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Gibberellin 2-oxidases (GA2oxs) regulate plant growth by inactivating endogenous bioactive gibberellins (GAs). Two classes of GA2oxs inactivate GAs through 2β-hydroxylation: a larger class of C₁₉ GA2oxs and a smaller class of C₂₀ GA2oxs. In this study, we show that members of the rice (Oryza sativa) GA2ox family are differentially regulated and act in concert or individually to control GA levels during flowering, tillering, and seed germination. Using mutant and transgenic analysis, C₂₀ GA2oxs were shown to play pleiotropic roles regulating rice growth and architecture. In particular, rice overexpressing these GA2oxs exhibited early and increased tillering and adventitious root growth. GA negatively regulated expression of two transcription factors, O. sativa homeobox 1 and TEOSINTE BRANCHED1, which control meristem initiation and axillary bud outgrowth, respectively, and that in turn inhibited tillering. One of three conserved motifs unique to the C₂₀ GA2oxs (motif III) was found to be important for activity of these GA2oxs. Moreover, C₂₀ GA2oxs were found to cause less severe GA-defective phenotypes than C₁₉ GA2oxs. Our studies demonstrate that improvements in plant architecture, such as semidwarfism, increased root systems and higher tiller numbers, could be induced by overexpression of wild-type or modified C₂₀ GA2oxs.

Summary A major challenge of modern agricultural biotechnology is the optimization of plant architecture for enhanced productivity, stress tolerance and water use efficiency (WUE). To optimize plant height and tillering that directly link to grain yield in cereals and are known to be tightly regulated by gibberellins (GAs), we attenuated the endogenous levels of GAs in rice via its degradation. GA 2‐oxidase (GA2ox) is a key enzyme that inactivates endogenous GAs and their precursors. We identified three conserved domains in a unique class of C20 GA2ox, GA2ox6, which is known to regulate the architecture and function of rice plants. We mutated nine specific amino acids in these conserved domains and observed a gradient of effects on plant height. Ectopic expression of some of these GA2ox6 mutants moderately lowered GA levels and reprogrammed transcriptional networks, leading to reduced plant height, more productive tillers, expanded root system, higher WUE and photosynthesis rate, and elevated abiotic and biotic stress tolerance in transgenic rice. Combinations of these beneficial traits conferred not only drought and disease tolerance but also increased grain yield by 10–30% in field trials. Our studies hold the promise of manipulating GA levels to substantially improve plant architecture, stress tolerance and grain yield in rice and possibly in other major crops.

In plants, source-sink communication plays a pivotal role in crop productivity, yet the underlying regulatory mechanisms are largely unknown. The SnRK1 A protein kinase and transcription factor MYBS1 regulate the sugar starvation signaling pathway during seedling growth in cereals. Here, we identified plant-specific SnRKIA-interacting negative regulators (SKINs). SKINs antagonize the function of SnRKIA, and the highly conserved GKSKSF domain is essential for SKINs to function as repressors. Overexpression of SKINs inhibits the expression of MYBS1 and hydrolases essential for mobilization of nutrient reserves in the endosperm, leading to inhibition of seedling growth. The expression of SKINs is highly inducible by drought and moderately by various stresses, which is likely related to the abscisic acid (ABA)-mediated repression of SnRKIA under stress. Overexpression of SKINs enhances ABA sensitivity for inhibition of seedling growth. ABA promotes the interaction between SnRKIA and SKINs and shifts the localization of SKINs from the nucleus to the cytoplasm, where it binds SnRKIA and prevents SnRKIA and MYBS1 from entering the nucleus. Our findings demonstrate that SnRKIA plays a key role regulating source-sink communication during seedling growth. Under abiotic stress, SKINs antagonize the function of SnRKIA, which is likely a key factor restricting seedling vigor.

