A dynamic phosphoproteomic analysis provides insight into the C4 plant maize (Zea mays L.) response to natural diurnal changes.

As sessile organisms, plants need to respond to rapid changes in numerous environmental factors, mainly diurnal changes of light, temperature, and humidity. Maize is the world's most grown crop, and as a C4 plant it exhibits high photosynthesis capacity, reaching the highest rate of net photosynthesis at midday; that is, there is no "midday depression." Revealing the physiological responses to diurnal changes and underlying mechanisms will be of great significance for guiding maize improvement efforts. In this study, we collected maize leaf samples and analyzed the proteome and phosphoproteome at nine time points during a single day/night cycle, quantifying 7424 proteins and 5361 phosphosites. The new phosphosites identified in our study increased the total maize phosphoproteome coverage by 8.5%. Kinase-substrate network analysis indicated that 997 potential substrates were phosphorylated by 20 activated kinases. Through analysis of proteins with significant changes in abundance and phosphorylation, we found that the response to a heat stimulus involves a change in the abundance of numerous proteins. By contrast, the high light at noon and rapidly changing light conditions induced changes in the phosphorylation level of proteins involved in processes such as chloroplast movement, photosynthesis, and C4 pathways. Phosphorylation is involved in regulating the activity of large number of enzymes; for example, phosphorylation of S55 significantly enhanced the activity of maize phosphoenolpyruvate carboxykinase1 (ZmPEPCK1). Overall, the database of dynamic protein abundance and phosphorylation we have generated provides a resource for the improvement of C4 crop plants.

The C4 photosynthesis bifunctional enzymes, PDRPs, of maize are co-opted to cytoplasmic viral replication complexes to promote infection of a prevalent potyvirus sugarcane mosaic virus.

In maize, two pyruvate orthophosphate dikinase (PPDK) regulatory proteins, ZmPDRP1 and ZmPDRP2, are respectively specific to the chloroplast of mesophyll cells (MCs) and bundle sheath cells (BSCs). Functionally, ZmPDRP1/2 catalyse both phosphorylation/inactivation and dephosphorylation/activation of ZmPPDK, which is implicated as a major rate-limiting enzyme in C4 photosynthesis of maize. Our study here showed that maize plants lacking ZmPDRP1 or silencing of ZmPDRP1/2 confer resistance to a prevalent potyvirus sugarcane mosaic virus (SCMV). We verified that the C-terminal domain (CTD) of ZmPDRP1 plays a key role in promoting viral infection while independent of enzyme activity. Intriguingly, ZmPDRP1 and ZmPDRP2 re-localize to cytoplasmic viral replication complexes (VRCs) following SCMV infection. We identified that SCMV-encoded cytoplasmic inclusions protein CI targets directly ZmPDRP1 or ZmPDRP2 or their CTDs, leading to their re-localization to cytoplasmic VRCs. Moreover, we found that CI could be degraded by the 26S proteasome system, while ZmPDRP1 and ZmPDRP2 could up-regulate the accumulation level of CI through their CTDs by a yet unknown mechanism. Most importantly, with genetic, cell biological and biochemical approaches, we provide evidence that BSCs-specific ZmPDRP2 could accumulate in MCs of Zmpdrp1 knockout (KO) lines, revealing a unique regulatory mechanism crossing different cell types to maintain balanced ZmPPDK phosphorylation, thereby to keep maize normal growth. Together, our findings uncover the genetic link of the two cell-specific maize PDRPs, both of which are co-opted to VRCs to promote viral protein accumulation for robust virus infection.

Gene duplications facilitate C4-CAM compatibility in common purslane.

Common purslane (Portulaca oleracea) integrates both C4 and crassulacean acid metabolism (CAM) photosynthesis pathways and is a promising model plant to explore C4-CAM plasticity. Here, we report a high-quality chromosome-level genome of nicotinamide adenine dinucleotide (NAD)-malic enzyme (ME) subtype common purslane that provides evidence for 2 rounds of whole-genome duplication (WGD) with an ancient WGD (P-ß) in the common ancestor to Portulacaceae and Cactaceae around 66.30 million years ago (Mya) and another (Po-α) specific to common purslane lineage around 7.74 Mya. A larger number of gene copies encoding key enzymes/transporters involved in C4 and CAM pathways were detected in common purslane than in related species. Phylogeny, conserved functional site, and collinearity analyses revealed that the Po-α WGD produced the phosphoenolpyruvate carboxylase-encoded gene copies used for photosynthesis in common purslane, while the P-ß WGD event produced 2 ancestral genes of functionally differentiated (C4- and CAM-specific) beta carbonic anhydrases involved in the C4 + CAM pathways. Additionally, cis-element enrichment analysis in the promoters showed that CAM-specific genes have recruited both evening and midnight circadian elements as well as the Abscisic acid (ABA)-independent regulatory module mediated by ethylene-response factor cis-elements. Overall, this study provides insights into the origin and evolutionary process of C4 and CAM pathways in common purslane, as well as potential targets for engineering crops by integrating C4 or CAM metabolism.

