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Background. The skin cutaneous melanoma (SKCM) is a devastating form of skin cancer triggered by genetic and environmental factors, and the incidence of SKCM has rapidly increased in recent years. Immune infiltration of the tumor microenvironment is positively associated with overall survival in many tumors. Triggering receptor expressed on myeloid cells 2 (TREM2) is a transmembrane receptor of the immunoglobulin superfamily and a crucial signaling hub for multiple pathological pathways that mediate immunity. Although numerous evidences suggest a crucial role for TREM2 in tumorigenesis of some tumors, no systematic SKCM analysis of TREM2 is available. Mehods. The relationship between TREM2 expression and diagnostic and prognostic value of SKCM patients via using The Cancer Genome Atlas (TCGA) data. The expression level of TREM2 and clinical characteristic correlation in SKCM patients were assessed by the Wilcoxon rank sum test. The cox regression methods, Kaplan-Meier (KM), and log-rank test were used to assess the impact of TREM2 expression on the overall survival (OS). Furthermore, the Gene Set Enrichment Analysis (GSEA) and TIMER were performed to evaluate the enrichment pathways and potential functions and quantify the immune cell infiltration level for TREM2 expression. Results. The TREM2 in SKCM sample expression levels was significantly higher than in normal tissues. Moreover, this expression level of TREM2 was also associated with the BMI of SKCM patients. KM overall survival analysis and OS curve displayed that a high-level TREM2 expression was significantly correlated with a better SKCM prognosis of patients as compared with a low level of TREM2 expression. The GSEA analysis also revealed that TREM2 was associated with immune functions, such as neutrophil activation. Conclusion. TREM2 played a crucial role in SKCM, which might be a prognostic biomarker and correlated with immune infifiltrates in SKCM patients.

Manual removal of the main stem tips of cotton (Gossypium hirsutum L.) is a traditional topping approach in China. However, chemical topping has become an inevitable trend. Therefore, it is of great significance to study the effect and appropriate concentration of agents for advancement of cotton whole process mechanization management technology. A two-year field experiment was conducted to evaluate the effects of different methods of topping on cotton yield and plant architecture in Shihezi, Xinjiang, China. Plant topping included manual topping, non-topping as the control, and chemical topping (high, medium, and low concentrations of topping agent) to determine a suitable topping method and topping agent concentration for machine-picked cotton. Chemical topping was performed using fortified mepiquat chloride (DPC+). Chemical topping and manual topping increased seed cotton yield compared with non-topping. Compared with non-topping, high, medium, and low concentrations of topping agent significantly increased the yield by 19.5–27.9%, 24.1–29.4%, and 24.3–28.4%, respectively. Topping treatment mainly regulated yield and total boll number per unit area by affecting the boll number per plant and had a certain positive effect on fiber strength but no significant effect on boll weight. Chemical topping affected both vertical and horizontal plant architecture characteristics of cotton; the plant height of low-, medium-, and high-concentration treatments increased by 7.2–11.4 cm, 4.0–5.7 cm, and 2.3–4.4 cm, respectively, compared with manual topping and decreased by 5.1–7.8 cm, 8.3–13.5 cm, and 9.4–16.9 cm, respectively, compared with non-topping. The number of main stem internodes was significantly different between high- and low-concentration treatments, which showed that the higher the concentration, the lower the number of the main stem internodes. Chemical topping controlled the increase in the length of the upper branches, the higher the concentration, the lower the increase in the length of the upper fruit branch. Compared with non-topping, the medium concentration of topping agent controlled the number of fruit branches, similar to manual topping. The role of upper internode length of cotton cannot be ignored under chemical topping. The peak leaf area index (LAI) of medium- and high-concentration treatments was delayed for 1 week in the late growth period (after topping for 28 d) compared with manual topping. The LAI values were high, and the duration of high values was prolonged. The optimal chemical topping agent was the medium concentration.

