A new flavonoid with chalcone skeleton was isolated from the dried aerial roots of Ficus microcarpa. The structure of the compound was elucidated on the basis of spectral methods including 1D and 2D NMR. The new compo...A new flavonoid with chalcone skeleton was isolated from the dried aerial roots of Ficus microcarpa. The structure of the compound was elucidated on the basis of spectral methods including 1D and 2D NMR. The new compound showed weak inhibitory effect on nitric oxide production and cytotoxicity against K562 and PC3 cells.展开更多
Recent studies have shown that mucilage secretion from aerial roots is an essential feature of modern maize inbred lines,with some retaining the nitrogen-fixing capabilities of ancient landraces.To explore the genetic...Recent studies have shown that mucilage secretion from aerial roots is an essential feature of modern maize inbred lines,with some retaining the nitrogen-fixing capabilities of ancient landraces.To explore the genetic basis of nitrogen fixation in mucilage and its evolution from teosinte(Zea mays ssp.mexicana)to modern maize,we developed a recombinant inbred line(RIL)population from teosinte and cultivated it under low-nitrogen conditions.Large-scale,multi-year,and multi-environment analyses of RIL-Teo,Doubled Haploid-A(DH-A),Doubled Haploid-B(DH-B),and association populations led to the identification of 15 quantitative trait loci(QTL),68 quantitative trait nucleotides(QTN),and 59 candidate genes linked to mucilage secretion from aerial roots.Functional verification of the candidate gene ZmAco3,which is associated with mucilage secretion in aerial roots,demonstrated that deletion of this gene resulted in a reduction in mucilage secretion in aerial roots.In addition,most maize inbred lines exhibited stronger mucilage secretion from aerial roots under low-nitrogen conditions than under normal-nitrogen conditions.We categorized mucilage secretion into constitutive and low-nitrogen-inducible types.Through genotype-by-environment interaction studies,8 QTL,16 QTN,and 19 candidate genes were identified,revealing the genetic mechanisms underlying mucilage secretion under low-nitrogen conditions.These findings provide a comprehensive genetic analysis of the mucilage-secreting ability of maize aerial roots,contributing to our understanding of nitrogen fixation and offering potential avenues for enhancing nitrogen fixation in modern maize lines.This research advances knowledge of plant nutrient acquisition strategies and has implications for sustainable agricultural practices.展开更多
Maize(Zea mays)requires substantial amounts of nitrogen,posing a challenge for its cultivation.Recent work discovered that some ancient Mexican maize landraces harbored diazotrophic bacteria in mucilage secreted by th...Maize(Zea mays)requires substantial amounts of nitrogen,posing a challenge for its cultivation.Recent work discovered that some ancient Mexican maize landraces harbored diazotrophic bacteria in mucilage secreted by their aerial roots.To see if this trait is retained in modern maize,we conducted a field study of aerial root mucilage(ARM)in 258 inbred lines.We observed that ARM secretion is common in modern maize,but the amount significantly varies,and only a few lines have retained the nitrogen‐fixing traits found in ancient landraces.The mucilage of the high‐ARM inbred line HN5‐724 had high nitrogen‐fixing enzyme activity and abundant diazotrophic bacteria.Our genome‐wide association study identified 17 candidate genes associated with ARM across three environments.Knockouts of one candidate gene,the subtilase family gene ZmSBT3,confirmed that it negatively regulates ARM secretion.Notably,the ZmSBT3 knockout lines had increased biomass and total nitrogen accumulation under nitrogen‐free culture conditions.High ARM was associated with three ZmSBT3 haplotypes that were gradually lost during maize domestication,being retained in only a few modern inbred lines such as HN5‐724.In summary,our results identify ZmSBT3 as a potential tool for enhancing ARM,and thus nitrogen fixation,in maize.展开更多
基金the Department of Science & Technology of Shandong Province(No.2007BS02005)the Visiting Project of the Department of Education of Shandong Province,China(2008)for financial support.
文摘A new flavonoid with chalcone skeleton was isolated from the dried aerial roots of Ficus microcarpa. The structure of the compound was elucidated on the basis of spectral methods including 1D and 2D NMR. The new compound showed weak inhibitory effect on nitric oxide production and cytotoxicity against K562 and PC3 cells.
基金supported by the National Natural Science Foundation of China(32401919)he Department of Science and Technology of Henan Province(242102111126).
文摘Recent studies have shown that mucilage secretion from aerial roots is an essential feature of modern maize inbred lines,with some retaining the nitrogen-fixing capabilities of ancient landraces.To explore the genetic basis of nitrogen fixation in mucilage and its evolution from teosinte(Zea mays ssp.mexicana)to modern maize,we developed a recombinant inbred line(RIL)population from teosinte and cultivated it under low-nitrogen conditions.Large-scale,multi-year,and multi-environment analyses of RIL-Teo,Doubled Haploid-A(DH-A),Doubled Haploid-B(DH-B),and association populations led to the identification of 15 quantitative trait loci(QTL),68 quantitative trait nucleotides(QTN),and 59 candidate genes linked to mucilage secretion from aerial roots.Functional verification of the candidate gene ZmAco3,which is associated with mucilage secretion in aerial roots,demonstrated that deletion of this gene resulted in a reduction in mucilage secretion in aerial roots.In addition,most maize inbred lines exhibited stronger mucilage secretion from aerial roots under low-nitrogen conditions than under normal-nitrogen conditions.We categorized mucilage secretion into constitutive and low-nitrogen-inducible types.Through genotype-by-environment interaction studies,8 QTL,16 QTN,and 19 candidate genes were identified,revealing the genetic mechanisms underlying mucilage secretion under low-nitrogen conditions.These findings provide a comprehensive genetic analysis of the mucilage-secreting ability of maize aerial roots,contributing to our understanding of nitrogen fixation and offering potential avenues for enhancing nitrogen fixation in modern maize lines.This research advances knowledge of plant nutrient acquisition strategies and has implications for sustainable agricultural practices.
基金the special fund at Henan Agricultural University
文摘Maize(Zea mays)requires substantial amounts of nitrogen,posing a challenge for its cultivation.Recent work discovered that some ancient Mexican maize landraces harbored diazotrophic bacteria in mucilage secreted by their aerial roots.To see if this trait is retained in modern maize,we conducted a field study of aerial root mucilage(ARM)in 258 inbred lines.We observed that ARM secretion is common in modern maize,but the amount significantly varies,and only a few lines have retained the nitrogen‐fixing traits found in ancient landraces.The mucilage of the high‐ARM inbred line HN5‐724 had high nitrogen‐fixing enzyme activity and abundant diazotrophic bacteria.Our genome‐wide association study identified 17 candidate genes associated with ARM across three environments.Knockouts of one candidate gene,the subtilase family gene ZmSBT3,confirmed that it negatively regulates ARM secretion.Notably,the ZmSBT3 knockout lines had increased biomass and total nitrogen accumulation under nitrogen‐free culture conditions.High ARM was associated with three ZmSBT3 haplotypes that were gradually lost during maize domestication,being retained in only a few modern inbred lines such as HN5‐724.In summary,our results identify ZmSBT3 as a potential tool for enhancing ARM,and thus nitrogen fixation,in maize.
