Agave REVEILLE1 regulates the onset and release of seasonal dormancy in Populus.

Deciduous woody plants like poplar (Populus spp.) have seasonal bud dormancy. It has been challenging to simultaneously delay the onset of bud dormancy in the fall and advance bud break in the spring, as bud dormancy, and bud break were thought to be controlled by different genetic factors. Here, we demonstrate that heterologous expression of the REVEILLE1 gene (named AaRVE1) from Agave (Agave americana) not only delays the onset of bud dormancy but also accelerates bud break in poplar in field trials. AaRVE1 heterologous expression increases poplar biomass yield by 166% in the greenhouse. Furthermore, we reveal that heterologous expression of AaRVE1 increases cytokinin contents, represses multiple dormancy-related genes, and up-regulates bud break-related genes, and that AaRVE1 functions as a transcriptional repressor and regulates the activity of the DORMANCY-ASSOCIATED PROTEIN 1 (DRM1) promoter. Our findings demonstrate that AaRVE1 appears to function as a regulator of bud dormancy and bud break, which has important implications for extending the growing season of deciduous trees in frost-free temperate and subtropical regions to increase crop yield.

Sucrose phosphate synthase 8 is required for the remobilization of carbon reserves in rice stems during grain filling.

Carbon reserve remobilization in stems is closely related to rice grain filling. Sucrose phosphate synthase (SPS) is highly associated with carbon reserve remobilization. In this study, we investigated the expression pattern of SPS genes in various rice tissues, and found that SPS8 is the major SPS isoform in rice stems during the grain-filling stage. We then constructed sps8 mutants using the CRISPR/Cas9 system. The SPS activity of the sps8 mutants was markedly reduced in the stems. In addition, the sps8 mutants exhibited significant starch accumulation in stems. 14C-labelling experiments revealed that the remobilization of non-structural carbohydrates from rice stems to grains was impaired in the sps8 mutants. In the sps8 mutants, grain filling was delayed and yield decreased by 15% due to a reduced percentage of ripened grains. RNA sequencing and quantitative PCR analyses indicated that the genes involved in starch synthesis and degradation were up-regulated in the sps8 mutant stems. In addition, the activity of the enzymes involved in starch synthesis and degradation was increased in the sps8 stems. These results demonstrate that SPS8 is required for carbon reserve remobilization from rice stems to grains, and that its absence may enhance 'futile cycles' of starch synthesis and degradation in rice stems.

Rapid generation of a tomato male sterility system and its feasible application in hybrid seed production.

KEY MESSAGE: A practical approach for the rapid generation and feasible application of green hypocotyl male-sterile (GHMS) tm6 dfr lines in tomato hybrid breeding was established. Male sterility enables reduced cost and high seed purity during hybrid seed production. However, progress toward its commercial application has been slow in tomato due to the disadvantages of most natural male-sterile mutants. Here, we developed a practical method for efficient tomato hybrid seed production using a male-sterile system with visible marker, which was rapidly generated by CRISPR/Cas9-mediated gene editing. Two closely linked genes, TM6 and DFR, which were reported to be candidates of ms15 (male sterile-15) and aw (anthocyanin without) locus, respectively, were knocked out simultaneously in two elite tomato inbred lines. Mutagenesis of both genes generated green hypocotyl male-sterile (GHMS) lines. The GHMS lines exhibited male sterility across different genetic backgrounds and environmental conditions. They also showed green hypocotyl due to defective anthocyanin accumulation, which serves as a reliable visible marker for selecting male-sterile plants at the seedling stage. We further proposed a strategy for multiplying the GHMS system and verified its high efficiency in stable male sterility propagation. Moreover, elite hybrid seeds were produced using GHMS system for potential side effects evaluation, and no adverse influences were found on seed yield, seed quality as well as important agronomic traits. This study provides a practical approach for the rapid generation and feasible application of male sterility in tomato hybrid breeding.

Boosting photocatalytic performances of lamellar BiVO4by constructing S-scheme heterojunctions with AgBr for efficient charge transfer.

