Comprehensive Proteome and Acetylome Analysis of Needle Senescence in Larix gmelinii.

Leaf senescence is essential for the growth and development of deciduous trees in the next season. Larix gmelinii, a deciduous coniferous tree, exhibits its most distinctive feature by turning yellow in the autumn and eventually shedding its leaves, resulting in significant changes in its appearance during the fall. Lysine acetylation plays an important role in diverse cellular processes; however, limited knowledge is available regarding acetylations in the needle senescence of L. gmelinii. In this study, the proteomics and acetylated modification omics of two phenotypic leaves, yellow and green (senescent and non-senescent) needles, were analyzed before autumn defoliation. In total, 5022 proteins and 4469 unique acetylation sites in 2414 lysine acylated proteins were identified, and this resulted in the discovery of 1335 differentially expressed proteins (DEPs) and 605 differentially expressed acetylated proteins (DAPs) in yellow versus green needles. There are significant differences between the proteome and acetylome; only 269 proteins were found to be DEP and DAP, of which 136 proteins were consistently expressed in both the DEP and DAP, 91 proteins were upregulated, and 45 proteins were down-regulated. The DEPs participate in the metabolism of starch and sucrose, while the DAPs are involved in glycolysis and the tricarboxylic acid cycle. Among them, DEPs underwent significant changes in glycolysis and citric acid cycling. Most of the enzymes involved in glycolysis and the citrate cycle were acetylated. DAPs were down-regulated in glycolysis and up-regulated in the citrate cycle. In all, the results of this study reveal the important role of lysine acetylation in the senescence of L. gmelinii needles and provide a new perspective for understanding the molecular mechanism of leaf senescence and tree seasonal growth.

The microplastics distribution characteristics and their impact on soil physicochemical properties and bacterial communities in food legumes farmland in northern China.

Microplastics (MPs) pose a threat to farmland soil quality and crop safety. MPs exist widely in food legumes farmland soil due to the extensive use of agricultural film and organic fertilizer, but their distribution characteristics and their impact on soil environment have not been reported. The abundance and characteristics of MPs, soil physical and chemical properties, and bacterial community composition were investigated in 76 soil samples from five provinces in northern China. The results showed that the abundance of MPs ranged from 1600 to 36,200 items/kg. MPs in soil were mostly fibrous, less than 0.2 mm, and white. Rayon, polyester and polyethylene were the main types of MPs. The influences of MPs on soil physicochemical properties and bacterial communities mainly depended on the type of MPs. Notably, polyethylene significantly decreased the proportion of silt particles, and increased the nitrate nitrogen content as well as the abundance of MPs-degrading bacteria Paenibacillus (p < 0.05). Moreover, bacteria were more sensitive to polyesters in soil with low concentration of organic matter. This study indicated that MPs in food legumes farmland soil presented a higher-level. And, they partially altered soil physicochemical properties, and soil bacteria especially in soil with low organic matter.

Usefulness of analyzing endoscopic features in identifying the colorectal serrated sessile lesions with and without dysplasia.

BACKGROUND: Sessile serrated lesions (SSLs) are often missed on colonoscopy, and studies have shown this to be an essential cause of interstitial colorectal cancer. The SSLs with dysplasia (SSL-D+), in particular, have a faster rate of carcinogenesis than conventional tubular adenomas. Therefore, there is a clinical need for some endoscopic features with independent diagnostic value for SSL-D+s to assist endoscopists in making immediate diagnoses, thus improving the quality of endoscopic examination and treatment. AIM: To compare the characteristics of SSLs, including those with and without dysplasia (SSL-D+ and SSL-D-), based on white light and image-enhanced endoscopy, to achieve an immediate differential diagnosis for endoscopists. METHODS: From January 2017 to February 2023, cases of colorectal SSLs confirmed by colonoscopy and histopathology at the Gastrointestinal Endoscopy Center of Beijing Tsinghua Changgung Hospital were collected. The general, endoscopic, and histopathological data were reviewed and analyzed to determine the diagnostic utility. Univariate analysis was used to find potential diagnostic factors, and then multivariate regression analysis was performed to derive endoscopic features with independent diagnostic values for the SSL-D+. RESULTS: A total of 228 patients with 253 lesions were collected as a result. There were 225 cases of colorectal SSL-D-s and 28 cases of SSL-D+s. Compared to the colorectal SSL-D-, the SSL-D+ was more common in the right colon (P = 0.027) with complex patterns of depression, nodule, and elevation based on cloud-like surfaces (P = 0.003), reddish (P < 0.001), microvascular varicose (P < 0.001), and mixed type (Pit II, II-O, IIIL, IV) of crypt opening based on Pit II-O (P < 0.001). Multifactorial logistic regression analysis indicated that lesions had a reddish color [odds ratio (OR) = 18.705, 95% confidence interval (CI): 3.684-94.974], microvascular varicose (OR = 6.768, 95%CI: 1.717-26.677), and mixed pattern of crypt opening (OR = 20.704, 95%CI: 2.955-145.086) as the independent predictors for SSL-D+s. CONCLUSION: The endoscopic feature that has independent diagnostic value for SSL-D+ is a reddish color, microvascular varicose, and mixed pattern of crypt openings.

