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Abstract Background Colorectal cancer (CRC) is one of the most common cancers worldwide. Comprehensive data on the economic burden of CRC at a population‐level is critical in informing policymaking, but such data are currently limited in China. Methods From a societal perspective, the economic burden of CRC in 2019 was estimated, including direct medical and nonmedical expenditure, disability, and premature‐death‐related indirect expenditure. Data on disease burden was taken from the GBD 2019 and analyzed using a prevalence‐based approach. The per‐person direct expenditure and work loss days were from a multicenter study; the premature‐death‐related expenditure was estimated using a human capital approach. Projections were conducted in different simulated scenarios. All expenditure data were in Chinese Yuan (CNY) and discounted to 2019. Results In 2019, the estimated overall economic burden of CRC in China was CNY170.5 billion (0.189% of the local GDP). The direct expenditure was CNY106.4 billion (62.4% of the total economic burden), 91.4% of which was a direct medical expenditure. The indirect expenditure was CNY64.1 billion, of which 63.7% was related to premature death. The predicted burden would reach CNY560.0 billion in 2030 given constant trends for disease burden; however, it would be alternatively reduced to

Abstract Background Most cancer disability-adjusted life year (DALY) studies worldwide have used broad, generic disability weights (DWs); however, differences exist among populations and types of cancers. Using breast cancer as example, this study aimed to estimate the population-level DALYs in females in China and the impact of screening as well as applying local DWs. Methods Using multisource data, a prevalence-based model was constructed. (1) Overall years lived with disability (YLDs) were estimated by using numbers of prevalence cases, stage-specific proportions, and local DWs for breast cancer. Numbers of females and new breast cancer cases as well as local survival rates were used to calculate the number of prevalence cases. (2) Years of life lost (YLLs) were estimated using breast cancer mortality rates, female numbers and standard life expectancies. (3) The prevalence of and mortality due to breast cancer and associated DALYs from 2020 to 2030 were predicted using Joinpoint regression. (4) Assumptions considered for screening predictions included expanding coverage, reducing mortality due to breast cancer and improving early-stage proportion for breast cancer. Results In Chinese females, the estimated number of breast cancer DALYs was 2251.5 thousand (of 17.3% were YLDs) in 2015, which is predicted to increase by 26.7% (60.3% among those aged ≥ 65 years) in 2030 (2852.8 thousand) if the screening coverage (25.7%) stays unchanged. However, if the coverage can be achieved to 40.7% in 2030 (deduced from the “Healthy China Initiative”), DALYs would decrease by 1.5% among the screened age groups. Sensitivity analyses found that using local DWs would change the base-case values by ~ 10%. Conclusion Estimates of DALYs due to breast cancer in China were lower (with a higher proportion of YLDs) than Global Burden of Disease Study numbers (2527.0 thousand, 8.2% were YLDs), suggesting the importance of the application of population-specific DWs. If the screening coverage remains unchanged, breast cancer-caused DALYs would continue to increase, especially among elderly individuals.

Obstructive sleep apnea hypopnea syndrome(OSAHS)is a group of diseases which occurred in the upper respiratory tract with transient, recurrent, partial or complete obstruction during night sleep. It can affect the regulation of hemodynamics, endocrine systems and autonomic nerve, and then result in the reduction of body oxygen saturation, chronic hypoxia and hypercapnia. Beside being an independent risk factor for cardiovascular and cerebrovascular diseases, many studies have shown that it is also associated with ocular surface diseases in OSAHS, such as floppy eyelid syndrome, dry eye, keratoconus, etc., but there is still a lack of perfect systematic analysis. This paper reviews the relationship between OSAHS and relevant ocular surface diseases including pathogenesis,clinical manifestations and treatment progress, in order to reduce the ophthalmic complications of OSAHS patients in clinical diagnosis and treatment,and better improve the quality of life of patients.

