Sugarcane mosaic virus (SCMV;genus Potyvirus, family Potyviridae) is a causal pathogen of sugarcane mosaic disease, and it is widespread in regions where sugarcane (Saccharum spp. hybrids) is grown. It is difficult to...Sugarcane mosaic virus (SCMV;genus Potyvirus, family Potyviridae) is a causal pathogen of sugarcane mosaic disease, and it is widespread in regions where sugarcane (Saccharum spp. hybrids) is grown. It is difficult to investigate the molecular mechanism of pathogen infection in sugarcane because of limited genomic information. Here, we demonstrated that SCMV strain FZ1 can systemically infect Brachypodium distachyon inbred line Bd21 and Nicotiana benthamiana through inoculation, double antibody sandwich enzyme-linked immunosorbent, transmission electron microscopy, and reverse transcription PCR assays. The leaves of Bd21 developed mosaic symptoms, while the leaves of N. benthamiana showed no obvious symptoms under the challenge of SCMV-FZ1. We concluded that B. distachyon inbred line Bd21 is a promising experimental model plant compared with N. benthamiana for study on the infectivity of SCMV. This is the first report on the SCMV infection of model plants B. distachyon inbred line Bd21 and N. benthamiana, which will shed light on the mechanism of SCMV infection of sugarcane and benefit sugarcane breeding against sugarcane mosaic disease.展开更多
Inoculation methods for rice blast fungus Magnaporthe oryzae to Brachypodium distachyon were developed to investigate the infection process and symptom development in comparison with those on rice （Oryza sativa） and...Inoculation methods for rice blast fungus Magnaporthe oryzae to Brachypodium distachyon were developed to investigate the infection process and symptom development in comparison with those on rice （Oryza sativa） and barley （Hordeum vulgare）.M.oryzae could infect leaves,sheathes,stems and panicles of B.distachyon and cause blast disease.Spraying conidial suspension on either intact seedlings or leaf segments induced typical symptoms on B.distachyon.During the intact seedling inoculation,the symptom developed on B.distachyon leaves closely resembled that on rice;but the lesions on B.distachyon had better uniformity in shapes and sizes than those on rice or barley.In the leaf segments inoculation,only initial and low-developed lesions could be found on rice,while normal symptoms on B.distachyon and barley.Inoculated with low-virulent mutants of M.oryzae,B.distachyon produced low-level symptoms.The symptom level of each mutant on B.distachyon corresponded well to that on rice.In addition,typical infection processes presented on B.distachyon leaves：forming melanized appressoria,penetrating into host epidermis and then forming hyphae in epidermal cells.According to these results,B.distachyon can be used as a candidate for studying fungus-plant interactions and as a probable source of disease resistance.展开更多
Barley stripe mosaic virus(BSMV) is the type member of the genus Hordeivirus. Brachypodium distachyon line Bd3-1 shows resistance to the BSMV ND18 strain, but is susceptible to an ND18 double mutant(βNDTGB1R390K, T39...Barley stripe mosaic virus(BSMV) is the type member of the genus Hordeivirus. Brachypodium distachyon line Bd3-1 shows resistance to the BSMV ND18 strain, but is susceptible to an ND18 double mutant(βNDTGB1R390K, T392K) in which lysine is substituted for an arginine at position 390 and for threonine at position 392 of the triple gene block 1(TGB1) protein. In order to understand differences in gene expression following infection with ND18 and double mutant ND18, Bd3-1 seedlings were subjected to RNA-seq analyses at 1, 6, and14 days post inoculation(dpi). The results revealed that basal immunity genes involved in cellulose synthesis and pathogenesis-related protein biosynthesis were enhanced in incompatible interactions between Bd3-1 and ND18. Most of the differentially expressed transcripts are related to trehalose biosynthesis, ethylene, jasmonic acid metabolism,protein phosphorylation, protein ubiquitination, transcriptional regulation, and transport process, as well as pathogenesis-related protein biosynthesis. In compatible interactions between Bd3-1 and ND18 mutant, Bd3-1 developed weak basal resistance responses to the virus. Many genes involved in cellulose biosynthesis, protein amino acid phosphorylation,protein biosynthesis, protein glycosylation, glycolysis and cellular macromolecular complex assembly that may be related to virus replication, assembly and movement were up-regulated. Some genes involved in oxidative stress responses were also up-regulated at14 dpi. BSMV ND18 mutant infection suppressed expression of genes functioning in regulation of transcription, protein kinase, cellular nitrogen compound biosynthetic process and photosynthesis. Differential expression patterns between compatible and incompatible interactions in Bd3-1 to the two BSMV strains provide important clues for understanding mechanism of resistance to BMSV in the model plant Brachypodium.展开更多
