ABSTRACT Tea plantations represent significant carbon (C) sinks in agricultural landscapes, yet how variety‐specific organic inputs are associated with the molecular composition and stability of soil organic carbon (SOC) within aggregate hierarchies remains unclear. Here, we examined soils from 15‐year‐old plantations of four tea varieties, including Chuancha No. 3 (CC3), Chuanmu No. 217 (CM217), Chuannong Huangyazao (CN), and Camellia sinensis “ Fuding Dabaicha ” (FD), in subtropical China. Soil samples were collected from topsoil (0–20 cm) and subsoil (20–40 cm) layers and fractionated into macro‐ (> 2 mm), large meso‐ (2–1 mm), meso‐ (1–0.25 mm), and microaggregates (< 0.25 mm). Solid‐state 13 C cross‐polarization magic‐angle spinning nuclear magnetic resonance spectroscopy was used to characterize aggregate‐associated SOC molecular composition. Aggregate‐associated SOC composition and carbon sequestration capacity differed significantly among tea varieties and soil layers. Across both topsoil (0–20 cm) and subsoil (20–40 cm), FD soils exhibited the highest SOC stocks, followed by CN, CM217, and CC3, indicating enhanced carbon sequestration potential under FD cultivation. The greater SOC accumulation in FD soils was accompanied by distinct molecular signatures, characterized by higher proportions of alkyl C and aromatic C and lower proportions of O‐alkyl C within aggregate fractions. FD soils also exhibited greater hydrophobicity, aromaticity, and humification indices, particularly in macroaggregates and microaggregates. Stability indices were positively correlated with alkyl C, aromatic C, and humification indices, suggesting that the enrichment of chemically resistant carbon components coupled with aggregate‐scale physical protection contributed to enhanced SOC stabilization. Our findings indicate that tea variety selection and management practices favoring stable aggregate formation may help enhance long‐term soil C sequestration.

Tea plantations can store substantial amounts of soil organic carbon (SOC), but the microbial mechanisms regulating SOC accumulation and stabilization during plantation development remain unclear. We sampled topsoil (0–20 cm) and subsoil (20–40 cm) across a chronosequence of tea plantations aged 4, 18, and 27 years and quantified SOC fractions and characterized microbial communities, microbial necromass carbon, and plant-derived carbon using phospholipid fatty acids (PLFAs), amino sugars, and lignin phenols, respectively. SOC stocks increased with plantation age, but accumulation rates declined significantly in both soil layers, while SOC composition shifted from labile to more recalcitrant fractions, indicating enhanced carbon stabilization. Microbial necromass carbon contributed 30.8–50.5 % of SOC, exceeding plant–derived carbon (11.2–27.8 %). The amino sugar–to–PLFA ratio (AS/PLFA) increased significantly only in the topsoil and showed no significant change in the subsoil. Depth–specific drivers differed: SOC dynamics in topsoil were primarily associated with fungal necromass accumulation per unit biomass (GluN/FPLFA), whereas subsoil SOC was more strongly related to bacterial necromass accumulation per unit biomass (MurA/BPLFA). These results highlight how microbial biomass turnover and necromass retention shape trade-offs between SOC accumulation and stabilization during plantation development.

It is important to know how microbial community and P cycling genes respond in rhizosphere of P-accumulating plants under different P treatments, and whether they would affect the changes in rhizosphere P availability and plant P uptake. Here, a pot experiment was conducted with a P-accumulating species Polygonum hydropiper under three P levels to analyze rhizosphere microbial structure and interactions, P cycling genes and their correlations with soil P availability and plant P accumulation. P. hydropiper showed an enhanced growth and P accumulation under high-P treatment compared with low-P and normal-P treatments. Available P (AP) concentration in rhizosphere soil was higher than in bulk soil under high-P treatment. Acidobacteria, Actinomycetota, Pseudomonadota, Verrucomicrobia, Ascomycota, Basidiomycota, and Chytridiomycota were significantly enriched in rhizosphere soil and closely related to other taxa within each intra-trophic network. Compared to bulk soil, the abundance of genes involved in P uptake and transport, and organic phosphonates degradation was higher in rhizosphere of P. hydropiper. Higher abundance of inorganic P solubilization genes were found in rhizosphere of P. hydropiper under high-P treatment than under normal-P treatment. Notably, phnW and gcd were the first two significant predictor of soil AP concentration in rhizosphere of P. hydropiper, followed by phnA and glpT, which were mainly harbored in Pseudomonadota, Actinomycetota, Acidobacteria, Verrucomicrobia, Bacteroidota, Chloroflexi, Gemmatimonadetes, and Nitrospirae. Moreover, these microbial taxa positively correlated with plant biomass production and P accumulation. These findings revealed that rhizosphere P mobilization was driven by microorganisms harboring key P-cycling genes, and thus facilitated plant P uptake.

