Application of slow-controlled release fertilizer coordinates the carbon flow in carbon-nitrogen metabolism to effect rice quality.

Slow-controlled release fertilizers are experiencing a popularity in rice cultivation due to their effectiveness in yield and quality with low environmental costs. However, the underlying mechanism by which these fertilizers regulate grain quality remains inadequately understood. This study investigated the effects of five fertilizer management practices on rice yield and quality in a two-year field experiment: CK, conventional fertilization, and four applications of slow-controlled release fertilizer (UF, urea formaldehyde; SCU, sulfur-coated urea; PCU, polymer-coated urea; BBF, controlled-release bulk blending fertilizer). In 2020 and 2021, the yields of UF and SCU groups showed significant decreases when compared to conventional fertilization, accompanied by a decline in nutritional quality. Additionally, PCU group exhibited poorer cooking and eating qualities. However, BBF group achieved increases in both yield (10.8 t hm-2 and 11.0 t hm-2) and grain quality reaching the level of CK group. The adequate nitrogen supply in PCU group during the grain-filling stage led to a greater capacity for the accumulation of proteins and amino acids in the PCU group compared to starch accumulation. Intriguingly, BBF group showed better carbon-nitrogen metabolism than that of PCU group. The optimal nitrogen supply present in BBF group suitable boosted the synthesis of amino acids involved in the glycolysis/ tricarboxylic acid cycle, thereby effectively coordinating carbon-nitrogen metabolism. The application of the new slow-controlled release fertilizer, BBF, is advantageous in regulating the carbon flow in the carbon-nitrogen metabolism to enhance rice quality.

Autonomous Electroluminescent Textile for Visual Interaction and Environmental Warning.

Visual interaction is a promising strategy for the externalized expression and transmission of information, having wide application prospects in wearable luminous textiles. Achieving an autonomous luminous display and dynamic light response to environmental stimuli is attractive but attracts little attention. Herein, we propose a liquid responsive structure based on alternating-current electroluminescent fibers and demonstrate conductive-liquid-bridging electroluminescent fabrics with high integration and personalized patterns. Impressively, our electroluminescent fibers and textiles could afford a sensitive response and high robustness to water, glycerol, ethanol, and sodium chloride solution. The final electroluminescent textiles show an excellent luminescence performance of 149.08 cd m-2. On the proof of concept, a rain-sensing umbrella, luminous sportswear, and liquid response glove are fabricated to demonstrate water detection, visual interaction, and environmental warning. The textile-type visualizing-responding strategy proposed in this work may open up new avenues for the application of ACEL devices in the field of visual interaction.

Unexpected Parabolic Temperature Dependency of CH4 Emissions from Rice Paddies.

Global warming is expected to affect methane (CH4) emissions from rice paddies, one of the largest human-induced sources of this potent greenhouse gas. However, the large variability in warming impacts on CH4 emissions makes it difficult to extrapolate the experimental results over large regions. Here, we show, through meta-analysis and multi-site warming experiments using the free air temperature increase facility, that warming stimulates CH4 emissions most strongly at background air temperatures during the flooded stage of ∼26 °C, with smaller responses of CH4 emissions to warming at lower and higher temperatures. This pattern can be explained by divergent warming responses of plant growth, methanogens, and methanotrophs. The effects of warming on rice biomass decreased with the background air temperature. Warming increased the abundance of methanogens more strongly at the medium air temperature site than the low and high air temperature sites. In contrast, the effects of warming on the abundance of methanotrophs were similar across the three temperature sites. We estimate that 1 °C warming will increase CH4 emissions from paddies in China by 12.6%─substantially higher than the estimates obtained from leading ecosystem models. Our findings challenge model assumptions and suggest that the estimates of future paddy CH4 emissions need to consider both plant and microbial responses to warming.

Sink Strength Promoting Remobilization of Non-Structural Carbohydrates by Activating Sugar Signaling in Rice Stem during Grain Filling.