Successful construction of heterojunction can improve the utilization efficiency of solar light by broadening the absorption range, facilitating charge-carrier separation, promoting carrier transportation and influencing surface-interface reaction. Herein, visible-light-driven AgBr was deposited on the surface of lamellar BiVO4which was prepared by a facile hydrothermal process to improve charge carrier separation, and subsequent photocatalytic effectiveness. The catalyst with an optimal AgBr/BiVO4ratio exhibited a superbly enhanced photocatalytic decolorization ability (about 6.85 times higher than that of pure BiVO4) and high stability after four cycles. The unique photocatalytic mechanism of S-scheme carrier migration was investigated on the bases of radical trapping tests and photo/electrochemical characterizations. Results showed that the enhanced migration strategy and intimately interfacial collaboration guaranteed the effective charge carriers separation/transfer, leading to magnificent photocatalytic performance as well as excellent stability.

miR-212 Promotes Cardiomyocyte Hypertrophy through Regulating Transcription Factor 7 Like 2.

To explore the role and possible mechanism of miRNA-212 in heart failure (HF). The rat model of abdominal aortic constriction was constructed, the changes of myocardial morphology were observed by hematoxylin-eosin (HE) staining, and the hypertrophy-related marker molecules were detected by quantitative real-time polymerase chain reaction (qRT-PCR). At the cellular level, phenylephrine and angiotensin II were added to induce cardiomyocyte hypertrophy. The overexpression of miR-212 adenovirus was constructed, and the expression of miR-212 was overexpressed, and its effect on cardiac hypertrophy (CH) was detected by immunofluorescence and qRT-PCR. Then, the mechanism of miR-212 regulating CH was verified by website prediction, luciferase reporter gene assay, qRT-PCR, and western blotting assay. In the successfully constructed rat model of abdominal aortic constriction and cardiomyocyte hypertrophy, ANP and myh7 were dramatically increased, myh6 expression was decreased, and miRNA-212 expression was increased. Overexpression of miRNA-212 in cardiomyocytes can promote cardiomyocyte hypertrophy, while knocking down miR-212 in cardiomyocytes can partially reverse cell hypertrophy. In addition, miR-212 targets TCF7L2 and inhibits the expression of this gene. miRNA-212 targets TCF7L2 and inhibits the expression of this gene, possibly through this pathway to promote cardiomyocyte hypertrophy.

First report of squash leaf curl China virus infecting tomato in China.

