Excessive apoptosis of Rip1-deficient T cells leads to premature aging.

In mammals, the most remarkable T cell variations with aging are the shrinking of the naïve T cell pool and the enlargement of the memory T cell pool, which are partially caused by thymic involution. However, the mechanism underlying the relationship between T-cell changes and aging remains unclear. In this study, we find that T-cell-specific Rip1 KO mice show similar age-related T cell changes and exhibit signs of accelerated aging-like phenotypes, including inflammation, multiple age-related diseases, and a shorter lifespan. Mechanistically, Rip1-deficient T cells undergo excessive apoptosis and promote chronic inflammation. Consistent with this, blocking apoptosis by co-deletion of Fadd in Rip1-deficient T cells significantly rescues lymphopenia, the imbalance between naïve and memory T cells, and aging-like phenotypes, and prolongs life span in T-cell-specific Rip1 KO mice. These results suggest that the reduction and hyperactivation of T cells can have a significant impact on organismal health and lifespan, underscoring the importance of maintaining T cell homeostasis for healthy aging and prevention or treatment of age-related diseases.

An L-type lectin receptor-like kinase promotes starch accumulation during rice pollen maturation.

Starch accumulation is key for the maturity of rice pollen grains; however, the regulatory mechanism underlying this process remains unknown. Here, we have isolated a male-sterile rice mutant, abnormal pollen 1 (ap1), which produces nonviable pollen grains with defective starch accumulation. Functional analysis revealed that AP1 encodes an active L-type lectin receptor-like kinase (L-LecRLK). AP1 is localized to the plasma membrane and its transcript is highly accumulated in pollen during the starch synthesis phase. RNA-seq and phosphoproteomic analysis revealed that the expression/phosphorylation levels of numerous genes/proteins involved in starch and sucrose metabolism pathway were significantly altered in the mutant pollen, including a known rice UDP-glucose pyrophosphorylase (OsUGP2). We further found that AP1 physically interacts with OsUGP2 to elevate its enzymatic activity, likely through targeted phosphorylation. These findings revealed a novel role of L-LecRLK in controlling pollen maturity via modulating sucrose and starch metabolism.

Deep Learning Radiomics Model of Dynamic Contrast-Enhanced MRI for Evaluating Vessels Encapsulating Tumor Clusters and Prognosis in Hepatocellular Carcinoma.

BACKGROUND: Vessels encapsulating tumor cluster (VETC) is a critical prognostic factor and therapeutic predictor of hepatocellular carcinoma (HCC). However, noninvasive evaluation of VETC remains challenging. PURPOSE: To develop and validate a deep learning radiomic (DLR) model of dynamic contrast-enhanced MRI (DCE-MRI) for the preoperative discrimination of VETC and prognosis of HCC. STUDY TYPE: Retrospective. POPULATION: A total of 221 patients with histologically confirmed HCC and stratified this cohort into training set (n = 154) and time-independent validation set (n = 67). FIELD STRENGTH/SEQUENCE: A 1.5 T and 3.0 T; DCE imaging with T1-weighted three-dimensional fast spoiled gradient echo. ASSESSMENT: Histological specimens were used to evaluate VETC status. VETC+ cases had a visible pattern (≥5% tumor area), while cases without any pattern were VETC-. The regions of intratumor and peritumor were segmented manually in the arterial, portal-venous and delayed phase (AP, PP, and DP, respectively) of DCE-MRI and reproducibility of segmentation was evaluated. Deep neural network and machine learning (ML) classifiers (logistic regression, decision tree, random forest, SVM, KNN, and Bayes) were used to develop nine DLR, 54 ML and clinical-radiological (CR) models based on AP, PP, and DP of DCE-MRI for evaluating VETC status and association with recurrence. STATISTICAL TESTS: The Fleiss kappa, intraclass correlation coefficient, receiver operating characteristic curve, area under the curve (AUC), Delong test and Kaplan-Meier survival analysis. P value <0.05 was considered as statistical significance. RESULTS: Pathological VETC+ were confirmed in 68 patients (training set: 46, validation set: 22). In the validation set, DLR model based on peritumor PP (peri-PP) phase had the best performance (AUC: 0.844) in comparison to CR (AUC: 0.591) and ML (AUC: 0.672) models. Significant differences in recurrence rates between peri-PP DLR model-predicted VETC+ and VETC- status were found. DATA CONCLUSIONS: The DLR model provides a noninvasive method to discriminate VETC status and prognosis of HCC patients preoperatively. EVIDENCE LEVEL: 4. TECHNICAL EFFICACY: Stage 2.

