Diverse O-methyltransferases catalyze the biosynthesis of floral benzenoids that repel aphids from the flowers of waterlily Nymphaea prolifera

Nymphaea is a key genus of the ANA grade(Amborellales,Nymphaeales,and Austrobaileyales)of basal flowering plants,which serve as a key model to study the early evolution of floral traits.In this study,we comprehensively investigated the emission,biosynthesis,and biological function of the floral scent in a night-blossoming waterlily Nymphaea prolifera.The headspace volatile collection combined with GC-MS analysis showed that the floral scent of N.prolifera is predominately comprised by methylated benzenoids including anisole,veratrole,guaiacol,and methoxyanisole.Moreover,the emission of these floral benzenoids in N.prolifera exhibited temporal and spatial pattern with circadian rhythm and tissue specificity.By creating and mining transcriptomes of N.prolifera flowers,12 oxygen methyltransferases(NpOMTs)were functionally identified.By in vitro enzymatic assay,NpOMT3,6,and 7 could produce anisole and NpOMT5,7,9,produce guaiacol,whereas NpOMT3,6,9,11 catalyzed the formation of veratrole.Methoxyanisole was identified as the universal product of all NpOMTs.Expression patterns of NpOMTs provided implication for their roles in the production of the respective benzenoids.Phylogenetic analysis of OMTs suggested a Nymphaea-specific expansion of the OMT family,indicating the evolution of lineage-specific functions.In bioassays,anisole,veratrole,and guaiacol in the floral benzenoids were revealed to play the critical role in repelling waterlily aphids.Overall,this study indicates that the basal flowering plant N.prolifera has evolved a diversity and complexity of OMT genes for the biosynthesis of methylated benzenoids that can repel insects from feeding the flowers.These findings provide new insights into the evolutional mechanism and ecological significance of the floral scent from early-diverged flowering plants.

Pangenome of water caltrop reveals structural variations and asymmetric subgenome divergence after allopolyploidization

Water caltrop(Trapa spp.,Lythraceae)is a traditional but currently underutilized non-cereal crop.Here,we generated chromosome-level genome assemblies for the two diploid progenitors of allotetraploid Trapa.natans(4x,AABB),i.e.,diploid T.natans(2x,AA)and Trapa incisa(2x,BB).In conjunction with four published(sub)genomes of Trapa,we used gene-based and graph-based pangenomic approaches and a pangenomic transposable element(TE)library to develop Trapa genomic resources.The pangenome displayed substantial gene-content variationwith dispensable and private gene clusters occupying a large proportion(51.95%)of the total cluster sets in the six(sub)genomes.Genotyping of presence-absence variation(PAVs)identified 40453 PAVs associated with 2570 genes specific to A-or B-lineages,of which 1428were differentially expressed,andwere enriched in organ development process,organic substancemetabolic process and response to stimulus.Comparative genome analyses showed that the allotetraploid T.natans underwent asymmetric subgenome divergence,with the B-subgenome being more dominant than the A-subgenome.Multiple factors,including PAVs,asymmetrical amplification of TEs,homeologous exchanges(HEs),and homeolog expression divergence,together affected genome evolution after polyploidization.Overall,this study sheds lights on the genome architecture and evolution of Trapa,and facilitates its functional genomic studies and breeding program.

The Application of Acidic Electrolyzed Water to Grape Cultivation in the Southern Regions

Experimental studies have shown that AEW( Acidic Electrolyzed Water) plays a strong role in killing grape virus,and it has instantaneous,broad-spectrum,efficient,safe and non-residual fungicidal properties. The results show that spraying AEW,and spraying alkaline electrolyzed water first and then AEW,can play a good role in controlling the virus damage of grape downy mildew,Botrytis cinerea,anthracnose,grape Alternaria spot,and anthrachose of grape,with foliar control effect of 93. 5%,96. 2%,93. 20%,100% and 87. 9%,respectively,and ear control effect of 88%,92%,84%,84% and 72%,respectively. AEW can replace pesticide,and can promote the average grape weight and sugar degree.

Design and experimental research on disc-type seeding device for single-bud sugarcane seeds

Mechanized sugarcane seeding is one of the effective technical measures for improving seeding uniformity and operation efficiency.However,the imperfection of supporting equipment limits the promotion and application of this technology.As there are some problems in domestic sugarcane planting machines currently,such as large auxiliary labor,high labor intensity,low seeding uniformity,and large amount of seeds,a disc-type single-bud sugarcane seed metering device was innovatively designed on the basis of the analysis of physical properties of single-bud sugarcane seeds and the combination with agronomic requirements for field planting in this paper.Solidworks was used to simulate and analyze the mechanism,check the theoretical parameters,and process the test prototype.Through single-factor experiments,the effective factors affecting seeding uniformity were determined.A multi-factor orthogonal rotation test was designed,data were collected and then SPSS was used to get the optimal parameters for the seeding uniformity:the advancement speed of machine is 0.22 m/s,the number of disc seeding grooves is 10,the rotating disc speed is 0.18 r/s,and the seeding uniformity is 86.2%;the seeding uniformity was verified by field trial,and the results showed that the average seeding uniformity of the field verification was 83%,with the error 3.2% relative to the optimization result.The relative error is within 10%,indicating that the optimization result is reliable and meets the requirements of seeding uniformity,thus providing theoretical basis for the research and development of the disc-type single-bud seeding device.