Southwestern China is abundant in a large species diversity of grasses and Brachypodium sylvaticum var. breviglume is unquestionably appropriate to serve as an ideal model to investigate the adaptation, evolution and ...Southwestern China is abundant in a large species diversity of grasses and Brachypodium sylvaticum var. breviglume is unquestionably appropriate to serve as an ideal model to investigate the adaptation, evolution and diversification of grasses in this region. In this study, a total of 37 microsatellite markers were screened and genetic variation was estimated for 100 individuals from the five natural populations of the species. Our results showed that seven of them were polymorphic for the five studied populations, while the other thirty were monomorphic. These seven SSR loci exhibited a high level of genetic diversity among populations, i.e. allele number varied from 5 to 24, with an average of 13.29;expected heterozygosity (He) ranged from 0.439 to 0.561, with an average of 0.488;percentage of polymorphic loci (PPL) ranged from 85.71% to 100%, with an average of 97. 14%. The FCA and UPGMA analyses revealed that the five populations were divided into three clusters. Our results indicate that these newly characterized SSR markers are useful for the exploration of genetic diversity and evolutionary history of the B. sylvaticum var. breviglume populations in Yunnan, China.展开更多
As sessile organisms,plants possess a complex system to cope with environmental changes.Ca^(2+)functions as a vital second messenger in the stress signaling of plants,and the CBL-interacting protein kinases(CIPKs)serv...As sessile organisms,plants possess a complex system to cope with environmental changes.Ca^(2+)functions as a vital second messenger in the stress signaling of plants,and the CBL-interacting protein kinases(CIPKs)serve as essential elements in the plant Ca^(2+)signaling pathway.In this study,calcineurin B-like protein-interacting protein kinase 26(BdCIPK26)from Brachypodium distachyon was characterized.Overexpression of BdCIPK26 enhanced tolerance to drought and salt stress of transgenic plants.Further investigations revealed that BdCIPK26 participated in abscisic acid(ABA)signaling,conferred hypersensitivity to exogenous ABA in transgenic plants,and promoted endogenous ABA biosynthesis.Moreover,BdCIPK26 was found to maintain ROS homeostasis in plants under stress conditions.Therefore,this study indicates that BdCIPK26 functions as a positive regulator in drought and salt stress response.展开更多
The rice Wsi18 promoter confers drought-inducible gene expression. This property makes it a useful candidate to drive relevant genes for developing drought resistant traits for different monocot crops. In this study, ...The rice Wsi18 promoter confers drought-inducible gene expression. This property makes it a useful candidate to drive relevant genes for developing drought resistant traits for different monocot crops. In this study, we showed that the Bradi2G47700 gene, the closest homologue to rice Wsi18, was upregulated in Brachypodium distachyon plants exposed to ABA and mannitol. Wsi18: uidA transgenic B. distachyon plants were produced and then subjected to ABA or mannitol treatment. The expression of uidA in three transgenic lines (line 10, 18 and 37) was significantly upregulated in plants exposed to ABA (fold increases of 5.61 ± 0.98, 2.88 ± 0.75 and 9.13 ± 1.96, respectively) compared to the same transgenic plant lines without treatment. The expression of uidA in two transgenic lines (lines 18 and 37) also showed upregulation when treated with mannitol (fold increases of 4.43 ± 1.07 and 8.47 ± 2.90, respectively) compared to the same transgenic plant lines without mannitol treatment. Moreover, GUS histochemical assay showed increased Wsi18 promoter activity in the leaves and stems of transgenic lines upon treatment with ABA or mannitol. This is the first report of the drought inducible rice Wsi18 promoter being active in B. distachyon which is a model plant for molecular biology research of various monocot plants. Taken together, the results indicate that the Wsi18 promoter and its homologue may be explored as a useful tool for drought stress-inducible gene expression in different monocot crops.展开更多
