Two interacting basic helix-loop-helix transcription factors control flowering time in rice.

Flowering time is one of the most important agronomic traits affecting the adaptation and yield of rice (Oryza sativa). Heading date 1 (Hd1) is a key factor in the photoperiodic control of flowering time. In this study, two basic helix-loop-helix (bHLH) transcription factors, Hd1 Binding Protein 1 (HBP1) and Partner of HBP1 (POH1) were identified as transcriptional regulators of Hd1. We generated knockout mutants of HBP1 and ectopically expressed transgenic lines of the two bHLH transcription factors and used these lines to investigate the roles of these two factors in regulating flowering time. HBP1 physically associated with POH1 forming homo- or heterodimers to perform their functions. Both HBP1 and POH1 bound directly to the cis-acting elements located in the promoter of Hd1 to activate its expression. CRISPR/Cas9-generated knockout mutations of HBP1, but not POH1 mutations, promoted earlier flowering time; conversely, HBP1 and POH1 overexpression delayed flowering time in rice under long-day and short-day conditions by activating the expression of Hd1 and suppressing the expression of Early heading date 1 (Ehd1), Heading date 3a (Hd3a), and Rice Flowering locus T 1 (RFT1), thus controlling flowering time in rice. Our findings revealed a mechanism for flowering time control through transcriptional regulation of Hd1 and laid theoretical and practical foundations for improving the growth period, adaptation, and yield of rice.

Natural variation in OsSEC13 HOMOLOG 1 modulates redox homeostasis to confer cold tolerance in rice.

Rice (Oryza sativa L.) is a cold-sensitive species that often faces cold stress, which adversely affects yield productivity and quality. However, the genetic basis for low-temperature adaptation in rice remains unclear. Here, we demonstrate that 2 functional polymorphisms in O. sativa SEC13 Homolog 1 (OsSEH1), encoding a WD40-repeat nucleoporin, between the 2 subspecies O. sativa japonica and O. sativa indica rice, may have facilitated cold adaptation in japonica rice. We show that OsSEH1 of the japonica variety expressed in OsSEH1MSD plants (transgenic line overexpressing the OsSEH1 allele from Mangshuidao [MSD], cold-tolerant landrace) has a higher affinity for O. sativa metallothionein 2b (OsMT2b) than that of OsSEH1 of indica. This high affinity of OsSEH1MSD for OsMT2b results in inhibition of OsMT2b degradation, with decreased accumulation of reactive oxygen species and increased cold tolerance. Transcriptome analysis indicates that OsSEH1 positively regulates the expression of the genes encoding dehydration-responsive element-binding transcription factors, i.e. OsDREB1 genes, and induces the expression of multiple cold-regulated genes to enhance cold tolerance. Our findings highlight a breeding resource for improving cold tolerance in rice.

Long term co-application of biochar and fertilizer could increase soybean yield under continuous cropping: insights from photosynthetic physiology.

BACKGROUND: Photosynthesis is the key to crop yield. The effect of biochar on photosynthetic physiology and soybean yield under continuous cropping is unclear. We conducted a long-term field experiment to investigate the effects of co-application of biochar and fertilizer (BCAF) on these parameters. Five treatments were established: F2 (fertilizer), B1F1 (3 t hm-2 biochar plus fertilizer), B1F2 (3 t hm-2 biochar plus reduced fertilizer), B2F1 (6 t hm-2 biochar plus fertilizer), and B2F2 (6 t hm-2 biochar plus reduced fertilizer). RESULTS: BCAF increased chlorophyll and leaf area, enhancing soybean photosynthesis. The net photosynthetic rate (Pn ), transpiration rate (Tr ), stomatal conductance (Gs ), water use efficiency (WUE) and intercellular carbon dioxide (CO2 ) concentration (Ci ) were enhanced by BCAF. In addition, BCAF improved soybean photosystem II (PSII) photosynthetic performance, driving force, potential photochemical efficiency (Fv /F0 ), and quantum yield of electron transfer (φE0 ). Furthermore, BCAF enhanced the accumulation of photosynthetic products, such as soluble proteins, soluble sugars and sucrose content, resulting in higher leaf dry weight. Consequently, BCAF increased the soybean yield, with the highest increase of 41.54% in B2F1. The correlation analysis revealed positive relationships between soybean yield and chlorophyll, leaf area, maximal quantum yield of PSII (Fv /Fm ), electron transport flux per cross-section at t = 0 (ET0 /CS0 ), trapped energy flux per cross-section at t = 0 (TR0 /CS0 ), composite blade driving force (DFTotal ), and leaf dry weight. CONCLUSIONS: We demonstrated that long-term BCAF enhances soybean photosynthesis under continuous planting, reduces fertilizer use and increases yield. This study reveals a novel way and theory to sustainably increase soybean productivity. © 2023 Society of Chemical Industry.