Metabolism-regulating non-coding RNAs in breast cancer: roles, mechanisms and clinical applications.

Breast cancer is one of the most common malignancies that pose a serious threat to women's health. Reprogramming of energy metabolism is a major feature of the malignant transformation of breast cancer. Compared to normal cells, tumor cells reprogram metabolic processes more efficiently, converting nutrient supplies into glucose, amino acid and lipid required for malignant proliferation and progression. Non-coding RNAs(ncRNAs) are a class of functional RNA molecules that are not translated into proteins but regulate the expression of target genes. NcRNAs have been demonstrated to be involved in various aspects of energy metabolism, including glycolysis, glutaminolysis, and fatty acid synthesis. This review focuses on the metabolic regulatory mechanisms and clinical applications of metabolism-regulating ncRNAs involved in breast cancer. We summarize the vital roles played by metabolism-regulating ncRNAs for endocrine therapy, targeted therapy, chemotherapy, immunotherapy, and radiotherapy resistance in breast cancer, as well as their potential as therapeutic targets and biomarkers. Difficulties and perspectives of current targeted metabolism and non-coding RNA therapeutic strategies are discussed.

Landscape fragmentation and regularity lead to decreased carbon stocks in basins: Evidence from century-scale research.

Landscapes evolution have significantly altered the Earth's energy balance and biogeochemical cycles, thereby exacerbating climate change. This, in turn, affects surface characteristics and the provision of ecosystem services, especially carbon storage. While recent centuries have witnessed unprecedented landscape changes, limited long-term studies have offered insights into the comparison between present-day features and historical conditions. This study utilized historical reconstruction data and remote sensing imagery to assess landscape evolution and its consequences for carbon stocks over 300 years. Employing multiple regression and random forest models were selected to quantify the influence of key landscape metrics on carbon stocks in the Dongting Lake basin, allowing for a thorough analysis across different sub-basins and land types. The results revealed that intensified human disturbances led to increased landscape fragmentation (+82%), regularity (+56%), and diversity (+37%) within the basin. Moreover, carbon stocks decreased from 4.13 Gt to 3.66 Gt, representing an 11.4% loss, with soil carbon stock experiencing the most considerable reduction (0.24 Gt, 51%). These changes in carbon stock metrics corresponded to shifts in landscape patterns, both undergoing significant transitions at the turn of the 21st century. Meanwhile, fragmentation and regularity played a vital role in explaining carbon stock changes, as their increase contributes to greater carbon losses. Likewise, an increase in landscape diversity correlated with decreased carbon stocks, challenging the prevailing notion that enhanced diversity promotes carbon stocks. The influence of landscape patterns on carbon stocks varies notably across distinct land types. An increase in the dominance of farmland and built-up land led to decreased carbon stocks, while the opposite holds true for forestland. Similarly, a decrease in regularity for farmland, forestland, and built-up land benefits carbon storage, while grassland demonstrates the opposite trend. These findings offer insights for countries and regions in the early stages of development or approaching development, suggesting improvements in land use practices and strategies to address climate change. This involves offsetting land-based carbon emissions through changes in landscape spatial configuration.

Lipopolysaccharide and Glycolipoprotein Coordinately Triggered Necroptosis Contributes to the Pathogenesis of Leptospira Infection in Mice.