The remobilization of non-structural carbohydrates (NSCs) in the stem is essential for rice grain filling so as to improve grain yield. We conducted a two-year field experiment to deeply investigate their relationship. Two large-panicle rice varieties with similar spikelet size, CJ03 and W1844, were used to conduct two treatments (removing-spikelet group and control group). Compared to CJ03, W1844 had higher 1000-grain weight, especially for the grain growth of inferior spikelets (IS) after removing the spikelet. These results were mainly ascribed to the stronger sink strength of W1844 than that of CJ03 contrasting in the same group. The remobilization efficiency of NSC in the stem decreased significantly after removing the spikelet for both CJ03 and W1844, and the level of sugar signaling in the T6P-SnRK1 pathway was also significantly changed. However, W1844 outperformed CJ03 in terms of the efficiency of carbon reserve remobilization under the same treatments. More precisely, there was a significant difference during the early grain-filling stage in terms of the conversion of sucrose and starch. Interestingly, the sugar signaling of the T6P and SnRK1 pathways also represented an obvious change. Hence, sugar signaling may be promoted by sink strength to remobilize the NSCs of the rice stem during grain filling to further advance crop yield.

Glucose-6-Phosphate Dehydrogenases: The Hidden Players of Plant Physiology.

Glucose-6-phosphate dehydrogenase (G6PDH) catalyzes a metabolic hub between glycolysis and the pentose phosphate pathway (PPP), which is the oxidation of glucose-6-phosphate (G6P) to 6-phosphogluconolactone concomitantly with the production of nicotinamide adenine dinucleotide phosphate (NADPH), a reducing power. It is considered to be the rate-limiting step that governs carbon flow through the oxidative pentose phosphate pathway (OPPP). The OPPP is the main supplier of reductant (NADPH) for several "reducing" biosynthetic reactions. Although it is involved in multiple physiological processes, current knowledge on its exact role and regulation is still piecemeal. The present review provides a concise and comprehensive picture of the diversity of plant G6PDHs and their role in seed germination, nitrogen assimilation, plant branching, and plant response to abiotic stress. This work will help define future research directions to improve our knowledge of G6PDHs in plant physiology and to integrate this hidden player in plant performance.

Melatonin improves K+ and Na+ homeostasis in rice under salt stress by mediated nitric oxide.

Rice (Oryza sativa L.) productivity is greatly affected by soil salinity and melatonin (MLT) has long been recognized as a positive molecule that can alleviate the damage caused by salt. Here, the role of nitric oxide (NO) in the regulation of salt tolerance by MLT was investigated in rice. MLT pretreatment increased the fresh and dry weight of rice seedlings under salt stress. Its beneficial effects include less relative electrolyte leakage (REL) and better K+/Na+ homeostasis. MLT increased the activity of nitric oxide synthase (NOS). The polyamines (PAs) content and the utilization of arginine were also increased, thereby increasing NO content in salt-stressed rice seedlings. Pharmacological approach showed that NO, as a necessary downstream signaling molecule, was involved in the regulation of MLT on the K+/Na+ homeostasis of rice. Under salt stress, MLT improved the H+-pumps activities in plasma membrane (PM) and vacuole membrane (VM) in roots, MLT also increased the ATP content of rice roots by increasing the NO content of rice. Thus, the efflux of Na+ and the influx of K+ were promoted. When endogenous NO was scavenged, the regulation of K+/Na+ homeostasis by MLT was blocked. Therefore, MLT mediated K+/Na+ homeostasis of rice under salt stress by mediating NO.

Complementary Proteome and Transcriptome Profiling in Developing Grains of a Notched-Belly Rice Mutant Reveals Key Pathways Involved in Chalkiness Formation.