Time-ordering japonica/geng genomes analysis indicates the importance of large structural variants in rice breeding.

Temperate japonica/geng (GJ) rice yield has significantly improved due to intensive breeding efforts, dramatically enhancing global food security. However, little is known about the underlying genomic structural variations (SVs) responsible for this improvement. We compared 58 long-read assemblies comprising cultivated and wild rice species in the present study, revealing 156 319 SVs. The phylogenomic analysis based on the SV dataset detected the putatively selected region of GJ sub-populations. A significant portion of the detected SVs overlapped with genic regions were found to influence the expression of involved genes inside GJ assemblies. Integrating the SVs and causal genetic variants underlying agronomic traits into the analysis enables the precise identification of breeding signatures resulting from complex breeding histories aimed at stress tolerance, yield potential and quality improvement. Further, the results demonstrated genomic and genetic evidence that the SV in the promoter of LTG1 is accounting for chilling sensitivity, and the increased copy numbers of GNP1 were associated with positive effects on grain number. In summary, the current study provides genomic resources for retracing the properties of SVs-shaped agronomic traits during previous breeding procedures, which will assist future genetic, genomic and breeding research on rice.

The six-year biochar retention interacted with fertilizer addition alters the soil organic nitrogen supply capacity in bulk and rhizosphere soil.

Nitrogen fractions in soil, like organic nitrogen, mineral nitrogen, and free amino acids, are sensitive pointers to the soil nitrogen pools involved in nutrient cycling. As a potential improvement measure, biochar might improve soil fertility and nutrient availability. However, few studies have focused on the long-term effects of biochar retention on the soil nitrogen supply capacity of bulk and rhizosphere soil in brown earth. Therefore, a six-year field experiment was conducted in 2013, concentrating on the impact of biochar retention on soil nitrogen fractions. Four biochar rates were tested: no biochar amendment (CK); 15.75 t ha-1 of biochar (BC1); 31.5 t ha-1 of biochar (BC2); 47.25 t ha-1 of biochar (BC3). Our results showed that the elevated application rates significantly enhanced soil organic matter (SOM), and total nitrogen (TN), and improved pH in both bulk and rhizosphere soils. Acid-hydrolyzable nitrogen (AHN) content in biochar treatments was higher than that of CK in bulk and rhizosphere soil. The content of non-hydrolyzable nitrogen (NHN) was increased in 47.25 t ha-1 of biochar retention. Ammonium nitrogen (AN) and amino sugar nitrogen (ASN) contents were higher in bulk soil than in rhizosphere soil. Neutral amino acid contents were the highest both in bulk and rhizosphere soil. Principal component analysis (PCA) showed that soil organic nitrogen was significantly influenced by BC3 treatment in bulk soil, and largely influenced by other treatments in rhizosphere soil. Partial least square path modeling (PLSPM) revealed that NH4+-N was mainly derived from amino acid nitrogen (AAN) and AN in bulk soil and AAN and ASN in rhizosphere soil. These results indicate that different biochar retention rates contributed to improve soil nutrients. Amino acid nitrogen was the prominent nitrogen source of NH4+-N in bulk and rhizosphere soils.