The use of 1,1-dimethyl-piperidinium chloride (DPC) in Xinjiang is one of the necessary measures for regulating cotton populations and optimizing canopy structure. However, mechanical spraying involves operation and energy consumption, which can alternatively be achieved via drip application. In the present study, to investigate the effect of drip application, two types of hydrophobic nano-released DPCs were used to regulate plant type at different dosages. DPC dripingation reduced plant height by more than 10 cm and plant width by more than 4 cm, and the effect improved with increasing concentration and times. The main effect of height control was at the 6th–10th nodes of the main stem, and the effect of width control was observed at the 1st and 2nd nodes of the fruit branch. The SPAD value was higher than that in the control group during the initial stages. An irregular downward trend was observed in the subsequent stages. The proline content was higher than that of the control and increased with higher concentrations of DPC. There was no significant difference in the soil DPC content at the different sites. The DPC content decreased by more than 30% at the seventh day after dripping, and the content was 2–4 μg·g−1 in each treatment. At 15 days after application, the soil DPC was lower than 1 μg·g−1 in all treatments. The number of harvested plants was more than 150,000 plants·hm−2, and the number of bolls per plant increased at least by one, compared with the control. The final yield of seed cotton increased by at least 300 kg·hm−2, with a maximum increase of 1672.01 kg·hm−2. Considering the different types of DPCs, nano-released types worked better than the conventional type in terms of plant height, plant width, degradation in soil and boll formation. Nano-released DPC can play an even better role than conventional DPC in chemical regulation with drip irrigation.

Thidiazuron (TDZ) is a widely used chemical defoliant in cotton and can stimulate the production of ethylene in leaves, which is believed to be the key factor in inducing leaf abscission. Ethephon (Eth) can also stimulate ethylene production in leaves, but it is less effective in promoting leaf shedding. In this study, the enzyme-linked immunosorbent assays (ELISA) and RNA-seq were used to determine specific changes at hormonal levels as well as transcriptomic mechanisms induced by TDZ compared with Eth. The TDZ significantly reduced the levels of auxin and cytokinin in cotton leaves, but no considerable changes were observed for Eth. In addition, TDZ specifically increased the levels of brassinosteroids and jasmonic acid in the leaves. A total of 13 764 differentially expressed genes that specifically responded to TDZ were identified by RNA-seq. The analysis of KEGG functional categories suggested that the synthesis, metabolism, and signal transduction of auxin, cytokinin, and brassinosteroid were all involved in the TDZ-induced abscission of cotton leaves. Eight auxin transport genes (GhPIN1-c_D, GhPIN3_D, GhPIN8_A, GhABCB19-b_A, GhABCB19-b_D, GhABCB2-b_D, GhLAX6_A, and GhLAX7_D) specifically responded to TDZ. The pro35S::GhPIN3a::YFP transgenic plants showed lower defoliation than the wild type treated with TDZ, and YFP fluorescence in leaves was almost extinguished after treatment with TDZ rather than Eth. This provides direct evidence that GhPIN3a is involved in the leaf abscission induced by TDZ. We found that 959 transcription factors (TFs) specifically responded to TDZ, and a co-expression network analysis (WGCNA) showed five hub TFs (GhNAC72, GhWRKY51, GhWRKY70, GhWRKY50, and GhHSF24) during chemical defoliation with TDZ. Our work sheds light on the molecular basis of TDZ-induced leaf abscission in cotton.

Neutropenia is a common complication in the treatment of hematological diseases and the most common predisposing factor for invasion by fungi, such as Candida krusei. Recent studies have shown that C. krusei, a life-threatening pathogen, has developed resistance to amphotericin B (AMB). However, the mechanisms that led to the rapid emergence of this AMB-resistant phenotype are unclear. In this study, we found the sensitivity for AMB could be promoted by inhibiting histone acyltransferase activity and western blot analysis revealed differences in the succinylation levels of C. krusei isolated from immunocompromised patients and of the corresponding AMB-resistant mutant. By comparative succinyl-proteome analysis, we identified a total of 383 differentially expressed succinylated sites in with 344 sites in 134 proteins being upregulated in the AMB-resistant mutant, compared to 39 sites in 23 proteins in the wild-type strain. These differentially succinylated proteins were concentrated in the ribosome and cell wall. The critical pathways associated with these proteins included those involved in glycolysis, gluconeogenesis, the ribosome, and fructose and mannose metabolism. In particular, AMB resistance was found to be associated with enhanced ergosterol synthesis and aberrant amino acid and glucose metabolism. Analysis of whole-cell proteomes, confirmed by parallel reaction monitoring, showed that the key enzyme facilitating lysine acylation was significantly upregulated in the AMB-resistant strain. Our results suggest that lysine succinylation may play an indispensable role in the development of AMB resistance in C. krusei. Our study provides mechanistic insights into the development of drug resistance in fungi and can aid in efforts to stifle the emergence of AMB-resistant pathogenic fungi.