Squash leaf curl China virus (SLCCNV) is a species in the genus Begomovirus that possess a bipartite genome. It is transmitted by the whitefly species Bemisia tabaci and infects cucurbit crops in various parts of the Old World (Wu et al., 2020). In 2020, tomato plants with curled, distorted and yellow leaves were found in a greenhouse in Shouguang, Shandong Province, China (Fig. S1). Leaves with these symptoms were collected from 11 plants and the total RNA was extracted with TRIzol reagent (Invitrogen, USA). Five RNA extracts of the highest quality were combined and a small RNA library was generated by the company (BGI-Shenzhen, China). About 22,338,920 clean reads (18-28nt) were acquired and assembled into larger contigs with the software Velvet 1.0.5. These were further compared against nucleotide sequences in the National Center for Biotechnology Information (NCBI) databases with BLASTn searches. Not unexpectedly, there were many assembled contigs that had high identities (90%-100% identities) with known tomato-infecting viruses, including 241 contigs matching tomato chlorosis virus, 26 contigs matching southern tomato virus, and 4 contigs matching tomato yellow leaf curl virus. However, 12 contigs had high identities (90%-100%) with the genomic DNA-A of SLCCNV, while 9 other contigs had high identities (90%-100%) with the genomic DNA-B of SLCCNV. To verify the presence of SLCCNV in tomato plants, two sets of primer pairs were designed according to the specific contigs assembled from derived small interfering RNAs (vsiRNAs). The primer pairs A742-F/A742-R (5'-GTAATACGAGCATCCGCACGGTAG-3'/5'-CGTGGAGGGCGAC AAACAGCTAACG-3') and B539-F/B539-R (5'-GCTACTTTCAAGGACGAAGAAGAGG-3'/5'-CG ACATAGATTTCTGGTCGGTGGGC-3') directed the amplification of 742 bp and 539 bp for DNA-A and DNA-B fragments, respectively, from the total genomic DNA of the 11 tomato samples. The DNA-A and DNA-B of SLCCNV were both detected from all of the tomato samples. After sequencing, the 742 bp PCR products shared 100% nucleotide sequence identity with the DNA-A of SLCCNV isolate GDXW (MW389919), whereas the PCR-amplified 539 bp fragments shared 100% nucleotide sequence identity with the DNA-B of SLCCNV isolate GDXW (MW389920). The full-length of DNA-A and DNA-B components were amplified with back-to-back primers A-F/A-R (Wu et al., 2020) and B-F/B-R (5'-GATAAACACGTCTCATTGCACCGC-3'/5'-GAGACGTGTTTATCAATATGGA CG-3'), respectively. The amplified fragments were further cloned into the PCE2TA/Blunt-Zero vector (Vazyme Biotech Co., China). After sequencing, the complete sequence of DNA-A was 2736 nt in length (MZ682117), while the DNA-B was 2718 nt in length (OK236348). The phylogenetic relationships of the DNA-A and DNA-B components were determined using MEGA 7 based on the full-length sequences of DNA-A and DNA-B, respectively (Kumar et al., 2016). Results showed that the DNA-A formed an independent cluster and was mostly related to the GDHY (MW389917) in the phylogenetic tree constructed using the neighbor-joining (NJ) method, while the DNA-B formed an independent cluster and was mostly related to the SLCCNV isolate BLDG (MW389928) and isolate GDBL (MW389922) (Fig. S2). The nt identities of DNA-A were also calculated with SDT v1.2 by comparison with other begomovirus sequences from the initial BLASTn analysis (Muhire et al., 2014), showing that the virus shared 99.4% sequence identity with SLCCNV isolate GDHY (MW389917). According to the current demarcation threshold for begomoviruses, recommended by the International Committee on Taxonomy of Viruses (ICTV) (91% nt identity) (Brown et al., 2015), this virus identified from tomato is a distinct strain of SLCCNV, designated SLCCNV-SDSG. To the best of our knowledge, this is the first report of a natural infection of SLCCNV on tomato in China. SLCCNV has caused serious problems in cucurbit production in some areas, so it will be important to investigate if tomato plays a role in the disease biology by serving as a reservoir host. The author(s) declare no conflict of interest. Funding: The funding for this research was supported by the Beijing Academy of Agriculture and Forestry Foundation, China (QNJJ202131, QNJJ201915, KJCX20200113). References: Brown et al. 2015. Arch Virol 160: 1593-1619 Kumar et al. 2016. Mol Biol Evol, 33: 1870-1874 Muhire et al. 2014. Plos One, 9 Wu et al. 2020. J Integr Agr, 19: 570-577.

Driver's Head Pose and Gaze Zone Estimation Based on Multi-Zone Templates Registration and Multi-Frame Point Cloud Fusion.

Head pose and eye gaze are vital clues for analysing a driver's visual attention. Previous approaches achieve promising results from point clouds in constrained conditions. However, these approaches face challenges in the complex naturalistic driving scene. One of the challenges is that the collected point cloud data under non-uniform illumination and large head rotation is prone to partial facial occlusion. It causes bad transformation during failed template matching or incorrect feature extraction. In this paper, a novel estimation method is proposed for predicting accurate driver head pose and gaze zone using an RGB-D camera, with an effective point cloud fusion and registration strategy. In the fusion step, to reduce bad transformation, continuous multi-frame point clouds are registered and fused to generate a stable point cloud. In the registration step, to reduce reliance on template registration, multiple point clouds in the nearest neighbor gaze zone are utilized as a template point cloud. A coarse transformation computed by the normal distributions transform is used as the initial transformation, and updated with particle filter. A gaze zone estimator is trained by combining the head pose and eye image features, in which the head pose is predicted by point cloud registration, and the eye image features are extracted via multi-scale spare coding. Extensive experiments demonstrate that the proposed strategy achieves better results on head pose tracking, and also has a low error on gaze zone classification.