Integrating ATAC-seq and RNA-seq to identify differentially expressed genes with chromatin-accessible changes during photosynthetic establishment in Populus leaves.

Leaves are the primary photosynthetic organs, providing essential substances for tree growth. It is important to obtain an anatomical understanding and regulatory network analysis of leaf development. Here, we studied leaf development in Populus Nanlin895 along a development gradient from the newly emerged leaf from the shoot apex to the sixth leaf (L1 to L6) using anatomical observations and RNA-seq analysis. It indicated that mesophyll cells possess obvious vascular, palisade, and spongy tissue with distinct intercellular spaces after L3. Additionally, vacuoles fuse while epidermal cells expand to form pavement cells. RNA-seq analysis indicated that genes highly expressed in L1 and L2 were related to cell division and differentiation, while those highly expressed in L3 were enriched in photosynthesis. Therefore, we selected L1 and L3 to integrate ATAC-seq and RNA-seq and identified 735 differentially expressed genes (DEGs) with changes in chromatin accessibility regions within their promoters, of which 87 were transcription factors (TFs), such as ABI3VP1, AP-EREBP, MYB, NAC, and GRF. Motif enrichment analysis revealed potential regulatory functions for the DEGs through upstream TFs including TCP, bZIP, HD-ZIP, Dof, BBR-BPC, and MYB. Overall, our research provides a potential molecular foundation for regulatory network exploration in leaf development during photosynthesis establishment.

OsTST1, a key tonoplast sugar transporter from source to sink, plays essential roles in affecting yields and height of rice (Oryza sativa L.).

MAIN CONCLUSION: OsTST1 affects yield and development and mediates sugar transportation of plants from source to sink in rice, which influences the accumulation of intermediate metabolites from tricarboxylic acid cycle indirectly. Tonoplast sugar transporters (TSTs) are essential for vacuolar sugar accumulation in plants. Carbohydrate transport across tonoplasts maintains the metabolic balance in plant cells, and carbohydrate distribution is crucial to plant growth and productivity. Large plant vacuoles store high concentrations of sugars to meet plant requirements for energy and other biological processes. The abundance of sugar transporter affects crop biomass and reproductive growth. However, it remains unclear whether the rice (Oryza sativa L.) sugar transport protein OsTST1 affects yield and development. In this study, we found that OsTST1 knockout mutants generated via CRISPR/Cas9 exhibited slower development, smaller seeds, and lower yield than wild type (WT) rice plants. Notably, plants overexpressing OsTST1 showed the opposite effects. Changes in rice leaves at 14 days after germination (DAG) and at 10 days after flowering (DAF) suggested that OsTST1 affected the accumulation of intermediate metabolites from the glycolytic pathway and the tricarboxylic acid (TCA) cycle. The modification of the sugar transport between cytosol and vacuole mediated by OsTST1 induces deregulation of several genes including transcription factors (TFs). In summary, no matter the location of sucrose and sink is, these preliminary results revealed that OsTST1 was important for sugar transport from source to sink tissues, thus affecting plant growth and development.

Deep neural network for modeling soliton dynamics in the mode-locked laser.

Integrating the information of the first cycle of an optical pulse in a cavity into the input of a neural network, a bidirectional long short-term memory (Bi_LSTM) recurrent neural network (RNN) with an attention mechanism is proposed to predict the dynamics of a soliton from the detuning steady state to the stable mode-locked state. The training and testing are based on two typical nonlinear dynamics: the conventional soliton evolution from various saturation energies and soliton molecule evolution under different group velocity dispersion coefficients of optical fibers. In both cases, the root mean square error (RMSE) for 80% of the test samples is below 15%. In addition, the width of the conventional soliton pulse and the pulse interval of the soliton molecule predicted by the neural network are consistent with the experimental results. These results provide a new insight into the nonlinear dynamics modeling of the ultrafast fiber laser.