Modeling of nonlinear and nonstationary stochasticity for atomic ensembles.

This paper addresses the problem of stochastic modeling of atomic ensembles under multi-source noise and makes the model interpretable. First, based on Itô's lemma and Allan variance analysis (ITÔ-AVAR), an approach is proposed to model nonstationary stochastic submodels of atomic ensembles. On this basis, the variance decomposition and nonlinear optimization algorithms are utilized to hybridize modeling atomic ensembles with nonlinear and nonstationary properties. Second, an Itô's lemma dynamic allan variance analysis (ITÔ-DAVAR) approach is developed for online modeling of atomic ensembles. Further, an atomic ensembles sensitivity enhancement scheme based on the proposed approach is given, which effectively promotes the progress of quantum instrument engineering. Finally, the proposed scheme are deployed in the optical pumping magnetometer and spin-exchange relaxation-free comagnetometer, respectively, while experimentally verifying the sensitivity of the spin-exchange relaxation-free comagnetometer reaches 5.36×10-6degs-1Hz-1/2.

Low-Temperature Plasma-Assisted Catalytic Dry Reforming of Methane over CeO2 Nanorod-Supported NiO Catalysts in a Dielectric Barrier Discharge Reactor.

Nonthermal plasma (NTP)-assisted catalytic dry reforming of methane (DRM) is considered a powerful single-stage reaction mechanism because of its ability to activate normally stable CO2 and CH4 at a low temperature under ambient conditions. The thermodynamic barrier of DRM requires a high operating temperature (>700 °C), which can be reduced by nonequilibrium plasma. Herein, we present a method for the wet-impregnation synthesis of CeO2 nanorod (NR)-supported 5 and 15 wt % NiO catalysts for efficient NTP-promoted DRM with an applied power in the range of 24.9-25.8 W (frequency: 20 kHz), a CH4:CO2 feed gas ratio of 100:250 sccm, and a total flow rate of 350 sccm. The presence of NTP dramatically increased the reaction activity, even at 150 °C, which is usually inaccessible for thermally catalyzed DRM. The CH4 and CO2 conversion reaches a maximum of 66 and 48%, respectively, at 500 °C with the 15 wt % NiO/CeO2 NR catalyst, which are much higher than the values obtained for the 5 wt % NiO/CeO2 NR catalyst under the same conditions. According to the X-ray photoelectron spectroscopy profile for 15 wt % NiO/CeO2 NR, a higher concentration of NiO on CeO2 increases the proportion of Ce3+ in the catalyst, suggesting enhanced oxygen vacancy concentration with an increased amount of NiO loading. Additionally, a higher NiO loading promotes a higher rate of replacement of Ce4+ with Ni2+, which generates more oxygen vacancies due to the induced charge imbalance and lattice distortion within the CeO2 lattice. As a result, it can be inferred that the incorporation of Ni ions into the CeO2 structure resulted in inhibited growth of CeO2 crystals due to the creation of a NixCe1-xO2-α solid solution and the production of oxygen vacancies.