Dual-Cameras-Based Driver's Eye Gaze Tracking System with Non-Linear Gaze Point Refinement.

The human eye gaze plays a vital role in monitoring people's attention, and various efforts have been made to improve in-vehicle driver gaze tracking systems. Most of them build the specific gaze estimation model by pre-annotated data training in an offline way. These systems usually tend to have poor generalization performance during the online gaze prediction, which is caused by the estimation bias between the training domain and the deployment domain, making the predicted gaze points shift from their correct location. To solve this problem, a novel driver's eye gaze tracking method with non-linear gaze point refinement is proposed in a monitoring system using two cameras, which eliminates the estimation bias and implicitly fine-tunes the gaze points. Supported by the two-stage gaze point clustering algorithm, the non-linear gaze point refinement method can gradually extract the representative gaze points of the forward and mirror gaze zone and establish the non-linear gaze point re-mapping relationship. In addition, the Unscented Kalman filter is utilized to track the driver's continuous status features. Experimental results show that the non-linear gaze point refinement method outperforms several previous gaze calibration and gaze mapping methods, and improves the gaze estimation accuracy even on the cross-subject evaluation. The system can be used for predicting the driver's attention.

Light-induced dilation in nanosheets of charge-transfer complexes.

We report the observation of a sizable photostrictive effect of 5.7% with fast, submillisecond response times, arising from a light-induced lattice dilation of a molecular nanosheet, composed of the molecular charge-transfer compound dibenzotetrathiafulvalene (DBTTF) and C60 An interfacial self-assembly approach is introduced for the thickness-controlled growth of the thin films. From photoabsorption measurements, molecular simulations, and electronic structure calculations, we suggest that photostriction within these films arises from a transformation in the molecular structure of constituent molecules upon photoinduced charge transfer, as well as the accommodation of free charge carriers within the material. Additionally, we find that the photostrictive properties of the nanosheets are thickness-dependent, a phenomenon that we suggest arises from surface-induced conformational disorder in the molecular components of the film. Moreover, because of the molecular structure in the films, which results largely from interactions between the constituent π-systems and the sulfur atoms of DBTTF, the optoelectronic properties are found to be anisotropic. This work enables the fabrication of 2D molecular charge-transfer nanosheets with tunable thicknesses and properties, suitable for a wide range of applications in flexible electronic technologies.

PM2.5 induces endothelial dysfunction via activating NLRP3 inflammasome.

PM2.5 (particulate matter <2.5 µm in diameter) is proven to contribute to the development of atherosclerosis. Endothelial cell dysfunction is the initial step of atherosclerosis. The underlying mechanisms of endothelial cell damage exposed to PM2.5 are still obscure. In our study, PM2.5 was administrated to C57BL/6 male mice by intranasal instillation for 2 weeks. Human umbilical vein endothelial cells (HUVECs) were also treated with PM2.5 to evaluate the adverse effect in vitro. The immunohistochemical staining of aortas showed that the expressions of proinflammatory cytokines and endothelial adhesion markers were significantly increased in PM2.5-exposed mice than that in saline-exposed mice. In vitro, PM2.5 could inhibit HUVECs viability and impair cell migration in a concentration-dependent manner. Besides, PM2.5 exposure downregulated eNOS expression while upregulated reactive oxygen species (ROS) levels. Mechanistically, PM2.5 activated the NLRP3 inflammasome in HUVECs while knockdown of NLRP3 could effectively reverse the downregulation of eNOS expression and production of ROS after PM2.5 exposure. In summary, our data showed that PM2.5 could cause endothelial dysfunction, and probably via NLRP3 inflammasome activation.

Constructing Asymmetrical Ni-Centered {NiN2O4} Octahedra in Layered Metal-Organic Structures for Near-Room-Temperature Single-Phase Magnetoelectricity.