PT-symmetric solitons and parameter discovery in self-defocusing saturable nonlinear Schrödinger equation via LrD-PINN.

We propose a physical information neural network with learning rate decay strategy (LrD-PINN) to predict the dynamics of symmetric, asymmetric, and antisymmetric solitons of the self-defocusing saturable nonlinear Schrödinger equation with the PT-symmetric potential and boost the predicted evolutionary distance by an order of magnitude. Taking symmetric solitons as an example, we explore the advantages of the learning rate decay strategy, analyze the anti-interference performance of the model, and optimize the network structure. In addition, the coefficients of the saturable nonlinearity strength and the modulation strength in the PT-symmetric potential are reconstructed from the dataset of symmetric soliton solutions. The application of more advanced machine learning techniques in the field of nonlinear optics can provide more powerful tools and richer ideas for the study of optical soliton dynamics.

OsAPL controls the nutrient transport systems in the leaf of rice (Oryza sativa L.).

MAIN CONCLUSION: OsAPL positively controls the seedling growth and grain size in rice by targeting the plasma membrane H+-ATPase-encoding gene, OsRHA1, as well as drastically affects genes encoding H+-coupled secondary active transporters. Nutrient transport is a key component of both plant growth and environmental adaptation. Photosynthates and nutrients produced in the source organs (e.g., leaves) need to be transported to the sink organs (e.g., seeds). In rice, the unloading of nutrients occurs through apoplastic transport (i.e., across the membrane via transporters) and is dependent on the efficiency and number of transporters embedded in the cell membrane. However, the genetic mechanisms underlying the regulation of these transporters remain to be determined. Here we show that rice (Oryza sativa L., Kitaake) ALTERED PHLOEM DEVELOPMENT (OsAPL), homologous to a MYB family transcription factor promoting phloem development in Arabidopsis thaliana, regulates the number of transporters in rice. Overexpression of OsAPL leads to a 10% increase in grain yield at the heading stage. OsAPL acts as a transcriptional activator of OsRHA1, which encodes a subunit of the plasma membrane H+-ATPase (primary transporter). In addition, OsAPL strongly affects the expression of genes encoding H+-coupled secondary active transporters. Decreased expression of OsAPL leads to a decreased expression level of nutrient transporter genes. Taken together, our findings suggest the involvement of OsAPL in nutrients transport and crop yield accumulation in rice.

PdeHCA2 affects biomass in Populus by regulating plant architecture, the transition from primary to secondary growth, and photosynthesis.

MAIN CONCLUSION: PdeHCA2 regulates the transition from primary to secondary growth, plant architecture, and affects photosynthesis by targeting PdeBRC1 and controlling the anatomy of the mesophyll, and intercellular space, respectively. Branching, secondary growth, and photosynthesis are vital developmental processes of woody plants that determine plant architecture and timber yield. However, the mechanisms underlying these processes are unknown. Here, we report that the Populus transcription factor High Cambium Activity 2 (PdeHCA2) plays a role in the transition from primary to secondary growth, vascular development, and branching. In Populus, PdeHCA2 is expressed in undifferentiated provascular cells during primary growth, in phloem cells during secondary growth, and in leaf veins, which is different from the expression pattern of its homolog in Arabidopsis. Overexpression of PdeHCA2 has pleiotropic effects on shoot and leaf development; overexpression lines showed delayed growth of shoots and leaves, reduced photosynthesis, and abnormal shoot branching. In addition, auxin-, cytokinin-, and photosynthesis-related genes were differentially regulated in these lines. Electrophoretic mobility shift assays and transcriptome analysis indicated that PdeHCA2 directly up-regulates the expression of BRANCHED1 and the MADS-box gene PdeAGL9, which regulate plant architecture, by binding to cis-elements in the promoters of these genes. Taken together, our findings suggest that HCA2 regulates several processes in woody plants including vascular development, photosynthesis, and branching by affecting the proliferation and differentiation of parenchyma cells.

Towards compact and snapshot channeled Mueller matrix imaging.