Abstract Background Benchmark data on the population-level economic burden are critical to inform policymakers about liver cancer control. However, comprehensive data in China are currently limited. Methods A prevalence-based approach from a societal perspective was used to quantify the annual economic burden of liver cancer in China from 2019 to 2030. Detailed per-case data on medical/non-medical expenditure and work-loss days were extracted from a multicenter survey. The numbers/rates of new/prevalent cases and deaths, survival, and population-related parameters were extracted from the Global Burden of Disease 2019 and the literature. All expenditure data were reported in both 2019 Chinese Yuan (CNY) and United States dollar (US$, for main estimations). Result The overall economic burden of liver cancer was estimated at CNY76.7/US$11.1 billion in China in 2019 (0.047% of the local GDP). The direct expenditure was CNY21.6/US$3.1 billion, including CNY19.7/US$2.9 billion for medical expenditure and CNY1.9/US$0.3 billion for non-medical expenditure. The indirect cost was CNY55.1/US$8.0 billion (71.8% of the overall burden), including CNY3.0/US$0.4 billion due to disability and CNY52.0/US$7.5 billion due to premature death. The total burden would increase to CNY84.2/US$12.2 billion, CNY141.7/US$20.5 billion, and CNY234.3/US$34.0 billion in 2020, 2025, and 2030, accounting for 0.102%, 0.138%, and 0.192% of China's GDP, respectively. However, if China achieves the goals of Healthy China 2030 or the United Nations' Sustainable Development Goals for non-communicable diseases, the burden in 2030 would be

Macrophages are involved in the whole process of atherosclerosis, which is characterized by accumulation of lipid and inflammation. Presently, clinically used lipid-lowering drugs cannot completely retard the progress of atherosclerosis. Liver X receptor (LXR) plays a key role in regulation of lipid metabolism and inflammation. Accumulating evidence have demonstrated that synthetic LXR agonists can significantly retard the development of atherosclerosis. However, these agonists induce sever hypertriglyceridemia and liver steatosis. These side effects have greatly limited their potential application for therapy of atherosclerosis. The rapid development of drug delivery system makes it possible to delivery interested drugs to special organs or cells using nanocarriers. Macrophages express various receptors which can recognize and ingest specially modified nanocarriers loaded with LXR agonists. In the past decades, a great progress has been made in this field. These macrophage-targeted nanocarriers loaded with LXR agonists are found to decrease atherosclerosis by reducing cholesterol accumulation and inflammatory reactions. Of important, these nanocarriers can alleviate side effects of LXR agonists. In this article, we briefly review the roles of macrophages in atherosclerosis, mechanisms of action of LXR agonists, and focus on the advances of macrophage-targeted nanocarriers loaded with LXR agonists. This work may promote the potential clinical application of these nanocarriers.

Atrial fibrillation (AF), the most prevalent type of sustained cardiac dysrhythmia globally, confers strikingly enhanced risks for cognitive dysfunction, stroke, chronic cardiac failure, and sudden cardiovascular demise. Aggregating studies underscore the crucial roles of inherited determinants in the occurrence and perpetuation of AF. However, due to conspicuous genetic heterogeneity, the inherited defects accounting for AF remain largely indefinite. Here, via whole-genome genotyping with genetic markers and a linkage assay in a family suffering from AF, a new AF-causative locus was located at human chromosome 7p14.2-p14.3, a ~4.89 cM (~4.43-Mb) interval between the markers D7S526 and D7S2250. An exome-wide sequencing assay unveiled that, at the defined locus, the mutation in the TBX20 gene, NM_001077653.2: c.695A>G; p.(His232Arg), was solely co-segregated with AF in the family. Additionally, a Sanger sequencing assay of TBX20 in another family suffering from AF uncovered a novel mutation, NM_001077653.2: c.862G>C; p.(Asp288His). Neither of the two mutations were observed in 600 unrelated control individuals. Functional investigations demonstrated that the two mutations both significantly reduced the transactivation of the target gene KCNH2 (a well-established AF-causing gene) and the ability to bind the promoter of KCNH2, while they had no effect on the nuclear distribution of TBX20. Conclusively, these findings reveal a new AF-causative locus at human chromosome 7p14.2-p14.3 and strongly indicate TBX20 as a novel AF-predisposing gene, shedding light on the mechanism underlying AF and suggesting clinical significance for the allele-specific treatment of AF patients.