Layered metal-organic structures (LMOSs) as magnetoelectric (ME) multiferroics have been of great importance for realizing new functional devices in nanoelectronics. Until now, however, achieving such room-temperature and single-phase ME multiferroics in LMOSs have proven challenging due to low transition temperature, poor spontaneous polarization, and weak ME coupling effect. Here, we demonstrate the construction of a LMOS in which four Ni-centered {NiN2O4} octahedra form in layer with asymmetric distortions using the coordination bonds between diphenylalanine molecules and transition metal Ni(II). Near room-temperature (283 K) ferroelectricity and ferromagnetism are observed to be both spontaneous and hysteretic. Particularly, the multiferroic LMOS exhibits strong magnetic-field-dependent ME polarization with low-magnetic-field control. The change in ME polarization with increasing applied magnetic field µ0H from 0 to 2 T decreases linearly from 0.041 to 0.011 µC/cm2 at the strongest ME coupling temperature of 251 K. The magnetic domains can be manipulated directly by applied electric field at 283 K. The asymmetrical distortion of Ni-centered octahedron in layer spurs electric polarization and ME effect and reduces spin frustration in the octahedral geometry due to spin-charge-orbital coupling. Our results represent an important step toward the production of room-temperature single-phase organic ME multiferroics.

PROTEIN PHOSHATASE 2A B'α and ß Maintain Centromeric Sister Chromatid Cohesion during Meiosis in Arabidopsis.

The correct separation of homologous chromosomes during meiosis I, and sister chromatids during meiosis II, relies on the tight control of the cohesion complex. The phosphorylation and subsequent cleavage of the meiotic recombination protein REC8 (REC8-like family protein [SYN1] in Arabidopsis [Arabidopsis thaliana]), the α-kleisin subunit of the cohesion ring, along the chromosome arms at meiosis I allows crossovers and separation of homologous chromosomes without chromatid dissociation. REC8 continues to localize and function at the centromeres up to metaphase II and, in yeast and vertebrates, is protected from cleavage by means of protein phosphatase 2A (PP2A)-mediated dephosphorylation. Here, we show that, in plants, centromeric sister chromatid cohesion until meiosis II also requires the activity of a PP2A-type phosphatase complex. The combined absence of the regulatory subunits PP2AB'α and PP2AB'ß leads to the premature loss of chromosome cohesion in meiosis I. Male meiocytes of the pp2ab'αß double mutant display premature depletion of SYN1. The PP2AA1 structural and B'α regulatory subunit localize specifically to centromeres until metaphase II, supporting a role for the PP2A complex in the SYN1-mediated maintenance of centromeric cohesion in plant meiosis.

Continuous Driver's Gaze Zone Estimation Using RGB-D Camera.

The driver gaze zone is an indicator of a driver's attention and plays an important role in the driver's activity monitoring. Due to the bad initialization of point-cloud transformation, gaze zone systems using RGB-D cameras and ICP (Iterative Closet Points) algorithm do not work well under long-time head motion. In this work, a solution for a continuous driver gaze zone estimation system in real-world driving situations is proposed, combining multi-zone ICP-based head pose tracking and appearance-based gaze estimation. To initiate and update the coarse transformation of ICP, a particle filter with auxiliary sampling is employed for head state tracking, which accelerates the iterative convergence of ICP. Multiple templates for different gaze zone are applied to balance the templates revision of ICP under large head movement. For the RGB information, an appearance-based gaze estimation method with two-stage neighbor selection is utilized, which treats the gaze prediction as the combination of neighbor query (in head pose and eye image feature space) and linear regression (between eye image feature space and gaze angle space). The experimental results show that the proposed method outperforms the baseline methods on gaze estimation, and can provide a stable head pose tracking for driver behavior analysis in real-world driving scenarios.

Solution-processed resistive switching memory devices based on hybrid organic-inorganic materials and composites.

