Polyamines (PAs) in plant play a critical role in growth and development and in response to environmental stress. Polyamine oxidase (PAO) is a flavin adenine dinucleotide dependent enzyme that plays ...a major role in PA catabolism. For the first time,
PAO
genes in tea plant were screened for the whole genome-wide and seven
CsPAO
genes were identified, which were named
CsPAO1-7
. Phylogenetic tree analysis revealed seven CsPAO protein sequences classed into three groups, including clade I, III, and IV. Compared with other plants, the tea plant lacked clade II members. Genetic structure and tissue specific expression analysis showed that there were significant differences among members of the
CsPAO
gene family. Among members of the
CsPAOs
family,
CsPAO4
and
CsPAO5
contain more introns and are highly expressed in various organizations.
CsPAO1
,
CsPAO4
, and
CsPAO5
genes were cloned and expressed heterologously to verify theirs function. Heat map showed high response of
CsPAO5
to drought stress, while
CsPAO
1 and
CsPAO
2 were sensitive to changes in nitrogen nutrition. Furthermore, exogenous abscisic acid (ABA) treatment indicated that the expression of most
CsPAO
genes in roots and leaves was significantly induced. In the root, Spm content increased significantly, while Put and Spd content decreased, suggesting that ABA has great influence on the biosynthesis of PAs. Anaerobic treatment of picked tea leaves showed that the decomposition of PAs was promoted to a certain extent. The above data help to clarify the role of
CsPAO
in response abiotic and nitrogen nutritional stresses in tea plants, and provide a reference perspective for the potential influence of PAs on the tea processing quality.
Amino acids are constituents of proteins, precursors of many secondary metabolites and nitrogen carriers in plants. Transport across intracellular membranes and translocation of amino acids within ...the plant is mediated by membrane amino acid transporters. However, the amino acid transport in tea plant is rarely reported. In this study, six cationic amino acid transporter (CAT) family genes were cloned. Phylogenetic analysis categorized these CsCATs into four subgroups. These CsCATs all contain the 12–14 transmembrane domains and the conserved CAT motifs. Their expression was tissue-specific, with higher expression levels in root and stem and correlated to the abundances of key free amino acids such as Theanine. Some CsCATs expression responded to some abiotic stress conditions and to the exogenous application of theanine (Thea), glutamine or ethylamine hydrochloride, an ethylamine precursor for Thea biosynthesis. Our results indicated that the
CsCATs
expression is regulated by amino acid contents and is sensitive to abiotic stresses. These findings shed light on the mechanism of amino acid transport in tea plants.
We introduce the path length probability density function（PPDF） method, which is based on an equivalence theorem and parameterizes the aerosol scattering effect by adding four factors to the ...atmospheric transmittance model. Using simulated observations in the O2-A band, we examined the utility of the PPDF-based method to account for the aerosol scattering effect. First, observations were simulated using a forward model under different aerosol conditions; PPDF factors were then retrieved using an optimal estimation method; PPDF factors were used to reconstruct the observations; and finally, simulated true observations and reconstructions were compared. Analysis of the difference between the true observations and reconstructions confirmed the utility of the PPDF-based method. Additionally, the O2 band was demonstrated to be an efficient observing band for assisting the remote sensing of atmospheric trace gases in the near-infrared band.
We propose an algorithm that combines a pre-processing step applied to the a priori state vector prior to retrievals, with the modified damped Newton method （MDNM）, to improve convergence. The ...initial constraint vector pre-processing step updates the initial state vector prior to the retrievals if the algorithm detects that the initial state vector is far from the true state vector in extreme cases where there are CO2 emissions. The MDNM uses the Levenberg-Marquardt parameter ~,, which ensures a positive Hessian matrix, and a scale factor a, which adjusts the step size to optimize the stability of the convergence. While the algorithm iteratively searches for an optimized solution using observed spectral radiances, MDNM adjusts parameters ）, and a to achieve stable convergence. We present simulated retrieval samples to evaluate the performance of our algorithm and comparing it to existing methods. The standard deviation of our retrievals adding random noise was less than 3.8 ppmv. After pre-processing the initial estimate when it was far from the true value, the CO2 retrieval errors in the boundary layers were within 1.2 ppmv. We tested the MDNM algorithm＇s performance using GOSAT Llb data with cloud screening. Our preliminary validations comparing the results to TCCON FTS measurements showed that the average bias was less than 1.8 ppm and the correlation coefficient was approximately 0.88, which was larger than for the GOSAT L2 product.
We propose a new method to estimate surface-level particulate matter （PM） concentrations by using satellite-retrieved Aerosol Optical Thickness （AOT）. This method considers the distribution and ...variation of Planetary Boundary Layer （PBL） height and relative humidity （RH） at the regional scale. The method estimates surface-level particulate matter concentrations using the data simulated by an atmospheric boundary layer model RAMS and satellite-retrieved AOT. By incorporation MODIS AOT, PBL height and RH simulated by RAMS, this method is applied to estimate the surface-level PM2.5 concentrations in North China region. The result is evaluated by using 16 ground-based observations deployed in the research region, and the result shows a good agreement between estimated PM2.5 concentrations and observations, and the coefficient of determination R2 is 0.61 between the estimated PM2.5 concentrations and the observations. In addition, surface-level PM2.5 concentrations are also estimated by using MODIS AOT, ground-based LIDAR observations and RH measurements. A comparison between the two es- timated PM2.5 concentrations shows that the new method proposed in this paper is better than the traditional method. The coef- ficient of determination R2 is improved from 0.32 to 0.62.