A polarization transformation can be fully described by a 4 × 4 matrix, known as the Mueller matrix. To fully image an object's polarization response, one needs to compute the Mueller matrix at each pixel of the image. Standard divison-of-time Mueller matrix imaging, because of its sequential nature, is ill-suited to applications requiring immediate and real-time imaging and is also bulky owing to multiple moving parts. In this work, we propose a new method for compact, snapshot Mueller matrix imaging, based on structured polarization illumination, and division-of-focal plane imaging, which can, in a single-shot, fully capture the Mueller matrix information of a band-limited signal.

A simple fluorescent strategy for liver capillary labeling with carbon quantum dot-lectin nanoprobe.

Taking the hepatic sinusoid (HS) as the main delivery area of liver nutrients and metabolic waste, recognizing its structure is important for a deep understanding of liver function. In this paper, based on lycopersicon esculentum lectin (LEL), with targeting ability for endothelial cells, and carbon quantum dots (CQDs), with high biosafety, an LEL-coupled CQD immunofluorescence probe (CQD@LEL) that can label microvessels is designed and used for the fluorescence labeling and imaging of HS in liver tissue sections. The CQD size is approximately 2 nm. Blue fluorescence is emitted under excitation; its optimal excitation wavelength is 400 nm while the emission is at about 450 nm. Gel electrophoresis and capillary electrophoresis confirm that glutaraldehyde can couple LEL to CQD, and the obtained CQD@LEL retains the fluorescence property and has good stability. Optimization experiments show that its labeling effect is positively correlated with time and probe concentration for dyeing the blood vessels of mouse liver slices. In order to improve the effect further, a probe concentration of 0.17 mg mL-1 and incubation time of 3 h were chosen to label the liver tissue sections. The results show that the liver microvessels are formed by interstitial structures among the hepatic cords, and the HS presents a granular or patchy appearance. H&E and ultrathin section TEM show that the microvascular wall of the liver is composed of discontinuous endothelial cells, and there are Kupffer cells and other cells in the tubes, proving that our probe can clearly label the structure and morphology of liver microvessels. This work is of great significance for the visualization of HS.

The deubiquitinase OTUB1 fosters papillary thyroid carcinoma growth through EYA1 stabilization.

Deubiquitinating enzyme OTU domain-containing ubiquitin aldehyde-binding proteins 1 (OTUB1) has been shown to have an essential role in multiple carcinomas. However, the function of OTUB1 in papillary thyroid cancer (PTC) and the underlying mechanisms regulating PTC cells proliferation remain poorly understood. In this study, OTUB1 was significantly upregulated in papillary thyroid carcinoma tissues and cells. Through in vitro and in vivo experiments, knockdown of OTUB1 suppressed PTC cells growth whereas OTUB1 overexpression enhanced the proliferation ability of PTC cells. Moreover, the eyes absent homologue 1 (EYA1) was recognized as a potential target of OTUB1 through mass spectrometry analysis, and we further verified that EYA1 protein level was positively correlated with OTUB1 expression in PTC cells and clinical samples. Mechanistically, OTUB1 could interact with EYA1 directly and deubiquitinate EYA1 to stabilize it. At last, EYA1 was found to play an essential role in OTUB1-derived PTC cells growth. Overall, our investigation reveals that OTUB1 is a previously unrecognized oncogenic factor in PTC cells proliferation and suggests that OTUB1 might be a novel therapeutic target in PTC.

Neurodevelopmental outcome at 1 year in offspring of women with gestational diabetes mellitus.

OBJECTIVE: To study the metabolic derangements in the second half of pregnancy caused by gestational diabetes mellitus(GDM), on the short term neurodevelopment of infants. DESIGN: A prospective cohort study of 555 mother-child pairs were recruited, which included 177 GDM patients and 378 pregnant women with normal glucose tolerance as controls. Clinical and demographic characteristics were obtained at enrollment, birth and follow-up. Neurodevelopment was examined with the Bayley Scales of Infant Development V.1 mental development index (MDI) and psychomotor development index (PDI). Fatty acids (FA) were analyzed by gas chromatography mass spectrometry (GC-MS). RESULTS: Statistically significant differences were found between the two groups in fasting plasma glucose (FPG) and triglyceride (TG). The scores of MDI and PDI of control group were higher than those of GDM group. The regression analysis showed that maternal age and saturated fatty acid (SFA) were independently associated with lower scores on the MDI whereas gestational age and docosahexaenoic acid (DHA) were associated with higher scores; in addition, lower scores on the PDI were associated with FPG and neonatal weigh associated with higher scores. CONCLUSION: SFA, DHA and FPG as indicators of lipid metabolism were associated with neurodevelopmental outcome at 1 year in offspring of women with gestational diabetes mellitus. Control the level of blood glucose and lipid during pregnancy and the appropriate supplementation of DHA during pregnancy in the second half of pregnancy may be beneficial to the neurodevelopment of infants.