Study on semi-bionic extraction of Astragalus polysaccharide and its anti-aging activity in vivo.

Astragalus membranaceus (A. membranaceus) is a homologous plant with high medicinal and edible value. Therefore, the extraction methods of Astragalus polysaccharide (APS) have attracted the attention of many research groups, but the yield of the active components is still not high. The aim of this study was to extract APS by a semi-bionic extraction method, optimize the extraction process, and evaluate the anti-aging activities of APS in vivo. The results showed that the APS yield was 18.23% when extracted by the semi-bionic extraction method. Anti-aging evaluation in rats showed that APS extracted by this method significantly decreased the malondialdehyde (MDA) content and increased superoxide dismutase (SOD) activity to cope with D-galactose-induced aging. Serum metabolomic analysis indicated that a total of 48 potential biomarkers showed significant differences, mainly involving 5 metabolic pathways. These altered metabolic pathways were mainly related to energy metabolism, amino acid metabolism, and lipid metabolism. These results indicated that the semi-bionic extraction method can effectively improve the yield of APS, and the extracted APS exhibited anti-aging activity in rats. Our study provided a novel and effective method to extract APS and indicated that APS can be used as functional food and natural medicine to delay aging and prevent its complications.

Real-time nondemolition measurement method for alkali vapor density and its application in a spin-exchange relaxation-free co-magnetometer.

This study presents a novel method for measuring the number density of K in K-Rb hybrid vapor cells using circularly polarized pump light on polarized alkali metal atoms. This proposed method eliminates the need for additional devices such as absorption spectroscopy, Faraday rotation, or resistance temperature detector technology. The modeling process involved considering wall loss, scattering loss, atomic absorption loss, and atomic saturation absorption, with experiments designed to identify the relevant parameters. The proposed method is real-time, highly stable, and a quantum nondemolition measurement that does not disrupt the spin-exchange relaxation-free (SERF) regime. Experimental results demonstrate the effectiveness of the proposed method, as the longitudinal electron spin polarization long-term stability increased by 204% and the transversal electron spin polarization long-term stability increased by 44.8%, as evaluated by the Allan variance.

Genome-Wide Analysis of WRKY Transcription Factors Involved in Abiotic Stress and ABA Response in Caragana korshinskii.

The WRKY transcription factor family plays a vital role in plant development and environmental response. However, the information of WRKY genes at the genome-wide level is rarely reported in Caragana korshinskii. In this study, we identified and renamed 86 CkWRKY genes, which were further classified into three groups through phylogenetic analysis. Most of these WRKY genes were clustered and distributed on eight chromosomes. Multiple sequence alignment revealed that the conserved domain (WRKYGQK) of the CkWRKYs was basically consistent, but there were also six variation types (WRKYGKK, GRKYGQK, WRMYGQK, WRKYGHK, WKKYEEK and RRKYGQK) that appeared. The motif composition of the CkWRKYs was quite conservative in each group. In general, the number of WRKY genes gradually increased from lower to higher plant species in the evolutionary analysis of 28 species, with some exceptions. Transcriptomics data and RT-qPCR analysis showed that the CkWRKYs in different groups were involved in abiotic stresses and ABA response. Our results provided a basis for the functional characterization of the CkWRKYs involved in stress resistance in C. korshinskii.

Current progress on the endoscopic features of colorectal sessile serrated lesions.

Along with the discovery and refinement of serrated pathways, the World Health Organization amended the classification of digestive system tumors in 2019, recommending the renaming of sessile serrated adenomas/polyps to sessile serrated lesions (SSLs). Given the particularity of the endoscopic appearance of SSLs, it could easily be overlooked and missed in colonoscopy screening, which is crucial for the occurrence of interval colorectal cancer. Existing literature has found that adequate bowel preparation, reasonable withdrawal time, and awareness of colorectal SSLs have improved the quality and accuracy of detection. More particularly, with the continuous advancement and development of endoscopy technology, equipment, and accessories, a potent auxiliary tool is provided for accurate observation and immediate diagnosis of SSLs. High-definition white light endoscopy, chromoendoscopy, and magnifying endoscopy have distinct roles in the detection of colorectal SSLs and are valuable in identifying the size, shape, character, risk degree, and potential malignant tendency. This article delves into the relevant factors influencing the detection rate of colorectal SSLs, reviews its characteristics under various endoscopic techniques, and expects to attract the attention of colonoscopists.