Leptospirosis is a recurring but neglected zoonotic disease caused by pathogenic Leptospira. The explicit underlying mechanism of necroptosis and its role in Leptospira infection have not yet been elucidated. Here we reported that leptospiral pathogen-associated molecular patterns, lipopolysaccharide, and glycolipoprotein activate the necroptotic RIPK1-RIPK3-MLKL cascade through the TLR4 signaling pathway in mouse macrophages. Using the murine acute leptospirosis model, we reveal that abolition of necroptosis exhibited significantly improved outcomes in acute phases, with enhanced eradication of Leptospira from liver, mild clinical symptoms, and decreased cytokine production. RIPK3 was also found to exert a necroptosis-independent function in CXCL1 production and neutrophil recruitment, with the consequence of improved Leptospira control. These findings improve our understanding of the mechanism of Leptospira-macrophage interactions, indicating potential therapeutic values by targeting necroptosis signaling pathways.

Grass-specific ABERRANT MICROSPORE DEVELOPMENT 1 is required for maintaining pollen fertility in rice.

Pollen development includes a series of biological events that require precise gene regulation. Although several transcription factors (TFs) have been shown to play roles in maintaining pollen fertility, the major regulatory networks underlying tapetum development and pollen wall formation are largely unknown. Herein, we report that ABERRANT MICROSPORE DEVELOPMENT1 (AMD1), a protein annotated previously as unknown protein, is required for tapetum development and pollen exine patterning in rice (Oryza sativa L.). AMD1 encodes a grass-specific protein exhibiting transactivation activity in the nucleus and is spatiotemporally expressed in the tapetum and microspores during pollen development. Further biochemical assays indicate that AMD1 directly activates the transcription of DEFECTIVE POLLEN WALL (DPW) and POLYKETIDE SYNTHASE2 (OsPKS2), which are both implicated in sporopollenin biosynthesis during exine formation. Additionally, AMD1 directly interacts with TAPETUM DEGENERATION RETARDATION (TDR), a key TF involved in the regulation of tapetum degradation and exine formation. Taken together, we demonstrate that AMD1 is an important regulatory component involved in the TDR-mediated regulatory pathway to regulate sporopollenin biosynthesis, tapetum degradation, and exine formation for pollen development. Our work provides insights into the regulatory network of rice sexual reproduction and a useful target for genetic engineering of new male-sterile lines for hybrid rice breeding.

SWOLLEN TAPETUM AND STERILITY 1 is required for tapetum degeneration and pollen wall formation in rice.

The pollen wall is important for protecting the male gametophyte and for fertilization. The lipid components of the pollen wall are mainly synthesized and transported from the sporophytic tapetum. Although several factors related to lipid biosynthesis have been characterized, the molecular mechanisms underlying lipid biosynthesis during pollen development in rice (Oryza sativa L.) remain elusive. Here, we showed that mutation in the SWOLLEN TAPETUM AND STERILITY 1 (STS1) gene causes delayed tapetum degradation and aborted pollen wall formation in rice. STS1 encodes an endoplasmic reticulum (ER)-localized protein that contains domain of unknown function (DUF) 726 and exhibits lipase activity. Lipidomic and transcriptomic analyses showed that STS1 is involved in anther lipid homeostasis. Moreover, STS1 interacts with Polyketide Synthase 2 (OsPKS2) and Acyl-CoA Synthetase 12 (OsACOS12), two enzymes crucial in lipidic sporopollenin biosynthesis in pollen wall formation, suggesting a potentially lipidic metabolon for sporopollenin biosynthesis in rice. Collectively, our results indicate that STS1 is an important factor for lipid biosynthesis in reproduction, providing a target for the artificial control of male fertility in hybrid rice breeding and insight into the function of DUF726-containing protein in plants.

Caspase-8 Promotes Pulmonary Hypertension by Activating Macrophage-Associated Inflammation and IL-1ß (Interleukin 1ß) Production.