Rice grain chalkiness is a highly complex trait involved in multiple metabolic pathways and controlled by polygenes and growth conditions. To uncover novel aspects of chalkiness formation, we performed an integrated profiling of gene activity in the developing grains of a notched-belly rice mutant. Using exhaustive tandem mass spectrometry-based shotgun proteomics and whole-genome RNA sequencing to generate a nearly complete catalog of expressed mRNAs and proteins, we reliably identified 38,476 transcripts and 3,840 proteins. Comparison between the translucent part and chalky part of the notched-belly grains resulted in only a few differently express genes (240) and differently express proteins (363), thus making it possible to focus on 'core' genes or common pathways. Several novel key pathways were identified as of relevance to chalkiness formation, in particular the shift of C and N metabolism, the down-regulation of ribosomal proteins and the resulting low abundance of storage proteins especially the 13 kDa prolamin subunit, and the suppressed photosynthetic capacity in the pericarp of the chalky part. Further, genes and proteins as transporters for carbohydrates, amino acid/peptides, proteins, lipids and inorganic ions showed an increasing expression pattern in the chalky part of the notched-belly grains. Similarly, transcripts and proteins of receptors for auxin, ABA, ethylene and brassinosteroid were also up-regulated. In summary, this joint analysis of transcript and protein profiles provides a comprehensive reference map of gene activity regarding the physiological state in the chalky endosperm.

Metabolomic analysis of pathways related to rice grain chalkiness by a notched-belly mutant with high occurrence of white-belly grains.

BACKGROUND: Grain chalkiness is a highly undesirable trait deleterious to rice appearance and milling quality. The physiological and molecular foundation of chalkiness formation is still partially understood, because of the complex interactions between multiple genes and growing environments. RESULTS: We report the untargeted metabolomic analysis of grains from a notched-belly mutant (DY1102) with high percentage of white-belly, which predominantly occurs in the bottom part proximal to the embryo. Metabolites in developing grains were profiled on the composite platforms of UPLC/MS/MS and GC/MS. Sampling times were 5, 10, 15, and 20 days after anthesis, the critical time points for chalkiness formation. A total of 214 metabolites were identified, covering most of the central metabolic pathways and partial secondary pathways including amino acids, carbohydrates, lipids, cofactors, peptides, nucleotides, phytohormones, and secondary metabolites. A comparison of the bottom chalky part and the upper translucent part of developing grains of DY1102 resulted in 180 metabolites related to chalkiness formation. CONCLUSIONS: Generally, in comparison to the translucent upper part, the chalky endosperm had lower levels of metabolites regarding carbon and nitrogen metabolism for synthesis of storage starch and protein, which was accompanied by perturbation of pathways participating in scavenging of reactive oxygen species, osmorugulation, cell wall synthesis, and mineral ion homeostasis. Based on these results, metabolic mechanism of chalkiness formation is discussed, with the role of embryo highlighted.

Nitrogen fertilizer application affects lodging resistance by altering secondary cell wall synthesis in japonica rice (Oryza sativa).

Stem mechanical strength is an important agricultural quantitative trait that is closely related to lodging resistance in rice, which is known to be reduced by fertilizer with higher levels of nitrogen. To understand the mechanism that regulates stem mechanical strength in response to nitrogen, we analysed stem morphology, anatomy, mechanical properties, cell wall components, and expression of cell wall-related genes, in two varieties of japonica rice, namely, Wuyunjing23 (lodging-resistant variety) and W3668 (lodging-susceptible variety). The results showed that higher nitrogen fertilizer increased the lodging index in both varieties due to a reduction in breaking strength and bending stress, and these changes were larger in W3668. Cellulose content decreased slightly under higher nitrogen fertilizer, whereas lignin content reduced remarkably. Histochemical staining revealed that high nitrogen application decreased lignin deposition in the secondary cell wall of the sclerenchyma cells and vascular bundle cells compared with the low nitrogen treatments, while it did not alter the pattern of cellulose deposition in these cells in both Wuyunjing23 and W3668. In addition, the expression of the genes involved in lignin biosynthesis, OsPAL, OsCoMT, Os4CL3, OsCCR, OsCAD2, OsCAD7, OsCesA4, and OsCesA7, were also down-regulated under higher nitrogen conditions at the early stage of culm growth. These results suggest that the genes involved in lignin biosynthesis are down-regulated by higher nitrogen fertilizer, which causes lignin deficiency in the secondary cell walls and the weakening of mechanical tissue structure. Subsequently, this results in these internodes with reduced mechanical strength and poor lodging resistance.

