[Objective] The aim was to explore the effects of drought stress on germination of tall fescue.[Method] Simulation drought experiment on 14 varieties of tall fescue seeds by PEG-6000 researched its germination effect ...[Objective] The aim was to explore the effects of drought stress on germination of tall fescue.[Method] Simulation drought experiment on 14 varieties of tall fescue seeds by PEG-6000 researched its germination effect under drought resistance.[Result] The relative germination rate of all tall fescue varieties declined with intensifying drought stress level with the water potential of-0.6 Mpa as the turning point;the relative germination rate of tall fescue existed linear relationship with drought stress：Y = 70.412X ＋ 103.11,r=0.988 8.The sensible water potential range was ≥-0.40 Mpa for tall fescue under drought stress.LC50 of water potential was-0.76 Mpa,the lethal water potential was-1.33 Mpa.Arid Ⅲ,Crossfire Ⅱ and Traple A had stronger drought resistant ability,but Pixie,Infero and Poppoint had weaker drought resistant ability.[Conclusion] This study had provided reference for cultivated pasture and drought resistant breeding.展开更多
ObjectiveThe aim was to explore the movement of nitrate nitrogen in tall-fescue soils by different kinds of slow release nitrogen fertilizers. MethodBased on infiltration-tanks and test plots, a new and environment fr...ObjectiveThe aim was to explore the movement of nitrate nitrogen in tall-fescue soils by different kinds of slow release nitrogen fertilizers. MethodBased on infiltration-tanks and test plots, a new and environment friendly fertilizer was explored. ResultThe results show that compared with urea treatment, slow-release nitrogen fertilizer treatments could reduce nitrate nitrogen content and leaching amount in soils. Compared with PCU30 and IU treatments, the PCU60 treatment became more efficient in reducing nitrate content and leaching amount in 0-90 cm soil layer. ConclusionIn summary, slow-release nitrogen fertilizer, which can reduce soil nitrate content and leaching losses, is a kind of novel fertilizer with high environmental benefit and promising application.展开更多
In order to improve stress tolerances of turf-type tall fescue （Festuca arundinacea Schreb.）, Agrobacterium tumefaciens strain EHA105 carrying plasmid pCMD containing stress tolerance-related CBF1 gene from Arabidop...In order to improve stress tolerances of turf-type tall fescue （Festuca arundinacea Schreb.）, Agrobacterium tumefaciens strain EHA105 carrying plasmid pCMD containing stress tolerance-related CBF1 gene from Arabidopsis thaliana was used to transform mature seeds-derived embryogenic calli of four cultivars. A total of 112 transgenic plants were regenerated from 32 independent lines and verified by histochemical detection of GUS activity, PCR assay and Southern hybridization analysis. The transformation frequency ranged from 0.92 to 2.87% with apparent differences among the cultivars. Stress tolerances of transgenic plants were enhanced, which was shown by the facts that transgenic plants had distinct growth superiority and significantly higher survival rate than non-transformed ones under high salinity and high osmosis stresses, and that relative electronic conductivity of in vitro leaves treated with low and high temoeratures, dehvdration and high salinity stresses was 25-30% lower in transgenic plants than in control plants.In addition,it was observed that growth of transgenic plants was inhibited due to constitutive overexpression of CBF1 gene under normal environmental conditions.展开更多
By assay of accelerated aging germination, germination index, vigor index, seedling length, seedling weight, electric conductivity, dehydrogenase activity, ATP content and acid phosphoesterase activity during seed dev...By assay of accelerated aging germination, germination index, vigor index, seedling length, seedling weight, electric conductivity, dehydrogenase activity, ATP content and acid phosphoesterase activity during seed development of turf-type tall fescue, the seed vigor of tall fescue were studied. Combining with seed moisture content and yield, the optimal harvesting time of tall fescue was determined. The results indicated that the seed vigor increased continuously along with seed maturity, and the higher seed vigor was achieved at 19th day after perk anthesis and maintained continuously until 31st day after peak anthesis. At 25th day after peak anthesis, the highest yield of 3 533 kg ha-1 and the good quality of seeds of tall fescue were harvested with 32.19% moisture content. From 22nd to 31st day after peak anthesis, the seed yield of 3 300 kg ha-1 and the good quality seeds of tall fescue were harvested with 40 - 12. 43% moisture content, and the span was the optimal harvesting time.展开更多
Tall fescue （Festuca arundinacea Schreb.） is a cool-season turfgrass used on fairways in golf courses. The object of this study was to develop a more efficient, reliable, and repeatable approach in transforming the ...Tall fescue （Festuca arundinacea Schreb.） is a cool-season turfgrass used on fairways in golf courses. The object of this study was to develop a more efficient, reliable, and repeatable approach in transforming the grass using Agrobacterium （EHA105）, where β-glucuronidase gene （uidA） was used as a reporter and hygromycin phosphotransferase gene （hyg） as a selectable marker. An effective expression of transgene was observed in transforming 2-month-old calli derived from mature seeds （cv. Bingo） cultured on MS medium supplemented with 9 mg·L^-1 2, 4-D. A two-step solid medium selection with increasing hygromycin concentration （from 30 to 50 mg· L^-1） was used to obtain resistant calli. Transgenic plants have been produced from many independent transformed calli. The presence of functional β-glucuronidase gene （uidA） was detected in hygromycin-resistant calli. Transgenic plants were regenerated and PCR and Southern blot confirmed transgene integration in the tall fescue genome.展开更多