In this letter, we presented a data-driven framework to optimize the out-of-plane stiffness for soft grippers to achieve mechanical properties as hard-to-twist and easy-to-bend. The effectiveness of this method is demonstrated in the design of a soft pneumatic bending actuator (SPBA). First, a new objective function is defined to quantitatively evaluate the out-of-plane stiffness as well as the bending performance. Then, sensitivity analysis is conducted on the parametric model of an SPBA design to determine the optimized design parameters with the help of Finite Element Analysis (FEA). To enable the computation of numerical optimization, a data-driven approach is employed to learn a cost function that directly represents the out-of-plane stiffness as a differentiable function of the design variables. A gradient-based method is used to maximize the out-of-plane stiffness of the SPBA while ensuring specific bending performance. The effectiveness of our method has been demonstrated in physical experiments taken on 3D-printed grippers.

Chronic mucocutaneous candidiasis (CMC) is characterized by recurrent or persistent infections with Candida of the skin, nails, and mucous membranes (e.g., mouth, esophagus, and vagina). Compared with that of other infectious diseases, the immune pathogenic mechanism of CMC is still poorly understood. We identified a signal transducer and activator of transcription 1 gain-of-function (c.Y289C) mutation in a CMC patient. Single-cell transcriptional profiling on peripheral blood mononuclear cells from this patient revealed decreases in immature B cells and monocytes. Further analysis revealed several differentially expressed genes related to immune regulation, including RGS1, TNFAIP3, S100A8/A9, and CTSS. In our review of the literature on signal transducer and activator of transcription 1 gain-of-function (c.Y289C) mutations, we identified seven cases in total. The median age of onset for CMC (n=4, data lacking for three cases) was 10.5 years (range: birth to 11 years), with an average onset age of 8 years. There were no reports linking tumors to the c.Y289C mutation, and the incidence of pre-existing clinical disease in patients with the c.Y289C mutation was similar to previous data.

Cotton constitutes 81% of the world’s natural fibers. Accurate and rapid cotton yield estimation is important for cotton trade and agricultural policy development. Therefore, we developed a remote sensing index that can intuitively represent cotton boll characteristics and support cotton yield estimation by extracting cotton boll pixels. In our study, the Density of open Cotton boll Pixels (DCPs) was extracted by designing different cotton boll indices combined with the threshold segmentation method. The relationship between DCP and field survey datasets, the Density of Total Cotton bolls (DTC), and yield were compared and analyzed. Five common yield estimation models, Linear Regression (LR), Support Vector Regression (SVR), Classification and Regression Trees (CART), Random Forest (RF), and K-Nearest Neighbors (KNN), were implemented and evaluated. The results showed that DCP had a strong correlation with yield, with a Pearson correlation coefficient of 0.84. The RF method exhibited the best yield estimation performance, with average R2 and rRMSE values of 0.77 and 7.5%, respectively (five-fold cross-validation). This study showed that RedGreenBlue (RGB) and Near Infrared Red (NIR) normalized, a normalized form index consisting of the RGB and NIR bands, performed best.