Abstract Background Cordyceps militaris is cultured widely as an edible mushroom and accumulating evidence in mice have demonstrated that the polysaccharides of Cordyceps species have lipid-lowering effects. However, lipid metabolism in mice is significantly different from that in humans, making a full understanding of the mechanisms at play critical. Methods After 5 months, the hamsters were weighed and sampled under anesthesia after overnight fasting. The lipid-lowering effect and mechanisms of the polysaccharide CM1 was investigated by cellular and molecular technologies. Furthermore, the effect of the polysaccharide CM1 (100 μg/mL) on inhibiting adipocyte differentiation was investigated in vitro. Results CM1, a polysaccharide from C. militaris, significantly decreased plasma total cholesterol, triglyceride and epididymal fat index in LDLR (+/−) hamsters, which have a human-like lipid profile. After 5 months’ administration, CM1 decreased the plasma level of apolipoprotein B48, modulated the expression of key genes and proteins in liver, small intestine, and epididymal fat. CM1 also inhibited preadipocyte differentiation in 3T3-L1 cells by downregulating the key genes involved in lipid droplet formation. Conclusions The polysaccharide CM1 lowers lipid and adipocyte differentiation by several pathways, and it has potential applications for hyperlipidemia prevention.

BackgroundInfective endocarditis is a complication with high mortality in patients with congenital heart disease, particularly for those with bioprosthetic valve.Case summaryWe report a case of a 54-year-old female with a history of tetralogy of Fallot who had been surgically repaired using a transannular patch due to severe pulmonary insufficiency with right heart enlargement and presented with worsening dyspnea. She had received transcatheter pulmonary valve implantation (TPVI) 5 years ago. Unfortunately, bioprosthesis-associated infective endocarditis occurred due to dental caries. Given persistent antibiotic medication, she became clinically stable with prosthesis functional recovery. However, dysfunctional bioprosthesis was still detected 3 years later, which was successfully treated by valve-in-valve TPVI with the help of modified buddy wire technique. At a 12-month follow-up after valve-in-valve TPVI, she was completely recovered with improved symptoms of heart failure.ConclusionThis is the first report of valve-in-valve TPVI of a self-expandable valve in a degenerated self-expandable valve. The case highlights increased surveillance for infective endocarditis of transcatheter pulmonary valve should be emphasized. Subsequent valve-in-valve TPVI is an effective treatment for valve failure in defined conditions improving the hemodynamics.

AIM: To evaluate the effectiveness of intravitreal bevacizumab(IVB)and ranibizumab(IVR)for the treatment of type 1 retinopathy of prematurity(ROP)by Meta-analysis.METHODS: The PubMed, Embase, Web of Science, the Cochrane Library, CNKI, CQVIP, CBM, OVID and Wanfang were systematically searched. All comparative studies of IVB or IVR as treatment for ROP were included. Two independent reviewers performed the date extraction and assessed study quality. Meta-analysis was performed using Review Manager 5.3 software. The retreatment rate was defined as the primary outcome. Secondary outcomes were prevalence of complete vascularization and myopic(spherical equivalent, SE).RESULTS: Eight non-randomized studies, including a total of 885 eyes were included in this study. Compared with IVB-treated children, IVR-treated children have higher retreatment rate [OR=0.55, 95% CI:0.34-0.88, P0.05].CONCLUSION: Both IVR and IVB can complete the vasculization of the retina in the treatment of type 1 ROP, but the two treatments have their own advantages. IVR has little effect on the refractive effect in children, but its effect in reducing the retreatment rate is worse than IVB.