Nitrogen (N) addition promotes phosphorus (P) accumulation in P-accumulating plants used for phytoextraction; however it remains unclear how N addition affects rhizosphere P availability, microbial interactions and functions to facilitate plant P uptake from high-P soils. The P-accumulating herb Polygonum hydropiper was treated with 100 mg N kg−1 and a control (0 mg N kg−1) in high-P soils to examine shifts in rhizosphere P availability and fractions, enzyme activities, microbial interactions and functions, and their relations with biomass and P accumulation. N addition significantly mobilized rhizosphere soil P of P. hydropiper, evidenced by increased concentration of CaCl2 extractable P (CaCl2-P), enzyme extractable P (enzyme-P), and microbial biomass P (MBP). Additionally, N addition significantly improved the activities of rhizosphere P-, N-, and C-related enzymes, and altered the structures and interactions of bacterial and fungal communities in high-P soils. This resulted in a notable increase in the complexity of intra-trophic and cross-tropic networks and the numbers of keystone species. The relative abundance of bacteria involved in chitinolysis, chemoheterotrophy, aerobic chemoheterotrophy, N fixation, and nitrate reduction was significantly improved by N addition. Additionally, significant positive correlations were observed among rhizosphere CaCl2-P, enzyme-P, MBP, enzyme activities, and bacterial communities in relation to shoot P accumulation. N addition triggered soil P mobilization and promoted plant P uptake through optimizing rhizosphere extracellular enzymes and microbiome. Our study provides new insights into the rhizosphere mechanisms of improving soil P availability and the P-phytoextraction capability of P-accumulating plants by N addition.

3,4-Dihydroxyphenylacetaldehyde synthase (DHPAAS) catalyzes oxygen-dependent conversion of 3,4-dihydroxyphenylalanine (dopa) to 3,4-dihydroxyphenylacetaldehyde (DHPAA), a likely cross-linking agent precursor of the insect cuticle. In the current study, extensive in vivo experiments in Aedes aegypti show that DHPAAS is essential for abdominal integrity, egg development and cuticle structure formation. Solid-state 13C nuclear magnetic resonance analysis of the Ae. aegypti cuticle molecular structure shows chemical shifts of 115 to 145 ppm, suggesting the presence of catechols derived from DHPAA. The crystal structure of insect DHPAAS was then solved, revealing an active site that is divergent from that of the homologous enzyme dopa decarboxylase. In the DHPAAS crystal structure, stabilization of the flexible 320-350 region accompanies the positioning of the 350-360 loop relatively close to the catalytic Asn192 residue while the conserved active site residue Phe103 adopts an open conformation away from the active center; these distinct features participate in the formation of a specific hydrophobic tunnel which potentially facilitates delivery of oxygen to pyridoxal 5'-phosphate in the conversion of dopa to DHPAA.

Fagopyrum tibeticum is a small woody shrub, which was initially classified under the genus Parapteropyrum (Polygonaceae) as Parapteryrum tibeticum. However, recent molecular evidences has shown that it should belong to Fagopyrum. By integrating cytological, morphological, and molecular biology evidences, we compare F. tibetium with the other Fagopyrum species, once again proving that F. tibeticum should belong to the Fagopyrum genus. Moreover, F. tibeticum is the only existing hexaploid species in the genus Fagopyrum. The speciation of F. tibeticum may be related to the uplift of the Qinghai Tibet Plateau and the distinctive climate environment.

Insect phenoloxidase, presented as an inactive precursor prophenoloxidase (PPO) in hemolymph, catalyzes melanin formation, which is involved in wound healing, pathogen killing, reversible oxygen collection during insect respiration, and cuticle and eggshell formation. Mosquitoes possess 9 to 16 PPO members across different genera, a number that is more than that found in other dipteran insects. However, the reasons for the redundancy of these PPOs and whether they have distinct biochemical properties and physiological functions remain unclear. Phylogenetic analysis confirmed that Aedes aegypti PPO6 (Aea-PPO6) is an ortholog to PPOs in other insect species, classified as the classical insect type, while other Aea-PPOs are unique to Diptera, herein referred to as the dipteran type here. We characterized two Aea-PPO members, Aea-PPO6, the classical insect type, and Aea-PPO10, a dipteran type, which exhibit distinct substrate specificities. By resolving Aea-PPO6’s crystal structure and creating a chimera protein (Aea-PPO6-cm) with Motif 1 ( 217 GDGPDSVVR 225 ) from Aea-PPO10, we identified the motif that determines PPO substrate specificity. In vivo, loss of Aea-PPO6 led to larval lethality, while Aea-PPO10 was involved in development, pigmentation, and immunity. Our results enhance the understanding of the functional diversification of mosquito PPOs.