Background Cotton production in China is challenged by high labor input including manual topping (MT). Recently, to replace MT in the Xinjiang cotton region of China, mepiquat chloride (MC) was applied once more than the traditional multiple-application; this was designated as chemical topping (CT), but it is unclear whether the amount of irrigation needs to be adjusted to accommodate CT. Results The main plots were assigned to three drip irrigation amounts [300 (I1), 480 (I2), and 660 (I3) mm], and the subplots were assigned to the CT treatments [450 (MC1), 750 (MC2), and 1 050 (MC3) mL·hm−2 25% MC] with MT as a control that was performed after early bloom. The optimum drip irrigation amount for CT was explored based on leaf photosynthesis, chlorophyll fluorescence, biomass accumulation, and yield. There were significant influences of drip irrigation, topping treatments and their interaction on chlorophyll fluorescence characteristics, gas exchange parameters and biomass accumulation characteristics as well as yield. The combination of I2 and MC2 (I2MC2) performed best. Compared with I2MT, the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and photochemical quenching coefficient (qP) of I2MC2 significantly increased by 4.0%∼7.2%, 6.8%∼17.1%, 5.2%∼17.6%, and 4.8%∼9.6%, respectively, from the peak flowering to boll opening stages. Moreover, I2MC2 showed fast reproductive organ biomass accumulation and the highest seed cotton yield; the latter was 6.6%∼12.8% higher than that of I2MT. Further analysis revealed that a 25% MC emulsion in water (MCEW) application resulted in yield improvement by increasing Pn, φPSII, and qP to promote biomass accumulation and transport to reproductive organs. Conclusion The results showed that the 480 mm drip irrigation combined with 750 mL·hm−2 MC increased the rate of dry matter accumulation in reproductive organs by increasing Pn, φPSII, and qP to improve photosynthetic performance, thus achieving higher yield.

The balance between vegetative and reproductive growth is the central objective in the cotton production system, which is associated with cotton maturity and yield. In China, manual topping (MT) has been performed many years prior to or during the flowering period to inhibit vegetative growth and enhance reproductive growth. MT is gradually being replaced by chemical topping (CT) with mepiquat chloride (MC, 180 g ha−1, 98% soluble powder) due to labor shortages and increasing labor cost. To determine whether CT influences cotton maturity and yield relative to MT, we carried out field experiments at four locations in the Yellow River Valley of China during 2018–2020. The results showed that CT did not alter the boll age, and although it produced taller and slender spatial boll distribution under several environments, it had little effect on the accumulation of boll fraction (the number of bolls in a given period divided by total boll number) over time at the end of blooming across locations. As a result, there were no significant differences between MT and CT in boll opening percentage in the late season. CT did not influence yield or yield components, except under severe drought. Therefore, CT with MC (180 g/ha, 98% soluble powder) during the flowering period will not compromise the maturity or yield of cotton in the Yellow River Valley of China. Similar outcomes would be achieved in other areas with similar ecological conditions and social conditions that require an alternative to extensive manual labor.

Thidiazuron (TDZ) is widely used as a defoliant to induce leaf abscission in cotton. However, the underlying molecular mechanism is still unclear. In this study, RNA-seq and enzyme-linked immunosorbent assays (ELISA) were performed to reveal the dynamic transcriptome profiling and the change of endogenous phytohormones upon TDZ treatment in leaf, petiole, and abscission zone (AZ). We found that TDZ induced the gene expression of ethylene biosynthesis and signal, and promoted ethylene accumulation earlier in leaf than that in AZ. While TDZ down-regulated indole-3-acetic acid (IAA) biosynthesis genes mainly in leaf and IAA signal and transport genes. Furthermore, the IAA content reduced more sharply in the leaf than that in AZ to change the auxin gradient for abscission. TDZ suppressed CTK biosynthesis genes and induced CTK metabolic genes to reduce the IPA accumulation for the reduction of ethylene sensitivity. Furthermore, TDZ regulated the gene expression of abscisic acid (ABA) biosynthesis and signal and induced ABA accumulation between 12–48 h, which could up-regulate ABA response factor genes and inhibit IAA transporter genes. Our data suggest that TDZ orchestrates metabolism and signal of ethylene, auxin, and cytokinin, and also the transport of auxin in leaf, petiole, and AZ, to control leaf abscission.

Background Mepiquat chloride (MC), a plant growth regulator, enhances root growth by promoting lateral root formation in cotton. However, the underlying molecular mechanisms of this phenomenon is still unknown. Methods In this study, we used 10 cotton (Gossypium hirsutum Linn.) cultivars to perform a seed treatment with MC to investigate lateral root formation, and selected a MC sensitive cotton cultivar for dynamic monitor of root growth and transcriptome analysis during lateral root development upon MC seed treatment. Results The results showed that MC treated seeds promotes the lateral root formation in a dosage-depended manner and the effective promotion region is within 5 cm from the base of primary root. MC treated seeds induce endogenous auxin level by altering gene expression of both gibberellin (GA) biosynthesis and signaling and abscisic acid (ABA) signaling. Meanwhile, MC treated seeds differentially express genes involved in indole acetic acid (IAA) synthesis and transport. Furthermore, MC-induced IAA regulates the expression of genes related to cell cycle and division for lateral root development. Conclusions Our data suggest that MC orchestrates GA and ABA metabolism and signaling, which further regulates auxin biosynthesis, transport, and signaling to promote the cell division responsible for lateral root formation.