Beckmannia syzigachne is a noxious weed for rice-wheat rotations in China.The B.syzigachne(AH-02)population evolved metabolic resistance to fenoxaprop-P-ethyl and mesosulfuron-methyl.To investigate the function of GT7...Beckmannia syzigachne is a noxious weed for rice-wheat rotations in China.The B.syzigachne(AH-02)population evolved metabolic resistance to fenoxaprop-P-ethyl and mesosulfuron-methyl.To investigate the function of GT73C1 in this population,the GT73C1 gene was amplified by reverse transcription-polymerase chain reaction,and the sequence was 100%consistent with the transcriptome data.Its phylogenetic tree was displayed and annotated using FigTree v1.4.4.The plant overexpression vector of GT73C1 gene was constructed and used to transform Brachypodium distachyon plants.Furthermore,the expression of GT73C1 was significantly induced by fenoxaprop-P-ethyl and mesosulfuron-methyl,which was consistent with the findings from the whole plant bioassay.These results indicate that GT73C1 is closely related to the metabolic resistance of B.distachyon.展开更多
Cereal cyst nematode（Heterodera avenae, CCN） distributes worldwide and has caused severe damage to cereal crops, and a model host will greatly aid in the study of this nematode. In this research, we assessed the sen...Cereal cyst nematode（Heterodera avenae, CCN） distributes worldwide and has caused severe damage to cereal crops, and a model host will greatly aid in the study of this nematode. In this research, we assessed the sensitivity of 25 inbred lines of Brachypodium distachyon to H. avenae from Beijing, China. All lines of B. distachyon were infested by secondstage juveniles（J2s） of H. avenae from Daxing District of Beijing population, but only 13 inbred lines reproduced 0.2–3 cysts/plant, showing resistance. The entire root system of the infested B. distachyon appeared smaller and the fibrous roots were shorter and less numerous. We found that a dose of 1 000 J2s of H. avenae was sufficient for nematode infestation. We showed that Koz-1 of B. distachyon could reproduce more cysts than TR2A line. Line Koz-1 also supported the complete life cycles of 5 CCN geographical populations belonging to the Ha1 or Ha3 pathotype group. Our results suggest that B. distachyon is a host for CCN.展开更多
CONSTANS(CO)是植物光周期诱导开花途径中的关键基因之一。为探究BdCO在光周期途径中的分子调控机制,本研究对野生型二穗短柄草(Brachypodium distachyon)Bd21植株、过表达BdCO基因型二穗短柄草(CO_OX)植株和BdCO基因敲除型二穗短柄草(C...CONSTANS(CO)是植物光周期诱导开花途径中的关键基因之一。为探究BdCO在光周期途径中的分子调控机制,本研究对野生型二穗短柄草(Brachypodium distachyon)Bd21植株、过表达BdCO基因型二穗短柄草(CO_OX)植株和BdCO基因敲除型二穗短柄草(CO_A3)植株进行转录组测序分析,对差异表达基因进行GO和KEGG功能富集分析,最后观察三种植株的开花表型。结果表明,对比Bd21 vs CO_OX和Bd21 vs CO_A3的基因表达量,分别检测到1382个和773个差异表达基因;GO功能富集分析发现,Bd21 vs CO_OX的差异表达基因主要富集在小核仁核糖核蛋白复合物、snoRNA结合和rRNA处理中,Bd21 vs CO_A3的差异表达基因主要富集在类囊体、色素结合和光合作用中;KEGG通路富集分析发现,Bd21 vs CO_OX的差异表达基因主要富集在植物激素信号转导、真核生物中的核糖体生物发生、光合作用-天线蛋白和昼夜节律-植物等通路,Bd21 vs CO_A3的差异表达基因主要富集在MAPK信号通路-植物、真核生物中的核糖体生物发生和光合作用-天线蛋白等通路;在长日照条件下,CO_OX植株的开花时间比野生型Bd21的提前约1.90 d,CO_A3植株的开花时间比野生型Bd21的延迟约7.92 d。综上,BdCO影响光周期途径相关基因的表达,同时影响二穗短柄草的开花时间,说明BdCO在二穗短柄草的光周期途径调控开花的过程中发挥重要作用。展开更多
The drought-tolerant grass Brachypodium distachyon is an emerging model species for temperate grasses and cereal crops. To explore the usefulness of this species for drought studies, a reproducible in vivo drought ass...The drought-tolerant grass Brachypodium distachyon is an emerging model species for temperate grasses and cereal crops. To explore the usefulness of this species for drought studies, a reproducible in vivo drought assay was developed. Spontaneous soil drying led to a 45% reduction in leaf size, and this was mostly due to a decrease in cell expansion, whereas cell division remained largely unaffected by drought. To investigate the molecular basis of the observed leaf growth reduction, the third Brachypodium leaf was dissected in three zones, namely proliferation, expan- sion, and mature zones, and subjected to transcriptome analysis, based on a whole-genome tiling array. This approach allowed us to highlight that transcriptome profiles of different developmental leaf zones respond differently to drought. Several genes and functional processes involved in drought tolerance were identified. The transcriptome data suggest an increased energy availability in the proliferation zones, along with an up-regulation of sterol synthesis that may influ-ence membrane fluidity. This information may be used to improve the tolerance of temperate cereals to drought, which is undoubtedly one of the major environmental challenges faced by agriculture today and in the near future.展开更多
