ZmbZIP27 regulates nitrogen-mediated leaf angle by modulating lignin deposition in maize

In grain crops such as maize(Zea mays),leaf angle(LA)is a key agronomic trait affecting light interception and thus planting density and yield.Nitrogen(N)affects LA in plants,but we lack a good understanding of how N regulates LA.Here,we report that N deficiency enhanced lignin deposition in the ligular region of maize seedlings.In situ hybridization showed that the bZIP transcription factor gene ZmbZIP27 is mainly expressed in the phloem of maize vascular bundles.Under N-sufficient conditions,transgenic maize overexpressing ZmbZIP27 showed significantly smaller LA compared with wild type(WT).By contrast,zmbzip27_(ems)mutant showed larger LA under both N-deficient and N-sufficient conditions compared with WT.Overexpression of ZmbZIP27 enhanced lignin deposition in the ligular region of maize in the field.We further demonstrated that ZmbZIP27 could directly bind the promoters of the microRNA genes ZmMIR528a and ZmMIR528b and negatively regulate the expression levels of ZmmiR528.ZmmiR528 knockdown transgenic maize displayed erect architecture in the field by increasing lignin content in the ligular region of maize.Taken together,these results indicate that ZmbZIP27 regulates N-mediated LA size by regulating the expression of ZmmiR528 and modulating lignin deposition in maize.

Changes of serum inflammatory factors and miR-145 expression in patients with osteoarthritis before and after treatment and their clinical value

BACKGROUND Osteoarthritis is a chronic degenerative disease with an incidence of 50%in people over 65 years old and 80%in people over 80 years old worldwide.It is the second leading reason of loss of working capacity after cardiovascular diseases and severely affects the society and families.Therefore,finding biological markers related to the diagnosis and treatment of osteoarthritis is of great significance in clinical practice.AIM To observe the changes and clinical value of serum inflammatory factors and miR-145 expression in patients with osteoarthritis before and after treatment.METHODS Eighty-three patients with knee osteoarthritis(observation group)who were admitted to our hospital from April 2013 to June 2015,and 60 healthy people(control group)during the same period were selected.After 4 wk of treatment,the levels of miR-145,tumor necrosis factor(TNF)-α,interleukin(IL)-6,and IL-10 were compared between the control group and the observation group before treatment.The correlation of miR-145,TNF-α,IL-6,and IL-10 levels with visual analogue scale(VAS),Lysholm,and Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)scores was assessed by Pearson correlation analysis.The correlation of the expression of miR-145,TNF-α,IL-6,and IL-10 with Kellgren-Lawrence(K-L)grades was assessed by Spearman correlation analysis.The critical levels of miR-145,TNF-α,IL-6,and IL-10 in distinguishing different K-L grades were determined by receiver operating characteristic(ROC)curve analysis.RESULTS The expression level of miR-145 in the observation group was significantly higher than that in the control group before treatment(P<0.05).After treatment,the expression level of miR-145 in the observation group was significantly lower than that before treatment(P<0.05).The levels of TNF-αand IL-6 in the observation group were significantly higher than those in the control group(P<0.05),and the level of IL-10 was significantly lower than that in the control group(P<0.05).After treatment,the levels of TNF-αand IL-6 in the observation group were significantly lower than those before treatment(P<0.05),and IL-I0 level was significantly higher than that before treatment(P<0.05).VAS and WOMAC scores were both positively correlated with miR-145,TNF-α,and IL-6(P<0.05),and negatively correlated with IL-10(P<0.05),while Lysholm scores were negatively correlated with miR-145,TNF-α,and IL-6(P<0.05),and positively correlated with IL-10(P<0.05).K-L grades were positively correlated with miR-145,TNF-α,and IL-6(P<0.05),and negatively correlated with IL-10(P<0.05).The area under the ROC curve(AUC)and specificity of TNF-αin differentiating K-L grades I-II were the highest,which were 0.785 and 97.45%,respectively,and miR145 had the highest sensitivity of 94.59%;the AUC and sensitivity of IL-6 in differentiating K-L grades II-III were the highest,which were 0.766 and 97.30%,respectively,and TNF-αhad the highest specificity of 86.68%.CONCLUSION MiR-145 and inflammatory factors have certain diagnostic value in osteoarthritis,and they are expected to become potential indicators for the diagnosis and evaluation of osteoarthritis in the future.

