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The yield loss of crops per year in the world is 11%–30% due to crop diseases and pests. A large number of chemical pesticides are used to control the spread of infectious crop diseases and pests every year, which not only pollutes the environment, but also seriously threatens food safety and human health. Therefore, the most economical and effective measure to control crop diseases and insects is to develop the resistant varieties by the utilization of resistance genes ( R ), and it is also the preferable way for sustainable development of future agriculture in China. In recent years, much progress has been made in molecular mechanism of plant innate immunity and isolation of many immune receptors including PRRs and NLRs from crops, molecular mechanism of interactions between insects and crops, and identification and cloning of crop insect resistance genes. We review the recent important breakthroughs in plant immunity and broad-spectrum resistance genes isolated in crops, and trade-off between resistance and other agronomic traits. We point out the bottlenecks in crop breeding for disease and insect resistance, and also propose new insights for plant disease and insect resistance research in China in the future.

Global food security is threatened by rice blast disease caused by the filamentous fungus Magnaporthe oryzae. An understanding of rice resistance mechanisms is fundamental to developing strategies for disease control. In this review, we summarize recent advances in pathogen-associated molecular pattern-triggered immunity, effector-triggered immunity, defense regulator-mediated immunity, and effects of nutrient elements on rice blast resistance. We outline strategies used for breeding rice cultivars with improved disease resistance. We also present the major research challenges for rice blast disease resistance and propose approaches for future investigation.

MicroRNA168 (miR168) is a key miRNA that targets Argonaute1 (AGO1), a major component of the RNA-induced silencing complex1,2. Previously, we reported that miR168 expression was responsive to infection by Magnaporthe oryzae, the causal agent of rice blast disease3. However, how miR168 regulates immunity to rice blast and whether it affects rice development remains unclear. Here, we report our discovery that the suppression of miR168 by a target mimic (MIM168) not only improves grain yield and shortens flowering time in rice but also enhances immunity to M. oryzae. These results were validated through repeated tests in rice fields in the absence and presence of rice blast pressure. We found that the miR168–AGO1 module regulates miR535 to improve yield by increasing panicle number, miR164 to reduce flowering time, and miR1320 and miR164 to enhance immunity. Our discovery demonstrates that changes in a single miRNA enhance the expression of multiple agronomically important traits. In rice, it is known that miR168 regulates AGO1. Using a target mimic approach to suppress the microRNA enhances resistance against rice blast disease, increases grain yield and shortens growth period, including in field trials.

Non-coding RNAs appear to be involved in the regulation of the nervous system. However, no competing endogenous RNA (ceRNA) network related to PM2.5 damage in the hippocampal function has yet been constructed. Herein, we used whole-transcriptome sequencing technology to systematically study the ceRNA network in rat hippocampi after PM2.5 exposure. We identified 100 circRNAs, 67 lncRNAs, 28 miRNAs, and 539 mRNAs and constructed the most comprehensive ceRNA network to date, to our knowledge. Gene Ontology and KEGG analyses showed that the network molecules are involved in synapses, neural projections, and neural development and involve signal pathways such as the synaptic vesicle cycle. Finally, the expression of the differentially expressed RNAs confirmed by quantitative real-time PCR was consistent with the sequencing data. This study systematically dissected the ceRNA atlas related to cognitive memory function in the hippocampal tissue of PM2.5-exposed rats for the first time, to our knowledge, and promotes the development of potential new treatments for cognitive impairment.

Trade-offs between plant growth and immunity are a well-known phenomenon in plants that are meant to ensure the best use of limited resources. Recently, many advances have been achieved on molecular regulations of the trade-offs between plant growth and immunity. Here, we provide an overview on molecular understanding of these trade-offs including those regulated at the transcriptional level or post-transcriptional level by transcriptional factors, microRNAs, and post-translational modifications of proteins, respectively The understanding on the molecular regulation of these trade-offs will provide new strategies to breed crops with high yield and enhanced resistance to disease.

bsr‐d1, an allele encoding a transcription factor identified from the rice cultivar Digu, confers durable, broad‐spectrum resistance to infections by strains of Magnaporthe oryzae. bsr‐d1 was predicted to inhibit M. oryzae‐induced expression of Bsr‐d1 RNA and degradation of hydrogen peroxide to achieve resistance to M. oryzae. However, the global effect of biological process and molecular function on blast resistance mediated by Bsr‐d1 remains unknown. In this study, we compared transcriptomic profiling between Bsr‐d1 knockout (Bsr‐d1KO) lines and the wild type, TP309. Our study revealed that bsr‐d1 mainly regulates the redox state of plant cells, but also affects amino acid and unsaturated fatty acid metabolism. We further found that BSR‐D1 indirectly regulates salicylic acid biosynthesis, metabolism, and signal transduction downstream of the activation of H2O2 signalling in the bsr‐d1‐mediated immune response. Furthermore, we identified a novel peroxidase‐encoding gene, Perox3, as a new BSR‐D1 target gene that reduces resistance to M. oryzae when overexpressed in TP309. These results provide new insights into the bsr‐d1‐mediated blast resistance., BSR‐D1 mainly regulates the redox state of plant cells by directly targeting another new gene, Perox3, but indirectly regulates salicylic acid biosynthesis and signal transduction after H2O2 signalling in the bsr‐d1‐mediated immune response.

It is well known that the interactions of insect herbivores and their host plant can be mediated by microbes. Our central hypothesis is that herbivore-associated fungi might directly or indirectly affect plant–insect interactions. In this study, we identified five orally secreted fungi from field-collected black cutworm, Agrotis ipsilon, including Aspergillus parasiticus, Aspergillus niger, Geotrichum candidum, Fusarium subglutinans, and Mucor circinelloides f. lusitanicus. We found that caterpillars inoculated with F. subglutinans or M. circinelloides f. lusitanicus induced higher defense responses in plants, but with different patterns between different plants. These herbivore-induced defense responses reduced the growth of caterpillars. However, direct application of fungi to mechanically wounded tomato did not induce JA-related defense responses. The application of regurgitant from fungi-inoculated or non-inoculated caterpillars, suggested that regurgitant might be responsible for the fungi-mediated defense response in plants against caterpillar attack. Furthermore, both F. subglutinans and M. circinelloides f. lusitanicus benefited caterpillar growth when they fed on detached tomato leaves, but had no influence when caterpillars fed on artificial diet. Our finding suggests that insect-associated fungi could influence plant–insect interactions by indirectly mediating plant defense responses, and directly affecting caterpillar performance on host plants.

Background The poor prognosis of esophageal squamous cell carcinoma (ESCC) highlights the need for novel strategies against this disease. Our previous study suggested the involvement of CCL2 and tumor associated macrophages (TAMs) in esophageal carcinogenesis. Despite the recognition of TAMs as a promising target for cancer treatment, mechanisms underlying its infiltration, activation and tumor-promotive function in ESCC remain unknown. Methods Human esophageal tissue array and TCGA database were used to evaluate the clinical relevance of CCL2 and TAMs in ESCC. F344 rats and C57BL/6 mice were treated with N-nitrosomethylbenzylamine (NMBA) to establish orthotopic models of esophageal carcinogenesis. CCL2/CCR2 gene knockout mice and macrophage-specific PPARG gene knockout mice were respectively used to investigate the role of infiltration and polarization of TAMs in ESCC. CCL2-mediated monocyte chemotaxis was estimated in malignantly transformed Het-1A cells. THP-1 cells were used to simulate TAMs polarization in vitro. RNA-sequencing was performed to uncover the mechanism. Results Increasing expression of CCL2 correlated with TAMs accumulation in esophageal carcinogenesis, and they both predicts poor prognosis in ESCC cohort. Animal studies show blockade of CCL2-CCR2 axis strongly reduces tumor incidence by hindering TAMs recruitment and thereby potentiates the antitumor efficacy of CD8+ T cells in the tumor microenvironment. More importantly, M2 polarization increases PD-L2 expression in TAMs, resulting in immune evasion and tumor promotion through PD-1 signaling pathway. Conclusion This study highlights the role of CCL2-CCR2 axis in esophageal carcinogenesis. Our findings provide new insight into the mechanism of immune evasion mediated by TAMs in ESCC, suggesting the potential of TAMs-targeted strategies for ESCC prevention and immunotherapy.