Several temperate cereals need vernalization to promote flowering. Little, however, is known about the vernalization-memory-related genes, and almost no comparative analysis has been performed. Here, RNA- Seq was used...Several temperate cereals need vernalization to promote flowering. Little, however, is known about the vernalization-memory-related genes, and almost no comparative analysis has been performed. Here, RNA- Seq was used for transcriptome analysis in non-vernalized, vernalized and post-vernalized Brachypodium distachyon （L.） Beauv. seedlings. In total, the expression of 1,665 genes showed significant changes （fold change 〉4） in response to vernalization. Among them, 674 putative vernalization-memory-related genes with a constant response to vernalization were significantly enriched in transcriptional regulation and monooxygenase-mediated biological processes. Comparative analysis of vernalization-memory-related genes with barley demonstrated that the oxidative-stress response was the most conserved pathway between these two plant species. Moreover, Brachypodium preferred to regulate transcription and protein phosphorylation processes, while vernalization-memory-related genes, whose products are cytoplasmic membrane-bound-vesicle-located proteins, were preferred to be regulated in barley. Correlation analysis of the vernalization-related genes with barley revealed that the vernalization mechanism was conserved between these two plant species. In summary, vernalization, including its memory mechanism, is conserved between Brachypodium and barley, although several species-specific features also exist. The data reported here will provide primary resources for subsequent functional research in vernalization.展开更多
Plant responses to drought are regulated by complex genetic and epigenetic networks leading to rapid reprogramming of plant growth, miRNAs have been widely indicated as key players in the regulation of growth and deve...Plant responses to drought are regulated by complex genetic and epigenetic networks leading to rapid reprogramming of plant growth, miRNAs have been widely indicated as key players in the regulation of growth and development. The role of miRNAs in drought response was investigated in young leaves of Brachypodium dis- tachyon, a drought-tolerant monocot model species. Adopting an in vivo drought assay, shown to cause a dramatic reduction in leaf size, mostly due to reduced cell expansion, small RNA libraries were produced from proliferating and expanding leaf cells. Next-generation sequencing data were analyzed using an in-house bioinformatics pipeline allowing the identification of 66 annotated miRNA genes and 122 new high confidence predictions greatly expand- ing the number of known Brachypodium miRNAs. In addition, we identified four TAS3 loci and a large number of siRNA-producing loci that show characteristics suggesting that they may represent young miRNA genes. Most miR- NAs showed a high expression level, consistent with their involvement in early leaf development and cell identity. Proliferating and expanding leaf cells respond differently to drought treatment and differential expression analyses suggest novel evidence for an miRNA regulatory network controlling cell division in both normal and stressed condi-tions and demonstrate that drought trigger a genetic reprogramming of leaf growth in which miRNAs are deeply involved.展开更多
This work evaluates the phenotypic response of the model grass （Brachypodium distacbyon （L.） P. Beauv.） to nitrogen and phosphorus nutrition using a combination of imaging techniques and destructive harvest of sho...This work evaluates the phenotypic response of the model grass （Brachypodium distacbyon （L.） P. Beauv.） to nitrogen and phosphorus nutrition using a combination of imaging techniques and destructive harvest of shoots and roots. Reference line Bd21-3 was grown in pots using 11 phosphorus and 11 nitrogen concentrations to establish a dose-response curve. Shoot biovolume and biomass, root length and biomass, and tissue phosphorus and nitrogen concentrations increased with nutrient concentration. Shoot biovolume, estimated by imaging, was highly correlated with dry weight （R2 〉 0.92） and both biovolume and growth rate responded strongly to nutrient availability. Higher nutrient supply increased nodal root length more than other root types. Photochemical efficiency was strongly reduced by low phosphorus concentrations as early as 1 week after germination, suggesting that this measurement may be suitable for high throughput screening of phosphorus response. In contrast, nitrogen concentration had little effect on photochemical efficiency. Changes in biovolume over time were used to compare growth rates of four accessions in response tonitrogen and phosphorus supply. We demonstrate that a time series image-based approach coupled with mathematical modeling provides higher resolution of genotypic response to nutrient supply than traditional destructive techniques and shows promise for high throughput screening and determina- tion of genomic regions associated with superior nutrient use efficiency.展开更多
FKF1是响应蓝光节律表达的基因,是光周期途径调控植物开花的重要因子之一。为探索BdFKF1基因在光周期途径中调控烟草植株开花的分子机制,该研究以野生型烟草(SR1)和转BdFKF1基因烟草(BdFKF1-OE)植株为材料,利用转录组学测序技术并进行RT...FKF1是响应蓝光节律表达的基因,是光周期途径调控植物开花的重要因子之一。为探索BdFKF1基因在光周期途径中调控烟草植株开花的分子机制,该研究以野生型烟草(SR1)和转BdFKF1基因烟草(BdFKF1-OE)植株为材料,利用转录组学测序技术并进行RT-qPCR验证,观测并记录2种材料的开花时间。结果表明:(1)在SR1 vs FKF1组中,共筛选出472个差异表达基因,包括上调基因248个、下调基因224个,其中与光周期相关的差异表达基因有14个,包括上调基因7个、下调基因7个。(2)GO富集分析发现,差异表达基因大量富集在U5小核核糖核蛋白体和氧化还原酶活性,作用于成对供体和蓝光反应等通路中,其中与光周期相关的差异表达基因主要富集在FK506结合、光周期和开花、光周期、磷脂酰乙醇胺结合、大环内酯结合、花发育调控等通路中。(3)KEGG富集分析发现,差异表达基因主要富集在ABC转运蛋白、内质网中的蛋白质加工、角质,木栓素和蜡的生物合成、昼夜节律-植物等通路中,其中与光周期相关的差异表达基因主要富集在植物激素信号转导、昼夜节律-植物通路中。(4)通过观察记录发现BdFKF1-OE植株开花时间比SR1提前3.9 d。(5)RT-qPCR结果与转录组学数据变化趋势基本一致,表明转录组数据有较高的可靠性。综上认为,在长日照条件下,BdFKF1基因会影响光周期途径相关基因的表达,同时过表达BdFKF1基因具有促进烟草植株开花的作用。展开更多