Abstract The metabolites of tall fescue leaves under normal and drought conditions were analyzed with LC-ESI-MS （ liquid chromatography tandem mass spec- trometry）. A total of 282 metabolites were stably detected in...Abstract The metabolites of tall fescue leaves under normal and drought conditions were analyzed with LC-ESI-MS （ liquid chromatography tandem mass spec- trometry）. A total of 282 metabolites were stably detected in the two groups using OPI.S-DA （orthogonal partial least squares discriminant analysis） method; 148 of which were down-regulated while 134 were up-regulated. After analyzed with MZ-minc software, 10 major metabolites （4 down, 6 up） were identified through searehing public database. Aromatic compounds, 3-p-eoumaroyll, 5-quinolaetone, aromatic free amino acids, styraxin mad methanofuran, were up-regulated ; grease metabolites, methyl 15-hydroperoxy-9Z, 12Z, 16E-octadecatrienoate, 9,12,13-Tri-HOME （10）, 3-oxo-dodecanoic acid, and 13 （S）-HpOTrE acid ester, were down-regulated; piperanine （alkaloids） was down-regulated while Methyl 7-epi-12-hydroxyjasmonate glucoside （indicant） was up-regulated. In a word, aromatic compounds and liquid metabolites may play vital roles in drought-resistant regulation of tall fescue.展开更多
[Objective] The differential expression analysis was performed for FaGF14- B and FaGF14-C genes in tall fescue so as to provide certain basis for follow-up functional analysis of genes. [Method] The sequence fragments...[Objective] The differential expression analysis was performed for FaGF14- B and FaGF14-C genes in tall fescue so as to provide certain basis for follow-up functional analysis of genes. [Method] The sequence fragments of FaGF14-B and FaGF14-C obtained from reverse transcription were used as templates, and the full- length cDNA sequences of FaGF14-B and FaGF14-C were amplified using the 5＇ RACE use 3＇RACE techniques. They were named as FaGF14-B and FaGF14-C, and used for nucleic acid sequence analysis, encoded protein analysis, protein con- served domain analysis, phylogenetic analysis and differential expression analysis. [Result] The FaGF14-B gene has a full length of 1 548 bp. It has a complete open reading frame （ORF, 449-1 228 bp）, and encodes a protein composed of 261 amino acids. The FaGF14-C gene has a full length of 1 250 bp. It also has a complete open reading frame （ORF, 66-848 bp）, and encodes a protein composed of 261 amino acids. The GF14-B and GF14-C proteins all have a typical domain 14-3-3, and their secondary structures all contain 9 conserved co-helical structures and non-conserved N- and C- terminals. The phylogenetic analysis showed that the FaGF14-B and FaGF14-C from tall rescue have high similarities with GF14 protein from gramineous plants, and they are divided into the same clade with closer ge- netic relationship. The real-time fluorescence quantitative PCR analysis showed that the expression of FaGF14-B and FaGF14-C genes is all sensitive to nitrogen stress. [Conclusion] This study will lay a theoretical basis for further screening of low nitrogen-tolerant genes and breeding of low nitrogen-tolerant grass germplasms.展开更多
To study the functions of 14-3-3 gene family in tall fescue, the potential functions of 13 14-3-3 proteins in Arabidopsis were investigated by bioinformatic analysis. Based on the sequences of 14-3-3 genes in tall fes...To study the functions of 14-3-3 gene family in tall fescue, the potential functions of 13 14-3-3 proteins in Arabidopsis were investigated by bioinformatic analysis. Based on the sequences of 14-3-3 genes in tall fescue by transcriptome and proteomic sequencing, the full-length cDNA sequences of 4 14-3-3 genes in tall fescue were obtained. Their sequences were aligned by Clustal W2. The results showed that the genetic relationships between 14-3-3A and 14-3-3D, 14-3-3B and 14-3-3C are closer, and their main structures are very conservative. The changes in expression levels of 14-3-3 genes under low nitrogen, drought, high temperature and high salt stresses were investigated by fluorescence quantitative PCR. The expres- sion level of 14-3-3A makes responses to low nitrogen, drought, high temperature and high salt stresses; the expression levels of other genes also make responses to abiotic stresses in varying degrees, but the relevant response mechanisms are not exactly the same. Therefore, it is speculated that the 14-3-3 gene family regu- lates stress resistance of plants through different pathways, and functional differenti- ation occurs during its evolution.展开更多
[Objective] This study was to construct RNAi expression vector targeting FaVRN1 gene. [Method] A 145 bp Arabidopsis actin intron was inserted into the expression vector to generate an intermediate vector pBI121-M-INT....[Objective] This study was to construct RNAi expression vector targeting FaVRN1 gene. [Method] A 145 bp Arabidopsis actin intron was inserted into the expression vector to generate an intermediate vector pBI121-M-INT. And then two pairs of specific primers with enzyme restriction sites spanning a 351 bp cDNA conserved sequence fragment of FaVRN1 gene were designed for RT-PCR to construct RNAi expression cassette. The amplified fragment was inserted forwardly and reversely at two sides of the intron to construct an RNAi expression vector with hairpin structure. [Result] Double enzyme digestion（HindIII＋BamHI） showed the intron had been successfully into the vector pBI121. PCR amplification and double enzyme digestion indicated the success of forward and reverse ligation of target FaVRN1 fragment into the intermediate vector. [Conclusion] This study laid foundation for breeding novel flowering-inhibited tall fescue varieties.展开更多
Heat stress in summer is a major factor limiting use of cool-season grasses in Shanghai area, China. The objectives of this study were to investigate effects of a crude extract product of a new strain of Streptomyces ...Heat stress in summer is a major factor limiting use of cool-season grasses in Shanghai area, China. The objectives of this study were to investigate effects of a crude extract product of a new strain of Streptomyces microflavus (TSS) on turf performance and physiological activities of tall fescue (Festuca arundinacea) in response to heat stress. Plants of tall fescue cultivar ‘Barlexus’ were exposed to 38/33 (°C) (day/night) high temperature in growth chamber after TSS applications. High temperature induced about 3.5 fold increases of initial shoot extension rate and clipping yield (6 d) and led to quick decline of plant growth after 18 d. TSS inhibited the extent of initial increases of shoot extension rate and clipping yield and maintained a longer period of steady growth under the heat stress. TSS also decreased the decline of leaf chlorophyll content, TNC, shoot density, and turf quality induced by heat stress. The results suggested that TSS application improved turf performance under heat stress, and the greater improvement of heat tolerance was associated with higher dose of application. This positive effect on heat tolerance could be related to the decreased carbohydrate consumption and loss, and reduced decomposition of leaf chlorophyll.展开更多