Purpose Glioblastoma (GBM) is the most common primary brain tumor with a poor therapeutic outcome. Polycomb group factor 1 (PCGF1), a member of the PcG (Polycomb group) family, is highly expressed in the developing nervous system of mice. However, the function and the mechanism of PCGF1 in GBM proliferation still remain unclear. Methods Knockdown of PCGF1 was performed in U87 GBM cell by shRNA strategy via lentivirus vector. MTT assay, colony formation assays, and flow cytometry were used to measure the properties of cell proliferation and cell cycle distribution, respectively. GeneChip analysis was performed to identify the downstream effector molecules. Rescue assay was constructed to verify the screening results. Results We first found that knockdown of PCGF1 led to the inhibition of U87 cells proliferation and decreased colony formation ability. The data from GeneChip expression profiling and Ingenuity Pathway Analysis (IPA) indicated that many of the altered gene cells are associated with the cell proliferation control pathways. We have further confirmed the suppression of AKT/GSK3β/c-Myc/cyclinD1 expressions by Western blotting analysis. The over-expression of c-Myc could partly restore the attenuated proliferation ability caused by knockdown of PCGF1. Conclusion All the above evidences suggested that PCGF1 might be closely associated with tumorigenesis and progression of glioblastoma (GBM), in which process the oncoprotein c-Myc may participate. PCGF1 could thus be a potential therapeutic target for the treatment of glioblastoma (GBM).

Background The cotton aphid Aphis gossypii Glover is one of the most destructive insect pests. It has evolved resistance to numerous insecticides around the world due to the application of insecticides. Uridine diphosphate (UDP)-glycosyltransferases (UGTs) have been reported to potentially facilitate the detoxification process of imidacloprid and thiamethoxam in A. gossypii. Results In this study, the field populations of A. gossypii developed different levels of resistance to multiple insecticides. A UGT inhibitor, 5-nitrouracil, dramatically increased the toxicity of acetamiprid in resistant populations, moderately increased the toxicity of sulfoxaflor in the imidacloprid susceptible (IMI_S) population, and populations from Yuncheng in Shanxi Province (SXYC) and Jingzhou in Hubei Province (HBJZ), and increased the toxicity of bifenthrin in the IMI_S and HBJZ populations, but there was no synergism on omethoate or carbosulfan. Quantitative real-time PCR analysis revealed that UGT344B4 and UGT344C7 were overexpressed in all field populations, and UGT344N4 was overexpressed in the SDBZ and HBZJ populations. Furthermore, the suppression of UGT344B4 or UGT344C7 by RNA interference significantly increased the susceptibility to bifenthrin in the IMI_S population and the susceptibility to sulfoxaflor in the SXYC population. Conclusion These results suggested that UGTs are potentially involved in the detoxification of neonicotinoid, sulfoximine, and pyrethroid insecticides in A. gossypii. Furthermore, the overexpression of UGTs could be associated with insecticide resistance in field populations of A. gossypii. The results might be helpful for the management of insecticide resistance in field populations of A. gossypii. © 2019 Society of Chemical Industry.

The cotton aphid, Aphis gossypii Glover, is a destructive global crop pest. Control of A. gossypii has relied heavily on the application of chemical insecticides. The cotton aphid has developed resistance to numerous insecticides, including imidacloprid, which has been widely used to control cotton pests in China since the 1990s. Our objective was to investigate the potential role of UDP-glycosyltransferases (UGTs) in imidacloprid resistance based on transcriptomic and proteomic analyses of field-originated imidacloprid-resistant (IMI_R) and -susceptible (IMI_S) A. gossypii clones. The transcriptomic and proteomic analyses revealed that 12 out of 512 differentially expressed genes and three out of 510 differentially expressed proteins were predicted as UDP-glycosyltransferase (UGT). Based on quantitative real-time PCR analysis, nine UGT genes, UGT343A4, UGT344A15, UGT344A16, UGT344B4, UGT344C7, UGT344C9, UGT344N4, UGT 24541, and UGT7630, were up-regulated in the IMI_R clone compared to the IMI_S clone. Meanwhile, UGT344A16, UGT344B4, UGT344C7, and UGT344N4 were overexpressed at the protein level based on western blot analysis. Furthermore, knockdown of UGT344B4 or UGT344C7 using RNA interference (RNAi) significantly increased sensitivity to imidacloprid in the IMI_R clone. In conclusion, UGTs potentially contributed to imidacloprid resistance in A. gossypii originating from cotton-growing regions of China. These results provide insights into the way we study insecticide resistance in cotton aphids.

The plant cell wall is the first physical and defensive barrier against pathogens. The plant cell wall usually undergoes dynamic remodeling as an immune response to prevent infection by pathogens. In this review, we summarize advances on relationship between cell wall and immunity in plants. In particular, we outline current progresses regarding the regulation of the cell wall components, including cellulose, hemicellulose, pectin and lignin, on plant disease resistance. We also discuss the impacts of cell wall-derived cellodextrin, oligogalacturonic acid and xyloglucan/xylan oligosaccharides as potent elicitors or signal molecules to trigger plant immune response. We further propose future studies on dissecting the molecular regulation of cell wall on plant immunity, which have potentials in practical application of crop breeding aiming at improvement of plant disease resistance.

The Masculinizer (Masc) gene has been known to control sex development and dosage compensation in lepidopterans. However, it remains unclear whether its ortholog exists and plays the same roles in distantly related lepidopterans such as Helicoverpa armigera. To address this question, we cloned Masc from H. armigera (HaMasc), which contains all essential functional domains of BmMasc, albeit with less than 30% amino acid sequence identity with BmMasc. Genomic PCR and qPCR analyses showed that HaMasc is a Z chromosome-linked gene since its genomic content in males (ZZ) was two times greater than that in females (ZW). RT-PCR and RT-qPCR analyses revealed that HaMasc expression was sex- and stage-biased, with significantly more transcripts in males and eggs than in females and other stages. Transfection of a mixture of three siRNAs of HaMasc into a male embryonic cell line of H. armigera led to the appearance of female-specific mRNA splicing isoforms of H. armigeradoublesex (Hadsx), a downstream target gene of HaMasc in the H. armigera sex determination pathway. The knockdown of HaMasc, starting from the third instar larvae resulted in a shift of Hadsx splicing from male to female isoforms, smaller male pupa and testes, fewer but larger/longer spermatocytes and sperm bundles, delayed pupation and internal fusion of the testes and follicles. These data demonstrate that HaMasc functions as a masculinizing gene in the H. armigera sex-determination cascade.

A link between the scent and color of Narcissus tazetta flowers can be anticipated due to their biochemical origin, as well as their similar biological role. Despite the obvious aesthetic and ecological significance of these colorful and fragrant components of the flowers and the molecular profiles of their pigments, fragrant formation has addressed in some cases. However, the regulatory mechanism of the correlation of fragrant components and color patterns is less clear. We simultaneously used one way to address how floral color and fragrant formation in different tissues are generated during the development of an individual plant by transcriptome-based weighted gene co-expression network analysis (WGCNA). A spatiotemporal pattern variation of flavonols/carotenoids/chlorophyll pigmentation and benzenoid/phenylpropanoid/ monoterpene fragrant components between the tepal and corona in the flower tissues of Narcissus tazetta, was exhibited. Several candidate transcription factors: MYB12, MYB1, AP2-ERF, bZIP, NAC, MYB, C2C2, C2H2 and GRAS are shown to be associated with metabolite flux, the phenylpropanoid pathway to the production of flavonols/anthocyanin, as well as related to one branch of the phenylpropanoid pathway to the benzenoid/phenylpropanoid component in the tepal and the metabolite flux between the monoterpene and carotenoids biosynthesis pathway in coronas. It indicates that potential competition exists between floral pigment and floral fragrance during Narcissus tazetta individual plant development and evolutionary development.

