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In order to study the deflection and deformation law of vertical shafts in deep and thick topsoil layer, the main and secondary shafts of Shandong Guotun Coal Mine are taken as the examples, and the wireline baseline method is adopted to carry out multi-period deformation monitoring. Based on the multi-period monitoring data, the dynamic information of shaft deflection was obtained, and combined with the geological conditions and mining activities, the temporal and spatial characteristics of shaft deflection and deformation were investigated to analyze the changes of the local parameters of the shaft, compare the differences in shaft deflection, and reveal the deflection and deformation law of the shafts in deep topsoil layer, which provides a reliable basis for demonstrating the mechanism of shaft deflection and the management of the shafts. The study shows that: the time characteristics of wellbore deflection in vertical wells affected by mining and grouting activities can be divided into three phases of “increasing-decreasing-stabilizing”, and the spatial characteristics are mainly manifested in that the bedrock layer is less deflected, while the topsoil layer shows a function-like significant change, and the dynamics of wellbore and its deflection in the topsoil layer are approximately equal, with the area of the largest wellbore deflection converging to the wellhead; the main and auxiliary wells are inclined to the northwest of the mining area and there is a difference in orientation. The overall inclination of the wellbore in the east-west direction accounts for more than 97%, while that in the north-south direction is only less than 20%, which is highly correlated with the working face direction in terms of the distance between the workings; the horizontal displacement of the deep topsoil layer triggered by the mining disturbance increases with the height of the wellbore, which is the main reason for the deflection of the wellbore.

Accurately extracting surface deformation is essential for the prevention and control of geological hazards caused by underground coal mining. By taking a working face in Guotun Coal Mine, Shandong Province, as the case study, this paper first obtains 18 Sentinel-1A satellite images during the extraction period of the working face (July 31, 2017, to May 3, 2018), and derives the surface deformation of the goaf area based on SBAS-InSAR technology. Then, driven by InSAR observations, the functional projection relationships for the three-dimensional parameters between the probability integration method (PIM) and line-of-sight (LOS) deformation derived by SBAS-InSAR are deduced, and a three-dimensional and full-parameter inversion model based on genetic algorithm with random error elimination (GAREE) is proposed. Based on this model, the subsidence parameters inside the study area are accurately retrieved with the deviation for each parameter less than 3% compared with the empirical parameters. Finally, by using the retrieved parameters, PIM is employed to predict the whole goad deformation with the predicted results highly consistent with the field leveling data. The root mean square errors (RMSE) on observation line A and line F are 0.083 m and 0.102 m, respectively, and the mean absolute errors (MAE) are 0.068 m and 0.089 m, respectively. Results show that the parameter inversion model proposed by this study can effectively obtain the subsidence information for the whole basin of a mining goaf in a low-cost way, providing scientific and significant importance for engineering application and potential disaster predictions in coal mining areas.

The surface subsidence in the thick loose layer and thin bedrock mining area in the east of China has the characteristics of large subsidence value, wide movement range and long settling time. Taking a coal mine in Southern Shandong Mining Area as an example,this paper discusses the variation rules of coal seam mining surface deformation parameters under different loose layer and bedrock thickness ratio conditions, on the basis of field measurements, using FLAC3D, and establishes a surface deformation calculation model for coal seam mining under the conditions of different loose layer bedrock thickness ratios (0.25−5.00), studies the characteristics of surface deformation, analyzed the influence of ratio of loose layer thickness to bedrock thickness on the parameters of probability integral method, and quantitatively analyzed and discussed the conditions of thick loose layer and thin bedrock from the perspective of mining subsidence. Research shows: ①Under the same mining thickness conditions,when the ratio of loose layer thickness to bedrock thickness increases, the surface deformation amount obviously increases first and then decrease, when the ratio reaches a certain limit, the ground surface deformation tends to be stabilized; ②The subsidence coefficient, the horizontal movement coefficient and the tangent of the main influence angle all increase first and then decreases, and the inflection point is 1.75,1.25 and 1.25, respectively; ③The proportion of loose bed thickness in the average mining depth has great influence on the angle of draw and boundary angle. The boundary angle and the angle of draw gradually decrease with the increase of the ratio. Based on the above research, it is proposed that the ratio of 1.25−1.75 is the critical value for the condition of thick loose bedding and thin bedrock, which provides a theoretical basis and technical reference for the prediction of surface deformation and the prevention and control of mining subsidence disasters in typical thick loose layer thin bedrock mining areas in eastern China.