基金Financial support was provided by the National Natural Science Foundation of China (31371688)
文摘Sugarcane mosaic virus (SCMV;genus Potyvirus, family Potyviridae) is a causal pathogen of sugarcane mosaic disease, and it is widespread in regions where sugarcane (Saccharum spp. hybrids) is grown. It is difficult to investigate the molecular mechanism of pathogen infection in sugarcane because of limited genomic information. Here, we demonstrated that SCMV strain FZ1 can systemically infect Brachypodium distachyon inbred line Bd21 and Nicotiana benthamiana through inoculation, double antibody sandwich enzyme-linked immunosorbent, transmission electron microscopy, and reverse transcription PCR assays. The leaves of Bd21 developed mosaic symptoms, while the leaves of N. benthamiana showed no obvious symptoms under the challenge of SCMV-FZ1. We concluded that B. distachyon inbred line Bd21 is a promising experimental model plant compared with N. benthamiana for study on the infectivity of SCMV. This is the first report on the SCMV infection of model plants B. distachyon inbred line Bd21 and N. benthamiana, which will shed light on the mechanism of SCMV infection of sugarcane and benefit sugarcane breeding against sugarcane mosaic disease.
文摘Inoculation methods for rice blast fungus Magnaporthe oryzae to Brachypodium distachyon were developed to investigate the infection process and symptom development in comparison with those on rice （Oryza sativa） and barley （Hordeum vulgare）.M.oryzae could infect leaves,sheathes,stems and panicles of B.distachyon and cause blast disease.Spraying conidial suspension on either intact seedlings or leaf segments induced typical symptoms on B.distachyon.During the intact seedling inoculation,the symptom developed on B.distachyon leaves closely resembled that on rice;but the lesions on B.distachyon had better uniformity in shapes and sizes than those on rice or barley.In the leaf segments inoculation,only initial and low-developed lesions could be found on rice,while normal symptoms on B.distachyon and barley.Inoculated with low-virulent mutants of M.oryzae,B.distachyon produced low-level symptoms.The symptom level of each mutant on B.distachyon corresponded well to that on rice.In addition,typical infection processes presented on B.distachyon leaves：forming melanized appressoria,penetrating into host epidermis and then forming hyphae in epidermal cells.According to these results,B.distachyon can be used as a candidate for studying fungus-plant interactions and as a probable source of disease resistance.
基金supported by the National Natural Science Foundation of China(No.31210103902)
文摘Barley stripe mosaic virus(BSMV) is the type member of the genus Hordeivirus. Brachypodium distachyon line Bd3-1 shows resistance to the BSMV ND18 strain, but is susceptible to an ND18 double mutant(βNDTGB1R390K, T392K) in which lysine is substituted for an arginine at position 390 and for threonine at position 392 of the triple gene block 1(TGB1) protein. In order to understand differences in gene expression following infection with ND18 and double mutant ND18, Bd3-1 seedlings were subjected to RNA-seq analyses at 1, 6, and14 days post inoculation(dpi). The results revealed that basal immunity genes involved in cellulose synthesis and pathogenesis-related protein biosynthesis were enhanced in incompatible interactions between Bd3-1 and ND18. Most of the differentially expressed transcripts are related to trehalose biosynthesis, ethylene, jasmonic acid metabolism,protein phosphorylation, protein ubiquitination, transcriptional regulation, and transport process, as well as pathogenesis-related protein biosynthesis. In compatible interactions between Bd3-1 and ND18 mutant, Bd3-1 developed weak basal resistance responses to the virus. Many genes involved in cellulose biosynthesis, protein amino acid phosphorylation,protein biosynthesis, protein glycosylation, glycolysis and cellular macromolecular complex assembly that may be related to virus replication, assembly and movement were up-regulated. Some genes involved in oxidative stress responses were also up-regulated at14 dpi. BSMV ND18 mutant infection suppressed expression of genes functioning in regulation of transcription, protein kinase, cellular nitrogen compound biosynthetic process and photosynthesis. Differential expression patterns between compatible and incompatible interactions in Bd3-1 to the two BSMV strains provide important clues for understanding mechanism of resistance to BMSV in the model plant Brachypodium.