As the most prevalent type of birth malformation, congenital heart disease (CHD) gives rise to substantial mortality and morbidity as well as a socioeconomic burden. Although aggregating investigations highlight the genetic basis for CHD, the genetic determinants underpinning CHD remain largely obscure. In this research, a Chinese family suffering from autosomal dominant CHD (atrial septal defect) and arrhythmias was enrolled. A genome-wide genotyping with microsatellite markers followed by linkage assay as well as sequencing analysis was conducted. The functional effects of the discovered genetic mutation were characterized by dual patch-clamp electrophysiological recordings in N2A cells and propidium iodide uptake assays in HeLa cells. As a result, a novel genetic locus for CHD and arrhythmias was located on chromosome 17q21.31-q21.33, a 4.82-cM (5.12 Mb) region between two markers of D17S1861 and D17S1795. Sequencing assays of the genes at the mapped locus unveiled a novel heterozygous mutation in the GJC1 gene coding for connexin 45 (Cx45), NM_005497.4:c.550A>G;p.R184G, which was in co-segregation with the disease in the whole family and was not observed in 516 unrelated healthy individuals or gnomAD. Electrophysiological analyses revealed that the mutation significantly diminished the coupling conductance in homomeric cell pairs (R184G/R184G) and in cell pairs expressing either R184G/Cx45 or R184G/Cx43. Propidium iodide uptake experiments demonstrated that the Cx45 R184G mutation did not increase the Cx45 hemichannel function. This investigation locates a new genetic locus linked to CHD and arrhythmias on chromosome 17q21.31-q21.33 and indicates GJC1 as a novel gene predisposing to CHD and arrhythmias, implying clinical implications for prognostic risk assessment and personalized management of patients affected with CHD and arrhythmias.

AIM: To observe and characterize imaging features of macular and optic disc areas in less than 60-year-old patients with early primary open angle glaucoma (POAG) by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA), and to evaluate the diagnostic value of OCT and OCTA. METHODS: Totally 15 patients (23 eyes) with early POAG as observation group and 30 health people (30 eyes) as normal control group were enrolled in this cross-sectional study. OCTA-based superficial macula vessel density, superficial macula perfusion density, superficial optic disc vessel density, superficial optic disc perfusion density and spectral domain OCT (SD-OCT)-based macular area thickness, ganglion cell complex (GCC) thickness and retinal nerve fiber layer (RNFL) thickness were measured in the two groups. Independent t-test and receiver operating characteristic curve were used for analysis. Area under the receiver operating characteristic curves (AUROC) were used to measure the diagnostic utility. RESULTS: Among all the parameters, the optimal diagnostic utility parameter was the superficial vessel density in the macular area (except the center of the macula), and the AUROC reached 0.98. The diagnostic utility of macular area perfusion density (except the center of the macula) was similar to that of superficial vessel density in the macular area, and the AUROC was above 0.97. Followed by the diagnostic utility of vessel density in the optic disc area, the best parameter was the inner ring of the vessel density, and its AUROC reached 0.97. The diagnostic utility of perfusion density in the optic disc area was slightly lower than that of vessel density in the optic disc area. The best parameter was the central optic disc perfusion density, and its AUROC was 0.95. The SD-OCT-based diagnostic utility parameters were generally lower than that mentioned above, the top three parameters were the inferior RNFL thickness (AUROC=0.919), the superior (AUROC=0.919) and the inferior GCC thickness (AUROC=0.9077). CONCLUSION: The OCT-based diagnostic utility parameters are generally lower than the OCTA-based diagnostic utility parameters. OCTA has an important clinical application value in diagnosis and evaluation for less than 60-year-old patients with early POAG.