Abstract Epithelial ovarian cancer (EOC) is a gynecological disease with the highest mortality. With the lack of understanding of its pathogenesis, no accurate early diagnosis and screening method has been established for EOC. Studies revealed the multi-faceted function of Wilms’ tumor (Wt1) genes in cancer, which may be related to the existence of multiple alternative splices. Our results show that Wt1 (+KTS) or Wt1 (−KTS) overexpression can significantly promote the proliferation and migration of human ovarian epithelial cells HOSEpiC, and Wt1 (+KTS) effects were more evident. To explore the Wt1 (+/−KTS) variant mechanism in HOSEpiC proliferation and migration and ovarian cancer (OC) occurrence and development, this study explored the differential regulation of Wt1 (+/−KTS) in HOSEpiC proliferation and migration by transcriptome sequencing. OC-related hub genes were screened by bioinformatics analysis to further explore the differential molecular mechanism of Wt1 (+/−KTS) in the occurrence of OC. Finally, we found that the regulation of Wt1 (+/−KTS) variants on the proliferation and migration of HOSEpiC may act through different genes and signaling pathways and screened out key genes and differentially regulated genes that regulate the malignant transformation of ovarian epithelial cells. The implementation of this study will provide new clues for the early diagnosis and precise treatment of OC.

Abstract The frequent and massive use of pesticides has led to pesticide residues in apricot, threatening food safety and human health. A reliable and simple modified QuEChERS method with ultra-performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of 11 pesticides in apricot. Method validation indicated that satisfied linearity (R2 ≥ 0.9959), accuracy (recoveries of 72–119%), sensitivity (limits of detection, 0.03–0.30 μg/kg; limits of quantification, 0.13–1.00 μg/kg), and precision (relative standard deviations ≤ 11.9%), and matrix effects were 0.89–1.13. Apricot samples from different ecological regions in China were collected and tested using the proposed methods. Monitoring results were used to assess the dietary intake risk of Chinese populations of different ages and genders. Dietary risk assessment revealed that the risk quotients were 0.003–1.184% for different gender and age groups in China, indicating none unacceptable public health risk for general population. This work was thus significant in developing a simpler, more efficient and economical analysis method and food safety risks of the 11 pesticides on apricot and facilitated the establishment of maximum residue limits.

IntroductionApricot fruits are edible and serve as a source of medicinal compounds. Flavonols are important plant secondary metabolites that have antioxidant and antitumor effects and may promote cardiovascular health. MethodsThe flavonoid content in three stages of the ‘Kuijin’ and the ‘Katy’ was observed, followed by the combination of metabolome and transcriptome analysis to explore the metabolic basis of flavonol synthesis.ResultsThe differences in the metabolite contents between stages (of the same cultivar) and between cultivars (at the same stage) revealed decreases in the flavonoid content as fruits developed (i.e., from 0.28 mg/g to 0.12 mg/g in ‘Kuijin’ and from 0.23 mg/g to 0.05 mg/g in ‘Katy’). To decipher the regulation of flavonol synthesis in apricot (Prunus armeniaca L.), the metabolomes and transcriptomes of fruit pulp at three developmental stages of ‘Kuijin’ and the ‘Katy’ were analyzed. A total of 572 metabolites were detected in ‘Kuijin’ and the ‘Katy’ pulp, including 111 flavonoids. The higher flavonol content young ‘Kuijin’ fruits at 42 days after full bloom is mainly due to 10 types of flavonols. Three pairs of significant differences in flavonol content were identified. From these three comparison groups, three structural genes were strongly correlated with the levels of 10 types of flavonols (Pearson correlation coefficients > 0.8, p value < 0.05), including PARG09190, PARG15135, and PARG17939. The weighted gene co-expression network analysis showed that the turquoise module genes were highly correlated with flavonol contents (P < 0.01). There were 4897 genes in this module. Out of 4897 genes, 28 transcription factors are associated with 3 structural genes based on weight value. Two of the transcription factors are not only associated with PARG09190 but also with PARG15135, indicating their critical importance in the flavonols biosynthesis. The two TFs are PARG27864 and PARG10875.DiscussionThese findings provide new insights into the biosynthesis of flavonols and may explain the significant differences in flavonoid content between the ‘Kuijin’ and the ‘Katy’ cultivars. Moreover, it will aid in genetic improvement to enhance the nutritional and health value of apricots.