文摘Southwestern China is abundant in a large species diversity of grasses and Brachypodium sylvaticum var. breviglume is unquestionably appropriate to serve as an ideal model to investigate the adaptation, evolution and diversification of grasses in this region. In this study, a total of 37 microsatellite markers were screened and genetic variation was estimated for 100 individuals from the five natural populations of the species. Our results showed that seven of them were polymorphic for the five studied populations, while the other thirty were monomorphic. These seven SSR loci exhibited a high level of genetic diversity among populations, i.e. allele number varied from 5 to 24, with an average of 13.29;expected heterozygosity (He) ranged from 0.439 to 0.561, with an average of 0.488;percentage of polymorphic loci (PPL) ranged from 85.71% to 100%, with an average of 97. 14%. The FCA and UPGMA analyses revealed that the five populations were divided into three clusters. Our results indicate that these newly characterized SSR markers are useful for the exploration of genetic diversity and evolutionary history of the B. sylvaticum var. breviglume populations in Yunnan, China.
基金funded by the Natural Science Foundation of Hubei Province,China(2019CFB388)the Guiding Project of Scientific Research Plan of the Hubei Provincial Department of Education(B2022007).
文摘As sessile organisms,plants possess a complex system to cope with environmental changes.Ca^(2+)functions as a vital second messenger in the stress signaling of plants,and the CBL-interacting protein kinases(CIPKs)serve as essential elements in the plant Ca^(2+)signaling pathway.In this study,calcineurin B-like protein-interacting protein kinase 26(BdCIPK26)from Brachypodium distachyon was characterized.Overexpression of BdCIPK26 enhanced tolerance to drought and salt stress of transgenic plants.Further investigations revealed that BdCIPK26 participated in abscisic acid(ABA)signaling,conferred hypersensitivity to exogenous ABA in transgenic plants,and promoted endogenous ABA biosynthesis.Moreover,BdCIPK26 was found to maintain ROS homeostasis in plants under stress conditions.Therefore,this study indicates that BdCIPK26 functions as a positive regulator in drought and salt stress response.
文摘The rice Wsi18 promoter confers drought-inducible gene expression. This property makes it a useful candidate to drive relevant genes for developing drought resistant traits for different monocot crops. In this study, we showed that the Bradi2G47700 gene, the closest homologue to rice Wsi18, was upregulated in Brachypodium distachyon plants exposed to ABA and mannitol. Wsi18: uidA transgenic B. distachyon plants were produced and then subjected to ABA or mannitol treatment. The expression of uidA in three transgenic lines (line 10, 18 and 37) was significantly upregulated in plants exposed to ABA (fold increases of 5.61 ± 0.98, 2.88 ± 0.75 and 9.13 ± 1.96, respectively) compared to the same transgenic plant lines without treatment. The expression of uidA in two transgenic lines (lines 18 and 37) also showed upregulation when treated with mannitol (fold increases of 4.43 ± 1.07 and 8.47 ± 2.90, respectively) compared to the same transgenic plant lines without mannitol treatment. Moreover, GUS histochemical assay showed increased Wsi18 promoter activity in the leaves and stems of transgenic lines upon treatment with ABA or mannitol. This is the first report of the drought inducible rice Wsi18 promoter being active in B. distachyon which is a model plant for molecular biology research of various monocot plants. Taken together, the results indicate that the Wsi18 promoter and its homologue may be explored as a useful tool for drought stress-inducible gene expression in different monocot crops.
基金Scientific Research Foundation for Ph.D.Programs of Zaozhuang University(21/1020708)Science and Technology Program of Zaozhuang(2020NS20)+1 种基金Project of Shandong Province Higher Educational Science and Technology Program(J18KA134)Shandong Provincial Natural Science Foundation(ZR2019PC011).
文摘Beckmannia syzigachne is a noxious weed for rice-wheat rotations in China.The B.syzigachne(AH-02)population evolved metabolic resistance to fenoxaprop-P-ethyl and mesosulfuron-methyl.To investigate the function of GT73C1 in this population,the GT73C1 gene was amplified by reverse transcription-polymerase chain reaction,and the sequence was 100%consistent with the transcriptome data.Its phylogenetic tree was displayed and annotated using FigTree v1.4.4.The plant overexpression vector of GT73C1 gene was constructed and used to transform Brachypodium distachyon plants.Furthermore,the expression of GT73C1 was significantly induced by fenoxaprop-P-ethyl and mesosulfuron-methyl,which was consistent with the findings from the whole plant bioassay.These results indicate that GT73C1 is closely related to the metabolic resistance of B.distachyon.