Tea pigments consisting of theabrownins (TBs), theaflavins (TFs), and thearubigins (TRs) affect the color and taste of tea. TBs include a variety of water-soluble compounds, but do not dissolve in n-butanol and ethyl acetate. Previously, the traditional method of TB extraction only mixed tea with n-butanol, and TBs were retained in the water phase. However, without ethyl acetate extraction, TFs and TRs remained in the water phase and affected the detection of TB content. Although an improved method had been devised by adding an ethyl acetate extraction step between tea production and n-butanol extraction, the proportional equation for calculating TB content (%) was not yet developed. In this study, we compared the absorbance at 380 nm (A380) of TB solutions from six major types of tea (green, yellow, oolong, white, black, and dark teas) extracted by improved and traditional methods from the same tea samples. Significantly lower A380 values were obtained from TB solutions via the improved method compared to the traditional method for six major types of tea, and the highest and lowest slops in TB concentrations from A380 analyses were from dark tea and green tea, respectively. Moreover, newly developed equations for TB content in those six tea types extracted by the improved methods were also established.

Abstract Background Pulmonary vein stenosis (PVS) after radiofrequency ablation for non-valvular atrial fibrillation (AF) is an uncommon but serious complication. PVS stenting can rapidly restore pulmonary flow and improve symptoms with long-term low incidence of restenosis. However, high risk of thrombosis remains if AF is recurrent, especially for CHA2DS2-VASc > 2. Case presentation A 67-year-old man with diabetes, hypertension and a history of stroke underwent radiofrequency pulmonary vein isolation for persistent AF 1 year ago. Six months later he developed recurrent respiratory infection and massive hemoptysis. Computed tomography pulmonary angiography revealed severe left pulmonary vein stenosis. Simultaneous percutaneous PVS stenting and left atrial appendage occlusion were performed to resolve recurrent hemoptysis and prevent stroke. The clinical follow-up indicated a good short and mid-term result with significant improvement of symptoms. Conclusions Simultaneous PVS stenting and left atrial appendage occlusion is feasible and effective in patients with recurrence of AF and hemoptysis induced by radiofrequency ablation for AF.

Abstract Background In cereal crop rice, auxin is known as an important class of plant hormone that regulates a plethora of plant growth and development. Glycosylation of auxin is known to be one of the important mechanisms mediating auxin homeostasis. However, the relevant auxin glucosyltransferase (GT) in rice still remains largely unknown. Results In this study, using known auxin glucosyltransferases from other species as queries, twelve putative auxin UDP-glycosyltransferase (UGT) genes were cloned from rice and the one showing highest sequence similarity, named as OsIAGT1, was expressed as recombinant protein. In vitro enzymatic analysis showed that recombinant OsIAGT1 was capable of catalyzing glucosylation of IAA, IBA and other auxin analogs, and that OsIAGT1 is quite tolerant to a broad range of reaction conditions with peak activity at 30 °С and pH 8.0. OsIAGT1 showed favorite activity towards native auxins over artificially synthesized ones. Further study indicated that expression of OsIAGT1 can be upregulated by auxin in rice, and with OsIAGT1 overexpressing lines we confirmed that OsIAGT1 is indeed able to glucosylate IAA in vivo. Consistently, ectopic expression of OsIAGT1 leads to declined endogenous IAA content, as well as upregulated auxin synthesis genes and reduced expression of auxin-responsive genes, which likely leads to the reduced plant stature and root length in OsIAGT1 overexpression lines. Conclusion Our result indicated that OsIAGT1 plays an important role in mediating auxin homeostasis by catalyzing auxin glucosylation, and by which OsIAGT1 regulates growth and development in rice.

Drought is one of the most important environmental constraints affecting plant growth and development and ultimately leads to yield loss. Uridine diphosphate (UDP)-dependent glycosyltransferases (UGTs) are believed to play key roles in coping with environmental stresses. In rice, it is estimated that there are more than 200 UGT genes. However, most of them have not been identified as their physiological significance. In this study, we reported the characterization of a putative glycosyltransferase gene UGT85E1 in rice. UGT85E1 gene is significantly upregulated by drought stress and abscisic acid (ABA) treatment. The overexpression of UGT85E1 led to an enhanced tolerance in transgenic rice plants to drought stress, while the ugt85e1 mutants of rice showed a more sensitive phenotype to drought stress. Further studies indicated that UGT85E1 overexpression induced ABA accumulation, stomatal closure, enhanced reactive oxygen species (ROS) scavenging capacity, increased proline and sugar contents, and upregulated expression of stress-related genes under drought stress conditions. Moreover, when UGT85E1 was ectopically overexpressed in Arabidopsis, the transgenic plants showed increased tolerance to drought as well as in rice. Our findings suggest that UGT85E1 plays an important role in mediating plant response to drought and oxidative stresses. This work may provide a promising candidate gene for cultivating drought-tolerant crops both in dicots and monocots.