Study on the mechanism of biochar affecting the effectiveness of phosphate solubilizing bacteria.

Low phosphorus utilization and phosphorus fertilizer pollution are serious issues primarily affecting soil health. To investigate the effects of biochar on the growth, phosphorus solubilization, and metabolites of phosphorus-solubilizing bacteria (PSB), rice husk biochar (RH) and rice straw biochar (RS) were incubated with Bacillus megatherium (BM1) and Bacillus mucilaginosus (BM2), respectively. The highest phosphorus solubilization was observed in BM2 following the addition of RS. The dissolved amount of phosphorus was 244.99 mg/L, which was 43.86% higher than that of the control group. Hence, biochar can improve the phosphorus solubilization capacity of PSB by affecting the organic acid and polysaccharide contents, and phosphatase activity secreted by the PSB, as the porous structure and surface characteristics of biochar ensured the adsorption of PSB. This study can help improve the functional activity of PSB and provide basis for improving the utilization of soil phosphorus, which in turn, aid in the development of biochar-based microbial fertilizers.

OsUGE3-mediated cell wall polysaccharides accumulation improves biomass production, mechanical strength, and salt tolerance.

Cell walls constitute the majority of plant biomass and are essential for plant resistance to environmental stresses. It is promising to improve both plant biomass production and stress resistance simultaneously by genetic modification of cell walls. Here, we report the functions of a UDP-galactose/glucose epimerase 3 (OsUGE3) in rice growth and salt tolerance by characterizing its overexpressing plants (OsUGE3-OX) and loss-of-function mutants (uge3). The OsUGE3-OX plants showed improvements in biomass production and mechanical strength, whereas uge3 mutants displayed growth defects. The OsUGE3 exhibits UDP-galactose/glucose epimerase activity that provides substrates for polysaccharides polymerization, consistent with the increased biosynthesis of cellulose and hemicelluloses and strengthened walls in OsUGE3-OX plants. Notably, the OsUGE3 is ubiquitously expressed and induced by salt treatment. The uge3 mutants were hypersensitive to salt and osmotic stresses, whereas the OsUGE3-OX plants showed improved tolerance to salt and osmotic stresses. Moreover, OsUGE3 overexpression improves the homeostasis of Na+ and K+ and induces a higher accumulation of hemicelluloses and soluble sugars during salt stress. Our results suggest that OsUGE3 improves biomass production, mechanical strength, and salt stress tolerance by reinforcement of cell walls with polysaccharides and it could be targeted for genetic modification to improve rice growth under salt stress.

FRAGILE CULM 18 encodes a UDP-glucuronic acid decarboxylase required for xylan biosynthesis and plant growth in rice.

Although UDP-glucuronic acid decarboxylases (UXSs) have been well studied with regard to catalysing the conversion of UDP-glucuronic acid into UDP-xylose, their biological roles in grasses remain largely unknown. The rice (Oryza sativa) genome contains six UXSs, but none of them has been genetically characterized. Here, we reported on the characterization of a novel rice fragile culm mutant, fc18, which exhibited brittleness with altered cell wall and pleiotropic defects in growth. Map-based cloning and transgenic analyses revealed that the FC18 gene encodes a cytosol-localized OsUXS3 and is widely expressed with higher expression in xylan-rich tissues. Monosaccharide analysis showed that the xylose level was decreased in fc18, and cell wall fraction determinations confirmed that the xylan content in fc18 was lower, suggesting that UDP-xylose from FC18 participates in xylan biosynthesis. Moreover, the fc18 mutant displayed defective cellulose properties, which led to an enhancement in biomass saccharification. Furthermore, expression of genes involved in sugar metabolism and phytohormone signal transduction was largely altered in fc18. Consistent with this, the fc18 mutant exhibited significantly reduced free auxin (indole-3-acetic acid) content and lower expression levels of PIN family genes compared with wild type. Our work reveals the physiological roles of FC18/UXS3 in xylan biosynthesis, cellulose deposition, and plant growth in rice.