The sequence fragment of PHYA, obtained from transcriptome sequencing,was used as the template, and the full-length c DNA sequence of PHYA gene in tall fescue was amplified using 3＇RACE and 5＇RACE techniques. The c ...The sequence fragment of PHYA, obtained from transcriptome sequencing,was used as the template, and the full-length c DNA sequence of PHYA gene in tall fescue was amplified using 3＇RACE and 5＇RACE techniques. The c DNA sequence of PHYA gene has a complete open reading frame（ORF, 293-6 682 bp）, and it encodes a protein composed of 1 129 amino acids. The N-terminal of Fa PHYA is composed of GAF and Phytochrome domains, and its C-terminal contains two repeated PAS domains, one histidine kinase A domain and one histidine kinase-like ATPase domain. The homology analysis showed that the amino acid sequences of Fa PHYA of tall fescue and PHYAs of gramineous plants have higher homologies（85%）, indicating close genetic relationships. However, the homologies between FaPHYA of tall fescue and PHYAs of monocotyledons are lower, indicating far genetic relationships.展开更多
Forages generally suffer more severe nutrition stress than other crops, but the corresponding theoretical studies still lag behind. In this study, metabo- lites in tall fescue leaves under normal and low nitrogen cond...Forages generally suffer more severe nutrition stress than other crops, but the corresponding theoretical studies still lag behind. In this study, metabo- lites in tall fescue leaves under normal and low nitrogen conditions were analyzed with LC-ESI-MS （ liquid chromatography-electrospray ionization-mass spectrome- try）. A total of 1 424 and 1 251 metabolites were detected from two groups of samples respectively using OPLS-DA （orthogonal partial least squares discriminant analysis）. The content of 13 major metabolites changed under low nitrogen stress, including auxin （indale acetic acid, IAA）. Quantitative real-time PCR （qRT- PCR） showed that eight genes related to IAA signaling pathway were up-regulated after nitrogen stress. Enzyme-linked immuno sorbent assay （ELISA） revealed that the IAA concentration was elevated in tall fescue leaves after nitrogen stress. Our research provides valuable information for studying the response mechanisms of tall feseue to low nitrogen. The results suggest that application of IAA could be used to alleviate the harmful effects of nitrogen deficiency.展开更多
Tal fescue （Festuca arundinacea Schreb.） is an important cool-season forage grasses and turfgrasses at home and abroad. In order to provide a reference for tal fescue breeding, we reviewed the genetic constitution a...Tal fescue （Festuca arundinacea Schreb.） is an important cool-season forage grasses and turfgrasses at home and abroad. In order to provide a reference for tal fescue breeding, we reviewed the genetic constitution and heritability, endo-phytic fungi and new tal fescue variety breeding, application of modern biological technology （expressed sequence tag, genetic linkage map construction and trans-genic breeding） in breeding new varieties of tal fescue and the breeding status of tal fescue in Guizhou region.展开更多
[Objective] This study aimed to investigate the physiological characteristics of tall fescue under nitrogen stress. [Method] A series of physiological changes in protein content, chlorophyll content, enzyme activities...[Objective] This study aimed to investigate the physiological characteristics of tall fescue under nitrogen stress. [Method] A series of physiological changes in protein content, chlorophyll content, enzyme activities and amino acids contents in tall fescue under nitrogen stress were analyzed. [Result] Under nitrogen stress, the leaf chlorophyll content in tall fescue was reduced, and superoxide dismutase（SOD）,peroxidase（POD）, glutamine synthetase（GS） activities were increased. Among the 18 kinds of amino acids analyzed, the contents of asparagine, serine, glycine, glutamine, glutamic acid, aspartic acid, threonine, alanine, arginine, methionine, valine,isoleucine and leucine were significantly reduced in tall fescue under nitrogen stress.[Conclusion] This study will provide certain reference for rational application of nitrogen and exploration of plant ecological potential in the future.展开更多
[ Objective ] This study aimed to construct RNAi expression vector targeting vemalizational gene FaCONSTANS （GenBank accession number： GU214996） in tall rescue. [ Method] A 145 bp long Arabidopsis actin gene intron...[ Objective ] This study aimed to construct RNAi expression vector targeting vemalizational gene FaCONSTANS （GenBank accession number： GU214996） in tall rescue. [ Method] A 145 bp long Arabidopsis actin gene intron was inserted into the expression vector to construct an intermediate vector pBI121-M-INT. Two pairs of specific primers with restriction sites were designed to amplify a 351 bp long cDNA conserved sequence fragment of vemalizational gene FaCONSTANS for RT-PCR. After restriction enzyme digestion, the amplified fragment was inserted forwardly and reversely at two sides of the intron of intermediate vector to construct an RNAi expression vector with hairpin structure. [ Result ] Double digestion （HindIII ＋ BamHI） showed that the intron was successfully insert- ed into the vector pBI121. PCR amplification and double digestion indicated that target fragment FaCONSTANS was successfully inserted forwardly and reversely in- to the intermediate vector. [ Conclusion] This study laid foundation for breeding novel flowering-inhibited tall rescue cultivars.展开更多
Endophyte infected tall fescue (E+) is the base diet for nearly all beef cattle in the southern USA. It has been linked to a variety of toxicological conditions due to the presence of large numbers of ergot alkaloids....Endophyte infected tall fescue (E+) is the base diet for nearly all beef cattle in the southern USA. It has been linked to a variety of toxicological conditions due to the presence of large numbers of ergot alkaloids. This study was designed to investigate the effects of E+ seed extract and selected ergot alkaloids on the detoxification pathway by cytochrome P450 (CYP3A4) enzyme system. Tests were performed using the P450- Glo CYP3A4 enzyme activity kit (Promega, WI), according to the manufacturer’s manual. Luminescence was measured using a single tube TD20/20 luminometer. Endophyte infected tall fescue seed was extracted with 50/50 methanol/25 mM ammonium carbonate, cleaned and concentrated on Strata-X reversed phase column (Phenomenex). The extracts were evaluated on an HPLC, and then tested using a serial dilution method. Commercially available ergonovine (EN), ergocorine (ER), bromocryptine (BC) and ergocryptine (EC) were tested individually using 0 to 44 nM concentrations. Seed extract of E+ produced a significant (P P < 0.05) dose dependent manner with EC being most potent, followed by ER, BC, and then EN (70%, 40%, 30% and 10% at 44 nM concentration). The similarity of the inhibition curves of seed extract to that of the commercially available ergot alkaloids suggests a related mode of action and that the use of such ergot alkaloids and CYP3A4 assay is a good model to study the toxicity of tall fescue. Furthermore, it provides the foundation to identify the individual toxic components of purified endophyte infected tall fescue extract.展开更多