Role of Soil and Foliar-Applied Carbon Dots in Plant Iron Biofortification and Cadmium Mitigation by Triggering Opposite Iron Signaling in Roots.

In China, iron (Fe) availability is low in most soils but cadmium (Cd) generally exceeds regulatory soil pollution limits. Thus, biofortification of Fe along with mitigation of Cd in edible plant parts is important for human nutrition and health. Carbon dots (CDs) are considered as potential nanomaterials for agricultural applications. Here, Salvia miltiorrhiza-derived CDs are an efficient modulator of Fe, manganese (Mn), zinc (Zn), and Cd accumulation in plants. CDs irrigation (1 mg mL-1 , performed every week starting at the jointing stage for 12 weeks) increased Fe content by 18% but mitigated Cd accumulation by 20% in wheat grains. This finding was associated with the Fe3+ -mobilizing properties of CDs from the soil and root cell wall, as well as endocytosis-dependent internalization in roots. The resulting excess Fe signaling mitigated Cd uptake via inhibiting TaNRAMP5 expression. Foliar spraying of CDs enhanced Fe (44%), Mn (30%), and Zn (19%) content with an unchanged Cd accumulation in wheat grains. This result is attributed to CDs-enhanced light signaling, which triggered shoot-to-root Fe deficiency response. This study not only reveals the molecular mechanism underlying CDs modulation of Fe signaling in plants but also provides useful strategies for concurrent Fe biofortification and Cd mitigation in plant-based foods.

Ultrafast microwave synthesis of MoTe2@graphene composites accelerating polysulfide conversion and promoting Li2S nucleation for high-performance Li-S batteries.

In this report, MoTe2 nanosheets were grown on highly conductive graphene support through a simple and ultrafast microwave-assisted chemical coupling and heating method to develop hybrid sulfur host materials for Li-S batteries. MoTe2 nanosheets with superb electrocatalytic activity combined with highly conductive graphene form a nano reservoir for containing elemental sulfur, intermediate polysulfide species, discharge product Li2S, and accelerating the electron transfer. Accordingly, the Li-S battery with the MoTe2@graphene@carbon cloth electrode exhibited a high initial discharge capacity of 1246 mAh g-1 at 0.2C for the first galvanostatic cycle, good cycle stability (98.7% capacity retention after 100 cycles at 0.2C) and superb rate performance. The synergistic effect of the chemical affinity and superior electrocatalytic capability of polar MoTe2, along with the effective physical confinement by graphene and free-standing carbon cloth, provides a promising way to design host materials to mitigate the shuttling effect in rechargeable Li-S batteries.

Adsorption-catalysis design with cerium oxide nanorods supported nickel-cobalt-oxide with multifunctional reaction interfaces for anchoring polysulfides and accelerating redox reactions in lithium sulfur battery.

The charge and discharge working mechanisms in lithium sulfur batteries contain multi-step complex reactions involving two-electron transfer and multiple phase transformations. The dissolution and diffusion of lithium polysulfides cause a huge loss of active material and fast capacity decay, preventing the practical use of lithium sulfur batteries. Herein, CeO2 nanorods supported bimetallic nickel cobalt oxide (NiCo2Ox) was investigated as a cathode host material for lithium sulfur batteries, which can provide adsorption-catalysis dual synergy to restrain the shuttle of polysulfides and stimulate rapid redox reaction for the conversion of polysulfides. The polar CeO2 nanorods with abundant surface defects exhibit chemisorption towards lithium polysulfides and the excellent electrocatalytic activity of NiCo2Ox nanoclusters can rev up the chain transformation of lithium polysulfides. The electrochemical results show that the battery with NiCo2Ox/CeO2 nanorods can demonstrate high discharge capacity, stable cycling, low voltage polarization and high sulfur utilization. The battery with NiCo2Ox/CeO2 nanorods unveils a high specific capacity of 1236 mAh g-1 with a very low capacity fading of 0.09% per cycle after 100 cycles at a 0.2C current rate. Moreover, the excellent performance with high sulfur loading (>5 mg cm-2) verifies a huge promise for future commercial applications.