Chalky part differs in chemical composition from translucent part of japonica rice grains as revealed by a notched-belly mutant with white-belly.

BACKGROUND: Chalkiness has a deleterious influence on rice appearance and milling quality. We identified a notched-belly mutant with a high percentage of white-belly, and thereby developed a novel comparison system that can minimize the influence of genetic background and growing conditions. Using this mutant, we examined the differences in chemical composition between chalky and translucent endosperm, with the aim of exploring relations between occurrence of chalkiness and accumulation of starch, protein and minerals. RESULTS: Comparisons showed a significant effect of chalkiness on chemical components in the endosperm. In general, occurrence of chalkiness resulted in higher total starch concentration and lower concentrations of the majority of the amino acids measured. Chalkiness also had a positive effect on the concentrations of As, Ba, Cd, Cr, Mn, Na, Sr and V, but was negatively correlated with those of B, Ca, Cu, Fe and Ni. By contrast, no significant chalkiness effect on P, phytic acid-P, K, Mg or Zn was observed. In addition, substantial influence of the embryo on endosperm composition was detected, with the embryo showing a negative effect on total protein, amino acids such as Arg, His, Leu, Lys, Phe and Tyr, and all the 17 minerals measured, excluding Ca, Cu, P and Sr. CONCLUSION: An inverse relation between starch and protein as well as amino acids was found with respect to chalkiness occurrence. Phytic acid and its colocalized elements K and Mg were not affected by chalkiness. The embryo exerted a marked influence on chemical components of the endosperm, in particular minerals, suggesting the necessity of examining the role of the embryo in chalkiness formation. © 2016 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Proteomic analysis of proteins related to rice grain chalkiness using iTRAQ and a novel comparison system based on a notched-belly mutant with white-belly.

BACKGROUND: Grain chalkiness is a complex trait adversely affecting appearance and milling quality, and therefore has been one of principal targets for rice improvement. Eliminating chalkiness from rice has been a daunting task due to the complex interaction between genotype and environment and the lack of molecular markers. In addition, the molecular mechanisms underlying grain chalkiness formation are still imperfectly understood. RESULTS: We identified a notched-belly mutant (DY1102) with high percentage of white-belly, which only occurs in the bottom part proximal to the embryo. Using this mutant, a novel comparison system that can minimize the effect of genetic background and growing environment was developed. An iTRAQ-based comparative display of the proteins between the bottom chalky part and the upper translucent part of grains of DY1102 was performed. A total of 113 proteins responsible for chalkiness formation was identified. Among them, 70 proteins are up-regulated and 43 down-regulated. Approximately half of these differentially expressed proteins involved in central metabolic or regulatory pathways including carbohydrate metabolism (especially cell wall synthesis) and protein synthesis, folding and degradation, providing proteomic confirmation of the notion that chalkiness formation involves diverse but delicately regulated pathways. Protein metabolism was the most abundant category, accounting for 27.4% of the total differentially expressed proteins. In addition, down regulation of PDIL 2-3 and BiP was detected in the chalky tissue, indicating the important role of protein metabolism in grain chalkiness formation. CONCLUSIONS: Using this novel comparison system, our comprehensive survey of endosperm proteomics in the notched-belly mutant provides a valuable proteomic resource for the characterization of pathways contributing to chalkiness formation at molecular and biochemical levels.

Functional study of two ER localized sterol C-14 reductases in Aspergillus oryzae.