基金funded by the National Key Basic Research Program of China (2013CB127501)the Special Fund for Agro-scientific Research in the Public Interest in China (201503114 and 200903040)the National Key Research and Development Program of China (SQ2017ZY060063-01)
文摘Cereal cyst nematode（Heterodera avenae, CCN） distributes worldwide and has caused severe damage to cereal crops, and a model host will greatly aid in the study of this nematode. In this research, we assessed the sensitivity of 25 inbred lines of Brachypodium distachyon to H. avenae from Beijing, China. All lines of B. distachyon were infested by secondstage juveniles（J2s） of H. avenae from Daxing District of Beijing population, but only 13 inbred lines reproduced 0.2–3 cysts/plant, showing resistance. The entire root system of the infested B. distachyon appeared smaller and the fibrous roots were shorter and less numerous. We found that a dose of 1 000 J2s of H. avenae was sufficient for nematode infestation. We showed that Koz-1 of B. distachyon could reproduce more cysts than TR2A line. Line Koz-1 also supported the complete life cycles of 5 CCN geographical populations belonging to the Ha1 or Ha3 pathotype group. Our results suggest that B. distachyon is a host for CCN.
文摘CONSTANS(CO)是植物光周期诱导开花途径中的关键基因之一。为探究BdCO在光周期途径中的分子调控机制,本研究对野生型二穗短柄草(Brachypodium distachyon)Bd21植株、过表达BdCO基因型二穗短柄草(CO_OX)植株和BdCO基因敲除型二穗短柄草(CO_A3)植株进行转录组测序分析,对差异表达基因进行GO和KEGG功能富集分析,最后观察三种植株的开花表型。结果表明,对比Bd21 vs CO_OX和Bd21 vs CO_A3的基因表达量,分别检测到1382个和773个差异表达基因;GO功能富集分析发现,Bd21 vs CO_OX的差异表达基因主要富集在小核仁核糖核蛋白复合物、snoRNA结合和rRNA处理中,Bd21 vs CO_A3的差异表达基因主要富集在类囊体、色素结合和光合作用中;KEGG通路富集分析发现,Bd21 vs CO_OX的差异表达基因主要富集在植物激素信号转导、真核生物中的核糖体生物发生、光合作用-天线蛋白和昼夜节律-植物等通路,Bd21 vs CO_A3的差异表达基因主要富集在MAPK信号通路-植物、真核生物中的核糖体生物发生和光合作用-天线蛋白等通路;在长日照条件下,CO_OX植株的开花时间比野生型Bd21的提前约1.90 d,CO_A3植株的开花时间比野生型Bd21的延迟约7.92 d。综上,BdCO影响光周期途径相关基因的表达,同时影响二穗短柄草的开花时间,说明BdCO在二穗短柄草的光周期途径调控开花的过程中发挥重要作用。
文摘The drought-tolerant grass Brachypodium distachyon is an emerging model species for temperate grasses and cereal crops. To explore the usefulness of this species for drought studies, a reproducible in vivo drought assay was developed. Spontaneous soil drying led to a 45% reduction in leaf size, and this was mostly due to a decrease in cell expansion, whereas cell division remained largely unaffected by drought. To investigate the molecular basis of the observed leaf growth reduction, the third Brachypodium leaf was dissected in three zones, namely proliferation, expan- sion, and mature zones, and subjected to transcriptome analysis, based on a whole-genome tiling array. This approach allowed us to highlight that transcriptome profiles of different developmental leaf zones respond differently to drought. Several genes and functional processes involved in drought tolerance were identified. The transcriptome data suggest an increased energy availability in the proliferation zones, along with an up-regulation of sterol synthesis that may influ-ence membrane fluidity. This information may be used to improve the tolerance of temperate cereals to drought, which is undoubtedly one of the major environmental challenges faced by agriculture today and in the near future.
基金supported by the Main Direction Program of Knowledge Innovation of the Chinese Academy of Sciences(KSCX2-EW-J -1)the National Natural Science Foundation of China (30970241)
文摘Several temperate cereals need vernalization to promote flowering. Little, however, is known about the vernalization-memory-related genes, and almost no comparative analysis has been performed. Here, RNA- Seq was used for transcriptome analysis in non-vernalized, vernalized and post-vernalized Brachypodium distachyon （L.） Beauv. seedlings. In total, the expression of 1,665 genes showed significant changes （fold change 〉4） in response to vernalization. Among them, 674 putative vernalization-memory-related genes with a constant response to vernalization were significantly enriched in transcriptional regulation and monooxygenase-mediated biological processes. Comparative analysis of vernalization-memory-related genes with barley demonstrated that the oxidative-stress response was the most conserved pathway between these two plant species. Moreover, Brachypodium preferred to regulate transcription and protein phosphorylation processes, while vernalization-memory-related genes, whose products are cytoplasmic membrane-bound-vesicle-located proteins, were preferred to be regulated in barley. Correlation analysis of the vernalization-related genes with barley revealed that the vernalization mechanism was conserved between these two plant species. In summary, vernalization, including its memory mechanism, is conserved between Brachypodium and barley, although several species-specific features also exist. The data reported here will provide primary resources for subsequent functional research in vernalization.