BACKGROUND: Macrophages are involved in the pathogenesis of pulmonary arterial hypertension (PAH). Caspase-8, an apical component of cell death pathways, is significantly upregulated in macrophages of PAH animal models. However, its role in PAH remains unclear. Caspase-8 plays a critical role in regulating inflammatory responses via inflammasome activation, cell death, and cytokine induction. This study investigated the mechanism of regulation of IL-1ß (interleukin 1ß) activation in macrophages by caspase-8. METHODS: A hypoxia + SU5416-induced PAH mouse model and monocrotaline-induced rat model of PAH were constructed and the role of caspase-8 was analyzed. RESULTS: Caspase-8 and cleaved-caspase-8 were significantly upregulated in the lung tissues of SU5416 and hypoxia-treated PAH mice and monocrotaline-treated rats. Pharmacological inhibition of caspase-8 alleviated PAH compared with wild-type mice, observed as a significant reduction in right ventricular systolic pressure, ratio of right ventricular wall to left ventricular wall plus ventricular septum, pulmonary vascular media thickness, and pulmonary vascular muscularization; caspase-8 ablated mice also showed significant remission. Mechanistically, increased proliferation of pulmonary arterial smooth muscle cellss is closely associated with activation of the NLRP3 (NOD [nucleotide oligomerization domain]-, LRR [leucine-rich repeat]-, and PYD [pyrin domain]-containing protein 3) inflammasome and the IL-1ß signaling pathway. Although caspase-8 did not affect extracellular matrix synthesis, it promoted inflammatory cell infiltration and pulmonary arterial smooth muscle cell proliferation via NLRP3/IL-1ß activation during the development stage of PAH. CONCLUSIONS: Taken together, our study suggests that macrophage-derived IL-1ß via caspase-8-dependent canonical inflammasome is required for macrophages to play a pathogenic role in pulmonary perivascular inflammation.

The Enzyme Lysine Malonylation of Calvin Cycle and Gluconeogenesis Regulated Glycometabolism in Nostoc flagelliforme to Adapt to Drought Stress.

Lysine malonylation (Kmal) is an evolutionarily conserved post-translational modification (PTM) that has been demonstrated to be involved in cellular and organismal metabolism. However, the role that Kmal plays in response to drought stress of the terrestrial cyanobacteria N. flagelliforme is still unknown. In this study, we performed the first proteomic analysis of Kmal in N. flagelliforme under different drought stresses using LC-MS/MS. In total, 421 malonylated lysine residues were found in 236 different proteins. GO and KEGG enrichment analysis indicated that these malonylated proteins were highly enriched in several metabolic pathways, including carbon metabolism and photosynthesis. Decreased malonylation levels were found to hinder the reception and transmission of light energy and CO2 fixation, which led to a decrease in photosynthetic activity. Kmal was also shown to inhibit the flux of the TCA cycle and activate the gluconeogenesis pathway in response to drought stress. Furthermore, malonylated antioxidant enzymes and antioxidants were synergistically involved in reactive oxygen species (ROS) scavenging. Malonylation was involved in lipid degradation and amino acid biosynthesis as part of drought stress adaptation. This work represents the first comprehensive investigation of the role of malonylation in dehydrated N. flagelliforme, providing an important resource for understanding the drought tolerance mechanism of this organism.

Carbon Metabolism and the ROS Scavenging System Participate in Nostoc flagelliforme's Adaptive Response to Dehydration Conditions through Protein Acetylation.

Acetylation represents an extensively occurring protein post-translational modification (PTM) that plays a key role in many cellular physiological and biochemical processes. However, studies on PTMs such as acetylation of lysine (LysAc) in cyanobacteria are still rare. In this study, a quantitative LysAc approach (acetylome) on the strains of Nostoc flagelliforme subjected to different dehydration treatments was conducted. We observed that starch contents were significantly accumulated due to dehydration treatments, and we identified 2474 acetylpeptides and 1060 acetylproteins based on acetylome analysis. Furthermore, an integrative analysis was performed on acetylome and nontargeted metabolism, and the results showed that many KEGG terms were overlapped for both omics analyses, including starch and sucrose metabolism, transporter activity, and carbon metabolism. In addition, time series clustering was analyzed, and some proteins related to carbon metabolism and the ROS scavenging system were significantly enriched in the list of differentially abundant acetylproteins (DAAPs). These protein expression levels were further tested by qPCR. A working model was finally proposed to show the biological roles of protein acetylation from carbon metabolism and the ROS scavenging system in response to dehydration in N. flagelliforme. We highlighted that LysAc was essential for the regulation of key metabolic enzymes in the dehydration stress response.