Ergosterol is an important component of fungal cell membrane. Ergosterol biosynthesis involves sterol C-14 reductase, a key enzyme in ergosterol biosynthesis, which has been well studied in Saccharomyces cerevisiae. However, little studies about this important enzyme in Aspergillus oryzae. In this study, two sterol C-14 reductases named AoErg24A and AoErg24B were identified in A. oryzae using bioinformatics analysis. Through phylogenetic tree, expression pattern, subcellular localization, and yeast functional complementation analyses, we discovered that both AoErg24A and AoErg24B are conserved and localized to the endoplasmic reticulum (ER). Both enzymes can partially restore the temperature sensitivity phenotype of a S. cerevisiae erg24 weak mutant. Overexpression of AoErg24A in A. oryzae increased 1.6 times of ergosterol content, while overexpression of AoErg24B led to a slight decrease of ergosterol. Both genes affect the sporulation of A. oryzae. These results uncovered that the two genes function differently in ergosterol biosynthesis. Thus, this study further enhances our understanding of ergosterol biosynthesis in A. oryzae and lays a good foundation for A. oryzae to be used in industrial ergosterol production.

Impacts of transglutaminase on the processing and digestion characteristics of glutinous rice flour: Insight of the interactions between enzymic crossing-linked protein and starch.

Glutinous rice is extensively consumed due to its nutritious content and wonderful flavor. However, glutinous rice flour has a high glycemic index, and the storage deterioration of sweet dumplingsissevere. Transglutaminase (TG) was used to cross-link glutinous rice protein and improve the characteristics of glutinous rice products. The findings demonstrated that TG significantly catalysed protein cross-linking to form a dense protein network, reduced the viscosity of glutinous rice paste and improved the thermal stability. The protein network may physically block the access of starch granules to digestive enzymes to lower the digestion rate of starch, and attenuate the damage of ice crystal molecules to the starch structure to improve the freezing stability of starch gels. The cracking rate and water loss of sweet dumplings prepared using glutinous rice flour with TG treated for 60 min reduced significantly. In conclusion, this study broadened the application of TG in starch products.

Methane emissions from rice fields under continuous straw return in the middle-lower reaches of the Yangtze River.

A three-year experiment was conducted in the middle-lower reaches of the Yangtze River in China to study the influence of continuous wheat straw return during the rice season and continuous rice straw return in wheat on methane (CH4) emissions from rice fields in which, the rice-wheat rotation system is the most dominant planting pattern. The field experiment was initiated in October 2009 and has continued since the wheat-growing season of that year. The analyses for the present study were conducted in the second (2011) and third (2012) rice growing seasons. Four treatments, namely, the continuous return of wheat straw and rice straw in every season (WR), of rice straw but no wheat straw return (R), of wheat straw but no rice straw return (W) and a control with no straw return (CK), were laid out in a randomized split-plot design. The total seasonal CH4 emissions ranged from 107.4 to 491.7 kg/ha (2011) and 160.3 to 909.6 kg/ha (2012). The increase in CH4 emissions for treatments WR and W were 289% and 230% in the second year and 185% and 225% in the third year, respectively, in relation to CK. We observed less methane emissions in the treatment R than in CK by 14%-43%, but not statistically significant. Treatment R could increase rice productivity while no more CH4 emission occurs. The difference in the total CH4 emissions mainly related to a difference in the methane flux rate during the first 30-35 days after transplant in the rice growing season, which was caused by the amount of dissolved oxygen in paddy water and the amount of reducible soil materials.

The expression pattern, subcellular localization and function of three sterol 14α-demethylases in Aspergillus oryzae.