As a powerful and low-cost instant information dissemination platform, large-scale online social networks (OSNs) play a pivotal role in shaping our modern information age. The efficient detection of wide-spreading information in OSNs is very important in many aspects including public opinion supervision, social governance, stock markets, counter-terrorism and presidential election. However, real-world OSNs have gigantic sizes and thus their full structural data are usually unavailable, making this problem extremely challenging. In this work, we illustrate the close mapping between efficient detection and optimal spreading from the perspective of network percolation theory. This analogy inspires us to propose a theory of using only limited local network information to select the optimal set of information sensors. Through extensive simulations on both synthetic and real-world networks, we find that for networks with theoretically infinite size, only a finite and small number of sensor nodes are needed to detect the global spreading information with almost certainty. Most importantly, we empirically confirm the utility of our theory on the largest micro blog in China by crawling almost the full Sina Weibo social network with 99,546,027 users in 2014 and the real spreading data of Weibo messages.

Previous studies have indicated that mechanical cotton harvesting requires a compact plant habit without fiber yield and quality reduction. The objective of this study was to determine the effects of planting date and plant density on plant habit, yield, early maturity, and fiber quality of cotton in the Yellow River valley region of China, and thus to identify the appropriate planting date and plant density suitable for its mechanical harvesting. Field experiments were conducted in 2013 and 2014 in Hejian, Hebei Province, using a split-plot design with planting date as the main plot and plant density as the subplot. The results indicated that moderately late planting in late April or early May (P2) was appropriate for mechanical harvesting of cotton as relative to P1 (local traditional planting date, 10 d earlier than P2) and P3 (10 d later than P2). P2 showed a 2.4–5.7 cm greater height to the first fruiting branch (from the bottom) and a 4.7–11.3 cm higher lowest boll (harvestable boll nearest to the ground) compared with P1, which is helpful for decreasing yield loss and reducing intake of residual plastic mulch. In addition, P2 produced slightly greater yield than P1 and P3, and the percentage of open bolls in late September for P2 was similar to that of P1 and greater than for P3, suggesting a low risk of late maturity. For plant density, 8.9 plants m−2 (D2) was appropriate for mechanical harvesting compared with 6.6 plants m−2 (D1), the local traditional density for manual harvesting, and 12.3 plants m−2 (D3). D2 showed a 2.5 cm greater height to the first fruiting branch and a 4.2 cm higher lowest boll, and exhibited 2.9–3.6 and 2.6–3.9 cm shorter lengths of lower and middle fruiting branches than D1, respectively. This type of compact plant habit is conducive to efficient mechanical harvesting. Moreover, D2 produced a similar yield to D1 for both the rainy 2013 and the dry 2014, indicating yield stability. Although D3 had a more suitable plant habit for mechanical cotton harvesting, its yield level and maturity varied across years. There were no significant interactions between planting date and plant density in the majority of tested traits. The results will contribute to the development of integrated cotton management for upcoming mechanical harvesting in the Yellow River valley region of China.

Based on the empirical analysis of panel data on new energy listed companies in China, the relationships among government subsidies, enterprise research and development input (R&amp, D input), and firm performance are explored to measure the impact of government subsidies on firm performance and the mediation mechanism of R&amp, D input. In addition, the effects of the moderation variables of regional characteristics and state ownership are measured from the enterprise heterogeneity perspective. The results show that government subsidies have a positive promoting effect on R&amp, D input, R&amp, D input has a two-year lag positive effect on firm performance, government subsidies have a two-year lag positive effect on firm performance through the mediation role of R&amp, D input. Regional characteristics and enterprise properties moderate the effect of government subsidies on firm performance. Government subsidies have a greater positive effect on firm performance in the eastern coastal areas than they do in mid-west coastal areas, and there is a crowding-out effect on the mid-west coastal areas. Government subsidies have a greater positive effect on the performance of non-state-owned enterprises than they do on state-owned enterprises. Suggestions are provided for the government to adjust subsidy policy and improve the performance of new energy enterprises.

