Soil salinity is a major threat to global agriculture.The recretohalophytic turfgrass species Zoysia matrella(L.)Merr.and Zoysia japonica Steud.possessunique salt glands that enable them to secrete excess salt.Underst...Soil salinity is a major threat to global agriculture.The recretohalophytic turfgrass species Zoysia matrella(L.)Merr.and Zoysia japonica Steud.possessunique salt glands that enable them to secrete excess salt.Understanding the molecular mechanisms underlying salt secretion could enable the introductionof salt secretion in other grasses,thereby improving their salt tolerance.In this study,we developed an in vitro leaf assay to investigate salt secretionpatterns and the expression of key sodium/potassium transporters,including HKTs and endosomal NHXs.The present study revealed that Z.matrellaconsistently exhibited a higher salt secretion rate than Z.japonica.In both species,salt secretion increased with rising salinity,peaking at 300 mM NaCl.Beyond this threshold,further increases in salinity did not significantly enhance secretion,suggesting a maximum capacity for the salt glands.Interestingly,at 900 mM NaCl,salt secretion was completely inhibited in Z.japonica,whereas Z.matrella maintained a low level of secretion.Among the HKT genes,HKT1;4was the most highly expressed in the leaves of both species,and its expression was negatively correlated with salt secretion.Additionally,NHX6 expressionin Z.matrella was negatively associated with secretion,a pattern not observed in Z.japonica.The contrasting expression patterns of endosomal NHX genesmay contribute to the differential salt tolerance between the two species.The in vitro leaf assay developed in this study provides an efficient tool forevaluating salt secretion in breeding programs.The present findings offer valuable insights into salt secretion and tolerance mechanisms in zoysiagrass,paving the way for the development of new salt-tolerant varieties.展开更多
Zoysia japonica(Z.japonica)is a warm-season perennial turfgrass commonly grown in the southeastern United States for its relatively low input requirements and general tolerance to drought,shade,and salinity.Improving ...Zoysia japonica(Z.japonica)is a warm-season perennial turfgrass commonly grown in the southeastern United States for its relatively low input requirements and general tolerance to drought,shade,and salinity.Improving freezing tolerance is critical for Z.japonica,as it could extend the northern boundaries that the species is able to be grown in.To deepen our understanding of the molecular basis of freezing tolerance in Z.japonica,a transcriptomic approach was utilized to identify genes involved in cold acclimation.‘Meyer',a freeze tolerant cultivar,and‘Victoria',a freeze susceptible cultivar were subjected to cold acclimation and non-cold acclimation treatments to determine the number of differentially expressed genes(DEGs).In response to cold acclimation,a total of 4,609 DEGs were up-regulated and 3,605 DEGs were down-regulated in‘Meyer',while 3,758 DEGs were up-regulated and 3,516 DEGs were down-regulated in‘Victoria'.GO and KEGG enrichment analysis showed several diverse pathways and biological processes,including photosynthesis,transmembrane transport,and plant hormone signal transduction.Integrating these information with previous studies on proteomics and QTL mapping,several candidate genes were identified to be associated with cold acclimation and freezing tolerance across different studies,such as LEA,CIPK,POD,HSF,HSP,MPK,PSII and multiple transcription factors.The candidate genes identified in this study showed great value in potentially being a target for future selection efforts for freeze-tolerant Z.japonica.展开更多
Zoysia grass(Zoysia japonica)is an important native grass species in China,while the slow regeneration speed limits its use.Two Z.japonica materials FM1(fast regeneration rate)and SM232(slow regeneration rate)were cho...Zoysia grass(Zoysia japonica)is an important native grass species in China,while the slow regeneration speed limits its use.Two Z.japonica materials FM1(fast regeneration rate)and SM232(slow regeneration rate)were chosen from 10 different Zoysia grass by phenotypic index in this study.The genetic differences associated with zoysia regeneration and metabolism pathway are elucidated based on the transcriptome analysis,determination of hormone,and molecular biological section.Transcriptome sequencing results showed that both FM1 and SM232 had the maximum number of DEGs at 2 h and 12 h after mowing,indicating it may be the key stage of Zoysia grass response to mowing.After mowing treatment,FM1 was