Sterol 14α-demethylase catalyzes lanosterol hydroxylation, which is one of the key reactions in the biosynthetic pathway of sterols. There is only one sterol 14α-demethylases gene named Erg11 in Saccharomyces cerevisiae genome. In this study, three sterol 14α-demethylases genes named AoErg11A, AoErg11B and AoErg11C were identified in Aspergillus oryzae genome through bioinformatics analysis. The function of these three genes were studied by yeast complementation, and the expression pattern/subcellular localization of these genes/proteins were detected. The results showed that the three AoErg11s were expressed differently at different growth times and under different abiotic stresses. All of the three proteins were located in endoplasmic reticulum. The AoErg11s could not restore the temperature-sensitive phenotype of S. cerevisiae erg11 mutant. Overexpression of the three AoErg11s affected both growth and sporulation, which may be due to the effect of AoErg11s on ergosterol content. Therefore, this study revealed the functions of three AoErg11s and their effects on the growth and ergosterol biosynthesis of A. oryzae, which may contribute to the further understanding of the ergosterol biosynthesis and regulation mechanism in this important filamentous fungus, A. oryzae.

Analyzing Nitrogen Effects on Rice Panicle Development by Panicle Detection and Time-Series Tracking.

Detailed observation of the phenotypic changes in rice panicle substantially helps us to understand the yield formation. In recent studies, phenotyping of rice panicles during the heading-flowering stage still lacks comprehensive analysis, especially of panicle development under different nitrogen treatments. In this work, we proposed a pipeline to automatically acquire the detailed panicle traits based on time-series images by using the YOLO v5, ResNet50, and DeepSORT models. Combined with field observation data, the proposed method was used to test whether it has an ability to identify subtle differences in panicle developments under different nitrogen treatments. The result shows that panicle counting throughout the heading-flowering stage achieved high accuracy (R2 = 0.96 and RMSE = 1.73), and heading date was estimated with an absolute error of 0.25 days. In addition, by identical panicle tracking based on the time-series images, we analyzed detailed flowering phenotypic changes of a single panicle, such as flowering duration and individual panicle flowering time. For rice population, with an increase in the nitrogen application: panicle number increased, heading date changed little, but the duration was slightly extended; cumulative flowering panicle number increased, rice flowering initiation date arrived earlier while the ending date was later; thus, the flowering duration became longer. For a single panicle, identical panicle tracking revealed that higher nitrogen application led to earlier flowering initiation date, significantly longer flowering days, and significantly longer total duration from vigorous flowering beginning to the end (total DBE). However, the vigorous flowering beginning time showed no significant differences and there was a slight decrease in daily DBE.

Static magnetic field improvement of the quality of rice dumpling subjected to freeze-thaw cycles: Roles of phase transition of water and changes in structural and physicochemical properties of glutinous rice flour.

This study aimed to investigate the effect of static magnetic field (SMF, 0-10 mT) on the quality of rice dumplings subjected to 7, 14, 21, and 28 freeze-thaw cycles. The underlying mechanism was explored by monitoring changes in water phase transition, water distribution, and structural and physicochemical properties of rice flour. Results suggested that SMF enables the formation of small ice crystals by accelerating freezing rate, shortening phase transition time, and increasing bound water content, which attributes to reducing the mechanical damage on starch granules and thus improves the quality of frozen rice dumpling. After 7-28 freeze-thaw cycles, SMF treatment increased the whiteness by 0.08-1.58, reduced the cracking ratio by 1.67 %-8.34 %, decreased the water loss ratio by 0-0.75 %, and significantly improved the texture of cooked rice dumplings. This study confirmed the feasibility of SMF in improving the quality of rice dumpling, which contributes to expanding the applications of magnetic freezer in the preservation of starch-based foods.

Comprehensive Evaluation of Rice Qualities under Different Nitrogen Levels in South China.