Background:Meadow fescue(Schedonorus pratensis(Huds.)P.Beauv.)is a reemerging pasture grass for temperate regions of North America.One disadvantage of this species is its lack of tolerance to frequent defoliation at l...Background:Meadow fescue(Schedonorus pratensis(Huds.)P.Beauv.)is a reemerging pasture grass for temperate regions of North America.One disadvantage of this species is its lack of tolerance to frequent defoliation at low residual sward heights.This experiment was designed to conduct one cycle of selection and evaluation for persistence under frequent defoliation.Methods:The experiment included four locations with intensive grazing:two on silt loam soils and two on loamy sand soils.A fifth location was managed with frequent mowing to a 5-cm residual sward height,approximately 12-15 mowings per year.One cycle of selection was conducted with a population size of 1000 plants and 20 plants were selected for survivorship and vigor.Seed of all selected populations was evaluated at all five selection locations.Results:Gains were made in all eight populations,both due to increases in endophyte infection frequency and genetic gains associated with improved host genotypes.Selection was successful on both silt loam and loamy sand soils,but none of those gains were realized on the alternate soil type.Selection was successful at two of the four grazing farms,the two located on silt loam soils,but these gains were not realized on the farms with loamy sand soils or under the frequent mowing method of defoliation.Conclusions:Selection for tolerance to intensive grazing should be conducted under grazing conditions and selection for adaptation to both sandy and silt loam soils will require a more complex and imaginative selection scheme.展开更多
Leaf senescence can be triggered by various abiotic stresses.Among these,heat stress emerges as a pivotal environmental factor,particularly in light of the predicted rise in global temperatures.However,the molecular m...Leaf senescence can be triggered by various abiotic stresses.Among these,heat stress emerges as a pivotal environmental factor,particularly in light of the predicted rise in global temperatures.However,the molecular mechanism underlying heat-induced leaf senescence remains largely unexplored.As a cool-season grass species,tall fescue(Festuca arundinacea)is an ideal and imperative material for investigating heat-induced leaf senescence because heat stress easily triggers leaf senescence to influence its forage yield and turf quality.Here,we investigated the role of FaNAC047 in heat-induced leaf senescence.Overexpression of FaNAC047 promoted heat-induced leaf senescence in transgenic tall fescue that was evidenced by a more seriously destructive photosystem and higher accumulation of reactive oxygen species(ROS),whereas knockdown of FaNAC047 delayed leaf senescence.Further protein-DNA interaction assays indicated that FaNAC047 directly activated the transcriptions of NON-YELLOW COLORING 1(FaNYC1),NYC1-like(FaNOL),and STAY-GREEN(FaSGR)but directly inhibited Catalases 2(FaCAT2)expression,thereby promoting chlorophyll degradation and ROS accumulation.Subsequently,protein-protein interaction assays revealed that FaNAC047 physically interacted with FaNAC058 to enhance its regulatory effect on FaNYC1,FaNOL,FaSGR,and FaCAT2.Additionally,FaNAC047 could transcriptionally activate FaNAC058 expression to form a regulatory cascade,driving senescence progression.Consistently,the knockdown of FaNAC058 significantly delayed heat-induced leaf senescence.Collectively,our results reveal that FaNAC047-FaNAC058 module coordinately mediates chlorophyll degradation and ROS production to positively regulate heat-induced leaf senescence.The findings illustrate the molecular network of heat-induced leaf senescence for breeding heat-resistant plants.展开更多
Background:Drought‐tolerant turfgrass cultivars are becoming more important each year as landscape irrigation practices are becoming more restrictive.Methods:In this study,we quantified the level of drought tolerance...Background:Drought‐tolerant turfgrass cultivars are becoming more important each year as landscape irrigation practices are becoming more restrictive.Methods:In this study,we quantified the level of drought tolerance(DT)in perennial ryegrass and tall fescue genotypes across years under different mowing(MH)and fertility(FL)rates.A total of 48 ryegrass and 38 tall fescue genotypes were planted in 2011 at NexGen,Albany,OR.The trial was divided into three subtrials:(i)DT;(ii)MH and DT;and(iii)FL and DT.Results:The results showed that there was significant genetic variance for most of the traits in both species.The genotype×year interaction was predominantly simple,indicating small changes in genotype ranking for both species.Lower MH improved DT in perennial ryegrass,whereas higher MH resulted in greater DT in tall fescue.For both species,higher MH improved the population mean for turf quality.Higher FL inputs led to higher turf quality for both species,but it did not affect the DT response.Conclusions:Using a selection index,six genotypes for perennial ryegrass and four for tall fescue were selected.展开更多