Sugarcane (Saccharum spp.), a dual-purpose crop valued for sugar and energy production, serves as an important industrial raw material and has substantial economic impact. However, its complex polyploid genome, characterized by highly variable chromosomal composition due to interspecific hybridization between S. officinarum and S. spontaneum, renders the detection of chromosomal rearrangements elusive. Here, we investigated the genome architecture of sugarcane cultivars using fluorescence in situ hybridization (FISH) with chromosome-specific painting probes (S. officinarum) and repetitive sequence probes (S. spontaneum). High-resolution karyotyping revealed extensive variation in chromosome numbers and structures of sugarcane. Analysis revealed lineage-specific chromosomal rearrangements, including high-frequency translocations exclusively associated with S. spontaneum genomic backgrounds. Molecular cytogenetic maps achieved single-chromosome resolution, enabling precise tracking of translocation fragments. Notably, chromosome-specific polymorphism patterns were uncovered, with chromosomes 4 and 10 exhibiting elevated susceptibility to rearrangements. These findings provide a well-characterized profile of the potential chromosomal rearrangements for each nonhomologous chromosome, and even homeologous chromosomes between S. officinarum and S. spontaneum. The established cytogenetic system will serve as a diagnostic toolkit for tracing chromosomal inheritance in sugarcane breeding programs, and lay a foundation for investigating the mechanistic basis of chromosome translocations.

Rutin is a crucial bioactive compound that determines the nutritional value of Tartary buckwheat (TB). However, the potential of utilizing TB as a dietary source of rutin for human consumption remains largely unexplored. This study aims to address these knowledge gaps by conducting a detailed analysis of rutin content distribution in TB tissues. Our findings revealed a significant variation in rutin content across different plant tissues. Notably, higher levels of rutin were found in embryos and cotyledons compared to other tissues, highlighting them as the primary sites of rutin accumulation in TB seeds and sprouts. Additional research on the processing of TB showed that sprouts and seeds retain high rutin levels even after boiling, steaming, deep-frying, stir-frying, and popping. Comparative analysis of different TB-derived products confirmed that cooked seeds and sprouts can serve as significant dietary sources of rutin. This study offers a foundational framework for the development of future dietary recommendations and applications of TB.

Nitrogen (N) application provides an effective way to enhance the efficiency of phosphorus (P) -phytoextraction. However, it remains unknown how N application facilitates P accumulation of P-accumulating plant by regulating rhizosphere P fractions. We investigated the P accumulation, rhizosphere P fractions and phosphatase activities of Polygonum hydropiper (P. hydropiper), a P-accumulating herb, across four growth periods in high-P soil (800 mg P kg(-1)) with different N applications (0 and 100 mg N kg(-1)). N application increased shoot P accumulation of P. hydropiper compared with the control, with the greatest shoot P accumulation in mining ecotype (ME) of P. hydropiper at 12 weeks. Compared with bulk soil, the concentration of H2O-Pi (Pi, inorganic P) and NaHCO3-P increased but the concentration of H2O-Po (Po, organic P) and NaOH-Po decreased in the rhizosphere after N application. Compared with the control, the stronger positive effects of NaHCO3-Po and HCl-Po on H2O-Pi and NaOH-Pi were observed after N application. The high activities of acid phosphomonoesterase (ACP) and alkaline phosphomonoesterase (ALP) in the rhizosphere of two ecotypes led to mineralization of Po. Overall, these results suggested that N application can enhance P-phytoextraction capability of P. hydropiper from high-P soil by increasing phosphatase activities and transforming P fractions. Our results also provided a practical optimization to extract excess P from high-P soil by P-accumulating plant.