Summary Root architecture and function are critical for plants to secure water and nutrient supply from the soil, but environmental stresses alter root development. The phytohormone jasmonic acid (JA) regulates plant growth and responses to wounding and other stresses, but its role in root development for adaptation to environmental challenges had not been well investigated. We discovered a novel JA Upregulated Protein 1 gene (JAUP1) that has recently evolved in rice and is specific to modern rice accessions. JAUP1 regulates a self‐perpetuating feed‐forward loop to activate the expression of genes involved in JA biosynthesis and signalling that confers tolerance to abiotic stresses and regulates auxin‐dependent root development. Ectopic expression of JAUP1 alleviates abscisic acid‐ and salt‐mediated suppression of lateral root (LR) growth. JAUP1 is primarily expressed in the root cap and epidermal cells (EPCs) that protect the meristematic stem cells and emerging LRs. Wound‐activated JA/JAUP1 signalling promotes crosstalk between the root cap of LR and parental root EPCs, as well as induces cell wall remodelling in EPCs overlaying the emerging LR, thereby facilitating LR emergence even under ABA‐suppressive conditions. Elevated expression of JAUP1 in transgenic rice or natural rice accessions enhances abiotic stress tolerance and reduces grain yield loss under a limited water supply. We reveal a hitherto unappreciated role for wound‐induced JA in LR development under abiotic stress and suggest that JAUP1 can be used in biotechnology and as a molecular marker for breeding rice adapted to extreme environmental challenges and for the conservation of water resources.

Using transfer DNA (T-DNA) with functions of gene trap and gene knockout and activation tagging, a mutant population containing 55,000 lines was generated. Approximately 81% of this population carries 1-2 T-DNA copies per line, and the retrotransposon Tos17 was mostly inactive in this population during tissue culture. A total of 11,992 flanking sequence tags (FSTs) have been obtained and assigned to the rice genome. T-DNA was preferentially (~80%) integrated into genic regions. A total of 19,000 FSTs pooled from this and another T-DNA tagged population were analyzed and compared with 18,000 FSTs from a Tos17 tagged population. There was difference in preference for integrations into genic, coding, and flanking regions, as well as repetitive sequences and centromeric regions, between T-DNA and Tos17; however, T-DNA integration was more evenly distributed in the rice genome than Tos17. Our T-DNA contains an enhancer octamer next to the left border, expression of genes within genetics distances of 12.5 kb was enhanced. For example, the normal height of a severe dwarf mutant, with its gibberellin 2-oxidase (GA2ox) gene being activated by T-DNA, was restored upon GA treatment, indicating GA2ox was one of the key enzymes regulating the endogenous level of GA. Our T-DNA also contains a promoterless GUS gene next to the right border. GUS activity screening facilitated identification of genes responsive to various stresses and those regulated temporally and spatially in large scale with high frequency. Our mutant population offers a highly valuable resource for high throughput rice functional analyses using both forward and reverse genetic approaches.

The facility layout problem is a typical combinational optimization problem. In this research, a slicing tree representation and a quadratically constrained program model are combined with harmony search to develop a heuristic method for solving the unequal-area block layout problem. Because of characteristics of slicing tree structure, we propose a regional structure of harmony memory to memorize facility layout solutions and two kinds of harmony improvisation to enhance global search ability of the proposed heuristic method. The proposed harmony search based heuristic is tested on 10 well-known unequal-area facility layout problems from the literature. The results are compared with the previously best-known solutions obtained by genetic algorithm, tabu search, and ant system as well as exact methods. For problems O7, O9, vC10Ra, M11*, and Nug12, new best solutions are found. For other problems, the proposed approach can find solutions that are very similar to previous best-known solutions.

A major challenge of modern agricultural biotechnology is the optimization of plant architecture for enhanced productivity, stress tolerance and water use efficiency (WUE). To optimize plant height and tillering that directly link to grain yield in cereals and are known to be tightly regulated by gibberellins (GAs), we attenuated the endogenous levels of GAs in rice via its degradation. GA 2-oxidase (GA2ox) is a key enzyme that inactivates endogenous GAs and their precursors. We identified three conserved domains in a unique class of C[sub.20] GA2ox, GA2ox6, which is known to regulate the architecture and function of rice plants. We mutated nine specific amino acids in these conserved domains and observed a gradient of effects on plant height. Ectopic expression of some of these GA2ox6 mutants moderately lowered GA levels and reprogrammed transcriptional networks, leading to reduced plant height, more productive tillers, expanded root system, higher WUE and photosynthesis rate, and elevated abiotic and biotic stress tolerance in transgenic rice. Combinations of these beneficial traits conferred not only drought and disease tolerance but also increased grain yield by 10-30% in field trials. Our studies hold the promise of manipulating GA levels to substantially improve plant architecture, stress tolerance and grain yield in rice and possibly in other major crops.