Effect of corn straw biochar on corn straw composting by affecting effective bacterial community.

This study investigated the effect of corn straw biochar on the decomposition, nutrient transformation, and bacterial community characteristics in the corn straw decomposition process. A 90-day microcosm incubation experiment was performed to assess the effects of corn straw biochar (500 °C, 1 h) on the corn straw decomposition process and the resulting product. Four biochar amendment rates (0%, 5, 10, and 15%, as mass fractions of biochar) and three different addition times (1st day, 30th day, and 60th day) were set in total. The results showed that corn straw biochar significantly increased the pH of the corn straw decomposition process by 0.71-0.73 and increased the electrical conductivity value by 0.64-1.07 µS/cm over that of the controls. In addition, biochar was shown to increase the temperature rise rate and temperature peak of the straw maturation system, and advance the process of straw maturation by 10 days. Thus, treatment with corn straw biochar could accelerate the corn straw decomposition process and change the conditions for microorganisms involved in the process. Furthermore, biochar additions significantly decreased the organic matter content by 9.67% under B3 and T1 treatment, and enhanced the N, P2O5, and K2O contents of the straw decomposition product by 0.36, 0.19, and 0.88% under B3 and T1 treatment. Biochar additions could increase the abundance of several effective bacteria closely related to the N, P2O5, and K2O contents of the straw maturation product. The growth of these bacteria was likely to be affected by the increase in pH with biochar addition, which enabled the improvement of the nutrient mineralization process.

Improvement of barley (Hordeum vulgare L.) germination by application of biochar leacheate in steeping solution to upgrade malt quality.

OBJECTIVE: To investigate an improvement of barley germination by application of biochar leacheate in the steeping solution for upgrading malt quality. RESULTS: Barley germination was improved when biochar leacheate was used in the steeping water during the first steeping cycle. A clear decrease in the time to reach 50% of final germination percentage was detected due to an addition of biochar leacheate, but no significant difference was observed in the percent germination at the end of germination. Hydrolase activities including α-amylase, proteinase and ß-glucanase in barley grains were maximally increased during the malting process when 10% biochar leacheate was added to the first steeping water. The wort yielding indexes including both glucose and maltose content and the free amino nitrogen content were significantly increased but the ß-glucan content was significantly decreased at a level of p < 0.05 when 10% biochar leacheate was added to the steeping water. CONCLUSIONS: Biochar leacheate could be used as a stimulator in the steeping solution during the first steeping cycle to improve barley germination and so upgrade malt quality.

Effects of organic molecules from biochar-extracted liquor on the growth of rice seedlings.

There are many reports indicating that biochar can promote growth; however, its mechanism of action remains unclear. The aim of this study was to show that organic molecules from biochar-extracted liquor affect the growth of rice seedlings. In this study, rice seedlings were cultured under water. Agronomic traits and growth-related genes and proteins were used as markers to describe more precisely the effects of biochar on specific growth parameters of rice seedlings. Our results demonstrated that the 3% biochar-extracted liquor amendment clearly promoted growth. The growth-related gene auxin binding protein 1 and its encoded protein were up-regulated. Molecular simulations revealed that 2-acetyl-5-methylfuran from biochar-extracted liquor could interact with auxin binding protein 1 in a similar way to indoleacetic acid binding. The growth of rice seedlings was therefore affected by biochar-extracted liquor, which acted on the ABP1 signalling pathway.

Hippocampal fractional amplitude of low-frequency fluctuation and functional connectivity changes in premenstrual syndrome.