With the improvement of people's living standards, people's consumption of meat is getting higher and higher, and pork has become the core of Chinese meat production and consumption structure. Among pig farmers, retail investors account for more than half, their risk resistance capacity is weak, and they are vulnerable to price shocks. The price of live pigs showed significant seasonal changes, and violent fluctuations not only affected the interests of various links in the pig industry chain and the welfare of consumers, but also affected the development of the entire Chinese pig industry. Effective hog price forecast which is conducive to social stability and unity can not only ensure the income of farmers, but also ensure relationship between supply and demand. The article synthesizes the main indicators related to pork prices in the Chinese pork market, applying DBN (Dynamic Bayesian network) method and the SVM (support vector machine) method, the BP neural network method, these Machine Learning methods, and compare with traditional methods of the ARIMA method, to establish a predictive model of pork prices. The experiment was conducted in R and Bayes Server using 2001-2016 price data from the National Bureau of Statistics. The price is forecasted and analysed, the prediction effects of the four models are compared in this paper. The results show that the accuracy of predicting the pork price based on DBN model is better than other methods, RMSE=1.200822, MAPE=1.137312, TIC=0.0351875, all belong to a minimum.

Widespread potassium (K) deficiencies in cotton (Gossypium hirsutum L.) have been documented throughout cotton producing countries. Potassium fertilizer is needed for high production of cotton yield. This study was conducted to determine whether K fertilizer management can improve efficiency of K nutrition in cotton. The effects of K source, rate, and application timing on yield and K use efficiency of cotton were investigated under conditions of cotton-stalk recycling to the field in the North China Plain (NCP). The results showed that there was no significant difference in yield between K sources of K₂SO₄ and KCl. However, we found that the low rate produced a 2 to 4% higher K agronomic efficiency (AEK) and a 12 to 93% higher K apparent recovery efficiency (REK) than the other rates, although there was little difference in yield among different K rates (45, 90, and 180 kg K₂O ha⁻¹). In addition, our results of application timing showed that the later split application at peak bloom acquired the highest lint yield as well as a 35 to 103% higher AEK and 23 to 58% higher REK than the earlier split application at peak squaring and full dose at preplanting. In conclusion, KCl should be the preferred K source because of its lower cost and fair effect on yield compared with K₂SO₄. The 45 kg K₂O ha⁻¹ of K rates is adequate for cotton in the NCP. The later split application of K at peak bloom is the best timing of K fertilizer for cotton yield and K use efficiency.

Additional file 8: Text S4. Identifying the PR (primary root) sections the LRGs (lateral root groups) belonged to.

Additional file 5: Text S3. Correction of time-course images.

Background In order to efficiently determine genotypic differences in rooting patterns of crops, novel hardware and software are needed simultaneously to characterize dynamics of root development. Results We describe a prototype robotic monitoring platform—the RhizoChamber-Monitor for analyzing growth patterns of plant roots automatically. The RhizoChamber-Monitor comprises an automatic imaging system for acquiring sequential images of roots which grow on a cloth substrate in custom rhizoboxes, an automatic irrigation system and a flexible shading arrangement. A customized image processing software was developed to analyze the spatio-temporal dynamics of root growth from time-course images of multiple plants. This software can quantify overall growth of roots and extract detailed growth traits (e.g. dynamics of length and diameter) of primary roots and of individual lateral roots automatically. It can also identify local growth traits of lateral roots (pseudo-mean-length and pseudo-maximum-length) semi-automatically. Two cotton genotypes were used to test both the physical platform and the analysis software. Conclusions The combination of hardware and software is expected to facilitate quantification of root geometry and its spatio-temporal growth patterns, and therefore to provide opportunities for high-throughput root phenotyping in support of crop breeding to optimize root architecture.