Subsidence prediction is essential for preventing and controlling geohazards in coal mining areas. However, the Interferometric Synthetic Aperture Radar (InSAR) technique is limited in deriving the goaf displacements with a large gradient and fast deformation rates, hindering its application for potential risk evaluation over the mining areas. In this study, we proposed a three-dimensional and full parameter inversion (TDFPI) model to derive the large-gradient subsidence and then investigate its application for building damage assessment over coal mining areas. By taking the Guotun coal mine as the case study, the TDFPI model was demonstrated to have effectively predicted the large-gradient deformation of the mining areas and successfully evaluated the house damage in Chelou village, which agrees well with our field investigations. Specifically, the predicted subsidence results were validated with high fitting accuracy against field measurements, with RMSE of 0.083 m and 0.102 m, respectively, on observation line A and line F. In addition, the classified damage levels are highly consistent with in situ field surveys for the house cracks in Chelou village, presenting its practicality and effectiveness for building damage evaluation, and thus can provide a useful tool for potential risk assessment and prevention over the mining areas.

Bagging-free apple is more vulnerable to postharvest disease, which severely limits the cultivation pattern transformation of the apple industry in China. This study aimed to ascertain the dominant pathogens in postharvest bagging-free apples, to evaluate the efficacy of essential oil (EO) on inhibition of fungal growth, and to further clarify the molecular mechanism of this action. By morphological characteristics and rDNA sequence analyses, Botryosphaeria dothidea (B. dothidea) and Colletotrichum gloeosporioides (C. gloeosporioides) were identified as the main pathogens isolated from decayed bagging-free apples. Cinnamon and clove EO exhibited high inhibitory activities against mycelial growth both in vapor and contact phases under in vitro conditions. EO vapor at a concentration of 60 μL L−1 significantly reduced the incidence and lesion diameter of inoculated decay in vivo. Observations using a scanning electron microscope (SEM) and transmission electron microscope (TEM) revealed that EO changed the mycelial morphology and cellular ultrastructure and destroyed the integrity and structure of cell membranes and major organelles. Using RNA sequencing and bioinformatics, it was demonstrated that clove EO treatment impaired the cell membrane integrity and biological function via downregulating the genes involved in the membrane component and transmembrane transport. Simultaneously, a stronger binding affinity of trans-cinnamaldehyde and eugenol with CYP51 was assessed by in silico analysis, attenuating the activity of this ergosterol synthesis enzyme. Moreover, pronounced alternations in the oxidation/reduction reaction and critical materials metabolism of clove EO-treated C. gloeosporioides were also observed from transcriptomic data. Altogether, these findings contributed novel antimicrobial cellular and molecular mechanisms of EO, suggesting its potential use as a natural and useful preservative for controlling postharvest spoilage in bagging-free apples.

Many studies have demonstrated that anthocyanin synthesis in apple peel is induced by light, but the color of bagged apple peel continues to change under dark conditions after light induction has not been characterized. Here, transcriptional and metabolic changes associated with changes in apple peel coloration in the dark after different light induction treatments were studied. Apple pericarp can achieve a normal color under complete darkness followed by light induction. Metabolomics analysis indicated that the expression levels of cyanidin-3-O-galactoside and cyanidin-3-O-glucoside were high, which might be associated with the red color development of apple peel. Transcriptome analysis revealed high expression levels of MdUFGTs, MdMYBs, and MdNACs, which might play a key role in light-induced anthocyanin accumulation under dark conditions. 13 key genes related to dark coloring after light induction was screened. The results of this study provide new insights into the mechanism of anthocyanin synthesis under dark conditions.