Resistive random-access memory (ReRAM) is expected to be the next-generation non-volatile memory device because of its fast operation speed and low power consumption. Switching media in most ReMAM are oxides which are rigid and require high-temperature processing. Here, we review two emerging types of low-cost solution-processed ReRAMs with sandwich structures: one is hybrid nanocomposites with charge-trapping nanoparticles (NPs) embedded in a polymer matrix, and the other is hybrid halide perovskites which have been intensively investigated recently for optoelectronic applications. We will review the recent developments in materials selection, device performance and operation mechanisms. Resistive switching in hybrid materials and composites is ubiquitous because of the abundant existence of charge-trapping defects and interfaces. The future challenges and potential breakthroughs will also be outlined.

Enhanced photocatalytic efficiency of C3N4/BiFeO3 heterojunctions: the synergistic effects of band alignment and ferroelectricity.

As one of the most promising photocatalysts, graphitic carbon nitride (g-C3N4) shows a visible light response and great chemical stability. However, its relatively low photocatalytic efficiency is a major obstacle to actual applications. Here an effective and feasible method to dramatically increase the visible light photocatalytic efficiency by forming C3N4/BiFeO3 ferroelectric heterojunctions is reported, wherein the band alignment and piezo-/ferroelectricity have synergistic positive effects in accelerating the separation of the photogenerated carriers. At the optimum composition of 10 wt% BiFeO3, the heterojunction shows 1.4 times improved photocatalytic efficiency than that of the pure C3N4. Most importantly, mechanical pressing and electrical poling can also improve the photocatalytic efficiencies by 1.3 times and 1.8 times, respectively. The optimized photocatalytic efficiency is even comparable with that of some noble metal based compounds. These results not only prove the improved photocatalytic activity of the C3N4-ferroelectric heterojunctions, but also provide a new approach for designing high-performance photocatalysts by taking advantage of ferroelectricity.

Genome-wide characterization of JASMONATE-ZIM DOMAIN transcription repressors in wheat (Triticum aestivum L.).

BACKGROUND: The JASMONATE-ZIM DOMAIN (JAZ) repressor family proteins are jasmonate co-receptors and transcriptional repressor in jasmonic acid (JA) signaling pathway, and they play important roles in regulating the growth and development of plants. Recently, more and more researches on JAZ gene family are reported in many plants. Although the genome sequencing of common wheat (Triticum aestivum L.) and its relatives is complete, our knowledge about this gene family remains vacant. RESULTS: Fourteen JAZ genes were identified in the wheat genome. Structural analysis revealed that the TaJAZ proteins in wheat were as conserved as those in other plants, but had structural characteristics. By phylogenetic analysis, all JAZ proteins from wheat and other plants were clustered into 11 sub-groups (G1-G11), and TaJAZ proteins shared a high degree of similarity with some JAZ proteins from Aegliops tauschii, Brachypodium distachyon and Oryza sativa. The Ka/Ks ratios of TaJAZ genes ranged from 0.0016 to 0.6973, suggesting that the TaJAZ family had undergone purifying selection in wheat. Gene expression patterns obtained by quantitative real-time PCR (qRT-PCR) revealed differential temporal and spatial regulation of TaJAZ genes under multifarious abiotic stress treatments of high salinity, drought, cold and phytohormone. Among these, TaJAZ7, 8 and 12 were specifically expressed in the anther tissues of the thermosensitive genic male sterile (TGMS) wheat line BS366 and normal control wheat line Jing411. Compared with the gene expression patterns in the normal wheat line Jing411, TaJAZ7, 8 and 12 had different expression patterns in abnormally dehiscent anthers of BS366 at the heading stage 6, suggesting that specific up- or down-regulation of these genes might be associated with the abnormal anther dehiscence in TGMS wheat line. CONCLUSION: This study analyzed the size and composition of the JAZ gene family in wheat, and investigated stress responsive and differential tissue-specific expression profiles of each TaJAZ gene in TGMS wheat line BS366. In addition, we isolated 3 TaJAZ genes that would be more likely to be involved in the regulation of abnormal anther dehiscence in TGMS wheat line. In conclusion, the results of this study contributed some novel and detailed information about JAZ gene family in wheat, and also provided 3 potential candidate genes for improving the TGMS wheat line.