PURPOSE: To investigate differences in hippocampal activity between premenstrual syndrome (PMS) patients and healthy controls, to elucidate the neural mechanisms of PMS. MATERIALS AND METHODS: Twenty female patients with PMS (PMS group) and 21 healthy controls (HC group) underwent a single-shot gradient-recalled echo planar imaging (EPI) sequence scan during the luteal phase in 3.0 Tesla MRI. Spontaneous neural activity in hippocampus (HIPP) was measured by fractional amplitude of low-frequency fluctuation (fALFF). Functional connectivity (FC) was used to examine the neural networks of PMS patients by selecting the abnormal HIPP as the seed region. All participants completed a daily record of severity of problems (DRSP) questionnaire to measure the severity of clinical symptoms. RESULTS: Results from a two-sample t-test showed increased left HIPP fALFF in the PMS group compared with the HC group (P = 0.042), while there was no between-group difference of fALFF in the right HIPP (P = 0.1011). A secondary analysis using a two-sample t-test with the left HIPP as the seed region, the results revealed that the PMS group exhibited increased FC between the left HIPP and left medial prefrontal cortex (mPFC), left posterior cingulate cortex (PCC), right middle cingulate cortex (MCC), and bilateral precentral cortex (PC), while decreased FC between the left HIPP and right orbitofrontal cortex (OFC). Moreover, the PMS group exhibited higher DRSP scores, which were positively correlated (r = 0.64, P = 0.003) with FC between the left HIPP and mPFC during the luteal phase. CONCLUSION: Altered spontaneous neural activity and connectivity of left HIPP may be involved in PMS. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:545-553.

Larger volume and different functional connectivity of the amygdala in women with premenstrual syndrome.

OBJECTIVES: To assess structural and functional changes of the amygdala due to premenstrual syndrome (PMS) using magnetic resonance imaging (MRI). METHODS: Twenty PMS patients and 21 healthy control (HC) subjects underwent a 6-min resting-state fMRI scan during the luteal phase as well as scanning high-resolution T1-weighted images. Subcortical amygdala-related volume and functional connectivity (FC) were estimated between the two groups. Each subject completed a daily record of severity of problems (DRSP) to measure the severity of clinical symptoms. RESULTS: Greater bilateral amygdalae volumes were found in PMS patients compared with HC subjects, and PMS patients had increased FC between the amygdala and certain regions of the frontal cortex (e.g. medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), right precentral gyrus), the right temporal pole and the insula, as well as decreased FC between the bilateral amygdalae and the right orbitofrontal cortex and right hippocampus. The strength of FC between the right amygdala and right precentral gyrus, left ACC and left mPFC were significantly and positively correlated with DRSP scores in PMS patients. CONCLUSIONS: Our findings may improve our understanding of the neural mechanisms involved in PMS. KEY POINTS: • Functional and structural MRI used to explore amygdala in PMS patients. • Aberrant amygdala structural and functional connectivity were found in PMS patients. • Amygdala strength FC was positively correlated with individual clinical symptom scores.

Influence of biochar application on potassium-solubilizing Bacillus mucilaginosus as potential biofertilizer.

Biochar can enhance soil fertility to increase agricultural productivity, whereas its improvement in soil microbial activity is still unclear. In this article, the influence of biochar on the cell growth and the potassium-solubilizing activity of Bacillus mucilaginosus AS1153 was examined. The impact on cell growth is related to the biochar-derived feedstocks and the particle size of biochar. Both intrinsic features and inner component fraction can promote the cell growth of B. mucilaginosus AS1153. The potassium-solubilizing activity was increased by 80% when B. mucilaginosus was incubated in conjunction with the biochar derived from corn stover. The survival time of B. mucilaginosus also was prolonged by adsorption in biochar. The experimental results suggested that the biochar containing B. mucilaginosus could be used as a potential biofertilizer to sustain crop production.