Discovery of the Ca-Cl type brine in deep aquifers and implications for the shallow giant glauberite deposits in the Lop Nur playa, Tarim Basin, NW China

1.Objective Lop Nur is currently one of the world’s largest playa and located in the easternmost of the Tarim Basin,northwestern China.It developed unique giant glauberite deposits during the Quaternary,of which analogue with such a scale deposit is rarely seen around the world.Moreover,potassium-rich brine hosted in these glauberite intercrystalline contains a resource of KCl up to 0.25×10^(9) t.

Factors affecting genomic selection revealed by empirical evidence in maize

Genomic selection(GS) as a promising molecular breeding strategy has been widely implemented and evaluated for plant breeding, because it has remarkable superiority in enhancing genetic gain, reducing breeding time and expenditure, and accelerating the breeding process. In this study the factors affecting prediction accuracy(rMG) in GS were evaluated systematically, using six agronomic traits(plant height, ear height, ear length, ear diameter,grain yield per plant and hundred-kernel weight) evaluated in one natural and two biparental populations. The factors examined included marker density, population size, heritability,statistical model, population relationships and the ratio of population size between the training and testing sets, the last being revealed by resampling individuals in different proportions from a population. Prediction accuracy continuously increased as marker density and population size increased and was positively correlated with heritability; rMGshowed a slight gain when the training set increased to three times as large as the testing set. Low predictive performance between unrelated populations could be attributed to different allele frequencies, and predictive ability and prediction accuracy could be improved by including more related lines in the training population. Among the seven statistical models examined, including ridge regression best linear unbiased prediction(RR-BLUP), genomic BLUP(GBLUP), Bayes A, Bayes B, Bayes C, Bayesian least absolute shrinkage and selection operator(Bayesian LASSO), and reproducing kernel Hilbert space(RKHS), the RKHS and additive-dominance model(Add + Dom model) showed credible ability for capturing non-additive effects, particularly for complex traits with low heritability. Empirical evidence generated in this study for GS-relevant factors will help plant breeders to develop GS-assisted breeding strategies for more efficient development of varieties.

Identification of traits and genes associated with lodging resistance in maize

Lodging is a major problem limiting maize yield worldwide. However, the mechanisms of lodging resistance remain incompletely understood for maize. Here, we evaluated 443 maize accessions for lodging resistance in the field. Five lodging-resistant accessions and five lodging-sensitive accessions were selected for further research. The leaf number, plant height, stem diameter, and rind penetrometer resistance were similar between lodging-resistant and-sensitive inbred lines. The average thickness of sclerenchymatous hypodermis layer was thicker and the vascular area was larger in the lodging-resistant lines compared with lodging-sensitive lines. Although total lignin content in stem tissue did not significantly differ between lodging-resistant and-sensitive lines, phloroglucinol staining revealed that the lignin content of the cell wall in the stem cortex and in the stem vascular tissue near the cortex was higher in the lodging-resistant lines than in the lodging-sensitive lines. Analysis of strand-specific RNA-seq transcriptome showed that a total of 793 genes were up-regulated and 713 genes were down-regulated in lodging-resistant lines relative to lodging-sensitive lines. The up-regulated genes in lodging-resistant lines were enriched in cell wall biogenesis. These results indicated that modification of cell wall biosynthesis would contribute to lodging resistance of maize.