Secretory lipid transfer protein OsLTPL94 acts as a target of EAT1 and is required for rice pollen wall development.

The plant pollen wall protects the male gametophyte from various biotic and abiotic stresses. The formation of a unique pollen wall structure and elaborate exine pattern is a well-organized process, which needs coordination between reproductive cells and the neighboring somatic cells. However, molecular mechanisms underlying this process remain largely unknown. Here, we report a rice male-sterile mutant (l94) that exhibits defective pollen exine patterning and abnormal tapetal cell development. MutMap and knockout analyses demonstrated that the causal gene encodes a type-G non-specific lipid transfer protein (OsLTPL94). Histological and cellular analyses established that OsLTPL94 is strongly expressed in the developing microspores and tapetal cells, and its protein is secreted to the plasma membrane. The l94 mutation impeded the secretory ability of OsLTPL94 protein. Further in vivo and in vitro investigations supported the hypothesis that ETERNAL TAPETUM 1 (EAT1), a basic helix-loop-helix transcription factor (bHLH TF), activated OsLTPL94 expression through direct binding to the E-box motif of the OsLTPL94 promoter, which was supported by the positive correlation between the expression of EAT1 and OsLTPL94 in two independent eat1 mutants. Our findings suggest that the secretory OsLTPL94 plays a key role in the coordinated development of tapetum and microspores with the regulation of EAT1.

Proteome profiling reveals changes in energy metabolism, transport and antioxidation during drought stress in Nostoc flagelliforme.

BACKGROUND: Drought is an important abiotic stress that constrains the growth of many species. Despite extensive study in model organisms, the underlying mechanisms of drought tolerance in Nostoc flagelliforme remain elusive. RESULTS: We characterized the drought adaptation of N. flagelliforme by a combination of proteomics and qRT-PCR. A total of 351 differentially expressed proteins involved in drought stress adaptation were identified. It was found that the expression of several nutrient influx transporters was increased, including molybdate ABC transporter substrate binding protein (modA), sulfate ABC transporter substrate-binding protein (sbp) and nitrate ABC transporter (ntrB), while that of efflux transporters for toxic substances was also increased, including arsenic transporting ATPase (ArsA), potassium transporter (TrkA) and iron ABC transporter substrate-binding protein (VacB). Additionally, photosynthetic components were reduced while sugars built up during drought stress. Non-enzymatic antioxidants, orange carotenoid protein (OCP) homologs, cytochrome P450 (CYP450), proline (Pro) and ascorbic acid (AsA) were all altered during drought stress and may play important roles in scavenging reactive oxygen species (ROS). CONCLUSION: In this study, N. flagelliforme may regulates its adaptation to drought stress through the changes of protein expression in photosynthesis, energy metabolism, transport, protein synthesis and degradation and antioxidation. HIGHLIGHTS: • A total of 351 DEPs involved in adaptation to drought stress were identified. • Changes in the expression of six OCP homologs were found in response to drought stress. • Differential expression of transporters played an important role in drought stress adaptation. • Most PSII proteins were downregulated, while PSI proteins were unchanged in response to drought stress. • Sugar metabolism was upregulated in response to drought stress.

Genome-wide association study-based identification genes influencing agronomic traits in rice (Oryza sativa L.).

Rice is one of the most important cereal crops, providing the daily dietary intake for approximately 50% of the global human population. Here, we re-sequenced 259 rice accessions, generating 1371.65 Gb of raw data. Furthermore, we performed genome-wide association studies (GWAS) on 13 agronomic traits using 2.8 million single nucleotide polymorphisms (SNPs) characterized in 259 rice accessions. Phenotypic data and best linear unbiased prediction (BLUP) values of each of the 13 traits over two years of each trait were used for the GWAS. The results showed that 816 SNP signals were significantly associated with the 13 agronomic traits. Then we detected candidate genes related to target traits within 200 kb upstream and downstream of the associated SNP loci, based on linkage disequilibrium (LD) blocks in the whole rice genome. These candidate genes were further identified through haplotype block constructions. This comprehensive study provides a timely and important genomic resource for breeding high yielding rice cultivars.