Cytochrome P450 monooxygenases (P450s) and UDP-glycosyltransferases (UGTs) are major detoxifying enzymes that metabolize plant toxins and insecticides. In the present study, the synergists of piperonyl butoxide, sulfinpyrazone and 5-nitrouracil significantly increased cyantraniliprole and α-cypermethrin toxicity against the resistant strain. The transcripts of UGT341A4, UGT344B4, UGT344D6, UGT344J2 and UGT344M2 increased significantly in the CyR strain compared with the susceptible strain. Among these upregulated genes (including P450s), CYP6CY7 and UGT344B4 were highly expressed in the midgut. Transgenic expression of the P450 and UGT genes in broad body tissues in Drosophila melanogaster indicated that the expression of CYP380C6, CYP4CJ1, UGT341A4, UGT344B4 and UGT344M2 is sufficient to confer cyantraniliprole resistance, and CYP380C6, CYP6CY7, CYP6CY21, UGT341A4 and UGT344M2 are related to α-cypermethrin cross-resistance. The midgut-specific overexpression of CYP380C6, CYP6CY7, CYP6CY21, CYP4CJ1, UGT341A4, UGT344B4 and UGT344M2 significantly increased insensitivity to cyantraniliprole, and CYP380C6, CYP6CY7, CYP6CY21, UGT344B4 and UGT344M2 confer α-cypermethrin cross-resistance. The expression of CYP380C6, CYP4CJ1, UGT341A4 and UGT344M2 in broad tissues or in midgut has similar effects on insensitivity to insecticides; however, CYP6CY7, CYP6CY21 and UGT344B4 are more effective in the midgut. This result indicates that broad body tissues and midgut tissue are involved in insecticide resistance mediated by the candidate P450s and UGTs examined.

Conventional methods utilizing in vitro protein activity assay or in vivo parasite survival to screen for malaria inhibitors suffer from high experimental background and/or inconvenience. Here, we introduce a yeast-based system to facilitate chemical screening for specific protein or pathway inhibitors. The platform comprises several isogeneic Pichia strains that differ only in the target of interest, so that a compound which inhibits one strain but not the other is implicated in working specifically against the target. We used Plasmodium falciparum NDH2 (PfNDH2), a type II NADH dehydrogenase, as a proof of principle to show how well this works. Three isogenic Pichia strains harboring, respectively, exogeneously introduced PfNDH2, its own complex I (a type I NADH dehydrogenase), and PfNDH2 with its own complex I, were constructed. In a pilot screen of more than 2,000 compounds, we identified a highly specific inhibitor that acts on PfNDH2. This compound poorly inhibits the parasites at the asexual blood stage; however, is highly effective in repressing oocyst maturation in the mosquito stage. Our results demonstrate that the yeast cell-based screen platform is feasible, efficient, economical, and has very low background noise. Similar strategies could be extended to the functional screen for interacting molecules of other targets.

Insect herbivores use phytochemicals as signals to induce expression of their phytochemical-detoxifying cytochrome P450 monooxygenases (P450s). The regulatory cascades that transduce phytochemical signals to enhanced expression of P450s are the focus of this review. At least seven signaling pathways, including RTK/MAPK, GPCR/CREB, GPCR/NFκB, ROS/CncC/Keap1, AhR/ARNT, cytosol NR, and nucleus-located NR, may be involved in phytochemical induction of P450s. Constitutive overexpression, overphosphorylation, and/or activation of one or more effectors in the corresponding pathway are common causes of P450 overexpression that lead to phytochemical or insecticide resistance. Future research should pay more attentions to the starting point of each pathway, the number of pathways and their cross talk for a given phytochemical, and the pathways for downregulation of P450s.

Many pathogenic fungi depend on the development of specialized infection structures called appressoria to invade their hosts and cause disease. Impairing the function of fungal infection structures therefore provides a potential means by which diseases could be prevented. In spite of this extraordinary potential, however, relatively few anti-penetrant drugs have been developed to control fungal diseases, of either plants or animals. In the present study, we report the identification of compounds that act specifically to prevent fungal infection. We found that the organization of septin GTPases, which are essential for appressorium-mediated infection in the rice blast fungus Magnaporthe oryzae, requires very-long-chain fatty acids (VLCFAs), which act as mediators of septin organization at membrane interfaces. VLCFAs promote septin recruitment to curved plasma membranes and depletion of VLCFAs prevents septin assembly and host penetration by M. oryzae. We observed that VLCFA biosynthesis inhibitors not only prevent rice blast disease, but also show effective, broad-spectrum fungicidal activity against a wide range of fungal pathogens of maize, wheat and locusts, without affecting their respective hosts. Our findings reveal a mechanism underlying septin-mediated infection structure formation in fungi and provide a class of fungicides to control diverse diseases of plants and animals.

miRNAs contribute to plant resistance against pathogens. Previously, we found that the function of miR398b in immunity in rice differs from that in Arabidopsis. However, the underlying mechanisms are unclear. In this study, we characterized the mutants of miR398b target genes and demonstrated that multiple superoxide dismutase genes contribute to miR398b‐regulated rice immunity against the blast fungus Magnaporthe oryzae. Out of the four target genes of miR398b, mutations in Cu/Zn‐Superoxidase Dismutase1 (CSD1), CSD2 and Os11g09780 (Superoxide DismutaseX,SODX) led to enhanced resistance to M. oryzae and increased hydrogen peroxide (H2O2) accumulation. By contrast, mutations in Copper Chaperone for Superoxide Dismutase (CCSD) resulted in enhanced susceptibility. Biochemical studies revealed that csd1, csd2 and sodx displayed altered expression of CSDs and other superoxide dismutase (SOD) family members, leading to increased total SOD enzyme activity that positively contributed to higher H2O2 production. By contrast, the ccsd mutant showed CSD protein deletion, resulting in decreased CSD and total SOD enzyme activity. Our results demonstrate the roles of different SODs in miR398b‐regulated resistance to rice blast disease, and uncover an integrative regulatory network in which miR398b boosts total SOD activity to upregulate H2O2 concentration and thereby improve disease resistance.

PubMed ID: 30590572, The cosmopolitan pest Aphis gossypii (Glover) causes considerable economic losses on various crops by its feeding damage and transmitting diseases around the world. Flupyradifurone is a novel butenolide pesticide; its toxicity on A. gossypii parent generation (F0) was estimated following treatment with LC 25 concentration for 48 h. The adult longevity and fecundity of the F0 individuals treated by flupyradifurone showed no significant decrease in comparison with the control. Life table method was used to evaluate the sublethal effects on progeny population (F1). Results showed that the development time of the fourth instar and the preadult as well as the total pre-reproductive period were significantly prolonged, while their fecundity was significantly decreased compared with the control. Additionally, the intrinsic rate of increase (r), the finite rate of increase, and the net reproductive rate (R 0) of F1 were all significantly lower in the group treated by LC 25 than in the control group. These results reveal that the sublethal concentration of flupyradifurone could suppress the population growth of A. gossypii and indicate that this novel insecticide may be as a useful tool in pest management. © The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved., National Natural Science Foundation of China, This work was supported by The National Natural Science Foundation of China (no. 31330064).