Background:Tall fescue(Festuca arundinacea[Schreb.],Lolium arundinaceum[Schreb.]Darbysh)and perennial ryegrass(Lolium perenne)are important cool-season forage and amenity grasses that have a mutualistic association wi...Background:Tall fescue(Festuca arundinacea[Schreb.],Lolium arundinaceum[Schreb.]Darbysh)and perennial ryegrass(Lolium perenne)are important cool-season forage and amenity grasses that have a mutualistic association with an endophytic fungus.Endophytes confer insect and drought resistance to plants but can produce mammalian toxins.Novel endophytes that do not produce mammalian toxins have been introduced to elite cultivars for commercial production.Seed companies need to maintain adequate levels of novel endophytes within the elite forage cultivars.Endophyte detection is performed using immunochemical and molecular techniques because of their speed and reliability.Early detection in seedlings is essential to evaluate the viability of the endophyte within seed lots.Methods:This research aimed to identify the earliest growth stage in which immunochemical and molecular methods can detect viable endophyte in seedlings of tall fescue cultivars BarOptima(e34),Texoma MaxQII(584),and Jesup MaxQ(542),as well as the perennial ryegrass cultivar Remington(NEA2).Results:Immunochemical testing detected endophytes in seedlings 14 days after germination(DAG),but the detection rate increased until 42 DAG in some cultivars tested.The molecular marker Tef1exon detected endophytes at a lower rate than the immunochemical method at 28–42 DAG.However,there was insufficient DNA to detect endophytes in 14 DAG seedlings using markers.Conclusions:We conclude that the most accurate detection of viable endophytes in seedlings was 42 DAG,at which sufficient and consistent endophyte colonization occurred.展开更多
基金Supported by Scientific and Technological Program of Ningxia~~
文摘[Objective] The aim was to explore the effects of drought stress on germination of tall fescue.[Method] Simulation drought experiment on 14 varieties of tall fescue seeds by PEG-6000 researched its germination effect under drought resistance.[Result] The relative germination rate of all tall fescue varieties declined with intensifying drought stress level with the water potential of-0.6 Mpa as the turning point;the relative germination rate of tall fescue existed linear relationship with drought stress：Y = 70.412X ＋ 103.11,r=0.988 8.The sensible water potential range was ≥-0.40 Mpa for tall fescue under drought stress.LC50 of water potential was-0.76 Mpa,the lethal water potential was-1.33 Mpa.Arid Ⅲ,Crossfire Ⅱ and Traple A had stronger drought resistant ability,but Pixie,Infero and Poppoint had weaker drought resistant ability.[Conclusion] This study had provided reference for cultivated pasture and drought resistant breeding.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201003014)Youth Foundation of Beijing Academy of Agricultural and Forestry Sciences(QNJJ201311)~~
文摘ObjectiveThe aim was to explore the movement of nitrate nitrogen in tall-fescue soils by different kinds of slow release nitrogen fertilizers. MethodBased on infiltration-tanks and test plots, a new and environment friendly fertilizer was explored. ResultThe results show that compared with urea treatment, slow-release nitrogen fertilizer treatments could reduce nitrate nitrogen content and leaching amount in soils. Compared with PCU30 and IU treatments, the PCU60 treatment became more efficient in reducing nitrate content and leaching amount in 0-90 cm soil layer. ConclusionIn summary, slow-release nitrogen fertilizer, which can reduce soil nitrate content and leaching losses, is a kind of novel fertilizer with high environmental benefit and promising application.
文摘In order to improve stress tolerances of turf-type tall fescue （Festuca arundinacea Schreb.）, Agrobacterium tumefaciens strain EHA105 carrying plasmid pCMD containing stress tolerance-related CBF1 gene from Arabidopsis thaliana was used to transform mature seeds-derived embryogenic calli of four cultivars. A total of 112 transgenic plants were regenerated from 32 independent lines and verified by histochemical detection of GUS activity, PCR assay and Southern hybridization analysis. The transformation frequency ranged from 0.92 to 2.87% with apparent differences among the cultivars. Stress tolerances of transgenic plants were enhanced, which was shown by the facts that transgenic plants had distinct growth superiority and significantly higher survival rate than non-transformed ones under high salinity and high osmosis stresses, and that relative electronic conductivity of in vitro leaves treated with low and high temoeratures, dehvdration and high salinity stresses was 25-30% lower in transgenic plants than in control plants.In addition,it was observed that growth of transgenic plants was inhibited due to constitutive overexpression of CBF1 gene under normal environmental conditions.
基金The study was supported by“948”Project of the Ministry of Agriculture of China.
文摘By assay of accelerated aging germination, germination index, vigor index, seedling length, seedling weight, electric conductivity, dehydrogenase activity, ATP content and acid phosphoesterase activity during seed development of turf-type tall fescue, the seed vigor of tall fescue were studied. Combining with seed moisture content and yield, the optimal harvesting time of tall fescue was determined. The results indicated that the seed vigor increased continuously along with seed maturity, and the higher seed vigor was achieved at 19th day after perk anthesis and maintained continuously until 31st day after peak anthesis. At 25th day after peak anthesis, the highest yield of 3 533 kg ha-1 and the good quality of seeds of tall fescue were harvested with 32.19% moisture content. From 22nd to 31st day after peak anthesis, the seed yield of 3 300 kg ha-1 and the good quality seeds of tall fescue were harvested with 40 - 12. 43% moisture content, and the span was the optimal harvesting time.
基金Foundation project： This paper was supported by Zhejiang Provincial Science and Technology Plan of China （Grant No. 2003C30053） and Zhejiang Provincial Natural Science Foundation of China （Grant No.Y504076）.
文摘Tall fescue （Festuca arundinacea Schreb.） is a cool-season turfgrass used on fairways in golf courses. The object of this study was to develop a more efficient, reliable, and repeatable approach in transforming the grass using Agrobacterium （EHA105）, where β-glucuronidase gene （uidA） was used as a reporter and hygromycin phosphotransferase gene （hyg） as a selectable marker. An effective expression of transgene was observed in transforming 2-month-old calli derived from mature seeds （cv. Bingo） cultured on MS medium supplemented with 9 mg·L^-1 2, 4-D. A two-step solid medium selection with increasing hygromycin concentration （from 30 to 50 mg· L^-1） was used to obtain resistant calli. Transgenic plants have been produced from many independent transformed calli. The presence of functional β-glucuronidase gene （uidA） was detected in hygromycin-resistant calli. Transgenic plants were regenerated and PCR and Southern blot confirmed transgene integration in the tall fescue genome.