Ferroelectric BiFeO3 as an Oxide Dye in Highly Tunable Mesoporous All-Oxide Photovoltaic Heterojunctions.

As potential photovoltaic materials, transition-metal oxides such as BiFeO3 (BFO) are capable of absorbing a substantial portion of solar light and incorporating ferroic orders into solar cells with enhanced performance. But the photovoltaic application of BFO has been hindered by low energy-conversion efficiency due to poor carrier transport and collection. In this work, a new approach of utilizing BFO as a light-absorbing sensitizer is developed to interface with charge-transporting TiO2 nanoparticles. This mesoporous all-oxide architecture, similar to that of dye-sensitized solar cells, can effectively facilitate the extraction of photocarriers. Under the standard AM1.5 (100 mW cm-2 ) irradiation, the optimized cell shows an open-circuit voltage of 0.67 V, which can be enhanced to 1.0 V by tailoring the bias history. A fill factor of 55% is achieved, which is much higher than those in previous reports on BFO-based photovoltaic devices. The results provide here a new viable approach toward developing highly tunable and stable photovoltaic devices based on ferroelectric transition-metal oxides.

TaOPR2 encodes a 12-oxo-phytodienoic acid reductase involved in the biosynthesis of jasmonic acid in wheat (Triticum aestivum L.).

The 12-oxo-phytodienoic acid reductases (OPRs) are involved in the various processes of growth and development in plants, and classified into the OPRⅠ and OPRⅡ subgroups. In higher plants, only OPRⅡ subgroup genes take part in the biosynthesis of endogenous jasmonic acid. In this study, we isolated a novel OPRⅡ subgroup gene named TaOPR2 (GeneBank accession: KM216389) from the thermo-sensitive genic male sterile (TGMS) wheat cultivar BS366. TaOPR2 was predicted to encode a protein with 390 amino acids. The encoded protein contained the typical oxidored_FMN domain, the C-terminus peroxisomal-targeting signal peptide, and conserved FMN-binding sites. TaOPR2 was mapped to wheat chromosome 7B and located on peroxisome. Protein evolution analysis revealed that TaOPR2 belongs to the OPRⅡ subgroup and shares a high degree of identity with other higher plant OPR proteins. The quantitative real-time PCR results indicated that the expression of TaOPR2 is inhibited by abscisic acid (ABA), salicylic acid (SA), gibberellic acid (GA3), low temperatures and high salinity. In contrast, the expression of TaOPR2 can be induced by wounding, drought and methyl jasmonate (MeJA). Furthermore, the transcription level of TaOPR2 increased after infection with Puccinia striiformis f. sp. tritici and Puccinia recondite f. sp. tritici. TaOPR2 has NADPH-dependent oxidoreductase activity. In addition, the constitutive expression of TaOPR2 can rescue the male sterility phenotype of Arabidopsis mutant opr3. These results suggest that TaOPR2 is involved in the biosynthesis of jasmonic acid (JA) in wheat.

Study on lily introgression breeding using allotriploids as maternal parents in interploid hybridizations.

Based on a recent hypothesis, "Five same genomes of endosperm are essential for its development in Lilium", it is expected that allotriploid lily (OTO) can be hybridized with diploid Oriental lily (OO) for introgression breeding in Lilium L.. To test the hypothesis, OTO lilies, 'Belladonna', 'Candy Club' and 'Travatore', were used as the maternal parents and crossed with two diploid OO cultivars, 'Siberia' and 'Sorbonne', and the species L. regale Wilson (TT). Results showed that capsules of all OTO × OO hybridizations developed well and 0.8~3.3 viable seedlings per ovary were obtained through normal pollination and embryo rescue; however, all OTO × TT crosses failed. Genomic in situ hybridization showed that the progenies of the OTO × OO hybridizations were aneuploid and a variable number of T-genome chromosomes were introduced into the progenies through the allotriploid lilies. The present results not only demonstrate that allotriploid OTO lilies, although male sterile, can be used as maternal parents to produce aneuploid progenies, but also strongly support the new hypothesis in lily breeding.