The growth regulator mepiquat chloride (MC) is globally used in cotton (Gossypium hirsutum L.) canopy manipulation to avoid excess growth and yield loss. However, little information is available as to whether the modification of plant architecture by MC is related to alterations in gibberellic acid (GA) metabolism and signaling. Here, the role of GA metabolism and signaling was investigated in cotton seedlings treated with MC. The MC significantly decreased endogenous GA3 and GA4 levels in the elongating internode, which inhibited cell elongation by downregulating GhEXP and GhXTH2, and then reducing plant height. Biosynthetic and metabolic genes of GA were markedly suppressed within 2-10d of MC treatment, which also downregulated the expression of DELLA-like genes. A remarkable feedback regulation was observed at the early stage of MC treatment when GA biosynthetic and metabolic genes expression was evidently upregulated. Mepiquat chloride action was controlled by temporal translocation and spatial accumulation which regulated GA biosynthesis and signal expression for maintaining GA homeostasis. The results suggested that MC application could reduce endogenous GA levels in cotton through controlled GA biosynthetic and metabolic genes expression, which might inhibit cell elongation, thereby shortening the internode and reducing plant height.

The effects of plant growth regulators (PGRs) and potassium (K) fertilizer on cotton (Gossypium hirsutum) yield have been well documented but the role of PGRs on K use efficiency is poorly understood. Our specific objective was to determine whether foliar application of PGRs could improve K use efficiency in field-grown cotton. Field experiments were conducted with or without K at two sites (Beijing and Hebei, China) varying in available soil K during 2010 and 2011, with cotton cvs. Guoxinmian3 (GX3) and SCRC28 as test materials. Foliar application of the PGRs, mepiquat chloride (MC) and Miantaijin [MTJ, a combination of MC with diethyl aminoethyl hexanoate (DA-6)] during squaring and flowering periods significantly increased the lint yield and K uptake in most situations at Beijing location and had a consistent tendency to increase lint yield across K fertilizers and years at Hebei location. The partial factor productivity (PFPK) and agronomic efficiency of K (AEK) were enhanced by the application of the PGRs in most situations in Beijing, especially in 2011 and for the cultivar GX3. Although differences in the apparent recovery efficiency of K (REK) between PGRs and control were not significant, a positive and consistent effectiveness of PGRs on REK was observed across sites, years and cultivars. Therefore, the application of PGRs would be a useful practice for improving K nutrition and lowering the cost of K fertilizer input in cotton production.

Mechanical harvesting has become inevitable for cotton production in China due to the rising labor cost in the country. It usually requires a moderate plant height and compact plant architecture. Correlation and stepwise regression were employed to analyze databases of our 24 field experiments between 2010 and 2017 in Hebei Province. The purpose is to identify the relationships between plant architecture traits and seed cotton yield within natural plant height range (58.6&ndash, 163.2 cm) or preferred plant height range (80&ndash, 120 cm) for mechanical harvesting in the Yellow River Valley of China, and define some important factors affecting seed cotton yield. Under natural plant height range across all experiments, there was a significantly negative correlation (r= &minus, 0.452) between plant height and yield. On limited plant height range desired for mechanical harvesting, the degree of this negative correlation decreased to r= &minus, 0.366. The correlation of plant height with seed cotton yield varied greatly with year, cultivar, plant density and mepiquat chloride (MC) application. Moreover, stepwise regression analysis picked internode length of the 1st (generally including 1st&ndash, 7th mainstem node from bottom), 2nd (8th&ndash, 12th node) and 4th (above 17th node) mainstem section and the length of lower fruiting branch (LFB) as significant factors influencing seed cotton yield under plant height range of 80&ndash, 120 cm. The results have implications for precise control of cotton plant architecture preferred for mechanized harvesting in China.

The significance of communities is an important inherent property of the community structure. It measures the degree of reliability of the community structure identified by the algorithm. Real networks obtained from complex systems always contain error links. Moreover, most of the community detecting algorithms usually involve random factors. Thus evaluating the significance of community structure is very important. In this paper, using the matrix perturbation theory, we propose a normalized index to efficiently evaluate the significance of community structure without detecting communities. Furthermore, we find that the peaks of this index can be used to determine the optimal number of communities and identify hierarchical community structure, which are two challenging problems in many community detecting algorithms. Lastly, the index is applied to 16 typical real networks, and we find that significant community structures exist in many social networks and in the C. elegans neural network. Comparatively insignificant community structures are identified in protein-interaction networks and metabolic networks. Our method can be generalized to broad clustering problems in data mining.