Seaweed extracts, which are naturally degradable and environmentally friendly, have become important components of organic fertilizers for fruit. In this study, the effects of seaweed-extract-based organic fertilizers on the levels of mineral elements, sugar–acid components, and hormones in ‘Fuji’ apples were evaluated. Eleven-year-old ‘Fuji’ apple (‘Yanfu 3’/M9/Malus robusta) trees were sprayed with seaweed-extract-based fertilizers SE1 (contained ≥20 g/L of algal polysaccharides, ≥100 g/L of amino acids, and ≥30 g/L of EDTA-Ca) and SE2 (contained ≥100 g/L of algal polysaccharides, ≥160 g/L of Ca, and ≥10 g/L of Mg) from early May to early October at two-week intervals in 2020. Water spraying was used as a control treatment. The preliminary results showed that SE1 and SE2 significantly increased the net photosynthetic rate, chlorophyll content and Rubisco enzyme activity in ‘Fuji’ apple leaves. SE1 and SE2 improved the quality of ‘Fuji’ apples. Compared to the single-fruit weight, soluble solid content (SSC), soluble sugar content, sugar–acid ratio, vitamin C (VC) content, and free amino acid content of control apples, those of SE1-treated and SE2-treated apples increased by 10.74% and 8.94%, 12.16% and 9.76%, 21.96% and 11.90%, 45.12% and 28.55%, 56.12% and 47.96%, and 17.15% and 13.42%, respectively. SE1 and SE2 significantly improved the levels of fructose, glucose, sucrose, and sorbitol, but decreased the levels of malic acid, oxalic acid, and tartaric acid in ‘Fuji’ apples. Meanwhile, SE1 and SE2 increased the levels of potassium, calcium, magnesium, iron, zinc, and boron in ‘Fuji’ apples. SE1 and SE2 significantly improved the levels of indole-3-acetic acid, zeatin riboside, and gibberellic acid, but significantly decreased the level of abscisic acid in ‘Fuji’ apples. In conclusion, spraying seaweed-extract-based foliar fertilizer is beneficial to the nutrient accumulation and flavor development in ‘Fuji’ apples.

This study was conducted at the Taidong Base of the Shandong Institute of Pomology, Tai’an City, Shandong Province, China, from May to October 2020. The effects of spraying calcium fertilizer on the photosynthetic characteristics, mineral element content, sugar and acid metabolism, and quality of apples were assessed. Fuji Apple Tianhong.2/SH/Malus robusta (M. robusta) was treated with the calcium fertilizers Niucui (Ca ≥ 100 g/L, B: 1–10 g/L) and Naipu 9 (Ca: 90 g/L, Mg: 21 g/L, N: 110 g/L) at the young fruit stage (25 May), the expansion stage (5 July), and the coloring stage (25 September). Water was sprayed as the control application. The results revealed that spraying calcium fertilizer increased the chloroplast pigment content and photosynthetic capacity of the apple leaves. Compared with the control, the net photosynthetic rate of apple leaves sprayed with Niucui increased by 4.3–34.6%, and that of leaves sprayed with Naipu 9 increased by 15.0–57.4%. Spraying calcium fertilizer promoted the accumulation of Ca, Mg, and B mineral elements in leaves and fruits while inhibiting the accumulation of Cu. Spraying calcium fertilizer improved the quality of apple fruit. Compared to the control fruit, the single fruit weight, fruit hardness, soluble solid content, and Vitamin C content of fruit sprayed with Niucui and Naipu 9 increased by 6.5 and 12.1%, 3.6 and 16.1%, 6.3 and 12.0%, and 30.5 and 29.4%, respectively. Spraying calcium fertilizer increased the sugar content and decreased the acid content of the apples. Naipu 9 was more effective at increasing fruit sugar content, especially sucrose and sorbitol, while Niucui was more effective at reducing the acid content, especially malic acid. This was observed because Naipu 9 increased the sugar metabolism enzyme activity, while Niucui increased the acid decomposition-related enzyme activity. In conclusion, according to the nutrition quality and flavor of the fruit, Naipu 9 application was determined to be the best fertilizer for the Fuji apple.

Light and low temperatures induce anthocyanin accumulation, but intense sunlight causes photooxidative sunburn. Nonetheless, there have been few studies of anthocyanin synthesis under different sunlight intensities and low nighttime temperatures. Here, low nighttime temperatures followed by low light intensity were associated with greater anthocyanin accumulation and the expression of anthocyanin biosynthesis genes in “Fuji” apple peel. UDP-glucose flavonoid-3-O-glucosyltransferase (UFGT) activity was positively associated with anthocyanin enrichment. Ascorbic acid can be used as an electron donor of APX to scavenge H2O2 in plants, which makes it play an important role in oxidative defense. Exogenous ascorbate altered the anthocyanin accumulation and reduced the occurrence of high light–induced photooxidative sunburn by removing hydrogen peroxide from the peel. Overall, low light intensity was beneficial for the accumulation of anthocyanin and did not cause photooxidative sunburn, whereas natural light had the opposite effect on the apple peel at low nighttime temperatures. This study provides an insight into the mechanisms by which low temperatures induce apple coloration and high light intensity causes photooxidative sunburn.