Atherosclerosis is a chronic disease starting with the entry of monocytes into the subendothelium and the subsequent differentiation into macrophages. Macrophages are the major immune cells in atherosclerotic plaques and are involved in the dynamic progression of atherosclerotic plaques. The biological properties of atherosclerotic plaque macrophages determine lesion size, composition, and stability. The heterogenicity and plasticity of atherosclerotic macrophages have been a hotspot in recent years. Studies demonstrated that lipids, cytokines, chemokines, and other molecules in the atherosclerotic plaque microenvironment regulate macrophage phenotype, contributing to the switch of macrophages toward a pro- or anti-atherosclerosis state. Of note, M1/M2 classification is oversimplified and only represent two extreme states of macrophages. Moreover, M2 macrophages in atherosclerosis are not always protective. Understanding the phenotypic diversity and functions of macrophages can disclose their roles in atherosclerotic plaques. Given that lipid-lowering therapy cannot completely retard the progression of atherosclerosis, macrophages with high heterogeneity and plasticity raise the hope for atherosclerosis regression. This review will focus on the macrophage phenotypic diversity, its role in the progression of the dynamic atherosclerotic plaque, and finally discuss the possibility of treating atherosclerosis by targeting macrophage microenvironment.

AIM: To evaluate the efficacy of intravitreal injection of conbercept (IVC) and ranibizumab (IVR) in patients with diabetic macular edema. METHODS: Reviewers have searched 12 databases, including PubMed, Medline, EMBASE, Web of Science, Springer, ScienceDirect, OVID, Cochrane Library, ClinicalTrials.gov, cqVIP, WanFangdata and China National Knowledge Infrastructure (CNKI), up to December 28, 2018. RevMan 5.3 (Cochrane Library Software, Oxford, UK) was employed for statistical analysis. Fixed and random effects models were applied to assess heterogeneity. Odds ratio (OR) was applied for dichotomous variables; weighted mean difference (WMD) was applied for continuous variables. The confidence interval (CI) was set at 95%. Central macular thickness (CMT) and best-corrected visual acuity (BCVA) were employed to analyze the improvement of DME patients. Inclusion criteria for picking out studies were retrospective studies and randomized controlled trials (RCTs) that compared IVC and IVR for the treatment of diabetic macular edema. RESULTS: Four retrospective studies and five RCTs were included with a total of 609 patients. No statistically significant difference was observed in mean CMT and mean BCVA in the baseline parameters [BCVA (WMD: -0.48; 95%CI: -1.06 to 0.10; P=0.1), CMT (WMD: -0.83; 95%CI: -15.15 to 13.49; P=0.91). No significant difference was found in the improvement of BCVA and adverse event (AE) in IVC group, compared with IVR group after treatment of loading dosage [the 1st month BCVA (WMD: 0.01; 95%CI: -0.26 to 0.27; P=0.96), the 3rd month BCVA (WMD: -0.04; 95%CI: -0.14 to 0.06; P=0.46); the 6th month BCVA (WMD: -0.24; 95%CI: -1.62 to 1.14; P=0.73)], AE (OR: 0.84; 95%CI: 0.38 to 1.84; P=0.66)]. A slight difference was found in the effectiveness rate (OR: 1.70; 95%CI: 0.97 to 2.96; P=0.06), There were statistically significant differences between IVC and IVR treatment in terms of CMT [1st month CMT (WMD: -19.88; 95%CI: -27.94 to -11.82; P