Map-based cloning of plant disease resistance (R) genes is time-consuming. Here, we reported the isolation of blast R gene Pid4 using comparative transcriptomic profiling and genome-wide sequence analysis. Pid4 encodes a coiled-coil nucleotide-binding site leucine-rich repeat (CC-NBS-LRR) protein and is constitutively expressed at diverse developmental stages in the rice variety Digu. The Pid4 protein is localized in both the nucleus and cytoplasm. Introduction of Pid4 into susceptible rice cultivars confers race-specific resistance to leaf and neck blast. Amino acid sequence comparison and blast resistance spectrum tests showed that Pid4 is a novel R gene, different from the previously reported R genes located in the same gene cluster. A Pid4 Indel marker was developed to facilitate the identification of Pid4 in different rice varieties. We demonstrated that a plant R gene can be quickly isolated using transcriptomic profiling coupled with genome-wide sequence analysis.

Insects have developed a good adaptive mechanism in response to environmental stresses in the long-term evolution. They have developed a helpful metabolism system to resist plant allelochemicals. Insects also harbor different kinds of symbiotic bacteria, which provide them a competitive advantage. Here, using cotton aphid as an example, we investigated the effects of four plant allelochemicals on the differential expression of symbiotic bacteria based on transcriptome data. We also studied the composition of symbiotic bacteria and function on pathway level in three kinds of aphids. We found that the bacteria have a significant role in resisting the plant allelochemicals stress and host plant selection by aphids. These results should be useful to investigate the environmental adaption mechanism of aphids in the view of symbiotic bacteria. These results would offer a new insight for improving strategy of aphids and developing new pest control systems.

Xanthomonas oryzae pv. oryzae is the causative agent of rice bacterial leaf blight. While the type III secretion system of X. oryzae pv. oryzae is essential for virulence, the biochemical activities and virulence mechanisms of non-transcription activator-like (non-TAL) effectors delivered by this system are largely unknown. Here, by screening for non-TAL effectors that contribute to X. oryzae pv. oryzae virulence, we revealed that Xanthomonas outer protein K (XopK) inhibits pathogen-associated molecular pattern-triggered immunity upstream of mitogen-activated protein kinase cascades. Specifically, XopK interacted with and directly ubiquitinated rice somatic embryogenic receptor kinase 2 (OsSERK2), resulting in its degradation. Accordingly, mutation of a putative ubiquitin-conjugation enzyme (E2) binding site abolished XopK-induced degradation of OsSERK2 and compromised XopK-dependent virulence. As crucial immune regulators associated with a multitude of immune receptors, SERKs have been shown to be perturbed by Pseudomonas effectors via different mechanisms. Our study revealed a distinct perturbation mechanism of SERK activity via ubiquitination achieved by Xanthomonas non-TAL effector.

Lesion mimic mutants are powerful tools for unveiling the molecular connections between cell death and pathogen resistance. Various proteins responsible for lesion mimics have been identified; however, the mechanisms underlying lesion formation and pathogen resistance are still unknown. Here, we identify a lesion mimic mutant in rice, lesion mimic leaf 1 (lml1). The lml1 mutant exhibited abnormal cell death and resistance to both bacterial blight and rice blast. LML1 is expressed in all types of leaf cells, and encodes a novel eukaryotic release factor 1 (eRF1) protein located in the endoplasmic reticulum. Protein sequences of LML1 orthologs are conserved in yeast, animals and plants. LML1 can partially rescue the growth delay phenotype of the LML1 yeast ortholog mutant, dom34. Both lml1 and mutants of AtLML1 (the LML1 Arabidopsis ortholog) exhibited a growth delay phenotype like dom34. This indicates that LML1 and its orthologs are functionally conserved. LML1 forms a functional complex with a eukaryotic elongation factor 1A (eEF1A)-like protein, SPL33/LMM5.1, whose mutant phenotype was similar to the lml1 phenotype. This complex was conserved between rice and yeast. Our work provides new insight into understanding the mechanism of cell death and pathogen resistance, and also lays a good foundation for studying the fundamental molecular function of Pelota/DOM34 and its orthologs in plants.

Significance Crops carrying broad-spectrum resistance loci provide an effective strategy for controlling infectious disease. Despite their importance, few broad-spectrum resistance loci have been reported, and the underlying mechanisms controlling the trait remain largely unknown. This report describes the identification of a gene, called “bsr-k1,” conferring broad-spectrum resistance and demonstrates that the encoded protein regulates immunity-related genes. Loss of function of BSR-K1 in rice leads to enhanced broad-spectrum resistance to two serious rice diseases with no major penalty on yield. This report provides insights into broad-spectrum resistance and offers an efficient strategy to breeding durably resistant rice., Crops carrying broad-spectrum resistance loci provide an effective strategy for controlling infectious disease because these loci typically confer resistance to diverse races of a pathogen or even multiple species of pathogens. Despite their importance, only a few crop broad-spectrum resistance loci have been reported. Here, we report the identification and characterization of the rice bsr-k1 (broad-spectrum resistance Kitaake-1) mutant, which confers broad-spectrum resistance against Magnaporthe oryzae and Xanthomonas oryzae pv oryzae with no major penalty on key agronomic traits. Map-based cloning reveals that Bsr-k1 encodes a tetratricopeptide repeats (TPRs)-containing protein, which binds to mRNAs of multiple OsPAL (OsPAL1–7) genes and promotes their turnover. Loss of function of the Bsr-k1 gene leads to accumulation of OsPAL1–7 mRNAs in the bsr-k1 mutant. Furthermore, overexpression of OsPAL1 in wild-type rice TP309 confers resistance to M. oryzae, supporting the role of OsPAL1. Our discovery of the bsr-k1 allele constitutes a significant conceptual advancement and provides a valuable tool for breeding broad-spectrum resistant rice.

Long non-coding RNAs (lncRNAs) represent the largest class of non-coding transcripts. They act a pivotal part in various insect developmental processes and stress responses. However, the investigation of lncRNA functions in insecticide resistant remains at an early phase. Herein, we conducted whole-transcriptome RNA sequencing for two cotton aphid (Aphis gossypii Glover) strains, i.e., insecticide-susceptible (SS) and spirotetramat-resistant (SR). We discovered 6059 lncRNAs in the RNA-Seq data, and 874 lncRNAs showed differential expression. In addition, 5 lncRNAs among 874 lncRNAs were predicted as targets of acetyl-CoA carboxylase (ACC). Reverse transcription real-time quantitative PCR (RT-qPCR) combined with RNA interference (RNAi) confirmed that selected ACC lncRNA was related to the expression of ACC. Moreover, we also identified two transcription factors, i.e., C/EBP and C/EBPzeta, that regulate the transcription level of ACC lncRNA. These results provide a good basis for the study of cotton aphid lncRNA functions in insecticide resistance development.

Aphis gossypii Glover is a destructive pest of numerous crops throughout the world. Although the expansion of Bt cotton cultivation has helped to control some insect pests, the damage from cotton aphids has not been mitigated. The evolution of aphid resistance to imidacloprid has made its chemical control more difficult since its introduction in 1991. Field populations of A. gossypii that were collected from different transgenic (Bt) cotton planting areas of China in 2014 developed different levels of resistance to imidacloprid. The IMI_R strain has developed high resistance to imidacloprid with the resistance ratio >1200-fold. Compared with the susceptible IMI_S strain, the IMI_R strain also developed a high level cross resistance to sulfoxaflor and acetamiprid. The limited synergism with either PBO or DEF suggests that resistance may be due to the site mutation of molecular target rather than to enhanced detoxification. Three target-site mutations within the nicotinic acetylcholine receptor (nAChR) β1 subunit were detected in the IMI_R strain. The R81T mutation has been reported to be responsible for imidacloprid resistance in A. gossypii and M. persicae. Both V62I and K264E were first detected in A. gossypii. These point mutations are also present in field populations, suggesting that they play a role in the resistance to imidacloprid. Furthermore, the expression level of transcripts encoding β1 subunit was decreased significantly in the IMI_R strain compared with the IMI_S strain, suggesting that both point mutations and the down-regulation of nAChR β1 subunit expression may be involved in the resistance mechanism for imidacloprid in A. gossypii. These results should be useful for the management of imidacloprid-resistant cotton aphids in Bt cotton fields in China.