accompanied by up-regulation of regeneration-related genes,such as the LOB protein family and amide synthesis family.However,SM232 showed a continuous down-regulation of protein-related genes of the LOB family.Transcriptome analysis showed that the expression of IAA-related genes in both groups showed a downward trend,which was consistent with the results of IAA content determination.The IAA content in FM1 was significantly higher than that in SM232.Changes in CTK-related genes were only detected in FM1.Mowing induces plant defense systems,and plant tissue regeneration is closely related to the plant defense system,which may be the focus of further research.These results provide a basis for further research on the molecular mechanism of grass regeneration.展开更多
The age-structure of natural population of Zoysia japonica in Xiuyan County of Liaoning Province was studied by generational method. The results showed that the highest tiller age class was three, but 1st age class ti...The age-structure of natural population of Zoysia japonica in Xiuyan County of Liaoning Province was studied by generational method. The results showed that the highest tiller age class was three, but 1st age class tillers held dominant posi-tion with proportions over 95% in each month during the growing seasons. The 2nd age class and 3rd age class tillers were minority in the population. So Z. japonica population was an expanding population. The zero age class buds on the rhizomes were dominant in buds age structures. The proportion of buds to tillers on quantity in each month was about 30% to 40% and reached the highest at the end of September. The increasing of buds proportion before dormancy guaranteed the quantity of tillers in the next spring. The biomass of 1st age class tillers changed with time. The biomass kept increasing from April to July and reached the highest at the end of July and then decreased.展开更多
[Objective] The paper was to analyze the expression and response mechanism of NCED gene of Zoysia japonica in initial infection stage of Rhizoctonia solani. [Method] The NCED gene fragments of Z. japonica‘Zenith'wer...[Objective] The paper was to analyze the expression and response mechanism of NCED gene of Zoysia japonica in initial infection stage of Rhizoctonia solani. [Method] The NCED gene fragments of Z. japonica‘Zenith'were screened and cloned on the basis of transcriptome data. The expression patterns of NCED gene in initial infection stage of R. solani( 0-48 h) were obtained via real-time quantitative PCR. [Result] The expression level of NCED gene in stress treatment was higher than that without infection,which first increased then decreased with the extension of time,and reached the maximum at 36 h. Further detection of ABA level in‘Zenith'roots showed that the change trend of ABA level within 0-48 h was consistent with the expression pattern of NCED gene,and flattened out after 48 h. [Conclusion] NCED gene regulates the synthesis of phytohormone ABA and probably further involves in plant disease resistance.展开更多
The study was conducted to determine the optimum fertilizer-N application rate formaximum seed yields of Zoysiagrass stands from seeding and transplant respectively, atJiaozhou, Shandong Province, China from 2001 to 2...The study was conducted to determine the optimum fertilizer-N application rate formaximum seed yields of Zoysiagrass stands from seeding and transplant respectively, atJiaozhou, Shandong Province, China from 2001 to 2003. In the third year after establishment,seed yields and yield components for both stands showed a similar response to fertilizer-N. Maximum fertile tiller numbers (3342 heads m-2 and 2941 heads m-2 from stands seeded inrows and transplanted, respectively) and the highest seed yields (844.50kgha-1 and 874.65kg ha-1 from stands seeded in rows and transplanted, respectively) were obtained at a Nfertilizer rate of 20kgha-1 in autumn and 10kgha-1 in spring (30kgha-1 N in total). Thefertile tillers and seed yields decreased with further increasing of N fertilizer rate.Fertilizer-N application could increase the length of spike, spikelets per fertiletiller, seed number per spike, setting percentage and thousand seed weight. The 1000-seed weight and the length of spike from transplant plots were higher than that fromseeding plots. The optimal harvest time of zoysiagrass at Jiaozhou was on the 36th dayafter peak anthesis, near June 15th, when the seed moisture content was 26-28%.展开更多
基金supported by the National Institute of Food and Agriculture(NIFA)-Specialty Crop Research Initiative(SCRI)(Grant No.2019-51181-30472)to Yu Q and Ambika Chandra.