Non-conventional peptides in plants:From gene regulation to crop improvement

Conventional peptides(CPs)and non-conventional peptides(NCPs)are generated from small open reading frames,but most CPs are derived from large precursors.NCPs,which are derived from sequences other than conventional open reading frames or annotated coding sequences regions,function in plant development and adaptation to stresses.Ribosome profiling,a technique for studying translational regulation,can be used to identify NCPs.Another new technique,peptidogenomics,which integrates mass spectrometry and genomics,is becoming more widely used for identifying plant NCPs.In recent years,numerous studies have investigated the roles in monocots and dicots of miRNA-derived peptides and upstream open reading frames,which have potential for improving agronomic traits.Investigating the biological functions of NCPs will advance molecular plant breeding by identifying regulators of plant growth and development.We present an overview of NCP identification methods and recent findings about NCP biological functions.

MicroRNA528 Affects Lodging Resistance of Maize by Regulating Lignin Biosynthesis under Nitrogen-Luxury Conditions

Lodging under nitrogen （N）-Iuxury conditions substantially reduces crop yield and seed quality. However, the molecular mechanisms of plant lodging resistance remain largely unclear, especially in maize. We report here that the expression of ZmmiR528, a monocot-specific microRNA, is induced by N luxury but reduced by N deficiency. We show by the thioacidolysis and acetyl bromide analysis that N luxury signifi- cantly reduces the generation of H, G, and S monomers of the lignin as well as its total content in maize shoots. We further demonstrate that ZmLACCASE3 （ZmLAC3） and ZmLACCASE5 （ZmLAC5）, which encode the copper-containing laccases, are the targets of ZmmiR528. In situ hybridization showed that ZmmiR528 is mainly expressed in maize vascular tissues. Knockdown of ZmmiR528 or overexpression of ZmLAC3 significantly increased the lignin content and rind penetrometer resistance of maize stems. In contrast, transgenic maize plants overexpressing ZmmiR528 had reduced lignin content and rind penetrometer resistance and were prone to lodging under N-luxury conditions. RNA-sequencing analysis revealed that ZmPAL7 and ZmPAL8 are upregulated in transgenic maize lines downregulating ZmmiR528. Under N-lux- ury conditions, the expression levels of ZmPALs were much higher in ZmmiR528-knockdown lines than in the wild type and transgenic maize lines overexpressing ZmmiR528. Taken together, these results indicate that, by regulating the expression of ZmLAC3 and ZmLAC5, ZmmiR528 affects maize lodging resistance un- der N-luxury conditions.

The development of laser-produced plasma EUV light source

Extreme ultraviolet lithography(EUVL)has been demonstrated to meet the industrial requirements of new-generation semiconductor fabrication.The development of high-power EUV sources is a long-term critical challenge to the implementation of EUVL in high-volume manufacturing(HVM),together with other technologies such as photoresist and mask.Historically,both theoretical studies and experiments have clearly indicated that the CO 2 laser-produced plasma(LPP)system is a promising solution for EUVL source,able to realize high conversion efficiency(CE)and output power.Currently,ASML’s NXE:3400B EUV scanner configuring CO_(2) LPP source sys-tem has been installed and operated at chipmaker customers.Mean-while,other research teams have made different progresses in the development of LPP EUV sources.However,in their technologies,some critical areas need to be further improved to meet the requirements of 5 nm node and below.Critically needed improvements include higher laser power,stable droplet generation system and longer collector life-time.In this paper,we describe the performance characteristics of the laser system,droplet generator and mirror collector for different EUV sources,and also the new development results.

