Alternative splicing of the PECTINESTERASE gene encoding a cell wall-degrading enzyme affects postharvest softening in grape

The firmness of table grape berries is a crucial quality parameter. Despite extensive research on postharvest fruit softening, its precise molecular mechanisms remain elusive. To enhance our comprehension of the underlying molecular factors, we initially identified differentially expressed genes(DEGs) by comparing the transcriptomes of folic acid(FA)-treated and water-treated(CK) berries at different time points. We then analyzed the sequences to detect alternatively spliced(AS) genes associated with postharvest softening. A total of 2,559 DEGs were identified and categorized into four subclusters based on their expression patterns, with subcluster-4 genes exhibiting higher expression in the CK group compared with the FA treatment group. There were 1,045 AS-associated genes specific to FA-treated berries and 1,042 in the CK-treated berries, respectively. Gene Ontology(GO) annotation indicated that the AS-associated genes in CK-treated berries were predominantly enriched in cell wall metabolic processes,particularly cell wall degradation processes. Through a comparison between treatment-associated AS genes and subcluster-4 DEGs, we identified eight genes, including Pectinesterase 2(VvPE2, Vitvi15g00704), which encodes a cell wall-degrading enzyme and was predicted to undergo an A3SS event. The reverse transcription polymerase chain reaction further confirmed the presence of a truncated transcript variant of VvPE2 in the FA-treated berries.Our study provides a comprehensive analysis of AS events in postharvest grape berries using transcriptome sequencing and underscores the pivotal role of VvPE2 during the postharvest storage of grape berries.

State-selective charge exchange cross sections in collisions of highly-charged sulfur ions with helium and molecular hydrogen

The state-selective cross section data are useful for understanding and modeling the x-ray emission in celestial observations.In the present work,using the cold target recoil ion momentum spectroscopy,for the first time we investigated the state-selective single electron capture processes for S^(q+)–He and H_(2)(q=11–15)collision systems at an impact energy of q×20 keV and obtained the relative state-selective cross sections.The results indicate that only a few principal quantum states of the projectile energy level are populated in a single electron capture process.In particular,the increase of the projectile charge state leads to the population of the states with higher principal quantum numbers.It is also shown that the experimental averaged n-shell populations are reproduced well by the over-barrier model.The database is openly available in Science Data Bank at 10.57760/sciencedb.j00113.00091.

Identification,characterization,and verification of miR399 target gene in grape

The microRNA miR399 plays an important role in phosphorus signal transduction pathways in plants.Previously,miR399 was shown to be closely associated with berry ripening in grape(Vitis vinifera).The objective of the present study was to elucidate the evolutionary characteristics of the miR399 gene family in grape and to verify the cleavage effect on the target genes.Grape miR399s were identified by miRNA sequencing and retrieval from the miRBase database.The mature sequences and precursor sequences were subjected to phylogenetic analysis to reconstruct evolutionary trees,as well as secondary structure analysis of the precursor sequence,and prediction of target genes.The cisacting elements in the miR399 promoter were predicted and the cleavage effect of grape miR399b on its target genes was verified.The grape miR399 family comprised nine precursor sequences and nine mature sequences.The precursor sequences formed a typical and stable stem—loop structure.The minimum folding free energy ranged from-55.70 kcal·mol^(-1)to-37.40 kcal·mol^(-1).Multiple sequence alignment revealed that the miR399 family was highly conserved.The grape miR399 family was phylogenetically closely related to peach,apple,and citrus miR399s.Grape miR399s were predicted to target inorganic phosphate transporter 1—3,phospholipase D delta-like,and beta-glucuronosyltransferase.The cleavage effect of grape miR399b on the target genes was verified by means of a dual-luciferase assay and 5’RLM-RACE.Histochemical GUS staining showed that the promoter activity of miR399b was promoted by GA3treatment.