DEAP1 encodes a fasciclin-like arabinogalactan protein required for male fertility in rice.

Arabinogalactan proteins (AGPs) are widely distributed in plant cells. Fasciclin-like AGPs (FLAs) belong to a subclass of AGPs that play important roles in plant growth and development. However, little is known about the biological functions of rice FLA. Herein, we report the identification of a male-sterile mutant of DEFECTIVE EXINE AND APERTURE PATTERNING1 (DEAP1) in rice. The deap1 mutant anthers produced aberrant pollen grains with defective exine formation and a flattened aperture annulus and exhibited slightly delayed tapetum degradation. DEAP1 encodes a plasma membrane-associated member of group III plant FLAs and is specifically and temporally expressed in reproductive cells and the tapetum layer during male development. Gene expression studies revealed reduced transcript accumulation of genes related to exine formation, aperture patterning, and tapetum development in deap1 mutants. Moreover, DEAP1 may interact with two rice D6 PROTEIN KINASE-LIKE3s (OsD6PKL3s), homologs of a known Arabidopsis aperture protein, to affect rice pollen aperture development. Our findings suggested that DEAP1 is involved in male reproductive development and may affect exine formation and aperture patterning, thereby providing new insights into the molecular functions of plant FLAs in male fertility.

Genome-wide association study and transcriptome analysis discover new genes for bacterial leaf blight resistance in rice (Oryza sativa L.).

BACKGROUND: Rice (Oryza sativa) bacterial leaf blight (BLB), caused by the hemibiotrophic Xanthomonas oryzae pv. oryzae (Xoo), is one of the most devastating diseases affecting the production of rice worldwide. The development and use of resistant rice varieties or genes is currently the most effective strategy to control BLB. RESULTS: Here, we used 259 rice accessions, which are genotyped with 2 888 332 high-confidence single nucleotide polymorphisms (SNPs). Combining resistance variation data of 259 rice lines for two Xoo races observed in 2 years, we conducted a genome-wide association study (GWAS) to identify quantitative trait loci (QTL) conferring plant resistance against BLB. The expression levels of genes, which contains in GWAS results were also identified between the resistant and susceptible rice lines by transcriptome analysis at four time points after pathogen inoculation. From that 109 candidate resistance genes showing significant differential expression between resistant and susceptible rice lines were uncovered. Furthermore, the haplotype block structure analysis predicted 58 candidate genes for BLB resistance based on Chr. 7_707158 with a minimum P-value (-log 10 P = 9.72). Among them, two NLR protein-encoding genes, LOC_Os07g02560 and LOC_Os07g02570, exhibited significantly high expression in the resistant line, but had low expression in the susceptible line of rice. CONCLUSIONS: Together, our results reveal novel BLB resistance gene resources, and provide important genetic basis for BLB resistance breeding of rice crops.

Identification of rice (Oryza sativa L.) genes involved in sheath blight resistance via a genome-wide association study.

Rice sheath blight (RSB) is an economically significant disease affecting rice yield worldwide. Genetic resistance to RSB is associated with multiple minor genes, with each providing a minor phenotypic effect, but the underlying dominant resistance genes remain unknown. A genome-wide association study (GWAS) of 259 diverse rice varieties, with genotypes based on a single nucleotide polymorphism (SNP) and haplotype, was conducted to assess their sheath blight reactions at three developmental stages (seedlings, tillering and booting). A total of 653 genes were correlated with sheath blight resistance, of which the disease resistance protein RPM1 (OsRSR1) and protein kinase domain-containing protein (OsRLCK5) were validated by overexpression and knockdown assays. We further found that the coiled-coil (CC) domain of OsRSR1 (OsRSR1-CC) and full-length OsRLCK5 interacted with serine hydroxymethyltransferase 1 (OsSHM1) and glutaredoxin (OsGRX20), respectively. It was found that OsSHM1, which has a role in the reactive oxygen species (ROS) burst, and OsGRX20 enhanced the antioxidation ability of plants. A regulation model of the new RSB resistance though the glutathione (GSH)-ascorbic acid (AsA) antioxidant system was therefore revealed. These results enhance our understanding of RSB resistance mechanisms and provide better gene resources for the breeding of disease resistance in rice.