基金Supported by Special Foundation of Guizhou Academy of Agriculture Science"Germplasm Innovation and Application of Drought and Heat Resistant Alfalfa"(QNKYYZX[2013]003)Special Breeding Project of Guizhou Agriculture Commission"Cultivation of Flowering-inhibitory Tall Fescue Varieties with RNA Interference Technique"(QNYZZ[2013]012)
文摘Abstract The metabolites of tall fescue leaves under normal and drought conditions were analyzed with LC-ESI-MS （ liquid chromatography tandem mass spec- trometry）. A total of 282 metabolites were stably detected in the two groups using OPI.S-DA （orthogonal partial least squares discriminant analysis） method; 148 of which were down-regulated while 134 were up-regulated. After analyzed with MZ-minc software, 10 major metabolites （4 down, 6 up） were identified through searehing public database. Aromatic compounds, 3-p-eoumaroyll, 5-quinolaetone, aromatic free amino acids, styraxin mad methanofuran, were up-regulated ; grease metabolites, methyl 15-hydroperoxy-9Z, 12Z, 16E-octadecatrienoate, 9,12,13-Tri-HOME （10）, 3-oxo-dodecanoic acid, and 13 （S）-HpOTrE acid ester, were down-regulated; piperanine （alkaloids） was down-regulated while Methyl 7-epi-12-hydroxyjasmonate glucoside （indicant） was up-regulated. In a word, aromatic compounds and liquid metabolites may play vital roles in drought-resistant regulation of tall fescue.
基金Supported by National Natural Science Foundation of China(31360576)~~
文摘[Objective] The differential expression analysis was performed for FaGF14- B and FaGF14-C genes in tall fescue so as to provide certain basis for follow-up functional analysis of genes. [Method] The sequence fragments of FaGF14-B and FaGF14-C obtained from reverse transcription were used as templates, and the full- length cDNA sequences of FaGF14-B and FaGF14-C were amplified using the 5＇ RACE use 3＇RACE techniques. They were named as FaGF14-B and FaGF14-C, and used for nucleic acid sequence analysis, encoded protein analysis, protein con- served domain analysis, phylogenetic analysis and differential expression analysis. [Result] The FaGF14-B gene has a full length of 1 548 bp. It has a complete open reading frame （ORF, 449-1 228 bp）, and encodes a protein composed of 261 amino acids. The FaGF14-C gene has a full length of 1 250 bp. It also has a complete open reading frame （ORF, 66-848 bp）, and encodes a protein composed of 261 amino acids. The GF14-B and GF14-C proteins all have a typical domain 14-3-3, and their secondary structures all contain 9 conserved co-helical structures and non-conserved N- and C- terminals. The phylogenetic analysis showed that the FaGF14-B and FaGF14-C from tall rescue have high similarities with GF14 protein from gramineous plants, and they are divided into the same clade with closer ge- netic relationship. The real-time fluorescence quantitative PCR analysis showed that the expression of FaGF14-B and FaGF14-C genes is all sensitive to nitrogen stress. [Conclusion] This study will lay a theoretical basis for further screening of low nitrogen-tolerant genes and breeding of low nitrogen-tolerant grass germplasms.
基金Supported by National Natural Science Foundation of China(31360576)~~
文摘To study the functions of 14-3-3 gene family in tall fescue, the potential functions of 13 14-3-3 proteins in Arabidopsis were investigated by bioinformatic analysis. Based on the sequences of 14-3-3 genes in tall fescue by transcriptome and proteomic sequencing, the full-length cDNA sequences of 4 14-3-3 genes in tall fescue were obtained. Their sequences were aligned by Clustal W2. The results showed that the genetic relationships between 14-3-3A and 14-3-3D, 14-3-3B and 14-3-3C are closer, and their main structures are very conservative. The changes in expression levels of 14-3-3 genes under low nitrogen, drought, high temperature and high salt stresses were investigated by fluorescence quantitative PCR. The expres- sion level of 14-3-3A makes responses to low nitrogen, drought, high temperature and high salt stresses; the expression levels of other genes also make responses to abiotic stresses in varying degrees, but the relevant response mechanisms are not exactly the same. Therefore, it is speculated that the 14-3-3 gene family regu- lates stress resistance of plants through different pathways, and functional differenti- ation occurs during its evolution.
基金Research Fund from Guizhou Academy of Agricultural Sciences([2009]038)Programs for Science and Technology Development in Guizhou Province([2009]3067)~~
文摘[Objective] This study was to construct RNAi expression vector targeting FaVRN1 gene. [Method] A 145 bp Arabidopsis actin intron was inserted into the expression vector to generate an intermediate vector pBI121-M-INT. And then two pairs of specific primers with enzyme restriction sites spanning a 351 bp cDNA conserved sequence fragment of FaVRN1 gene were designed for RT-PCR to construct RNAi expression cassette. The amplified fragment was inserted forwardly and reversely at two sides of the intron to construct an RNAi expression vector with hairpin structure. [Result] Double enzyme digestion（HindIII＋BamHI） showed the intron had been successfully into the vector pBI121. PCR amplification and double enzyme digestion indicated the success of forward and reverse ligation of target FaVRN1 fragment into the intermediate vector. [Conclusion] This study laid foundation for breeding novel flowering-inhibited tall fescue varieties.
基金Item supported by national natural sciencefoundation of China(No.30270089)science and technologycommission of Shanghai(No.03JC14047)
文摘Heat stress in summer is a major factor limiting use of cool-season grasses in Shanghai area, China. The objectives of this study were to investigate effects of a crude extract product of a new strain of Streptomyces microflavus (TSS) on turf performance and physiological activities of tall fescue (Festuca arundinacea) in response to heat stress. Plants of tall fescue cultivar ‘Barlexus’ were exposed to 38/33 (°C) (day/night) high temperature in growth chamber after TSS applications. High temperature induced about 3.5 fold increases of initial shoot extension rate and clipping yield (6 d) and led to quick decline of plant growth after 18 d. TSS inhibited the extent of initial increases of shoot extension rate and clipping yield and maintained a longer period of steady growth under the heat stress. TSS also decreased the decline of leaf chlorophyll content, TNC, shoot density, and turf quality induced by heat stress. The results suggested that TSS application improved turf performance under heat stress, and the greater improvement of heat tolerance was associated with higher dose of application. This positive effect on heat tolerance could be related to the decreased carbohydrate consumption and loss, and reduced decomposition of leaf chlorophyll.