Variations in DENSE AND ERECT PANICLE 1 (DEP1) contribute to the diversity of the panicle trait in high-yielding japonica rice varieties in northern China.

Rice is one of mankind's major food staples, and the erect panicle architecture in rice is an important morphological improvement. The dense and erect panicle 1 (DEP1) locus corresponds with the formation of erect panicles and has been widely used in rice breeding. However, the genetic diversity of DEP1 remains narrow. In order to improve the genetic diversity of DEP1, we used a rice germplasm collection of 72 high yielding japonica rice varieties to analyze the contribution of DEP1 to the panicle traits. We found 45 SNPs and 26 insertions and deletions (indels) within the DNA fragment of DEP1. We further detected 7 haplotypes and found that the replacement of 637 bp by a 12 bp fragment could explain the erect panicle architecture in all 72 germplasms. An SNP (G/C) at the -1253 bp of the promoter region caused a core sequence shift (TGGGCC) of a site II transcriptional regulatory element. The association analysis showed that the SNP(G/C) largely affects the number of primary and secondary branches, and grain number per panicle. Our results provide novel insights into the function and genetic diversity of DEP1. The SNP (G/C) at the promoter region will contribute to the flexible application of DEP1 in rice breeding.

Relationship between grain yield and quality in rice germplasms grown across different growing areas.

Rice grain yield and quality are two major foci of rice breeding. In this study, Chinese regional rice test data provide us the unique opportunity to analyze the relationship between yield and quality in rice, because China has an unusually wide range of rice cultivars. We analyzed the relationships between grain yield, yield components, and grain quality of 300 rice germplasms. Japonica was superior in both yield and quality compared with indica. A high setting rate improved the head rice ratio. A higher 1000 grain weight was negatively correlated with quality characteristics but had a positive correlation with yield. A high spikelet density (number of grains per centimeter on the panicle) not only benefits the yield but also the head rice ratio and chalkiness traits. According to our results, global rice production can be increased to at least 8500 kg/ha to meet projected demands in 2025 without sacrificing grain quality.

Characterization and fine mapping of thermo-sensitive chlorophyll deficit mutant1 in rice (Oryza sativa L.).

Chlorophyll content is one of the most important traits controlling crop biomass and economic yield in rice. Here, we isolated a spontaneous rice mutant named thermo-sensitive chlorophyll deficit 1 (tscd1) derived from a backcross recombinant inbred line population. tscd1 plants grown normally from the seedling to tiller stages showed yellow leaves with reduced chlorophyll content, but showed no significant differences after the booting stage. At temperatures below 22°C, the tscd1 mutant showed the most obvious yellowish phenotype. With increasing temperature, the yellowish leaves gradually turned green and approached a normal wild type color. Wild type and tscd1 mutant plants had obviously different chloroplast structures and photosynthetic pigment precursor contents, which resulted in underdevelopment of chloroplasts and a yellowish phenotype in tscd1. Genetic analysis indicated that the mutant character was controlled by a recessive nuclear gene. Through map-based cloning, we located the tscd1 gene in a 34.95 kb region on the long arm of chromosome 2, containing two BAC clones and eight predicted candidate genes. Further characterization of the tscd1 gene is underway. Because it has a chlorophyll deficit phenotype before the tiller stage and little influence on growth vigor, it may play a role in ensuring the purity of hybrids.

Analysis of Erect-Panicle Japonica Rice in Northern China: Yield, Quality Status, and Quality Improvement Directions.