Genome-wide association study of 23 f lowering phenology traits and 4 f loral agronomic traits in tree peony (Paeonia section Moutan DC.) reveals five genes known to regulate f lowering time

Tree peony is a unique traditional f lower in China,with large,fragrant,and colorful f lowers.However,a relatively short and concentrated f lowering period limits the applications and production of tree peony.A genome-wide association study(GWAS)was conducted to accelerate molecular breeding for the improvement of f lowering phenology traits and ornamental phenotypes in tree peony.A diverse panel of 451 tree peony accessions was phenotyped for 23 f lowering phenology traits and 4 f loral agronomic traits over 3 years.Genotyping by sequencing(GBS)was used to obtain a large number of genome-wide single-nucleotide polymorphisms(SNPs)(107050)for the panel genotypes,and 1047 candidate genes were identified by association mapping.Eighty-two related genes were observed during at least 2 years for f lowering,and seven SNPs repeatedly identified for multiple f lowering phenology traits over multiple years were highly significantly associated with five genes known to regulate f lowering time.We validated the temporal expression profiles of these candidate genes and highlighted their possible roles in the regulation of f lower bud differentiation and f lowering time in tree peony.This study shows that GWAS based on GBS can be used to identify the genetic determinants of complex traits in tree peony.The results expand our understanding of f lowering time control in perennial woody plants.Identification of markers closely related to these f lowering phenology traits can be used in tree peony breeding programs for important agronomic traits.

Creation of a watermelon haploid inducer line via ClDMP3-mediated single fertilization of the central cell

The use of doubled haploids is one of the most efficient breeding methods in modern agriculture.Irradiation of pollen grains has been shown to induce haploids in cucurbit crops,possibly because it causes preferential fertilization of the central cell over the egg cell.Disruption of the DMP gene is known to induce single fertilization of the central cell,which can lead to the formation of haploids.In the present study,a detailed method of creating a watermelon haploid inducer line via ClDMP3 mutation is described.The cldmp3 mutant induced haploids in multiple watermelon genotypes at rates of up to 1.12%.These haploids were confirmed via fluorescent markers,flow cytometry,molecular markers,and immuno-staining.The haploid inducer created by this method has the potential to greatly advance watermelon breeding in the future.

Integrated analysis of transcriptomic and proteomic data from tree peony(P.ostii)seeds reveals key developmental stages and candidate genes related to oil biosynthesis and fatty acid metabolism

Tree peony(Paeonia section Moutan DC.)seeds are an excellent source of beneficial natural compounds that promote health,and they contain high levels of alpha-linolenic acid(ALA).In recent years,tree peony has been emerging as an oil crop.Therefore,combined analysis of the transcriptome and proteome of tree peony(P.ostii)seeds at 25,32,39,53,67,81,88,95,and 109 days after pollination(DAP)was conducted to better understand the transcriptional and translational regulation of seed development and oil biosynthesis.A total of 38,482 unigenes and 2841 proteins were identified.A total of 26,912 differentially expressed genes(DEGs)and 592 differentially expressed proteins(DEPs)were clustered into three groups corresponding to the rapid growth,seed inclusion enrichment and conversion,and late dehydration and mature stages of seed development.Fifteen lipid metabolism pathways were identified at both the transcriptome and proteome levels.Pathway enrichment analysis revealed that a period of rapid fatty acid biosynthesis occurred at 53–88 DAP.Furthermore,211 genes and 35 proteins associated with the fatty acid metabolism pathway,63 genes and 11 proteins associated with the biosynthesis of unsaturated fatty acids(UFAs),and 115 genes and 24 proteins associated with ALA metabolism were identified.Phylogenetic analysis revealed that 16 putative fatty acid desaturase(FAD)-encoding genes clustered into four FAD groups,eight of which exhibited the highest expression at 53 DAP,suggesting that they play an important role in ALA accumulation.RT-qPCR analysis indicated that the temporal expression patterns of oil biosynthesis genes were largely similar to the RNA-seq results.The expression patterns of fatty acid metabolism-and seed development-related proteins determined by MRM were also highly consistent with the results obtained in the proteomic analysis.Correlation analysis indicated significant differences in the number and abundance of DEGs and DEPs but a high level of consistency in expression patterns and metabolic pathways.The results of the present study represent the first combined transcriptomic and proteomic analysis of tree peony seeds and provide insight into tree peony seed development and oil accumulation.