基金Supported by National Natural Science Foundation of China(31360576)~~
文摘The sequence fragment of PHYA, obtained from transcriptome sequencing,was used as the template, and the full-length c DNA sequence of PHYA gene in tall fescue was amplified using 3＇RACE and 5＇RACE techniques. The c DNA sequence of PHYA gene has a complete open reading frame（ORF, 293-6 682 bp）, and it encodes a protein composed of 1 129 amino acids. The N-terminal of Fa PHYA is composed of GAF and Phytochrome domains, and its C-terminal contains two repeated PAS domains, one histidine kinase A domain and one histidine kinase-like ATPase domain. The homology analysis showed that the amino acid sequences of Fa PHYA of tall fescue and PHYAs of gramineous plants have higher homologies（85%）, indicating close genetic relationships. However, the homologies between FaPHYA of tall fescue and PHYAs of monocotyledons are lower, indicating far genetic relationships.
基金Supported by Science and Technology Innovation Talents Team Foundation of Guizhou ProvinceSpecial Foundation from Guizhou Academy of Agriculture Science([2013]003)Natural Science Foundation of Guizhou Province(Qian J[2015]2080)
文摘Forages generally suffer more severe nutrition stress than other crops, but the corresponding theoretical studies still lag behind. In this study, metabo- lites in tall fescue leaves under normal and low nitrogen conditions were analyzed with LC-ESI-MS （ liquid chromatography-electrospray ionization-mass spectrome- try）. A total of 1 424 and 1 251 metabolites were detected from two groups of samples respectively using OPLS-DA （orthogonal partial least squares discriminant analysis）. The content of 13 major metabolites changed under low nitrogen stress, including auxin （indale acetic acid, IAA）. Quantitative real-time PCR （qRT- PCR） showed that eight genes related to IAA signaling pathway were up-regulated after nitrogen stress. Enzyme-linked immuno sorbent assay （ELISA） revealed that the IAA concentration was elevated in tall fescue leaves after nitrogen stress. Our research provides valuable information for studying the response mechanisms of tall feseue to low nitrogen. The results suggest that application of IAA could be used to alleviate the harmful effects of nitrogen deficiency.
基金Supported by the Key Agricultural Technology R&D Program of Guizhou Province(Qiankehe NY(2008)3070Qiankehe NY(2010)3044)+1 种基金the Foundation for Science andTechnology of Guizhou Province(Qiankehe J(2009)2133Qiankehe J(2012)2202)~~
文摘Tal fescue （Festuca arundinacea Schreb.） is an important cool-season forage grasses and turfgrasses at home and abroad. In order to provide a reference for tal fescue breeding, we reviewed the genetic constitution and heritability, endo-phytic fungi and new tal fescue variety breeding, application of modern biological technology （expressed sequence tag, genetic linkage map construction and trans-genic breeding） in breeding new varieties of tal fescue and the breeding status of tal fescue in Guizhou region.
基金Supported by National Natural Science Foundation of China(31360576)~~
文摘[Objective] This study aimed to investigate the physiological characteristics of tall fescue under nitrogen stress. [Method] A series of physiological changes in protein content, chlorophyll content, enzyme activities and amino acids contents in tall fescue under nitrogen stress were analyzed. [Result] Under nitrogen stress, the leaf chlorophyll content in tall fescue was reduced, and superoxide dismutase（SOD）,peroxidase（POD）, glutamine synthetase（GS） activities were increased. Among the 18 kinds of amino acids analyzed, the contents of asparagine, serine, glycine, glutamine, glutamic acid, aspartic acid, threonine, alanine, arginine, methionine, valine,isoleucine and leucine were significantly reduced in tall fescue under nitrogen stress.[Conclusion] This study will provide certain reference for rational application of nitrogen and exploration of plant ecological potential in the future.
基金Supported by Outstanding Young Scientific and Technological Talent Training Fund of Guizhou Province"Study on Innovation and Application of Tall Fescue Germplasms"
文摘[ Objective ] This study aimed to construct RNAi expression vector targeting vemalizational gene FaCONSTANS （GenBank accession number： GU214996） in tall rescue. [ Method] A 145 bp long Arabidopsis actin gene intron was inserted into the expression vector to construct an intermediate vector pBI121-M-INT. Two pairs of specific primers with restriction sites were designed to amplify a 351 bp long cDNA conserved sequence fragment of vemalizational gene FaCONSTANS for RT-PCR. After restriction enzyme digestion, the amplified fragment was inserted forwardly and reversely at two sides of the intron of intermediate vector to construct an RNAi expression vector with hairpin structure. [ Result ] Double digestion （HindIII ＋ BamHI） showed that the intron was successfully insert- ed into the vector pBI121. PCR amplification and double digestion indicated that target fragment FaCONSTANS was successfully inserted forwardly and reversely in- to the intermediate vector. [ Conclusion] This study laid foundation for breeding novel flowering-inhibited tall rescue cultivars.
文摘Endophyte infected tall fescue (E+) is the base diet for nearly all beef cattle in the southern USA. It has been linked to a variety of toxicological conditions due to the presence of large numbers of ergot alkaloids. This study was designed to investigate the effects of E+ seed extract and selected ergot alkaloids on the detoxification pathway by cytochrome P450 (CYP3A4) enzyme system. Tests were performed using the P450- Glo CYP3A4 enzyme activity kit (Promega, WI), according to the manufacturer’s manual. Luminescence was measured using a single tube TD20/20 luminometer. Endophyte infected tall fescue seed was extracted with 50/50 methanol/25 mM ammonium carbonate, cleaned and concentrated on Strata-X reversed phase column (Phenomenex). The extracts were evaluated on an HPLC, and then tested using a serial dilution method. Commercially available ergonovine (EN), ergocorine (ER), bromocryptine (BC) and ergocryptine (EC) were tested individually using 0 to 44 nM concentrations. Seed extract of E+ produced a significant (P P < 0.05) dose dependent manner with EC being most potent, followed by ER, BC, and then EN (70%, 40%, 30% and 10% at 44 nM concentration). The similarity of the inhibition curves of seed extract to that of the commercially available ergot alkaloids suggests a related mode of action and that the use of such ergot alkaloids and CYP3A4 assay is a good model to study the toxicity of tall fescue. Furthermore, it provides the foundation to identify the individual toxic components of purified endophyte infected tall fescue extract.