China is the only country that extensively cultivates the indica and japonica rice varieties, with the largest japonica rice production area being in northeast China. A study of the relationship between the yield and quality of japonica rice and the effect of nitrogen fertilizer application on this relationship is important. In this paper, we aimed to assess the current yield and quality of japonica rice in northeast China. We selected erect-panicle varieties as the test materials. Field experiments were conducted using different nitrogen fertilizer levels for two consecutive years to analyze the rice varieties' yield, quality, interrelationship, and nitrogen fertilizer response. The average yield following high- and low-nitrogen treatments exceeded 10,000.00 kg/hm2, with a maximum of 12,285.63 kg/hm2. The high-yield-high-nitrogen treatment group had more panicles, a higher seed-setting rate, and a higher 1000-grain weight than the other groups. The high-yield-low-nitrogen group had a higher number of panicles and seed-setting rate than the other groups. The low-yield-high-nitrogen group had a lower number of whole grains, grain length-to-width ratio, and taste value than the other groups. The low-yield-low-nitrogen group had fewer primary branches than the other groups; excluding the primary branch-setting rate and 1000-grain weight, the values of the other panicle traits of the group were significantly higher than those of the other groups. The high-nitrogen-high-flavor group had lower panicle and spikelet numbers and higher spikelet fertility rates than the other groups. The low-nitrogen-high-flavor group had higher spikelet fertility rates and 1000-grain weight than the other groups. Compared to the other groups, the low-nitrogen-high-flavor group had a higher head rice yield, and the high-nitrogen-high-flavor group had a lower chalkiness rate. The main goal of the breeding and cultivation of high-yield and high-quality erect-panicle japonica rice in northern China is to achieve "dual high, dual low, and one high and one low" conditions, signifying a high yield with high or low nitrogen levels, low protein and amylose contents, high head rice rates, and low chalkiness. This study provides a new technique for enhancing the taste of northern erect-panicle japonica rice to promote the sustainable, high-yield, and high-quality development of japonica rice in northern China.

Fully Printable and Reconfigurable Hufu-type Electroluminescent Devices for Visualized Encryption.

Hufu, serving as evidence of imperial authorization in ancient China, comprises two parts in the form of tiger-shaped tallies that only become effective when matched. Drawing inspiration from the concept of Hufu, a reconfigurable electroluminescent (EL) device is designed by separating conventional integral devices into two parts that contain the EL layer (part A) and the transparent electrode (part B), respectively. The key to realizing such strategy is employing an adhesive and stretchable polymer gel composite as the transparent electrodes for the EL devices. The polymer gel composite facilitates robust yet reversible contact between the EL layer and transparent electrode, enabling high-performance and stretchable EL devices that can be readily disassembled and reassembled: the EL devices can maintain ≈81% of their initial luminance after 1000 times of repeated disassembly and reassembly. Moreover, the precursor ink of the polymer gel composite is compatible with a wide variety of coating and printing technologies, such as spin-coating, inkjet printing, dispensing, and brush painting. Importantly, the reconfigurable feature of the devices opens up a new path to encryption display systems, and as a proof-of-concept, EL encrypted password, and content-changeable digital clock are demonstrated.

Introgression and selection shaping the genome and adaptive loci of weedy rice in northern China.

As a weed of rice paddy fields, weedy rice has spread worldwide. In northern China, the expansion of weedy rice has been rapid over the past two decades. Its evolutionary history and adaptive mechanisms are poorly understood. Evolutionary relationships between northern weedy rice and rice cultivars were analyzed using presumed neutral markers sampled across the rice genome. Genes involved in rice domestication were evaluated for their potential roles in weedy rice adaptation. Seed longevity, a critical trait of weedy rice, was examined in an F(2) population derived from a cross between weedy rice and a rice cultivar to evaluate weedy rice adaptation and the potential effect of candidate genes. Weedy rice in northern China was not derived directly from closely related wild Oryza species or from the introgression of indica subspecies. Introgression with local cultivars, coupled with selection that maintained weedy identity, shaped the evolution of weedy rice in northern China. Weedy rice is a unique system with which to investigate how weedy plants adapt to an agricultural environment. Our finding that extensive introgression from local cultivars, combined with the continuing ability to maintain weedy genes, is characteristic of weedy rice in northern China provides a clue for the field control of weedy rice.