A major challenge of modern agricultural biotechnology is the optimization of plant architecture for enhanced productivity, stress tolerance and water use efficiency ( WUE ). To optimize plant height and tillering that directly link to grain yield in cereals and are known to be tightly regulated by gibberellins ( GA s), we attenuated the endogenous levels of GA s in rice via its degradation. GA 2‐oxidase ( GA 2ox) is a key enzyme that inactivates endogenous GA s and their precursors. We identified three conserved domains in a unique class of C 20 GA 2ox, GA 2ox6, which is known to regulate the architecture and function of rice plants. We mutated nine specific amino acids in these conserved domains and observed a gradient of effects on plant height. Ectopic expression of some of these GA 2ox6 mutants moderately lowered GA levels and reprogrammed transcriptional networks, leading to reduced plant height, more productive tillers, expanded root system, higher WUE and photosynthesis rate, and elevated abiotic and biotic stress tolerance in transgenic rice. Combinations of these beneficial traits conferred not only drought and disease tolerance but also increased grain yield by 10–30% in field trials. Our studies hold the promise of manipulating GA levels to substantially improve plant architecture, stress tolerance and grain yield in rice and possibly in other major crops.

Background Direct-acting antiviral (DAA) therapy for chronic hepatitis C (CHC) achieves high sustained virologic response (SVR) rates; however, hepatocellular carcinoma (HCC) can still develop after viral eradication. Reliable biomarkers for predicting the post-SVR HCC risk are lacking. This study aimed to identify baseline serum extracellular vesicle microRNAs (EV-miRNAs) associated with HCC development following SVR. Materials and methods Eleven CHC patients who achieved SVR were retrospectively enrolled as a discovery cohort to identify candidate EV-miRNAs at SVR12 predictive of future HCC. An independent validation cohort of 89 CHC patients was also analyzed. HCC development was defined as the occurrence of HCC at ≥ 12 months after SVR. EV-miRNA profiles were assessed by small RNA sequencing and validated using a miRNA enzyme immunoassay (miREIA). Results In the discovery cohort, four EV-miRNAs (EV-miR-1-3p, EV-miR-148a-3p, EV-miR-223-3p, and EV-miR-4433b-5p) were significantly different between patients who later developed HCC and those who remained HCC-free at SVR12. In the 89-patient validation cohort, 51 (57.3%) developed HCC with a median disease-free survival (DFS) of 23.1 months, and 12 (13.5%) patients died during a median follow-up of 77 months. High baseline EV-miR-1-3p and EV-miR-148a-3p levels and low EV-miR-4433b-5p were associated with remaining HCC-free. Elevated EV-miR-1-3p and EV-miR-148a-3p levels were also correlated with longer DFS ( p  < 0.05). In multivariate analysis, EV-miR-1-3p was the only independent predictor of longer DFS (adjusted hazard ratio [HR] 0.459, p  = 0.014) and improved overall survival (OS) (adjusted HR 0.390, p  = 0.016) after SVR12. Among all biomarkers evaluated, baseline EV-miR-1-3p demonstrated the highest predictive accuracy for HCC occurrence (area under the curve [AUC] 0.843, vs. 0.769 for alpha-fetoprotein [AFP] and 0.755 for FIB-4; p  < 0.001) and for OS (AUC 0.876, vs. 0.480 for AFP and 0.655 for FIB-4; p  < 0.001). Furthermore, patients with high EV-miR-1-3p levels showed higher platelet counts and albumin, and a lower proportion with FIB-4 ≥ 3.25, suggesting that high EV-miR-1-3p reflects better preserved liver function and less advanced fibrosis. Conclusions Baseline serum EV-miR-1-3p serves as a protective biomarker for stratifying HCC risk and predicting survival in CHC patients after HCV eradication via DAA therapy.

Graphene thin films have great potential to function as transparent electrodes in organic electronic devices, due to their excellent conductivity and high transparency. Recently, organic light-emitting diodes (OLEDs)have been successfully demonstrated to possess high luminous efficiencies with p-doped graphene anodes. However, reliable methods to fabricate n-doped graphene cathodes have been lacking, which would limit the application of graphene in flexible electronics. In this paper, we demonstrate fully solution-processed OLEDs with n-type doped multilayer graphene as the top electrode. The work function and sheet resistance of graphene are modified by an aqueous process which can also transfer graphene on organic devices as the top electrodes. With n-doped graphene layers used as the top cathode, all-solution processed transparent OLEDs can be fabricated without any vacuum process.