The intelligent adaptive cutting of the shearer is one of the key technologies to realize the intelligent working face. However, since the “memory cut” technology is the mainstream technology, which cannot actively adapt to the coal seam variations, the trailing drum usually cuts at a fixed height without a planned cutting path. This paper analyzes the shearer’s location characteristics before and after the advancement to propose a complete calculation method for the advancing path of the shearer, which simulates all of its possible advancing paths for subsequent n cuttings. The multitree and depth-first search algorithms are utilized to filter out the optimal advance path under different mining requirements. Simultaneously, this paper indicates that the vertical curvature of the armored face conveyor (AFC) should be considered in the calculation process of the optimal advancing path at different positions of the working face to obtain the shearer’s planned cutting path for subsequent n cuttings. The proposed algorithm in this paper has apparent advantages over the “memory cut” technology and provides a good solution for the intelligent planning of cutting and pitch steering of the shearers.

Apple replant disease (ARD) is a frequently occurring plant disease in replanted orchards around Bohai Gulf, which causes growth inhibition and even death of plants. The aim of this study was to investigate the etiology of ARD around Bohai Gulf. In this study, the primary growth inhibition of apple seedlings was evaluated in ten replanted soils, sampled around Bohai Gulf. A fungal clone library was used to identify changes in the structure and composition of the soil fungal community. The results revealed that the Simpson diversity indices of Laizhou and Pulandian orchards were higher than others, presenting severe ARD. Ascomycota dominated around Bohai Gulf at the phyla level. Fusarium and Saccharomyces were abundant in all replanted soils. In addition, correlations between the relative abundance of fungal genera in soils and the severity of ARD were analyzed. The results showed that Fusarium was correlated positively with the severity of ARD, but Mortierella was negatively correlated. Furthermore, the quantitative PCR of Fusarium oxysporum, which was regarded as a factor of ARD, was performed. Overall, this study demonstrated that ARD was strongly associated with an unbalanced microbial ecosystem with more pathogenic fungi, while Fusarium in the apple replanted soil was the key factor for ARD around Bohai Gulf. Keywords: apple, replanted disease, Fungi clone library, fusarium, fungal community

Abstract Anthocyanin synthesis and degradation processes were analyzed at transcript, enzyme, and metabolite levels to clarify the effects of high temperature on the concentration of anthocyanin in plum fruit (Prunus salicina Lindl.). The transcript levels of PsPAL, PsCHS, and PsDFR decreased while those of PsANS and PsUFGT were similar at 35 °C compared with 20 °C. The activities of the enzymes encoded by these genes were all increased in fruits at 35 °C. The concentrations of anthocyanins were higher at 35 °C on day 5 but then decreased to lower values on day 9 compared with that at 20 °C. Furthermore, high temperature (35 °C) increased the concentration of hydrogen peroxide and the activity of class III peroxidase in the fruit. The concentration of procatechuic acid, a product of the reaction between anthocyanin and hydrogen peroxide, hardly changed at 20 °C but was significantly increased at 35 °C on day 9, indicating that anthocyanin was degraded by hydrogen peroxide, which was catalyzed by class III peroxidase. Based on mathematical modeling, it was estimated that more than 60–70% was enzymatically degraded on day 9 when the temperature increased from 20 °C to 35 °C. We conclude that at the high temperature, the anthocyanin content in plum fruit depend on the counterbalance between its synthesis and degradation.

Water-saving irrigation is an important way to realize the sustainable development of the apple industry. In order to screen the best irrigation pattern for apple, taking 9-year-old 'Yanfu 10' Fuji/Malus robusta apple a the material, the effects of different irrigation methods (drip imgation, sprinkling imgation, and flood imgation) on the growth, fruit quality, and yield of apple trees were studied. The results showed that compared with the flood irrigation, drip irrigation and sprinkling irrigation significantly increased the spring shoot length by 14. 8% and 9. 1%, respectively, and decreased the autumn shoot length by 11. 7% and 8. 8%, respectively. Drip irrigation and sprinkling irrigation signiicantly increased the leaf area, chlorophyll content, and leaf weight, the leaf area increased by 3. 0% and1.9%, respectively, the chlorophyll content increased by 13.9% and 11.5%, respectively, and the leaf weight increased by 5. 8 % and 5.1%, respectively. Drip irrigation and sprinkling imgation could slightly increase the single fruit weight and fruit shape index, significantly increase the coloring index and smoothness index. The single fruit weight increaed by 3. 2% and 1. 9%, the coloring index increased by 6. 1% and 4.1 %, the smoothness index increaed by 4. 7% and 2. 8%, and the proportion of red fruit increased by 4.2% and 2. 2%, respectively. The content of soluble solids in drip imgation and sprinkling irrigation was signiicantly higher than that in flood imgation, which was 13.0% and 2.6% higher than CK, respectively. The fruit hardness in drip imgation and sprinkling imgation was 7.9% and 2.2% higher than CK, respectively, and that in drip imgation increaed significantly. The yield in drip imgation and sprinkling imgation was 12. 1% and 8.2% higher than CK, respectively. In conclusion, drip irrigation and sprinkling irrigation could promote the growth of apple trees, improve the fruit quality, and increase the yield of apple trees, and the effect of drip imgation is better than sprinkling irrigation. [ABSTRACT FROM AUTHOR]