Ultrasensitive electrochemical biosensors based on zinc sulfide/graphene hybrid for rapid detection of SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) is a highly contagious and fatal disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In general, the diagnostic tests for COVID-19 are based on the detection of nucleic acid, antibodies, and protein. Among different analytes, the gold standard of the COVID-19 test is the viral nucleic acid detection performed by the quantitative reverse transcription polymerase chain reaction (qRT-PCR) method. However, the gold standard test is time-consuming and requires expensive instrumentation, as well as trained personnel. Herein, we report an ultrasensitive electrochemical biosensor based on zinc sulfide/graphene (ZnS/graphene) nanocomposite for rapid and direct nucleic acid detection of SARS-CoV-2. We demonstrated a simple one-step route for manufacturing ZnS/graphene by employing an ultrafast (90 s) microwave-based non-equilibrium heating approach. The biosensor assay involves the hybridization of target DNA or RNA samples with probes that are immersed into a redox active electrolyte, which are detectable by electrochemical measurements. In this study, we have performed the tests for synthetic DNA samples and, SARS-CoV-2 standard samples. Experimental results revealed that the proposed biosensor could detect low concentrations of all different SARS-CoV-2 samples, using such as S, ORF 1a, and ORF 1b gene sequences as targets. This microwave-synthesized ZnS/graphene-based biosensor could be reliably used as an on-site, real-time, and rapid diagnostic test for COVID-19. Supplementary Information: The online version contains supplementary material available at 10.1007/s42114-023-00630-7.

Fractional Exponential Feedback Control for Finite-Time Stabilization and its Application in a Spin-Exchange Relaxation-Free Comagnetometer.

This article is the first work to propose a series of control strategies for the longitudinal electron spin polarization of the spin-exchange relaxation-free comagnetometer system to ensure its ultrastable measurement. Two types of finite-time control strategies are presented for a nonlinear system with affine input. The first control strategy is finite-time fractional exponential feedback control (FEFC), which ensures that the trajectories of an autonomous system converge to an equilibrium state in a finite time that can be specified. The second control strategy is finite-time robust FEFC, which provides a finite-time stability of a nonautonomous system with unknown structures under disturbance and perturbations, and its upper bound of the settling time can be estimated. The theoretical results are supported by numerical simulations.

Formation of emerging disinfection byproducts from agricultural biomass-derived DOM: Overlooked health risk source.

Carbon-derived dissolved organic matter (CDOM) are inevitably released to surface water during returning agricultural biomass carbon to farmland, which are potential precursors of disinfection byproducts (DBPs). In this study, CDOM was extracted from aerobic incineration ("OX") and anoxic pyrolysis ("PY") of three kinds of straw (wheat, corn, and rice), and the emerging DBPs from them were deciphered. The CDOM with molecular weight < 1 kDa in the OX and PY groups accounted for 53-87%, and it was higher in the PY group. A total 1343-2107 of CHO and 641-1761 of CHNO formulas were detected in the CDOM derived from the OX group, among which 74%-83% contained aromatic structures rich in oxygen containing groups. 1919-3289 of CHO and 785-1954 of CHNO formulas were observed in the PY group, and 77%-86% of them were lignins/CRAM-like compounds. Surprisingly, 765-2158 and 895-1648 of emerging DBPs were identified in the OX and PY groups, and the proportions of N-DBPs were 20.3-54.8% and 2.8-4.8%, respectively. Based on HOCl addition and Cl substitution mechanisms, the H/C ratios of the DBP precursors in the OX and PY groups were in the range of 0.2-1.5 and 0.6-2.0, respectively. The DBPs derived from the OX group exhibited higher cytotoxicity and genotoxicity due to the higher aromaticity and more N-DBPs. Thus, returning agricultural biomass carbon, particularly that produced by direct combustion, to farmland brought potential threat to drinking water safety.