The long non-coding RNA PILNCR2 increases low phosphate tolerance in maize by interfering with miRNA399-guided cleavage of ZmPHT1s

Theopen reading regions of ZmPHT1s(inorganic phosphate[Pij transporters)inmaize possess target sites of microRNA399(miR399).However,the relationship between miR399 and ZmPHT1s and its functional importance in response to Pi deficiency remain to be explored.We show here that ZmPHT1;1,ZmPHT1;3,and ZmPHT1;13 are the targets of ZmmiRNA399.We found that a long non-coding RNA,PILNCR2(Pi-deficiency-induced IncRNA 2),is transcribed from the opposing DNA strand of ZmPHT1;1 and predominantly localized in the cytoplasm.A ribonuclease protection assay and an RNA-RNA binding assay showed that PILNCR2 and ZmPHT1s could form the RNA/RNA duplexes in vivo and in vitro.A co-expression assay in N.benthamiana revealed that the PILNCR2/ZmPHT1 RNA/RNA duplexes interfere with miR399-guided cleavage of ZmPHT1 mRNAs.Overexpression of PILNCR2 increased low-Pi tolerance in maize,whereas its knockout and knockdown decreased low-Pi tolerance in maize.Consistently,ZmPHT1;3 and ZmPHT1;13 mRNA abundance was increased in transgenic plants overexpressing PILNCR2 but reduced in its knock-out mutants,suggesting that PILNCR2 positively regulates the mRNA abundance of ZmPHT1;3 and ZmPHT1;13 in maize.Collectively,these results indicate that PILNCR2 plays an important role in maize Pihomeostasisby interfering with miRNA399-guided cleavageof ZmPHT1mRNAs.

Nitrogen supply affects ion homeostasis by modifying root Casparian strip formation through the miR528-LAC3 module in maize

Although nitrogen(N)is known to affect mineral element homeostasis in plants,the molecular mechanisms of interactions between N and other nutrients remain largely unclear.Wereport here that N supply affects ion homeostasis inmaize.Berberine hemisulfate staining and a propidiumiodide penetration assay showed that N luxury significantly delayed Casparian strip(CS)formation in maize roots.We further demonstrated that N-mediated CS formation in maize was independent of RBOHF-activated H2O2 production.N luxury induced the expression of ZmmiR528 inwhole roots and root tips.Knockdown and loss-of-function ofZmmiR528 promoted CS formation under both N-luxury and N-deficient conditions.Both ZmMIR528a and ZmMIR528b contribute to early CS formation under different N conditions.RNA-seq and real-time RT-PCR analysis demonstrated that ZmLAC3,but not ZmLAC5,responded to N treatments.Consistent with results obtained with ZmmiR528 TM transgenic maize and mir528a/b loss-of-function mutants,transgenic maize overexpressing ZmLAC3 displayed early CS formation under different N conditions.Under field conditions,K,Ca,Mn,Cu,Mg,and Zn concentrations were greater in the ear leaf of ZmLAC3-overexpressing transgenicmaize than in the wild type.These results indicate that ZmmiR528 affects CS formation in maize by regulating the expression of ZmLAC3,and modification of CS formation has the potential to improve maize quality.

Identification and functional characterization of the AGO1 ortholog in maize

Eukaryotic Argonaute proteins play primary roles in mi RNA and si RNA pathways that are essential for numerous developmental and biological processes. However, the functional roles of the four Zm AGO1 genes have not yet been characterized in maize（Zea mays L.）. In the present study, Zm AGO1 a was identified from four putative Zm AGO1 genes for further characterization. Complementation of the Arabidopsis ago1-27 mutant with Zm AGO1 a indicated that constitutive overexpression of Zm AGO1 a could restore the smaller rosette, serrated leaves, later flowering and maturation, lower seed set, and darker green leaves at late stages of the mutant to the wild-type phenotype. The expression profiles of Zm AGO1 a under five different abiotic stresses indicated that Zm AGO1 a shares expression patterns similar to those of Argonaute genes in rice, Arabidopsis, and wheat.Further, variation in Zm AGO1 a alleles among diverse maize germplasm that resulted in several amino acid changes revealed genetic diversity at this locus. The present data suggest that Zm AGO1 a might be an important AGO1 ortholog in maize. The results presented provide further insight into the function of ZmAGO1a.