摘要Soil salinity is a major threat to global agriculture.The recretohalophytic turfgrass species Zoysia matrella(L.)Merr.and Zoysia japonica Steud.possessunique salt glands that enable them to secrete excess salt.Understanding the molecular mechanisms underlying salt secretion could enable the introductionof salt secretion in other grasses,thereby improving their salt tolerance.In this study,we developed an in vitro leaf assay to investigate salt secretionpatterns and the expression of key sodium/potassium transporters,including HKTs and endosomal NHXs.The present study revealed that Z.matrellaconsistently exhibited a higher salt secretion rate than Z.japonica.In both species,salt secretion increased with rising salinity,peaking at 300 mM NaCl.Beyond this threshold,further increases in salinity did not significantly enhance secretion,suggesting a maximum capacity for the salt glands.Interestingly,at 900 mM NaCl,salt secretion was completely inhibited in Z.japonica,whereas Z.matrella maintained a low level of secretion.Among the HKT genes,HKT1;4was the most highly expressed in the leaves of both species,and its expression was negatively correlated with salt secretion.Additionally,NHX6 expressionin Z.matrella was negatively associated with secretion,a pattern not observed in Z.japonica.The contrasting expression patterns of endosomal NHX genesmay contribute to the differential salt tolerance between the two species.The in vitro leaf assay developed in this study provides an efficient tool forevaluating salt secretion in breeding programs.The present findings offer valuable insights into salt secretion and tolerance mechanisms in zoysiagrass,paving the way for the development of new salt-tolerant varieties.
基金supported in part by funding provided by the NC State University Plant Breeding Consortium,the NC State University Center for Turfgrass Environmental Research and Education,and the United States Golf Association.
摘要Zoysia japonica(Z.japonica)is a warm-season perennial turfgrass commonly grown in the southeastern United States for its relatively low input requirements and general tolerance to drought,shade,and salinity.Improving freezing tolerance is critical for Z.japonica,as it could extend the northern boundaries that the species is able to be grown in.To deepen our understanding of the molecular basis of freezing tolerance in Z.japonica,a transcriptomic approach was utilized to identify genes involved in cold acclimation.‘Meyer',a freeze tolerant cultivar,and‘Victoria',a freeze susceptible cultivar were subjected to cold acclimation and non-cold acclimation treatments to determine the number of differentially expressed genes(DEGs).In response to cold acclimation,a total of 4,609 DEGs were up-regulated and 3,605 DEGs were down-regulated in‘Meyer',while 3,758 DEGs were up-regulated and 3,516 DEGs were down-regulated in‘Victoria'.GO and KEGG enrichment analysis showed several diverse pathways and biological processes,including photosynthesis,transmembrane transport,and plant hormone signal transduction.Integrating these information with previous studies on proteomics and QTL mapping,several candidate genes were identified to be associated with cold acclimation and freezing tolerance across different studies,such as LEA,CIPK,POD,HSF,HSP,MPK,PSII and multiple transcription factors.The candidate genes identified in this study showed great value in potentially being a target for future selection efforts for freeze-tolerant Z.japonica.