BACKGROUND The cotton aphid, Aphis gossypii (Glover), is a destructive pest that affects numerous crops throughout the world. Pyrethroid resistance has become endemic in A. gossypii populations in the cotton growing areas of China due to wide- spread application of insecticides. To assess the extent of pyrethroid resistance, bioassays were conducted on field populations collected from several cotton cultivation areas from 2010–2015. The frequency of a known resistance-associated sodium channel mutation (M918L) in A. gossypii was evaluated and the bioassay of bifenthrin with or without the synergist was performed to illuminate the mechanisms underlying resistance to pyrethroids. RESULTS The field populations exhibited very high levels of resistance to both beta-cypermethrin and deltamethrin. Pretreatment with synergists, DEF and PBO, significantly increased the toxicity of bifenthrin to cotton aphid populations collected from Bt cotton fields in China. Further, 96.8%-100% of individuals with the M918L mutation (including both RR and RS individuals) were observed in various populations, and only 2.8%-3.2% of individuals with wild-type homozygotes (SS) were detected. CONCLUSION The mutation M918L in the voltage-gated sodium channel along with detoxifying metabolism was contributed to the pyrethroid resistance in the field populations of Aphis gossypii from cotton growing regions of China. And insecticides with different modes of action should be recommended for the control of A. gossypii in the future.

Glioblastomas rapidly become refractory to anti-VEGF therapies. We previously showed that cytochrome P450 (CYP) 4A-derived 20-hydroxyeicosatetraenoic acid (20-HETE) promotes angiogenesis. Here, we tested whether a novel flavonoid (FLA-16) prolongs survival and normalizes tumor vasculature in glioma through CYP4A inhibition. FLA-16 improved survival, reduced tumor burden, and normalized vasculature, accompanied with the decreased secretion of 20-HETE, VEGF and TGF-β in tumor-associated macrophages (TAMs) and endothelial progenitor cells (EPCs) in C6 and U87 gliomas. FLA-16 attenuated vascular abnormalization induced by co-implantation of GL261 glioma cells with CYP4A10high macrophages or EPCs. Mechanistically, the conditional medium from TAMs and EPCs treated with FLA-16 enhanced the migration of pericyte cells, and decreased the proliferation and migration of endothelial cells, which were reversed by CYP4A overexpression or exogenous addition of 20-HETE, VEGF and TGF-β. Furthermore, FLA-16 prevented crosstalk between TAMs and EPCs during angiogenesis. These results suggest that CYP4A inhibition by FLA-16 prolongs survival and normalizes vasculature in glioma through decreasing production of TAMs and EPCs-derived VEGF and TGF-β. This may represent a potential therapeutic strategy to overcome resistance to anti-VEGF treatment by effects on vessels and immune cells.

Plant architecture, a collection of genetically controlled agronomic traits, is one of the decisive factors that determine grain production. IDEAL PLANT ARCHITECTURE1 (IPA1) encodes a key transcription factor with pleiotropic effects on regulating plant architecture in rice (Oryza sativa), and IPA1 expression is controlled at the posttranscriptional level by microRNA156 and microRNA529. Here, we report the identification and characterization of IPA1 INTERACTING PROTEIN1 (IPI1), a RING-finger E3 ligase that can interact with IPA1 in the nucleus. IPI1 promotes the degradation of IPA1 in panicles, while it stabilizes IPA1 in shoot apexes. Consistent with these findings, the ipi1 loss-of-function mutants showed markedly altered plant architecture, including more tillers, enlarged panicles, and increased yield per plant. Moreover, IPI1 could ubiquitinate the IPA1-mediated complex with different polyubiquitin chains, adding K48-linked polyubiquitin chains in panicles and K63-linked polyubiquitin chains in the shoot apex. These results demonstrate that IPI1 affects plant architecture through precisely tuning IPA1 protein levels in different tissues in rice and provide new insight into the tissue-specific regulation of plant architecture and important genetic resources for molecular breeding.

Uridine diphosphate (UDP)-glycosyltransferases (UGTs) catalyze the conjugation of small lipophilic endogenous and exogenous compounds with sugars to produce water-soluble glycosides, playing an important role in insect endobiotic regulation and xenobiotic detoxification. In this study, two UGT-inhibitors, sulfinpyrazone and 5-nitrouracil, significantly increased spirotetramat toxicity against third instar nymphs of resistant Aphis gossypii, whereas there were no synergistic effects in apterous adult aphids, suggesting UGT involvement in spirotetramat resistance in cotton aphids. Furthermore, the UHPLC-MS/MS was employed to determine the content of spirotetramat and its four metabolites (S-enol, S-glu, S-mono, S-keto) in the honeydew of resistant cotton aphids under spirotetramat treatment. No residual spirotetramat was detected in the honeydew, while its four metabolites were detected at a S-enol: S-glu: S-mono: S-keto ratio of 69.30: 6.54: 1.44: 1.00. Therefore, glycoxidation plays a major role in spirotetramat inactivation and excretion in resistant aphids. Compared with the susceptible strain, the transcriptional levels of UGT344M2 were significantly upregulated in nymphs and adults of the resistant strain. RNA interference of UGT344M2 dramatically increased spirotetramat toxicity in nymphs, but no such effect were found in the resistant adult aphids. Overall, UGT-mediated glycoxidation were found to be involved in spirotetramat resistance. The suppression of UGT344M2 significantly increased the sensitivity of resistant nymphs to spirotetramat, suggesting that UGT344M2 upregulation might be associated with spirotetramat detoxification. This study provides an overview of the involvement of metabolic factors, UGTs, in the development of spirotetramat resistance.

Structural variations (SVs) and gene copy number variations (gCNVs) have contributed to crop evolution, domestication, and improvement. Here, we assembled 31 high-quality genomes of genetically diverse rice accessions. Coupling with two existing assemblies, we developed pan-genome-scale genomic resources including a graph-based genome, providing access to rice genomic variations. Specifically, we discovered 171,072 SVs and 25,549 gCNVs and used an Oryza glaberrima assembly to infer the derived states of SVs in the Oryza sativa population. Our analyses of SV formation mechanisms, impacts on gene expression, and distributions among subpopulations illustrate the utility of these resources for understanding how SVs and gCNVs shaped rice environmental adaptation and domestication. Our graph-based genome enabled genome-wide association study (GWAS)-based identification of phenotype-associated genetic variations undetectable when using only SNPs and a single reference assembly. Our work provides rich population-scale resources paired with easy-to-access tools to facilitate rice breeding as well as plant functional genomics and evolutionary biology research.

Broad-spectrum resistance is highly preferred in crop breeding programmes. Previously, we have reported the identification of the broad-spectrum resistance-Digu 1 (bsr-d1) allele from rice Digu. The bsr-d1 allele prevents activation of Bsr-d1 expression by Magnaporthe oryzae infection and degradation of H2 O2 by peroxidases, leading to resistance to M. oryzae. However, it remains unknown whether defence pathways other than H2 O2 burst and peroxidases contribute to the bsr-d1-mediated immunity. Blast resistance was determined in rice leaves by spray and punch inoculations. Target genes of OsMYB30 were identified by one-hybrid assays in yeast and electrophoretic mobility shift assay. Lignin content was measured by phloroglucinol-HCl staining, and acetyl bromide and thioacidolysis methods. Here, we report the involvement of the OsMYB30 gene in bsr-d1-mediated blast resistance. Expression of OsMYB30 was induced during M. oryzae infection or when Bsr-d1 was knocked out or downregulated, as occurs in bsr-d1 plants upon infection. We further found that OsMYB30 bound to and activated the promoters of 4-coumarate:coenzyme A ligase genes (Os4CL3 and Os4CL5) resulting in accumulation of lignin subunits G and S. This action led to obvious thickening of sclerenchyma cells near the epidermis, inhibiting M. oryzae penetration at the early stage of infection. Our study revealed novel components required for bsr-d1-mediated resistance and penetration-dependent immunity, and advanced our understanding of broad-spectrum disease resistance.

