelet or anticoagulant agents increased gradually from 1547 (0.08%) and 3575 (0.19%) in 2000 to 4676 (0.23%) and 15,297 (0.79%) in 2008, respectively. GBE was mostly prescribed to patients aged 60 years or older. The adjusted odds ratio for co-prescriptions associated with the risk of hemorrhage is 1.5 (95% confidence interval, 0.5-5.0). The risk of hemorrhage was associated with patients aged ≥65 and male patients, who were prescribed GBE alone (adjusted odds ratio: 3.8 and 1.4; 95% confidence interval, 2.8-5.2 and 1.1-1.9). Conclusions: Although the combination of G. biloba extract with antiplatelet or anticoagulants showed insignificant correlation to the risk of hemorrhage, patients using ginkgo, particularly those with known bleeding risks and elderly, should take a particular attention to the possibility of increasing risk of bleeding. [ABSTRACT FROM AUTHOR]

Background: Pentatricopeptide repeat (PPR) proteins compose a large protein family whose members are involved in both RNA processing in organelles and plant growth. Previous reports have shown that E-subgroup PPR proteins are involved in RNA editing. However, the additional functions and roles of the E-subgroup PPR proteins are unknown. Results: In this study, we developed and identified a new maize kernel mutant with arrested embryo and endosperm development, i.e., defective kernel (dek) 55 (dek55). Genetic and molecular evidence suggested that the defective kernels resulted from a mononucleotide alteration (C to T) at + 449 bp within the open reading frame (ORF) of Zm00001d014471 (hereafter referred to as DEK55). DEK55 encodes an E-subgroup PPR protein within the mitochondria. Molecular analyses showed that the editing percentage of 24 RNA editing sites decreased and that of seven RNA editing sites increased in dek55 kernels, the sites of which were distributed across 14 mitochondrial gene transcripts. Moreover, the splicing efficiency of nad1 introns 1 and 4 and nad4 intron 1 significantly decreased in dek55 compared with the wild type (WT). These results indicate that DEK55 plays a crucial role in RNA editing at multiple sites as well as in the splicing of nad1 and nad4 introns. Mutation in the DEK55 gene led to the dysfunction of mitochondrial complex I. Moreover, yeast two-hybrid assays showed that DEK55 interacts with two multiple organellar RNA-editing factors (MORFs), i.e., ZmMORF1 (Zm00001d049043) and ZmMORF8 (Zm00001d048291). Conclusions: Our results demonstrated that a mutation in the DEK55 gene affects the mitochondrial function essential for maize kernel development. Our results also provide novel insight into the molecular functions of E-subgroup PPR proteins involved in plant organellar RNA processing. [ABSTRACT FROM AUTHOR]

Brassinosteroids (BRs) are a class of plant-specific steroid hormones and play an essential role in plant growth and development. The DWARF4 (DWF4) gene encodes a C-22 hydroxylase, which is a rate-limiting enzyme in BR biosynthesis pathway. Here, the DWF4 (ZmDWF4) in maize (Zea mays L.), the ortholog of Arabidopsis DWF4 (CYP90B1), was transformed into elite inbred Q319 and driven maize ubiquitin promoter. In transgenic lines, the level of the endogenous BR precursor canosterone (CS) was significantly enhanced. ZmDWF4 overexpression greatly improved grain yield per ear from 28.3 to 33.5% in transgenic lines compared with that in non-transgenic Q319 plants. Moreover, ZmDWF4 overexpression significantly enhanced heterosis of combinations by increasing both seed number and seed weight up to 20.4% in transgenic hybrids. Further analysis revealed that ZmDWF4 overexpression significantly improved several agronomic traits and leaf photosynthetic ability in transgenic lines. Finally, RNA-seq analysis suggested that overexpressing ZmDWF4 improved cell growth, cell division, and nutrient assimilation in transgenic kernels. Altogether, our results demonstrate that manipulating BR level by overexpressing ZmDWF4 effectively improves maize agronomic traits, and thus, provides a useful biotechnological strategy for the genetic improvement and further commercially favorable maize breeding. [ABSTRACT FROM AUTHOR]

Mitochondria, the main energy transducers in plant cells, require the proper assembly of respiratory chain complexes I–V for their function. The NADH dehydrogenase 4 (nad4) gene encodes mitochondrial respiratory chain complex I subunit IV, but the mechanism underlying nad4 transcript splicing is unclear. Here, we report that the P‐type pentatricopeptide repeat (PPR) protein DEFECTIVE KERNEL 43 (DEK43) is responsible for cis‐splicing of the nad4 transcript in maize. We demonstrate that DEK43 localizes to both the nucleus and mitochondria. The mutation of Dek43 resulted in embryo‐lethal and light‐colored defective kernels. Among the 22 mitochondrial group II introns, the splicing efficiency of nad4 introns 1 and 3 was reduced by up to 50% compared to the wild type. The levels of complex I and supercomplex I+III2 were also reduced in dek43. Furthermore, in‐gel NADH dehydrogenase assays indicated that the activities of these complexes were significantly reduced in dek43. Further, the mitochondrial ultrastructure was altered in the mutant. Together, our findings indicate that DEK43, a dual‐localized PPR protein, plays an important role in maintaining mitochondrial function and maize kernel development. [ABSTRACT FROM AUTHOR]