Light is an essential factor for pigment formation and fruit body development in
Cordyceps militaris
, a well-known edible and medicinal fungus.
Cmwc-1
, a homolog of the blue-light receptor gene
...white collar-1
(
wc-1
) in
Neurospora crassa
, was cloned from the
C. militaris
genome in our previous study. Here,
Cmwc-1
gene inactivation results in thicker aerial hyphae, disordered fruit body development, a significant reduction in conidial formation, and carotenoid and cordycepin production. These characteristics were restored when the Δ
Cmwc
-
1
strains were hybridized with wild-type strains of the opposite mating type. A genome-wide expression analysis revealed that there were 1042 light-responsive genes in the wild-type strain and only 458 in the Δ
Cmwc
-
1
strain. Among five putative photoreceptors identified, Vivid, cryptochrome-1, and cyclobutane pyrimidine dimer photolyase are strongly induced by light in a
Cmwc-1
-dependent manner, while phytochrome and cryptochrome-2 were not induced. The transcription factors involved in the fungal light reaction were mainly of the Zn
2
Cys
6
type. CmWC-1 regulates adenylosuccinate synthase, an important enzyme for adenosine de novo synthesis, which could explain the reduction in cordycepin production. Some G protein-coupled receptors that control fungal fruit body formation and the sexual cycle were regulated by CmWC-1, and the cAMP pathway involved in light signal transduction in
N. crassa
was not critical for the photoreaction in the fungus here. A transcriptional analysis indicated that steroid biosynthesis was more active in the Δ
Cmwc-1
strain, suggesting that CmWC-1 might switch the vegetative growth state to primordia differentiation by suppressing the expression of related genes.
Training a supernet matters for one-shot neural architecture search (NAS) methods since it serves as a basic performance estimator for different architectures (paths). Current methods mainly hold the ...assumption that a supernet should give a reasonable ranking over all paths. They thus treat all paths equally, and spare much effort to train paths. However, it is harsh for a single supernet to evaluate accurately on such a huge-scale search space (e.g., 7^21). In this paper, instead of covering all paths, we ease the burden of supernet by encouraging it to focus more on evaluation of those potentially-good ones, which are identified using a surrogate portion of validation data. Concretely, during training, we propose a multi-path sampling strategy with rejection, and greedily filter the weak paths. The training efficiency is thus boosted since the training space has been greedily shrunk from all paths to those potentially-good ones. Moreover, we further adopt an exploration and exploitation policy by introducing an empirical candidate path pool. Our proposed method GreedyNAS is easy-to-follow, and experimental results on ImageNet dataset indicate that it can achieve better Top-1 accuracy under same search space and FLOPs or latency level, but with only ~60% of supernet training cost. By searching on a larger space, our GreedyNAS can also obtain new state-of-the-art architectures.
Abstract
Piezoelectric materials convert mechanical stress to electrical energy and thus are widely used in energy harvesting and wearable devices. However, in the piezoelectric family, there are two ...pairs of properties that improving one of them will generally compromises the other, which limits their applications. The first pair is piezoelectric strain and voltage constant, and the second is piezoelectric performance and mechanical softness. Here, we report a molecular bond weakening strategy to mitigate these issues in organic-inorganic hybrid piezoelectrics. By introduction of large-size halide elements, the metal-halide bonds can be effectively weakened, leading to a softening effect on bond strength and reduction in polarization switching barrier. The obtained solid solution C
6
H
5
N(CH
3
)
3
CdBr
2
Cl
0.75
I
0.25
exhibits excellent piezoelectric constants (
d
33
= 367 pm/V,
g
33
= 3595 × 10
−3
Vm/N), energy harvesting property (power density is 11 W/m
2
), and superior mechanical softness (0.8 GPa), promising this hybrid as high-performance soft piezoelectrics.
Due to the lack of early diagnostic and effective treatment modalities, hepatocellular carcinoma (HCC) is still the most lethal cancer with a high mortality on a global scale. Recent studies have ...highlighted the key roles of microRNAs (miRs) in HCC development. In the study, we attempted to investigate the potential role of miR-9-5p in the progression of HCC. Expression of pyruvate dehydrogenase kinase 4 (PDK4) and miR-9-5p was examined in HCC tissues collected from HCC patients and cell lines. The proliferation, migration, invasion, and apoptosis of HCC cells, and levels of oxygen consumption rate, extracellular acidification rate and reactive oxygen species (ROS) as well as the tumorigenicity of transfected cells in vivo were measured after gain- and loss-of-function experiments in HCC cells. It was revealed that miR-9-5p was upregulated, while PDK4 was poorly expressed in HCC tissues and cells, associating with a poor prognosis of HCC patients. miR-9-5p directly targeted PDK4 and could downregulate its expression, thus leading to promoted cell proliferation, invasion and migration, enhanced mitochondrial activity and energy metabolism, and suppressed apoptosis in HCC cells, along with increased tumorigenicity in mouse xenograft models. Altogether, miR-9-5p facilitated mitochondrial energy metabolism of HCC cells by downregulating PDK4, promoting the development of HCC. miR-9-5p and PDK4 may serve as potential therapeutic targets for preventing recurrence and metastasis of HCC.
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