The extent of structural variants (SVs), in particular copy number variations (CNVs) in plant and animal genomes remains unknown, mainly due to the lack of population-scale truly high-quality genomes. Here, we de novo assembled and annotated 31 gold-standard reference genomes from varieties representing all major cultivated rice subtypes, and accurately detected 107,251 non-redundant SVs affecting 644.91Mbp. A position-resolved pan-genome comprising 66,636 genes enabled our discovery that more than 38% of protein-coding genes in cultivated rice harbor CNVs, a far greater proportion than previous estimate. Illustrating functional consequences of these variations, CNVs of Awn3-1, OsVIL1 and OsMADS18, as well as a 345kb inversion likely contributed to major events in rice evolution, domestication and environmental adaptation. Beyond fully resolving the SVs of cultivated rice and comprehensively cataloguing CNVs among protein-coding genes, our study suggests that SVs-affected genes likely contribute to many mechanisms underlying domestication and phenotypic variation in rice.

Bradysia odoriphaga is a destructive insect pest, damaging more than 30 crop species. Nicotinic acetylcholine receptors (nAChRs) mediating fast excitatory transmission in the central nervous system in insects are the molecular targets of some economically important insecticides including imidacloprid, which has been widely used to control B. odoriphaga in China since 2013. However, the clear characterization about nAChRs in B. odoriphaga is still unknown. Hence, our objective is to identify and characterize the nAChR gene family in B. odoriphaga based on the transcriptome database and sequence, phylogenetic and expression profiles analysis. In this study, we cloned seven nAChR subunit genes from B. odoriphaga, including Boα1, Boα2, Boα3, Boα7, Boα8, Boβ1 and Boβ3. Sequence analysis revealed that the seven nAChR subunits of B. odoriphaga shared the typical structural features with Drosophila melanogaster nAChR α1 subunit, including an extracellular N-terminal domain containing six functional loops (loop A-F), a signature Cys-loop with two disulfide bond-forming cysteines separated by 13 amino acid residues, and four typical transmembrane helices (TM1-TM4) in the C-terminal region. Phylogenetic analysis suggested that seven nAChR subunit genes in B. odoriphaga are evolutionarily conserved among four model insects, including D. melanogaster, Bombyx mori, Apis mellifera and Tribolium castaneum. Meanwhile, nAChR α4, α5, α6 and β2 subunit genes may potentially exist in B. odoriphaga, which need further study. Furthermore, quantitative real-time PCR analysis revealed the specific expression pattern of nAChR subunits in three body parts including head, thorax and abdomen, and developmental expression pattern of nAChR subunits throughout the B. odoriphaga life cycle. These results provided necessary information for further investigating the diverse functions of nAChRs in B. odoriphaga.

Circular RNAs (circRNAs) have vital roles in great variety of biological processes. However, expression levels and functions of circRNAs related to heat acclimation (HA) are poorly understood. This study is the first time an in-depth circRNA expression profiling were used to investigate circRNA–miRNA interactions in HA rats in order to further comprehend the mechanisms underlying HA. CircRNA expression profile was performed in rats’ hypothalamus of HA and control group with microarray assays and their functions were predicted by using Bioinformatics analysis. Differential circRNAs and their regulated downstream miRNAs and mRNAs were quantitatively validated by means of quantitative polymerase chain reaction in real-time (RT-qPCR). Enzyme-linked immunosorbent assay (ELISA) was then applied to predict the expression of proteins. In total, 53 circRNAs were expressed distinctively between the HA and Control; up- and down-regulation of circRNAs were 28 and 25, respectively, in HA (fold change > 1.5, P < 0.05). Three circRNAs and two miRNAs and three predicted mRNAs were obviously regulated after validated by RT-qPCR in HA rats. Two proteins expression were proportional to their mRNA changes. Further analysis demonstrates that circRNAs closest to HA can be categorized into three signal pathways: including rno_circRNA_014301-vs-rno-miR-3575-vs-Hif-1α, rno_circRNA_014301-vs-rno-miR-3575-vs-Lppr4, and rno_circRNA_010393-vs-rno-miR-20b-3p-vs-Mfap4 in hypoxia response pathways, substance/energy metabolism, and inflammatory response pathways. Our findings implicate that many circRNAs regulate expressions of genes that interact with each other to exert their functions during HA.

Background Epidermal growth factor receptor (EGFR) mutation represents a good response to EGFR-tyrosine kinase inhibitor and an advantageous prognostic factor in advanced-stage non-small cell lung cancer (NSCLC). However, the predictive value of EGFR mutation for prognosis in NSCLC patients after complete surgery, which more reflective of natural process, remains controversial. We sought to examine the predictive value of EGFR mutation in NSCLC. Several studies with small sample sizes have been reported but small studies bring bias especially in a postoperative setting. Therefore, we sought to pool all current evidence to show the true effects. Methods Electronic databases were used to search the relevant articles. Disease-free survival (DFS), which will be less effected by subsequent treatments after recurrence, was the primary endpoint. The DFS between EGFR mutated and wild-type patients were compared focus on stage I patients who are rarely received adjuvant therapy. Besides, the DFS of patients with 19 exon deletion (19del) and 21 exon L858R mutation (L858R) were compared. A random effects model was used. Results A total of 19 relevant studies which involved 4,872 cases were enrolled and 2,086 patients were EGFR-mutated. The majority of studies used PCR-based methods to detect EGFR mutations. Through meta-analysis, we observed the DFS of EGFR-mutated patients were similar to wild type patients in overall population (HR 0.93, 95% CI: 0.74 to 1.17). Similar results were observed in stage I subgroup (HR 0.82, 95% CI: 0.50 to 1.33). DFS of 19 del patients were potentially inferior to L858R patients but the difference was not significant (HR 1.38, 95% CI: 0.76 to 2.52). Conclusions There was no significant difference in postoperative DFS between EGFR-mutant patients and wild-type with resected NSCLC. In addition, there is still insufficient evidence to support different postoperative treatment strategies (especially for stage I) for both mutated and wild-type patients. However, 19 del may be a negative factor, which may require more strict management. Thus, we strongly encourage reporting specific prognostic impacts of different mutation types.

Background With the increasing incidence of papillary thyroid carcinoma (PTC), PTC continues to garner attention worldwide; however its pathogenesis remains to be elucidated. The purpose of this study was to explore key biomarkers and potential new therapeutic targets for, PTC. Methods GEO2R and Venn online software were used for screening of differentially expressed genes. Hub genes were screened via STRING and Cytoscape, followed by Gene Ontology and KEGG enrichment analysis. Finally, survival analysis and expression validation were performed using the UALCAN online software and immunohistochemistry. Results We identified 334 consistently differentially expressed genes (DEGs) comprising 136 upregulated and 198 downregulated genes. Gene Ontology enrichment analysis results suggested that the DEGs were mainly enriched in cancer-related pathways and functions. PPI network visualization was performed and 17 upregulated and 13 downregulated DEGs were selected. Finally, the expression verification and overall survival analysis conducted using the Gene Expression Profiling Interactive Analysis Tool (GEPIA) and UALCAN showed that LPAR5, TFPI, and ENTPD1 were associated with the development of PTC and the prognosis of PTC patients, and the expression of LPAR5, TFPI and ENTPD1 was verified using a tissue chip. Conclusions In summary, the hub genes and pathways identified in the present study not only provide information for the development of new biomarkers for PTC but will also be useful for elucidation of the pathogenesis of PTC.