Abiotic stresses greatly influence plant growth and productivity. While glycosyltransferases are widely distributed in plant kingdom, their biological roles in response to abiotic stresses are largely unknown. In this study, a novel Arabidopsis glycosyltransferase gene UGT85A5 was identified as significantly induced by salt stress. Ectopic expression of UGT85A5 in tobacco enhanced the salt stress tolerance in the transgenic plants. There were higher seed germination rates, better plant growth and less chlorophyll loss in transgenic lines compared to wild type plants under salt stress. This enhanced tolerance of salt stress was correlated with increased accumulations of proline and soluble sugars, but with decreases in malondialdehyde accumulation and Na(+)/K(+) ratio in UGT85A5-expressing tobacco. Furthermore, during salt stress, expression of several carbohydrate metabolism-related genes including those for sucrose synthase, sucrose-phosphate synthase, hexose transporter and a group2 LEA protein were obviously upregulated in UGT85A5-expressing transgenic plants compared with wild type controls. Thus, these findings suggest a specific protective role of this glycosyltransferase against salt stress and provide a genetic engineering strategy to improve salt tolerance of crops.

The nuclear factor Y (NF-Y), which is a ubiquitous transcription factor found in eukaryotes, is composed of three distinct subunits, namely, NF-YA, NF-YB, and NF-YC. Here, we firstly characterized the detailed function of the Arabidopsis NFYA1 factor. It is found that the 35S::AtNFYA1-overexpressed lines were hypersensitive to salt stress and Abscisic acid (ABA) during the early-postgermination growth stages. The transgenic lines exhibited a severe postgermination growth arrest compared with the wild-type (WT) under salt stress and ABA treatment. Interestingly, sodium tungstate, which is an ABA synthesis inhibitor, restored the salt-sensitive phenotype of the 35S::AtNFYA1 lines. Results of the qRT-PCR analysis showed that the mRNA levels of ABI3 and ABI5, as well as their downstream genes AtEM1 and AtEM6, were more greatly upregulated under salt stress during seed germination in the transgenic lines compared with those in WT. On the other hand, the NFYA1-RNAi lines were found to be insensitive to salt stress and exhibited decreased levels of ABI3, ABI5, EM1, and EM6 transcripts. Our results provide clear evidence supporting a role of AtNFYA1 in regulating postgermination growth arrest under salt stress.

Auxin is one type of phytohormones that plays important roles in nearly all aspects of plant growth and developmental processes. The glycosylation of auxins is considered to be an essential mechanism to control the level of active auxins. Thus, the identification of auxin glycosyltransferases is of great significance for further understanding the auxin regulation. In this study, we biochemically screened the group L of Arabidopsis thaliana glycosyltransferase superfamily for enzymatic activity toward auxins. UGT74D1 was identified to be a novel auxin glycosyltransferase. Through HPLC and LC-MS analysis of reaction products in vitro by testing eight substrates including auxins and other compounds, we found that UGT74D1 had a strong glucosylating activity toward indole-3-butyric acid [IBA], indole-3-propionic acid [IPA], indole-3-acetic acid [IAA] and naphthaleneacetic acid [NAA], catalyzing them to form corresponding glucose esters. Biochemical characterization showed that this enzyme had a maximum activity in HEPES buffer at pH 6.0 and 37°C. In addition, the enzymatic activity analysis of crude protein and the IBA metabolite analysis from transgenic Arabidopsis plants overexpressing UGT74D1 gene were also carried out. Experimental results indicated that over-production of the UGT74D1 in plants indeed led to increased level of the glucose conjugate of IBA. Moreover, UGT74D1 overexpression lines displayed curling leaf phenotype, suggesting a physiological role of UGT74D1 in affecting the activity of auxins. Our current data provide a new target gene for further genetic studies to understand the auxin regulation by glycosylation in plants.