To elucidate the phytohormonal basis of the feedback regulation of leaf senescence induced by potassium (K) deficiency in cotton (Gossypium hirsutum L.), two cultivars contrasting in sensitivity to K deficiency were self- and reciprocally grafted hypocotyl-to-hypocotyl, using standard grafting (one scion grafted onto one rootstock), Y grafting (two scions grafted onto one rootstock), and inverted Y grafting (one scion grafted onto two rootstocks) at the seedling stage. K deficiency (0.03mM for standard and Y grafting, and 0.01mM for inverted Y grafting) increased the root abscisic acid (ABA) concentration by 1.6- to 3.1-fold and xylem ABA delivery rates by 1.8- to 4.6-fold. The K deficiency also decreased the delivery rates of xylem cytokinins [CKs; including the zeatin riboside (ZR) and isopentenyl adenosine (iPA) type] by 29-65% and leaf CK concentration by 16-57%. The leaf ABA concentration and xylem ABA deliveries were consistently greater in CCRI41 (more sensitive to K deficiency) than in SCRC22 (less sensitive to K deficiency) scions under K deficiency, and ZR- and iPA-type levels were consistently lower in the former than in the latter, irrespective of rootstock cultivar or grafting type, indicating that cotton shoot influences the levels of ABA and CKs in leaves and xylem sap. Because the scions had little influence on phytohormone levels in the roots (rootstocks) of all three types of grafts and rootstock xylem sap (collected below the graft union) of Y and inverted Y grafts, it appears that the site for basipetal feedback signal(s) involved in the regulation of xylem phytohormones is the hypocotyl of cotton seedlings. Also, the target of this feedback signal(s) is more likely to be the changes in xylem phytohormones within tissues of the hypocotyl rather than the export of phytohormones from the roots.

Defoliants can increase machine harvest efficiency of cotton (Gossypium hirusutum L.), prevent lodging and reduce the time from defoliation to harvest. Coronatine (COR) is a chlorosis-inducing non-host-specific phytotoxin that induces leaf and/or fruit abscission in some crops. The present study investigates how COR might induce cotton leaf abscission by modulating genes involved in cell wall hydrolases and ACC (ethylene precursor) in various cotton tissues. The effects of COR on cotton boll ripening, seedcotton yield, and seed development were also studied. After 14 d of treatment with COR, cells within the leaf abscission zone (AZ) showed marked differentiation. Elevated transcripts of GhCEL1, GhPG and GhACS were observed in the AZs treated with COR and Thidiazuron (TDZ). The relative expression of GhCEL1 and GhACS in TDZ treated plants was approximately twice that in plants treated with COR for 12 h. However, only GhACS expression increased in leaf blade and petiole. There was a continuous increase in the activity of hydrolytic enzymes such as cellulase (CEL) and polygalacturonase (PG), and ACC accumulation in AZs following COR and TDZ treatments, but there was greater increase in ACC activity of COR treated boll crust, indicating that COR had greater ripening effect than TDZ. Coronatine significantly enhanced boll opening without affecting boll weight, lint percentage and seed quality. Therefore, COR can be a potential cotton defoliant with different physiological mechanism of action from the currently used TDZ.

The growth regulator mepiquat chloride (MC) is used in cotton production across the globe to control plant growth and maximize yield and quality of cotton. With the conversion from hand picking to mechanical harvesting in China, plant densities are increased, and more compact plants are required, leading to the need to reconsider MC application schedules. Experiments were carried out in 2009 and 2010 to identify optimal use schedules of MC at four plant densities: 3.0, 4.5, 6.0 and 7.5 plants m−2. Eleven MC schedules were compared with respect to their effect on cotton yield and quality. Application of MC at squaring stage or at both squaring and flowering stages significantly improved cotton quality parameters: fiber length (by 1.7%) and fiber strength (by 2.8%) at all tested plant densities without significant loss of yields. However, average lint yield of all MC treatments over all densities and years was decreased by 4.6% due to a decrease in boll density and lint percentage which was only partly offset by an increase in boll weight. No effects on yield were also observed if MC applications were started at flowering stage, but such later starting application schedules only slightly improved fiber quality. The results suggest that use of MC at squaring or at both squaring and flowering stages is a viable strategy to improve cotton architecture, productivity and quality at high plant density in mechanized cotton production in the Yellow River cotton growing region in China.