Crops are exposed to attacks by various pathogens that cause substantial yield losses and severely threaten food security. To cope with pathogenic infection, crops have elaborated strategies to enhance resistance against pathogens. In addition to the role of protein-coding genes as key regulators in plant immunity, accumulating evidence has demonstrated the importance of non-coding RNAs (ncRNAs) in the plant immune response. Here, we summarize the roles and molecular mechanisms of endogenous ncRNAs, especially microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), in plant immunity. We discuss the coordination between miRNAs and small interfering RNAs (siRNAs), between lncRNAs and miRNAs or siRNAs, and between circRNAs and miRNAs in the regulation of plant immune responses. We also address the role of cross-kingdom mobile small RNAs in plant–pathogen interactions. These insights improve our understanding of the mechanisms by which ncRNAs regulate plant immunity and can promote the development of better approaches for breeding disease-resistant crops., This review summarizes the roles of miRNAs, siRNAs, lncRNAs, and circRNAs in signal perception, transduction, and downstream responses of plant immunity. Interactions between miRNAs and siRNAs, between lncRNAs and miRNAs or siRNAs, and between circRNAs and miRNAs in the defense against various pathogens are addressed. Finally, the role of cross-kingdom mobile small RNAs in plant–pathogen interactions is discussed.

Leaves are the main organs in which photosynthates are produced. Leaf senescence facilitates the translocation of photosynthates and nutrients from source to sink, which is important for plant development and especially for crop yield. However, the molecular mechanism of leaf senescence is unknown. Here, we identified a mutant, yellow leaf and dwarf 1 (yld1), which exhibited decreased plant height and premature leaf senescence. Nitroblue tetrazolium and diamiobenzidine staining analyses revealed that the concentrations of reactive oxygen species were higher in yld1 leaves than in wild type leaves. The photosynthetic pigment contents were significantly decreased in yld1. The yld1 chloroplasts had collapsed and were filled with abnormal starch granules. Combining bulk segregant and MutMap gene mapping approaches, the mutation responsible for the yld1 phenotype was mapped to a 7.3 Mb centromeric region, and three non-synonymous single nucleotide polymorphisms located in three novel genes were identified in this region. The expression patterns of the three candidate genes indicated that LOC_Os06g29380 had the most potential for functional verification. Plant hormone measurements showed that salicylic acid was highly accumulated in yld1 leaves when compared with wild type leaves, and yld1 was more sensitive to salicylic acid than wild type. This work lays the foundation for understanding the molecular regulatory mechanism of leaf senescence, and may reveal new connections among the molecular pathways related to leaf senescence, starch metabolism and salicylic acid signaling.

Ethylene plays diverse roles in plant growth, development and stress responses. However, the roles of ethylene signaling in immune responses remain largely unknown. In this study, we showed that the blast fungus Magnaporthe oryzae infection activated ethylene biosynthesis in rice. Resistant rice cultivars accumulated higher levels of ethylene than susceptible ones. Ethylene signaling components OsEIN2 and the downstream transcription factor OsEIL1 positively regulated disease resistance. Mutation of OsEIN2 led to enhanced disease susceptibility. Whole-genome transcription analysis revealed that responsive genes of ethylene, jasmonates (JAs) and reactive oxygen species (ROS) signaling as well as phytoalexin biosynthesis genes were remarkably induced. Transcription of OsrbohA/B, which encode NADPH oxidases, and OsOPRs, the JA biosynthesis genes, were induced by M. oryzae infection. Furthermore, we demonstrated that OsEIL1 binds to the promoters of OsrbohA/OsrbohB and OsOPR4 to activate their expression. These data suggest that OsEIN2-mediated OsrbohA/OsrbohB and OsOPR transcription may play essential roles in ROS generation, JA biosynthesis and the subsequent phytoalexin accumulation. Therefore, the involvement of ethylene signaling in disease resistance is probably by activation of ROS and phytoalexin production in rice during M. oryzae infection.

Acetyl-coenzyme A carboxylase (acetyl-CoA carboxylase, ACC) catalyses the carboxylation of acetyl-CoA to produce malonyl-CoA during de novo fatty acid synthesis. A laboratory-selected spirotetramat-resistant strain (SR) of cotton aphid was used in this study. RT-qPCR results demonstrated significant increases in the levels of ACC transcript in the resistant strain compared to the susceptible strain. Depletion of overexpressed ACC transcripts by RNAi also significantly enhanced the sensitivity of the resistant aphid to spirotetramat. We hypothesized that ACC gene expression is subject to post-transcriptional regulation. To investigate the underlying mechanism, the 66 known miRNAs of Aphis gossypii were used for target prediction, eight of which were predicted to target ACC. Validation identified two miRNAs, miR-276 and miR-3016, with abundance levels that were highly inversely correlated with ACC transcript levels. This result suggests that the miRNAs miR-276 and miR-3016 may play major roles in the post-transcriptional regulation of the ACC gene. Modulation of the abundance of miR-276 and miR-3016 through addition of inhibitors/mimics of miR-276 or miR-3016 to the artificial diet significantly altered both ACC transcript levels and the tolerance of A. gossypii to spirotetramat, thus confirming the roles of these two miRNAs in the regulation of spirotetramat resistance.

Leaf color is directly associated with plant photosynthesis. Here, we have isolated and identified a spontaneous rice mutant named yd1 that has yellowish leaves and dwarf stature. Map-based cloning reveals that YD1 encodes a previously reported kinesin protein from the kinesin-4 subfamily, BC12/GDD1. Arginine-328 is replaced by leucine in yd1, BC12328Leu. YD1 is mainly expressed in leaves and is involved in chlorophyll (Chl) synthesis. The yd1 mutant had less Chl and a reduced and disordered thylakoid ultrastructure. In yd1 plants, Chl biosynthesis and photosynthesis associated gene expression was decreased and Chl degradation gene expression was increased, thereby leading to a reduced photosynthesis rate and grain yield. In this study we reveal that the novel BC12328Leu allele of BC12 modulated plant leaf color in yd1 plants, which has not been previously reported in studies of BC12/GDD1/MTD1/SRG1. Gene knockout results indicated that YD1 regulates leaf color in the indica rice background, but not in the japonica rice background. Our study provides new insights into molecular regulation of rice growth by BC12/GDD1 in different genetic backgrounds.

Epidemiologic studies show that the levels of air pollutants and particulate matter are positively associated with the morbidity and mortality of cardiovascular diseases. Here we demonstrate that the intratracheal instillation of multi-walled carbon nanotubes (MWCNTs), a standard fine particle, exacerbate doxorubicin (DOX)-induced cardiotoxicity in mice through altering gut microbiota and pulmonary and colonic macrophage phenotype. MWCNTs (25 μg/kg per day, 5 days a week for 3 weeks) promoted cardiotoxicity and apoptosis in the DOX (2 mg/kg, twice a week for 5 weeks)-treated C57BL/6 mice. MWCNTs exaggerated DOX-induced gut microbiota dysbiosis characterized by the increased abundances of Helicobacteraceae and Coriobacteriaceae. In addition, MWCNTs promoted DOX-induced M1-like polarization of colonic macrophages with an increase in TNF-α, IL-1β and CC chemokine ligand 2 in peripheral blood. Importantly, treatment with the antibiotics attenuated MWCNTs plus DOX-induced apoptosis of cardiomyocytes and M1-like polarization of colonic macrophages. The fecal microbiota transplantation demonstrated that MWCNTs exaggerated DOX-induced cardiotoxicity with M1-like polarization of colonic macrophages. The conditioned medium from MWCNTs-treated pulmonary macrophages promoted DOX-induced gut microbiota dysbiosis and colonic macrophage polarization. Furthermore, the co-culture of macrophages and fecal bacteria promoted M1-like macrophage polarization and their production of TNF-α and IL-1β, and thereby exacerbated the effects of MWCNTs. Moreover, IL-1β and TNF-α blockade, either alone or in combination attenuated MWCNTs-exacerbated cardiotoxicity. In summary, MWCNTs exacerbate DOX-induced cardiotoxicity in mice through gut microbiota and pulmonary and colonic macrophage interaction. Our findings identify a novel mechanism of action of inhaled particle-driven cardiotoxicity.