基金Agricultural Research Service,Grant/Award Number:5090-21000-065-00D。
文摘Background:Meadow fescue(Schedonorus pratensis(Huds.)P.Beauv.)is a reemerging pasture grass for temperate regions of North America.One disadvantage of this species is its lack of tolerance to frequent defoliation at low residual sward heights.This experiment was designed to conduct one cycle of selection and evaluation for persistence under frequent defoliation.Methods:The experiment included four locations with intensive grazing:two on silt loam soils and two on loamy sand soils.A fifth location was managed with frequent mowing to a 5-cm residual sward height,approximately 12-15 mowings per year.One cycle of selection was conducted with a population size of 1000 plants and 20 plants were selected for survivorship and vigor.Seed of all selected populations was evaluated at all five selection locations.Results:Gains were made in all eight populations,both due to increases in endophyte infection frequency and genetic gains associated with improved host genotypes.Selection was successful on both silt loam and loamy sand soils,but none of those gains were realized on the alternate soil type.Selection was successful at two of the four grazing farms,the two located on silt loam soils,but these gains were not realized on the farms with loamy sand soils or under the frequent mowing method of defoliation.Conclusions:Selection for tolerance to intensive grazing should be conducted under grazing conditions and selection for adaptation to both sandy and silt loam soils will require a more complex and imaginative selection scheme.
基金National Natural Science Foundation of China(NSFC)(Grant Nos.32471765,32101430,and 32441039)the Major Science and Technology Innovation Project of Shandong Province(No.2022LZGC018)+2 种基金the National Science Foundation for Distinguished Young Scholars of Hubei Province(No.2021CFA060)International Science and Technology Cooperation Project of Hubei Province(No.2021EHB021)the Science&Technology Specific Projects in Agricultural Hightech Industrial Demonstration Area of the Yellow River Delta(No.2022SZX13).
文摘Leaf senescence can be triggered by various abiotic stresses.Among these,heat stress emerges as a pivotal environmental factor,particularly in light of the predicted rise in global temperatures.However,the molecular mechanism underlying heat-induced leaf senescence remains largely unexplored.As a cool-season grass species,tall fescue(Festuca arundinacea)is an ideal and imperative material for investigating heat-induced leaf senescence because heat stress easily triggers leaf senescence to influence its forage yield and turf quality.Here,we investigated the role of FaNAC047 in heat-induced leaf senescence.Overexpression of FaNAC047 promoted heat-induced leaf senescence in transgenic tall fescue that was evidenced by a more seriously destructive photosystem and higher accumulation of reactive oxygen species(ROS),whereas knockdown of FaNAC047 delayed leaf senescence.Further protein-DNA interaction assays indicated that FaNAC047 directly activated the transcriptions of NON-YELLOW COLORING 1(FaNYC1),NYC1-like(FaNOL),and STAY-GREEN(FaSGR)but directly inhibited Catalases 2(FaCAT2)expression,thereby promoting chlorophyll degradation and ROS accumulation.Subsequently,protein-protein interaction assays revealed that FaNAC047 physically interacted with FaNAC058 to enhance its regulatory effect on FaNYC1,FaNOL,FaSGR,and FaCAT2.Additionally,FaNAC047 could transcriptionally activate FaNAC058 expression to form a regulatory cascade,driving senescence progression.Consistently,the knockdown of FaNAC058 significantly delayed heat-induced leaf senescence.Collectively,our results reveal that FaNAC047-FaNAC058 module coordinately mediates chlorophyll degradation and ROS production to positively regulate heat-induced leaf senescence.The findings illustrate the molecular network of heat-induced leaf senescence for breeding heat-resistant plants.
基金National Institute of Food and Agriculture,Grant/Award Number:Hatch project 1018058。
文摘Background:Drought‐tolerant turfgrass cultivars are becoming more important each year as landscape irrigation practices are becoming more restrictive.Methods:In this study,we quantified the level of drought tolerance(DT)in perennial ryegrass and tall fescue genotypes across years under different mowing(MH)and fertility(FL)rates.A total of 48 ryegrass and 38 tall fescue genotypes were planted in 2011 at NexGen,Albany,OR.The trial was divided into three subtrials:(i)DT;(ii)MH and DT;and(iii)FL and DT.Results:The results showed that there was significant genetic variance for most of the traits in both species.The genotype×year interaction was predominantly simple,indicating small changes in genotype ranking for both species.Lower MH improved DT in perennial ryegrass,whereas higher MH resulted in greater DT in tall fescue.For both species,higher MH improved the population mean for turf quality.Higher FL inputs led to higher turf quality for both species,but it did not affect the DT response.Conclusions:Using a selection index,six genotypes for perennial ryegrass and four for tall fescue were selected.
基金The University of Georgia Cultivar Research and Development Fund。
文摘Background:Tall fescue(Festuca arundinacea[Schreb.],Lolium arundinaceum[Schreb.]Darbysh)and perennial ryegrass(Lolium perenne)are important cool-season forage and amenity grasses that have a mutualistic association with an endophytic fungus.Endophytes confer insect and drought resistance to plants but can produce mammalian toxins.Novel endophytes that do not produce mammalian toxins have been introduced to elite cultivars for commercial production.Seed companies need to maintain adequate levels of novel endophytes within the elite forage cultivars.Endophyte detection is performed using immunochemical and molecular techniques because of their speed and reliability.Early detection in seedlings is essential to evaluate the viability of the endophyte within seed lots.Methods:This research aimed to identify the earliest growth stage in which immunochemical and molecular methods can detect viable endophyte in seedlings of tall fescue cultivars BarOptima(e34),Texoma MaxQII(584),and Jesup MaxQ(542),as well as the perennial ryegrass cultivar Remington(NEA2).Results:Immunochemical testing detected endophytes in seedlings 14 days after germination(DAG),but the detection rate increased until 42 DAG in some cultivars tested.The molecular marker Tef1exon detected endophytes at a lower rate than the immunochemical method at 28–42 DAG.However,there was insufficient DNA to detect endophytes in 14 DAG seedlings using markers.Conclusions:We conclude that the most accurate detection of viable endophytes in seedlings was 42 DAG,at which sufficient and consistent endophyte colonization occurred.