Formation of halogenated macromolecular organics induced by Br- and I- during plasma oxidation/chlorination of DOM: Highlighting competitive mechanisms.

Understanding the effects of halogens on the production of macromolecular disinfection byproducts (DBPs) is critical for drinking water safety. The effects of Br- and I- on the chemical diversity of dissolved organic matter (DOM) during plasma preoxidation and the subsequent formation of macromolecular halogenated DBPs after chlorination were deciphered. Plasma preoxidation changed DOM diversity from aromatic component-oriented to lignin and tannin component-oriented, resulting in 62.0% and 21.2% decreases in N-DBPs (CkHnOmNzClx formulas) and C-DBPs (CkHnOmClx formulas) after chlorination, respectively. Br- could induce the formation of organobromine compounds (OBrCs) during plasma oxidation; however, the intensities of OBrCs decreased by 56.3% (CHO formulas) and 75.2% (CHON formulas) after further chlorination. OBrCs still accounted for 79.8% of the total organohalogen compounds (OXCs, X=Cl or Br) due to the higher substitutability of bromine. I-promoted OIC production in the DOM preoxidation process, and OICs acted as intermediates to form OClCs during chlorination. When Br-and I-coexisted, Br- promoted OIC production in the DOM preoxidation process; therefore, more OBrCs and OClCs were generated due to intermediates of OICs in subsequent chlorination. Connections between OXCs and their precursors were established using network computation. The precursors of OClCs were located in the aromatic structure region (0.2 < H/C ≤ 0.7; O/C ≤ 0.67); those of OBrCs and OICs were located in the lignin (0.7 < H/C ≤ 1.5; 0.1 < O/C < 0.67) and tannin (0.6 ≤ H/C ≤ 1.5, 0.67 < O/C < 1.0) regions with relatively greater H/C and O/C ratios, respectively.

Analysis of Pollution Characteristics and Sources in Surface Water in Typical Crop-Producing Areas of Qinghai Province.

Currently used pesticides and organochlorine pesticides (OCPs), nitrogen and phosphorus were analyzed in surface water from 26 sampling sites of agricultural areas in Qinghai Province to elucidate their pollution characteristics and sources. The results showed that most of these currently used pesticides, with the exception of chlorpyrifos, were generally not detected. However, two OCPs were commonly detected in surface water from four typical crop-producing areas. The residual concentrations of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) measured 0~1.68 ng/L and 0.41~2.41 ng/L, respectively, in the water from the four crop-producing areas. The residues of these two OCPs pesticides were much lower than the standard limit of surface water environmental quality. The main forms of HCHs and DDTs were ß-HCH and pp'-DDE, respectively, indicating that the residues of HCHs and DDTs in the surface water of the four crop-producing areas in Qinghai were mainly derived from historical drugs that had degraded for a long time. The average concentrations of TN, NO3--N and NH4+-N in the surface water of 26 sampling sites of four typical crop areas in Qinghai Province were 2.95, 1.71 and 0.17 mg/L, respectively. According to the national surface water environmental quality standards, TN concentrations in 57.7% of these sampling sites exceeded the Class V water standards. The average concentration of NO3--N was more than 70 times that of NH4+-N. Nonetheless, there were no significant differences in the concentrations of TN, NO3--N and NH4+-N in the four crop-producing areas. The concentrations of NO3--N and NO3--N in the surface water were positively correlated with the TN concentration (p < 0.05), indicating that the sources of nitrogen in the surface water were relatively consistent. The average value of TP concentrations in the surface water from these sampling sites was 0.034 mg/L, with no significant differences among different producing areas. The N/P values in surface water from the four crop-producing areas of Qinghai Province had a range of 9.2~302. Phosphorus was the limiting factor for the proliferation of plankton in water. Reducing the input of phosphorus in these areas may be the key to preventing the deterioration of water quality. Significant negative and positive correlations exist between HCHs and nitrate nitrogen, and total phosphorus, respectively, which may be attributed to the proliferation of degrading microorganisms caused by the eutrophication of water. The research results will help to identify the characteristics and sources of surface water pollution in the crop-producing areas of Qinghai Province, and provide data support for Qinghai Province to build an export area for green organic agricultural and livestock products.