Checkpoint blockade therapy has been proven efficacious in lung cancer patients. However, primary/acquired resistance hampers its efficacy. Therefore, there is an urgent need to develop novel strategies to improve checkpoint blockade therapy. Here we tested whether dual inhibition of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) by flavonoid melafolone improves program death 1 (PD-1) checkpoint blockade therapy through normalizing tumor vasculature and PD-1 ligand (PD-L1) downregulation. Virtual screening assay, cellular thermal shift assay, and enzyme inhibition assay identified melafolone as a potential inhibitor of COX-2 and EGFR. In Lewis lung carcinoma (LLC) and CMT167 models, dual inhibition of COX-2 and EGFR by melafolone promoted survival, tumor growth inhibition, and vascular normalization, and ameliorated CD8+ T-cell suppression, accompanied by the downregulation of transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), and PD-L1 in the tumor cells. Mechanistically, dual inhibition of COX-2 and EGFR in lung cancer cells by melafolone increased the migration of pericyte, decreased the proliferation and migration of endothelial cells, and enhanced the proliferation and effector function of CD8+ T cells through VEGF, TGF-β, or PD-L1 downregulation and PI3K/AKT inactivation. Notably, melafolone improved PD-1 immunotherapy against LLC and CMT167 tumors. Together, dual inhibition of COX-2 and EGFR by melafolone improves checkpoint blockade therapy through vascular normalization and PD-L1 downregulation and, by affecting vessels and immune cells, may be a promising combination strategy for the treatment of human lung cancer.

Autophagy is essential for appressorium-mediated plant infection by Magnaporthe oryzae, the causal agent of rice blast disease and a major threat to global food security. The regulatory mechanism of pathogenicity-associated autophagy, however, remains largely unknown. Here, we report the identification and functional characterization of a plausible ortholog of yeast SNT2 in M. oryzae, which we term MoSNT2. Deletion mutants of MoSNT2 are compromised in autophagy homeostasis and display severe defects in autophagy-dependent fungal cell death and pathogenicity. These mutants are also impaired in infection structure development, conidiation, oxidative stress tolerance and cell wall integrity. MoSnt2 recognizes histone H3 acetylation through its PHD1 domain and thereby recruits the histone deacetylase complex, resulting in deacetylation of H3. MoSnt2 binds to promoters of autophagy genes MoATG6, 15, 16, and 22 to regulate their expression. In addition, MoTor controls MoSNT2 expression to regulate MoTor signaling which leads to autophagy and rice infection. Our study provides evidence of a direct link between MoSnt2 and MoTor signaling and defines a novel epigenetic mechanism by which MoSNT2 regulates infection-associated autophagy and plant infection by the rice blast fungus. Abbreviations: M. oryzae: Magnaporthe oryzae; S. cerevisiae: Saccharomyces cerevisiae; F. oxysporum: Fusarium oxysporum; U. maydis: Ustilago maydis; Compl.: complemented strains of ΔMosnt2 expressing MoSNT2-GFP; ATG: autophagy-related; HDAC: histone deacetylase complex; Tor: target of rapamycin kinase; MTOR: mechanistic target of rapamycin kinase in mammals; MoSnt2: DNA binding SaNT domain protein in M. oryzae; MoTor: target of rapamycin kinase in M. oryzae; MoAtg8: autophagy-related protein 8 in M. oryzae; MoHos2: hda one similar protein in M. oryzae; MoeIf4G: eukaryotic translation initiation factor 4 G in M. oryzae; MoRs2: ribosomal protein S2 in M. oryzae; MoRs3: ribosomal protein S3 in M. oryzae; MoIcl1: isocitrate lyase in M. oryzae; MoSet1: histone H3K4 methyltransferase in M. oryzae; Asd4: ascus development 4; Abl1: AMP-activated protein kinase β subunit-like protein; Tig1: TBL1-like gene required for invasive growth; Rpd3: reduced potassium dependency; KAT8: lysine (K) acetyltransferase 8; PHD: plant homeodomain; ELM2: Egl-27 and MTA1 homology 2; GFP: green fluorescent protein; YFP: yellow fluorescent protein; YFP(CTF): C-terminal fragment of YFP; YFP(NTF): N-terminal fragment of YFP; GST: glutathione S-transferase; bp: base pairs; DEGs: differentially expressed genes; CM: complete medium; MM-N: minimum medium minus nitrogen; CFW: calcofluor white; CR: congo red; DAPI: 4ʹ, 6-diamidino-2-phenylindole; BiFC: bimolecular fluorescence complementation; RT: reverse transcription; PCR: polymerase chain reaction; qPCR: quantitative polymerase chain reaction; RNAi: RNA interference; ChIP: chromatin immunoprecipitation

Flexible growth and immune responses in rice Plants that are fighting microbial pathogens often divert resources that could be used for growth into the immune response. For crops, this translates into lower yield when plant immunity is activated. Wang et al. show that, in rice, reversible phosphorylation of a key transcription factor allows the plant to defend against fungal attack when needed but then, within days, reallocate resources back to growth (see the Perspective by Greene and Dong). Thus, both pathogen defense and crop yield can be sustained. Science , this issue p. 1026 ; see also p. 976

Cucurbitacin B is a natural triterpene present in plants of Cucurbitaceae family, which are among the host plants for melon aphid, Aphis gossypii. In present study we characterized the effects of two cucurbitacin B concentrations on the biological parameters of adults (F0) and of juveniles and adults of their progeny (F1). The results showed that cucurbitacin B at 25 ppm significantly reduced the adult longevity and fecundity of both F0 and F1 generation. Exposure of F0 generation to 25 ppm though reduced the demographic traits of F1 including the intrinsic rate of increase r (day−1), generation time T (day), finite rate of increase λ (day−1), however, only net reproductive rate R0 (offspring/individual) decreased significantly. While 100 ppm reduced not only the longevity and fecundity of F0 generation but also the longevity of F1 generation. Fecundity of F1 was not affected by 100 ppm of cucurbitacin B, however, R0 (offspring/individual) and T (day) of F1 generation were lower than the control population. These results support the hypothesis that high contents of cucurbitacin B caused negative impact on melon aphid and could be used as a lead for classical selection of resistant varieties of plants that are main hosts for the melon aphid.

Receptor-like cytoplasmic kinases (RLCKs) represent a large family of proteins in plants. However, few RLCKs have been well characterized. Here, we report the functional characterization of four rice RLCKs - OsRLCK57, OsRLCK107, OsRLCK118 and OsRLCK176 from subfamily VII. These OsRLCKs interact with the rice brassinosteroid receptor, OsBRI1 in yeast cell, but not the XA21 immune receptor. Transgenic lines silenced for each of these genes have enlarged leaf angles and are hypersensitive to brassinolide treatment compared to wild type rice. Transgenic plants silenced for OsRLCK57 had significantly fewer tillers and reduced panicle secondary branching, and lines silenced for OsRLCK107 and OsRLCK118 produce fewer seeds. Silencing of these genes decreased Xa21 gene expression and compromised XA21-mediated immunity to Xanthomonas oryzae pv. oryzae. Our study demonstrates that these OsRLCKs negatively regulate BR signalling, while positively regulating immune responses by contributing to the expression of the immune receptor XA21.