Genome-wide transcriptome and proteome profiles indicate an active role of alternative splicing during de-etiolation of maize seedlings.

MAIN CONCLUSION: AS events affect genes encoding protein domain composition and make the single gene produce more proteins with a certain number of genes to satisfy the establishment of photosynthesis during de-etiolation. The drastic switch from skotomorphogenic to photomorphogenic development is an excellent system to elucidate rapid developmental responses to environmental stimuli in plants. To decipher the effects of different light wavelengths on de-etiolation, we illuminated etiolated maize seedlings with blue, red, blue-red mixed and white light, respectively. We found that blue light alone has the strongest effect on photomorphogenesis and that this effect can be attributed to the higher number and expression levels of photosynthesis and chlorosynthesis proteins. Deep sequencing-based transcriptome analysis revealed gene expression changes under different light treatments and a genome-wide alteration in alternative splicing (AS) profiles. We discovered 41,188 novel transcript isoforms for annotated genes, which increases the percentage of multi-exon genes with AS to 63% in maize. We provide peptide support for all defined types of AS, especially retained introns. Further in silico prediction revealed that 58.2% of retained introns have changes in domains compared with their most similar annotated protein isoform. This suggests that AS acts as a protein function switch allowing rapid light response through the addition or removal of functional domains. The richness of novel transcripts and protein isoforms also demonstrates the potential and importance of integrating proteomics into genome annotation in maize.

Ion Current Rectification in High-Salt Environment from Mesoporous TiO2 Microplug in Situ Grown at the Tip of a Micropipette Induced by Space-Confined Evaporation.

In this work, in situ growth of a titanium dioxide microplug (TDMP) having mesoporous channels at the tip of a glass micropipette induced by space-confined evaporation is reported. Moreover, clear ion current rectification (ICR) of a single-material nanopore in a saturated potassium chloride solution is observed for the first time. TDMP presents an asymmetrical channel structure with the top and bottom apertures of 12.3 ± 6.1 and 42.6 ± 19.7 nm, respectively. TDMP exhibits outstanding ICR capability as the ions get transported through it due to the applied potential. The values for the rectification coefficient (r = log2|I+1 V/I-1 V|) in a saturated KCl solution under acidic (pH of 3.0) and alkaline (pH of 10.0) environments are 1.32 and -0.84, respectively. The intensity and direction of ICR can be adjusted by pH or through the modification of citric acid. Meanwhile, the length and ion transport behavior of TDMP under different growth conditions (time and diameter) were also investigated. TDMP with asymmetric mesoporous channels, maintaining ICR in a saturated salt solution, is expected to expand the application of nanopores in high-salt environments. Furthermore, growth of mesoporous material in the micropipette facilitates the miniaturization of the nanopore device, which further promotes its application potential.

The developmental dynamics of the Populus stem transcriptome.

The Populus shoot undergoes primary growth (longitudinal growth) followed by secondary growth (radial growth), which produces biomass that is an important source of energy worldwide. We adopted joint PacBio Iso-Seq and RNA-seq analysis to identify differentially expressed transcripts along a developmental gradient from the shoot apex to the fifth internode of Populus Nanlin895. We obtained 87 150 full-length transcripts, including 2081 new isoforms and 62 058 new alternatively spliced isoforms, most of which were produced by intron retention, that were used to update the Populus annotation. Among these novel isoforms, there are 1187 long non-coding RNAs and 356 fusion genes. Using this annotation, we found 15 838 differentially expressed transcripts along the shoot developmental gradient, of which 1216 were transcription factors (TFs). Only a few of these genes were reported previously. The differential expression of these TFs suggests that they may play important roles in primary and secondary growth. AP2, ARF, YABBY and GRF TFs are highly expressed in the apex, whereas NAC, bZIP, PLATZ and HSF TFs are likely to be important for secondary growth. Overall, our findings provide evidence that long-read sequencing can complement short-read sequencing for cataloguing and quantifying eukaryotic transcripts and increase our understanding of the vital and dynamic process of shoot development.