文摘Plant responses to drought are regulated by complex genetic and epigenetic networks leading to rapid reprogramming of plant growth, miRNAs have been widely indicated as key players in the regulation of growth and development. The role of miRNAs in drought response was investigated in young leaves of Brachypodium dis- tachyon, a drought-tolerant monocot model species. Adopting an in vivo drought assay, shown to cause a dramatic reduction in leaf size, mostly due to reduced cell expansion, small RNA libraries were produced from proliferating and expanding leaf cells. Next-generation sequencing data were analyzed using an in-house bioinformatics pipeline allowing the identification of 66 annotated miRNA genes and 122 new high confidence predictions greatly expand- ing the number of known Brachypodium miRNAs. In addition, we identified four TAS3 loci and a large number of siRNA-producing loci that show characteristics suggesting that they may represent young miRNA genes. Most miR- NAs showed a high expression level, consistent with their involvement in early leaf development and cell identity. Proliferating and expanding leaf cells respond differently to drought treatment and differential expression analyses suggest novel evidence for an miRNA regulatory network controlling cell division in both normal and stressed condi-tions and demonstrate that drought trigger a genetic reprogramming of leaf growth in which miRNAs are deeply involved.
基金supported by the Office of Science (BER), U.S. Department of Energy through Interagency Agreement DE-SC0001526the Australian Grain Research and Development Corporation (GRDC)
文摘This work evaluates the phenotypic response of the model grass （Brachypodium distacbyon （L.） P. Beauv.） to nitrogen and phosphorus nutrition using a combination of imaging techniques and destructive harvest of shoots and roots. Reference line Bd21-3 was grown in pots using 11 phosphorus and 11 nitrogen concentrations to establish a dose-response curve. Shoot biovolume and biomass, root length and biomass, and tissue phosphorus and nitrogen concentrations increased with nutrient concentration. Shoot biovolume, estimated by imaging, was highly correlated with dry weight （R2 〉 0.92） and both biovolume and growth rate responded strongly to nutrient availability. Higher nutrient supply increased nodal root length more than other root types. Photochemical efficiency was strongly reduced by low phosphorus concentrations as early as 1 week after germination, suggesting that this measurement may be suitable for high throughput screening of phosphorus response. In contrast, nitrogen concentration had little effect on photochemical efficiency. Changes in biovolume over time were used to compare growth rates of four accessions in response tonitrogen and phosphorus supply. We demonstrate that a time series image-based approach coupled with mathematical modeling provides higher resolution of genotypic response to nutrient supply than traditional destructive techniques and shows promise for high throughput screening and determina- tion of genomic regions associated with superior nutrient use efficiency.
文摘FKF1是响应蓝光节律表达的基因,是光周期途径调控植物开花的重要因子之一。为探索BdFKF1基因在光周期途径中调控烟草植株开花的分子机制,该研究以野生型烟草(SR1)和转BdFKF1基因烟草(BdFKF1-OE)植株为材料,利用转录组学测序技术并进行RT-qPCR验证,观测并记录2种材料的开花时间。结果表明:(1)在SR1 vs FKF1组中,共筛选出472个差异表达基因,包括上调基因248个、下调基因224个,其中与光周期相关的差异表达基因有14个,包括上调基因7个、下调基因7个。(2)GO富集分析发现,差异表达基因大量富集在U5小核核糖核蛋白体和氧化还原酶活性,作用于成对供体和蓝光反应等通路中,其中与光周期相关的差异表达基因主要富集在FK506结合、光周期和开花、光周期、磷脂酰乙醇胺结合、大环内酯结合、花发育调控等通路中。(3)KEGG富集分析发现,差异表达基因主要富集在ABC转运蛋白、内质网中的蛋白质加工、角质,木栓素和蜡的生物合成、昼夜节律-植物等通路中,其中与光周期相关的差异表达基因主要富集在植物激素信号转导、昼夜节律-植物通路中。(4)通过观察记录发现BdFKF1-OE植株开花时间比SR1提前3.9 d。(5)RT-qPCR结果与转录组学数据变化趋势基本一致,表明转录组数据有较高的可靠性。综上认为,在长日照条件下,BdFKF1基因会影响光周期途径相关基因的表达,同时过表达BdFKF1基因具有促进烟草植株开花的作用。