The aromatic components and contents in fruit of apricot cultivar Jinkaite were analyzed in green ripe period, commercial ripe period and full ripe period by static headspace and gas chromatography-mass spectrometry. The results showed that total 46 kinds of aromatic components were detected in Jinkaite apricot fruit. The main aromatic components included esters, alcohols, hydrocarbons and aldehydes. The aromatic components and contents had significant differences between various fruit developmental periods. Specifically, 31, 32 and 24 kinds of aromatic components were detected in green ripe period, commercial ripe period and full ripe period, respectively. The contents of esters were the highest at the 3 developmental stages with the percentages of 61.14%, 70.02% and 61.48%, respectively. Hexyl acetate, ethyl hexanoate, hexyl 2-methyl propionate and 1-hexanol were characteristic aromatic components in fruit of apricot Jinkaite, and their aroma values in full ripe period were 448.50, 29.86, 7.85 and 3. 5 4, respectively. [ABSTRACT FROM AUTHOR]

The effects of bagging at different times in Mengyin area on the fruit quality and disease and pest incidence of Huimin short-cut Fuji apple were investigated, with unbagged fruit as the control. The results showed that among the apples bagged on May 5, May 15, May 25, June 2 and June 12 , the single fruit weight and fruit shape index of the apples bagged on June 2 were highest, 308.1 g and 0.868 , respectively; the peeled harness of the apples bagged during May 5-25 was higher than that of the control; the peeled harness of the apples bagged on June 2 and June 12 was lower than that of the control; the soluble solids content of bagged fruit was lower than that of unbagged ones, and no significant differences were found among different treatments; the coloring index of the apples bagged on June 2 was up to 100% ; the smooth finish index of the apples bagged on May 5 reached 96.67% , the highest; the red chromatic value (a*) of bagged fruit was higher than that of unbagged ones, and there were no significant differences among different bagging treatments. The earlier the bagging was, the higher the incidence of black spot and bitter pit was. The incidence of black spot and bitter pit in bagged fruit was higher than that in unbagged ones. In conclusion, in Mengyin area of Shandong Province, bagging is better to be carried out on June 2,45 d after the full bloom. [ABSTRACT FROM AUTHOR]

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After germination, cotyledons undertake the major role in supplying nutrients to the pre-photoautorophy angiosperm seedlings until they senesce. Like other senescence processes, cotyledon senescence is a programmed degenerative process. Nitric oxide can induce premature cotyledon senescence in Arabidopsis thaliana, yet the underlying mechanism remains elusive. A screen for genetic mutants identified the nes1 mutant, in which cotyledon senescence was accelerated by nitric oxide. Map-based cloning revealed that NES1 is allelic to a previously reported mitotic checkpoint family gene, MAD1. The nes1/mad1 mutants were restored to the wild type, in response to nitric oxide, by transforming them with pNES1::NES1. Ectopic expression of NES1 in the wild type delayed nitric oxide-mediated cotyledon senescence, confirming the repressive role of NES1. Moreover, two positive regulators of leaf senescence, the ethylene signalling component EIN2 and the transcription factor ORE1/AtNAC2/ANAC092, were found to function during nitric oxide-induced senescence in cotyledons. The block of ORE1 function delayed senescence and ectopic expression induced the process, revealing the positive role of ORE1. EIN2 was required to induce ORE1. Furthermore, the genetic interaction analysis between NES1 and ORE1 showed that the ore1 loss-of-function mutants were epistatic to nes1, suggesting the dominant role of ORE1 and the antagonistic role of NES1 during nitric oxide-induced cotyledon senescence in Arabidopsis. [ABSTRACT FROM AUTHOR]