Spatiotemporal dislocation of urbanization and ecological construction increased the ecosystem service supply and demand imbalance.

The spatiotemporal dislocation of urbanization and ecological construction may lead to differences in the spatiotemporal pattern and matching of the ecosystem service supply and demand, which are significantly important in altering the ecosystem service supply and demand equilibrium. This study quantified and mapped the supply and demand of carbon sequestration services in the Xiangjiang River Basin (XRB) from 1990 to 2015 using the InVEST and population distribution models and identified the spatial distribution characteristics and changes in the supply and demand relationship on the sub-basin scale using the spatial autocorrelation method and Z-scores. The results show that the expansion of land urbanization greater than 50% was concentrated in the midstream and downstream, while the ecological construction was mainly distributed in the upstream. On the whole-basin scale, the supply of carbon sequestration services slightly decreased by 21.62%, while the demand sharply increased by 376.86%. The carbon sequestration services supply-demand ratio (CSDR) reduced from 0.16 (1990) to -0.03 (2015). This meant that the status of the supply and demand in the XRB had changed from oversupply to overdemand, and this tide turned in 2005 (-0.01). Furthermore, the spatial distribution pattern of the sub-basins' CSDR in the upstream was the High-High cluster, while it was the Low-Low cluster in the downstream. These results revealed the high spatial distribution consistency between the CSDR and urbanization and ecological construction. The slight increase in the carbon sinks caused by the ecological construction in the upstream could not offset the rapidly increased carbon emissions from the downstream for urbanization. Meanwhile, the lack of ecological concern during the urbanization process had led to a persistent reduction in the carbon sinks in the downstream, which also exacerbated the disequilibrium of the ecosystem service supply and demand in the XRB. Consequently, this study suggests that the scale and speed of the urbanization of land should be reasonably controlled and that the ecological construction in rapid urbanization regions should be strengthened to meet the demand for ecosystem services.

Defective Leptotene Chromosome 1 (DLC1) encodes a type-B response regulator and is required for rice meiosis.

Meiosis is critical for sexual reproduction and the generation of new allelic variations in most eukaryotes. In this study, we report the isolation of a meiotic gene, DLC1, using a map-based cloning strategy. The dlc1 mutant is sterile in both male and female gametophytes due to an earlier defect in the leptotene chromosome and subsequent abnormalities at later stages. DLC1 is strongly expressed in the pollen mother cells (PMCs) and tapetum and encodes a nucleus-located rice type-B response regulator (RR) with transcriptional activity. Further investigations showed that DLC1 interacts with all five putative rice histidine phosphotransfer proteins (HPs) in yeast and planta cells, suggesting a possible participation of the two-component signalling systems (TCS) in rice meiosis. Our results demonstrated that DLC1 is required for rice meiosis and fertility, providing useful information for the role of TCS in rice meiosis.

OsSHOC1 and OsPTD1 are essential for crossover formation during rice meiosis.

Meiosis is essential for eukaryotic sexual reproduction and plant fertility, and crossovers (COs) are essential for meiosis and the formation of new allelic combinations in gametes. In this study, we report the isolation of a meiotic gene, OsSHOC1, and the identification of its partner, OsPTD1. Osshoc1 was sterile both in male and female gametophytes, and it showed a striking reduction in the number of meiotic COs, indicating that OsSHOC1 was required for normal CO formation. Further investigations showed that OsSHOC1 physically interacted with OsPTD1 and that the latter was also required for normal CO formation and plant fertility. Additionally, the expression profiles of both genes were consistent with their functions. Our results suggest that OsSHOC1 and OsPTD1 are essential for rice fertility and CO formation, possibly by stabilizing the recombinant intermediates during meiosis.