Multi-omics analysis reveals the molecular changes accompanying heavy-grazing-induced dwarfing of Stipa grandis.

Heavy grazing significantly reduces Stipa grandis growth. To enhance our understanding of plant responses to heavy grazing, we conducted transcriptomic, proteomic, and metabolic analyses of the leaves of non-grazed plants (NG) and heavy-grazing-induced dwarf plants (HG) of S. grandis. A total of 101 metabolites, 167 proteins, and 1,268 genes differed in abundance between the HG and NG groups. Analysis of Kyoto Encyclopedia of Genes and Genomes pathways among differentially accumulated metabolites (DAMs) revealed that the most enriched pathways were flavone and flavonol biosynthesis, tryptophan metabolism, and phenylpropanoid biosynthesis. An integrative analysis of differentially expressed genes (DEGs) and proteins, and DAMs in these three pathways was performed. Heavy-grazing-induced dwarfism decreased the accumulation of DAMs enriched in phenylpropanoid biosynthesis, among which four DAMs were associated with lignin biosynthesis. In contrast, all DAMs enriched in flavone and flavonol biosynthesis and tryptophan metabolism showed increased accumulation in HG compared with NG plants. Among the DAMs enriched in tryptophan metabolism, three were involved in tryptophan-dependent IAA biosynthesis. Some of the DEGs and proteins enriched in these pathways showed different expression trends. The results indicated that these pathways play important roles in the regulation of growth and grazing-associated stress adaptions of S. grandis. This study enriches the knowledge of the mechanism of heavy-grazing-induced growth inhibition of S. grandis and provides valuable information for restoration of the productivity in degraded grassland.

The S40 family members delay leaf senescence by promoting cytokinin synthesis.

Leaf senescence is regulated by both endogenous hormones and environmental stimuli in a programmed and concerted way. The members of the S40 family have been reported to play roles in leaf senescence. Here we identified an S40 family member, CiS40-11, from Caragana intermedia. Phylogenetic analysis revealed that the CiS40-11 protein had the highest identity with AtS40-5 (AT1G11700) and AtS40-6 (AT1G61930) of Arabidopsis thaliana. CiS40-11 was highly expressed in leaves and was down-regulated after dark treatment. The subcellular localization analysis showed that CiS40-11 was a cytoplasm-nucleus dual-localized protein. Leaf senescence was delayed in both the CiS40-11 overexpressed A. thaliana and its transiently expressed C. intermedia. Transcriptomic analysis and endogenous hormones assay revealed that CiS40-11 inhibited leaf senescence via promoting the biosynthesis of cytokinins by blocking AtMYB2 expression in the CiS40-11 overexpression lines. Furthermore, overexpression of either AtS40-5 or AtS40-6 showed similar phenotype as the CiS40-11 overexpressing lines, while in the ats40-5a or ats40-6a mutants, the AtMYB2 expression was increased and their leaves exhibited a premature senescence phenotype. These results provide a new molecular mechanism of the S40 family in leaf senescence regulation of plants.

Selection and validation of reference genes for RT-qPCR analysis of different organs at various development stages in Caragana intermedia.

Reverse transcription quantitative PCR (RT-qPCR) is a technique widely used to investigate the expression of genes. An appropriate reference gene (RG) is essential for RT-qPCR analysis to obtain accurate and reliable results. Caragana intermedia plays an important role in afforestation as a bush. However, due to the lack of appropriate RGs, the research on development-related genes is limited. In this study, the selection for suitable RGs of different organs at various development stages to normalize the results of RT-qPCR about development-related genes was performed. To test the expression stability across all samples, we used the software algorithms such as geNorm, NormFinder, BestKeeper, and RefFinder to evaluate all the candidate RGs. Our results showed that CiEF1α was the most stable RG with little fluctuation among all samples. In addition, CiGAPDH in roots, CiSKIP1 in stems and leaves, and CiEF1α in different organs were selected as the most stable RGs. To confirm the applicability of the most stable RGs, the relative expression of CiWRKY17 was normalized using different candidate RGs. Taken together, our research laid a foundation for the study of development-related genes in C. intermedia.