Atomic structure and collision dynamics with highly charged ions

The research progresses on the investigations of atomic structure and collision dynamics with highly charged ions based on the heavy ion storage rings and electron ion beam traps in recent 20 years are reviewed.The structure part covers test of quantum electrodynamics and electron correlation in strong Coulomb field studied through dielectronic recombi-nation spectroscopy and VUV/x-ray spectroscopy.The collision dynamics part includes charge exchange dynamics in ion-atom collisions mainly in Bohr velocity region,ion-induced fragmentation mechanisms of molecules,hydrogen-bound and van de Waals bound clusters,interference,and phase information observed in ion-atom/molecule collisions.With this achievements,two aspects of theoretical studies related to low energy and relativistic energy collisions are presented.The applications of data relevant to key atomic processes like dielectronic recombination and charge exchanges involving highly charged ions are discussed.At the end of this review,some future prospects of research related to highly charged ions are proposed.

Geometric structure of N_(2)O^(q+)(q=5,6)studied by Ne^(8+)ion-induced Coulomb explosion imaging

We report the study on the complete three-body Coulomb explosion(CE)of N_(2)O^(q+)(q=5,6)induced by 56-keV/u Ne8+ion collision with N2O gaseous molecule.Six CE channels for N_(2)O^(5+)and seven for N_(2)O^(6+)are identified by measuring three ionic fragments and the charge-changed projectile in quadruple coincidence.Correspondingly the kinetic energy release(KER)and momentum correlation angle(MCA)distributions of three ionic fragments for each of the CE channels are also deduced.Numerical computation is presented to reconstruct the geometric structure of N_(2)O^(q+0prior to dissociation based on the measured KER and MCA.The N–N and N–O bond lengths and the N–N–O bond angles of N_(2)O^(q+)for each of the channels are determined.

OVEREXPRESSION OF PTRLEA7,A LATE EMBRYOGENESIS ABUNDANT FAMILY GENE FROM PONCIRUS TRIFOLIATA,CONFERS ENHANCED DROUGHT TOLERANCE BY ENHANCING ANTIOXIDANT CAPACITY

Late embryogenesis abundant(LEA)genes encode highly hydrophilic proteins that are essential in abiotic stress responses.However,most LEA genes in higher plants have not yet been investigated.This study identified an LEA family gene(PtrLEA7)from Poncirus trifoliata and studied its function in drought tolerance.The full-length coding sequence of PtrLEA7 was 420 bp encoding a protein of 139 amino acids.Phylogenetic analysis shows that PtrLEA7 protein belongs to the LEA_4 subfamily.Expression profiling by qPCR found that PtrLEA7 was strongly induced by dehydration,cold and ABA treatments,and slightly induced by salt stress.Subcellular localization reveals that PtrLEA7 protein was located in both cytoplasm and nucleus.To investigate its function,transgenic plants of both tobacco and Poncirus trifoliata overexpressing PtrLEA7 were obtained.Stress tolerance assays show that overexpression lines had enhanced dehydration and drought tolerance compared with wild type plants,indicating that PtrLEA7 positively regulates drought tolerance.In addition,transgenic plants had much higher expression levels of three antioxidant enzyme genes(CAT,SOD and POD)and significantly increased catalase enzyme activity,accompanied by reduced reactive oxygen species accumulation in comparison with wild type plants.Collectively,this study demonstrates that PtrLEA7 can confer enhanced drought tolerance partially via enhancing antioxidant capacity.