摘要Zoysia grass(Zoysia japonica)is an important native grass species in China,while the slow regeneration speed limits its use.Two Z.japonica materials FM1(fast regeneration rate)and SM232(slow regeneration rate)were chosen from 10 different Zoysia grass by phenotypic index in this study.The genetic differences associated with zoysia regeneration and metabolism pathway are elucidated based on the transcriptome analysis,determination of hormone,and molecular biological section.Transcriptome sequencing results showed that both FM1 and SM232 had the maximum number of DEGs at 2 h and 12 h after mowing,indicating it may be the key stage of Zoysia grass response to mowing.After mowing treatment,FM1 was accompanied by up-regulation of regeneration-related genes,such as the LOB protein family and amide synthesis family.However,SM232 showed a continuous down-regulation of protein-related genes of the LOB family.Transcriptome analysis showed that the expression of IAA-related genes in both groups showed a downward trend,which was consistent with the results of IAA content determination.The IAA content in FM1 was significantly higher than that in SM232.Changes in CTK-related genes were only detected in FM1.Mowing induces plant defense systems,and plant tissue regeneration is closely related to the plant defense system,which may be the focus of further research.These results provide a basis for further research on the molecular mechanism of grass regeneration.
基金This study was supported by the NKBRSF (G1999043407-1) Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-406+3 种基金 SCXZD0101) NKTRDP (2001BA510B-07 2002BA516A20) and Education Committee Projects of Liaong Province (990121400
摘要The age-structure of natural population of Zoysia japonica in Xiuyan County of Liaoning Province was studied by generational method. The results showed that the highest tiller age class was three, but 1st age class tillers held dominant posi-tion with proportions over 95% in each month during the growing seasons. The 2nd age class and 3rd age class tillers were minority in the population. So Z. japonica population was an expanding population. The zero age class buds on the rhizomes were dominant in buds age structures. The proportion of buds to tillers on quantity in each month was about 30% to 40% and reached the highest at the end of September. The increasing of buds proportion before dormancy guaranteed the quantity of tillers in the next spring. The biomass of 1st age class tillers changed with time. The biomass kept increasing from April to July and reached the highest at the end of July and then decreased.
基金Supported by National High Technology Research and Development Program("863"Program) of China(2013AA102607)
摘要[Objective] The paper was to analyze the expression and response mechanism of NCED gene of Zoysia japonica in initial infection stage of Rhizoctonia solani. [Method] The NCED gene fragments of Z. japonica‘Zenith'were screened and cloned on the basis of transcriptome data. The expression patterns of NCED gene in initial infection stage of R. solani( 0-48 h) were obtained via real-time quantitative PCR. [Result] The expression level of NCED gene in stress treatment was higher than that without infection,which first increased then decreased with the extension of time,and reached the maximum at 36 h. Further detection of ABA level in‘Zenith'roots showed that the change trend of ABA level within 0-48 h was consistent with the expression pattern of NCED gene,and flattened out after 48 h. [Conclusion] NCED gene regulates the synthesis of phytohormone ABA and probably further involves in plant disease resistance.
基金The study was supported by 948 Project sponsored by the Ministry of Agriculture,China(202099).
摘要The study was conducted to determine the optimum fertilizer-N application rate formaximum seed yields of Zoysiagrass stands from seeding and transplant respectively, atJiaozhou, Shandong Province, China from 2001 to 2003. In the third year after establishment,seed yields and yield components for both stands showed a similar response to fertilizer-N. Maximum fertile tiller numbers (3342 heads m-2 and 2941 heads m-2 from stands seeded inrows and transplanted, respectively) and the highest seed yields (844.50kgha-1 and 874.65kg ha-1 from stands seeded in rows and transplanted, respectively) were obtained at a Nfertilizer rate of 20kgha-1 in autumn and 10kgha-1 in spring (30kgha-1 N in total). Thefertile tillers and seed yields decreased with further increasing of N fertilizer rate.Fertilizer-N application could increase the length of spike, spikelets per fertiletiller, seed number per spike, setting percentage and thousand seed weight. The 1000-seed weight and the length of spike from transplant plots were higher than that fromseeding plots. The optimal harvest time of zoysiagrass at Jiaozhou was on the 36th dayafter peak anthesis, near June 15th, when the seed moisture content was 26-28%.