Focal segmental glomerulosclerosis, excluding atypical lesion, is a predictor of renal outcome in patients with membranous nephropathy: a retrospective analysis of 716 cases.

BACKGROUND: Focal segmental lesions (FSLs) are not uncommon in idiopathic membranous nephropathy (IMN). The reported percentage of IMN patients with focal segmental glomerulosclerosis (FSGS) lesions varies widely between studies. The objective of this study was to differentiate atypical FSL (aFSL) from typical FSGS in IMN and to analyse the clinicopathological predictors of primary outcome of IMN patients. METHODS: A total of 716 patients with biopsy-proven IMN between January 1, 2007 and December 31, 2017 were enrolled in the study. An atypical focal segmental lesion was defined as pure synechia, segmental hyperplasia of podocytes or thickening of the GBM accompanied by proliferation of the mesangial matrix, and absence of typical FSGS. The patients were divided into three groups: patients without FSL (FSL-), patients with typical FSGS (FSGS+), and patients with aFSL (aFSL+).The primary outcome was a 50% decline in the initial estimated glomerular filtration rate or end-stage renal disease (ESRD) incidence. Secondary outcomes included all-cause death and ESRD. RESULTS: FSGS was present in 174 patients, while aFSL was noted in 161 patients. Systolic blood pressure was higher in both aFSL+ group and FSGS+ groups compared with the FSL- group. IMN patients without FSL and with aFSL had lower serum creatinine levels than IMN patients with FSGS. Both the FSGS+ and aFSL+ groups had higher levels of proteinuria and lower albumin levels than the FSL- group. Renal tissue lesions, including tubulointerstitial fibrosis, glomerular obsolescence, and vascular sclerosis were significantly more severe in the FSGS+ group. Cox multivariate analysis showed that older age ≥ 60 years, eGFR< 60 ml/(min·1.73m2), tubulointerstitial fibrosis area ≥ 15% and FSGS at biopsy were independent risk factors for the primary outcome. CONCLUSIONS: No significant difference in outcome was found between the FSL- and aFSL+ groups, although the patients with aFSL had lower levels of serum albumin and eGFR, higher level of urinary protein, more severe renal lesions with proliferation of the mesangial area,tubulointerstitial fibrosis and vascular sclerosis. FSGS, excluding atypical lesions, was an independent predictor of the primary outcome.

Dynamic N-glycoproteome analysis of maize seedling leaves during de-etiolation using Concanavalin A lectin affinity chromatography and a nano-LC-MS/MS-based iTRAQ approach.

KEY MESSAGE: The identification of N -glycosylated proteins with information about changes in the level of N -glycosylation during de-etiolation provides a database that will aid further research on plant N -glycosylation and de-etiolation. N-glycosylation is one of the most prominent and abundant protein post-translational modifications in all eukaryotes and in plants it plays important roles in development, stress tolerance and immune responses. Because light-induced de-etiolation is one of the most dramatic developmental processes known in plants, seedlings undergoing de-etiolation are an excellent model for investigating dynamic proteomic profiles. Here, we present a comprehensive, quantitative N-glycoproteomic profile of maize seedlings undergoing 12 h of de-etiolation obtained using Concanavalin A (Con A) lectin affinity chromatography enrichment coupled with a nano-LC-MS/MS-based iTRAQ approach. In total, 1084 unique N-glycopeptides carrying 909 N-glycosylation sites and corresponding to 609 proteins were identified and quantified, including 186 N-glycosylation sites from 162 proteins that were significantly regulated over the course of the 12 h de-etiolation period. Based on hierarchical clustering analysis, the significantly regulated N-glycopeptides were divided into seven clusters that showed different N-glycosylation patterns during de-etiolation. We found no obvious difference in the enriched MapMan bincode categories for each cluster, and these clustered significantly regulated N-glycoproteins (SRNPs) are enriched in miscellaneous, protein, cell wall and signaling, indicating that although the N-glycosylation regulation patterns of these SRNPs might differ, they are involved in similar biological processes. Overall, this study represents the first large-scale quantitative N-glycoproteome of the model C4 plant, maize, which is one of the most important cereal and biofuel crops. Our results greatly expand the maize N-glycoproteomic database and also shed light on the potential roles of N-glycosylation modification during the greening of maize leaves.