There is a need to comprehensively evaluate the rice quality of different rice varieties under different nitrogen treatments. Therefore, in this study, we used twenty-one hybrid indica rice varieties and twenty-three inbred japonica rice varieties with three nitrogen fertilizer levels to investigate differences in rice qualities. As compared with hybrid indica rice, inbred japonica rice had lower coefficient of variation values for grain shape, mild rice percentage, and head rice percentage, but relatively higher coefficient of variation values for chalkiness traits, appearance, and taste value of cooked rice. A principal component analysis and membership function method were used to comprehensively evaluate the qualities of rice. The overall eating quality value by sensory evaluation and head rice percentage explained 61.3% and 67.9% of the variations in comprehensive quality of hybrid indica rice and inbred japonica rice across different nitrogen levels, respectively. We also found that rice comprehensive quality was better under low nitrogen levels for hybrid indica rice, while for inbred japonica rice, properly increasing nitrogen application could improve the comprehensive quality.

A novel marker integrating multiple genetic alterations better predicts platinum sensitivity in ovarian cancer than HRD score.

Introduction: Platinum-based chemotherapy is the first-line treatment strategy for ovarian cancer patients. The dismal prognosis of ovarian cancer was shown to be stringently associated with the heterogeneity of tumor cells in response to this therapy, therefore understanding platinum sensitivity in ovarian cancer would be helpful for improving patients' quality of life and clinical outcomes. HRDetect, utilized to characterize patients' homologous recombination repair deficiency, was used to predict patients' response to platinum-based chemotherapy. However, whether each of the single features contributing to HRD score is associated with platinum sensitivity remains elusive. Methods: We analyzed the whole-exome sequencing data of 196 patients who received platinum-based chemotherapy from the TCGA database. Genetic features were determined individually to see if they could indicate patients' response to platinum-based chemotherapy and prognosis, then integrated into a Pt-score employing LASSO regression model to assess its predictive performance. Results and discussion: Multiple genetic features, including bi-allelic inactivation of BRCA1/2 genes and genes involved in HR pathway, multiple somatic mutations in genes involved in DNA damage repair (DDR), and previously reported HRD-related features, were found to be stringently associated with platinum sensitivity and improved prognosis. Higher contributions of mutational signature SBS39 or ID6 predicted improved overall survival. Besides, arm-level loss of heterozygosity (LOH) of either chr4p or chr5q predicted significantly better disease-free survival. Notably, some of these features were found independent of HRD. And SBS3, an HRD-related feature, was found irrelevant to platinum sensitivity. Integrated all candidate markers using the LASSO model to yield a Pt-score, which showed better predictive ability compared to HRDetect in determining platinum sensitivity and predicting patients' prognosis, and this performance was validated in an independent cohort. The outcomes of our study will be instrumental in devising effective strategies for treating ovarian cancer with platinum-based chemotherapy.

The Inferior Grain Filling Initiation Promotes the Source Strength of Rice Leaves.

Poor grain-filling initiation in inferior spikelets severely impedes rice yield improvement, while photo-assimilates from source leaves can greatly stimulate the initiation of inferior grain-filling (sink). To investigate the underlying mechanism of source-sink interaction, a two-year field experiment was conducted in 2019 and 2020 using two large-panicle rice cultivars (CJ03 and W1844). The treatments included intact panicles and partial spikelet removal. These two cultivars showed no significant difference in the number of spikelets per panicle. However, after removing spikelet, W1844 showed higher promotion on 1000-grain weight and seed-setting rate than CJ03, particularly for inferior spikelets. The reason was that the better sink activity of W1844 led to a more effective initiation of inferior grain-filling compared to CJ03. The inferior grain weight of CJ03 and W1844 did not show a significant increase until 8 days poster anthesis (DPA), which follows a similar pattern to the accumulation of photo-assimilates in leaves. After removing spikelets, the source leaves of W1844 exhibited lower photosynthetic inhibition compared to CJ03, as well as stronger metabolism and transport of photo-assimilates. Although T6P levels remained constant in both cultivars under same conditions, the source leaves of W1844 showed notable downregulation of SnRK1 activity and upregulation of phytohormones (such as abscisic acid, cytokinins, and auxin) after removing spikelets. Hence, the high sink strength of inferior spikelets plays a role in triggering the enhancement of source strength in rice leaves, thereby fulfilling grain-filling initiation demands.