[Display omitted] • We evaluated the genes involved in catechins biosynthesis in C. sinensis. • In total, 47,717 unigenes were obtained from two cultivars of C. sinensis. • KEGG database analysis identified 13 key enzymes involved in catechins biosynthesis. • The structures of LAR and ANR were spatially modeled. • Our findings established a basis for further studies of catechins biosynthesis. Camellia sinensis (L.) O. Kuntze is used to produce tea, a beverage consumed worldwide. Catechins are major medically active components of C. sinensis and can be used clinically to treat hyperglycaemia, hypertension, and cancer. In this study, we aimed to identify the genes involved in catechins biosynthesis. To this end, we analysed transcriptome data from two different cultivars of C. sinensis using DNBSEQ technology. In total, 47,717 unigenes were obtained from two cultivars of C. sinensis , of which 9429 were predicted as new unigenes. In our analyses of the Kyoto Encyclopedia of Genes and Genomes database, 212 unigenes encoding 13 key enzymes involved in catechins biosynthesis were identified; the structures of leucoanthocyanidin reductase and anthocyanidin reductase were spatially modelled. Some of these key enzymes were verified by real-time quantitative polymerase chain reaction, and multiple genes encoding plant resistance proteins or transcription factors were identified and analysed. Furthermore, two microRNAs involved in the regulation of catechins biosynthesis were explored. Differentially expressed genes involved in the flavonoid biosynthesis pathway were identified from pairwise comparisons of genes from different cultivars of tea plants. Overall, our findings expanded the number of publicly available transcript datasets for this valuable plant species and identified candidate genes related to the biosynthesis of C. sinensis catechins, thereby establishing a foundation for further in-depth studies of catechins biosynthesis in varieties or cultivars of C. sinensis. [ABSTRACT FROM AUTHOR]

• ZmNPF7.9 is specifically expressed in the basal endosperm transfer layer cells of maize endosperm. • ZmNPF7.9 is a low-affinity, pH-dependent bidirectional nitrate transporter. • ZmNPF7.9 plays a specific role in seed development and grain weight by regulating nitrate transport and nutrition metabolism. Nitrogen is an essential macronutrient for plants and regulates many aspects of plant growth and development. Nitrate is one of the major forms of nitrogen in plants. However, the role of nitrate uptake and allocation in seed development is not fully understood. Here, we identified the maize (Zea mays) small-kernel mutant zmnpf7.9 and characterized the candidate gene, ZmNPF7.9 , which was the same gene as nitrate transport 1.5 (NRT1.5) in maize. This gene is specifically expressed in the basal endosperm transfer layer cells of maize endosperm. Dysfunction of ZmNPF7.9 resulted in delayed endosperm development, abnormal starch deposition and decreased hundred-grain weight. Functional analysis of cRNA-injected Xenopus oocytes showed that ZmNPF7.9 is a low-affinity, pH-dependent bidirectional nitrate transporter. Moreover, the amount of nitrate in mature seeds of the zmnpf7.9 mutant was reduced. These suggest that ZmNPF7.9 is involved in delivering nitrate from maternal tissues to the developing endosperm. Moreover, most of the key genes associated with glycolysis/gluconeogenesis, carbon fixation, carbon metabolism and biosynthesis of amino acids pathways in the zmnpf7.9 mutant were significantly down-regulated. Thus, our results demonstrate that ZmNPF7.9 plays a specific role in seed development and grain weight by regulating nutrition transport and metabolism, which might provide useful information for maize genetic improvement. [ABSTRACT FROM AUTHOR]

The time interval distribution law of mergers and acquisitions (M&As) is a key breakthrough in understanding the M&As dynamics in financial markets. Using the stock composite index (SCI) data of the Shanghai Stock Exchange (SSE) and the merger and acquisition (M&A) activities data in China's stock market (1996–2014) as samples, we analyze the heavy-tailed distribution characteristics of the M&As time intervals and test the positive correlation between the SCI volatility and M&A activity fluctuations. We then establish an M&A dynamics model based on mixed investment motives and verify the correctness of the model through simulations. The result shows that the different volatility signals of SCI will trigger different investment motivations on short-term speculative and long-term value M&A, which are the direct reason for the heavy-tailed distribution phenomenon of M&A time intervals in financial markets. • Heavy-tailed distribution characteristics of M&As time intervals are analyzed. • The positive correlation between SCI volatility and M&A activity fluctuations are tested. • Establish an M&A dynamics model based on hybrid investment motivations. • Simulation experiment verifies that hybrid M&A motivations lead to heavy tail phenomenon. [ABSTRACT FROM AUTHOR]