Background Tartary buckwheat, Fagopyrum tataricum , is a pseudocereal crop with worldwide distribution and high nutritional value. However, the origin and domestication history of this crop remain to be elucidated. Results Here, by analyzing the population genomics of 567 accessions collected worldwide and reviewing historical documents, we find that Tartary buckwheat originated in the Himalayan region and then spread southwest possibly along with the migration of the Yi people, a minority in Southwestern China that has a long history of planting Tartary buckwheat. Along with the expansion of the Mongol Empire, Tartary buckwheat dispersed to Europe and ultimately to the rest of the world. The different natural growth environments resulted in adaptation, especially significant differences in salt tolerance between northern and southern Chinese Tartary buckwheat populations. By scanning for selective sweeps and using a genome-wide association study, we identify genes responsible for Tartary buckwheat domestication and differentiation, which we then experimentally validate. Comparative genomics and QTL analysis further shed light on the genetic foundation of the easily dehulled trait in a particular variety that was artificially selected by the Wa people, a minority group in Southwestern China known for cultivating Tartary buckwheat specifically for steaming as a staple food to prevent lysine deficiency. Conclusions This study provides both comprehensive insights into the origin and domestication of, and a foundation for molecular breeding for, Tartary buckwheat.

Phosphorus (P)-hyperaccumulators for phytoextraction from P-polluted areas generally show rapid growth and accumulate large amounts of P without any toxicity symptom, which depends on a range of physiological processes and gene expression patterns that have never been explored. We investigated growth, leaf element concentrations, P fractions, photosynthetic traits, and leaf metabolome and transcriptome response in amphibious P-hyperaccumulators, Polygonum hydropiper and P. lapathifolium, to high-P exposure (5 mmol L-1), with 0.05 mmol L-1 as the control. Under high-P exposure, both species demonstrated good growth, allocating more P to metabolite P and inorganic P (Pi) accompanied by high potassium and calcium. The expression of a cluster of unigenes associated with photosynthesis was maintained or increased in P. lapathifolium, explaining the increase in net photosynthetic rate and the rapid growth under high-P exposure. Metabolites of trehalose metabolism, including trehalose 6-phosphate and trehalose, were sharply increased in both species by the high-P exposure, in line with the enhanced expression of associated unigenes, indicating that trehalose metabolic pathway was closely related to high-P tolerance. These findings elucidated the physiological and molecular responses involved in the photosynthesis and trehalose metabolism in P-hyperaccumulators to high-P exposure, and provides potential regulatory pathways to improve the P-phytoextraction capability.

Arylalkylamine N-acetyltransferase (aaNAT) is a crucial enzyme that catalyses the transfer of acetyl groups from acetyl coenzyme A to arylalkylamines and arylamines. Evolutionary studies have identified a distinct class of aaNATs specific to mosquitoes, yet their functions remain elusive. This study focuses on Ae-aaNAT7, a mosquito-unique gene in Aedes aegypti (Diptera:Culicidae), to explore its functionality. Temporal and spatial expression analysis of Ae-aaNAT7 mRNA revealed high expression during embryonic development and in first-instar larvae, with notable expression in the limbs of adult mosquitoes based on tissue expression profiling. By further employing CRISPR/Cas9 technology for loss-of-function studies, our investigation revealed a reduction in the area of white spotting in the limbs of Ae-aaNAT7 mutant adult mosquitoes. Further investigation revealed a significant decrease in the fecundity and hatchability of the mutants. Dissection of the ovaries from Ae-aaNAT7 heterozygous mutants showed a noticeable reduction in the oocyte area compared with wild type. Dissection of the exochorion of the eggs from Ae-aaNAT7 homozygous mutants consistently revealed a striking absence of mature embryos. In addition, RNA interference experiments targeting Ae-aaNAT7 in males resulted in a reduction in fecundity, but no effect on hatchability was observed. These collective insights underscore the substantial impact of Ae-aaNAT7 on reproduction and its pivotal contribution to adult limb pigmentation in Ae. aegypti. These revelations offer insights pivotal for the strategic design of future insecticide targets.

Little is known about the blood-feeding physiology of arbovirus vector Aedes aegypti although this type of mosquito is known to transmit infectious diseases dengue, Zika, yellow fever, and chikungunya. Blood feeding in the female A. aegypti mosquito is essential for egg maturation and for transmission of disease agents between human subjects. Here, we identify the A. aegypti sulfakinin receptor gene SKR from the A. aegypti genome and show that SKR is expressed at different developmental stages and in varied anatomical localizations in the adult mosquito (at three days after eclosion), with particularly high expression in the CNS. Knockingdown sulfakinin and sulfakinin receptor gene expression in the female A. aegypti results in increased blood meal intake, but microinjection in the thorax of the sulfakinin peptide 1 and 2 both inhibits dose dependently blood meal intake (and delays the time course of blood intake), which is reversible with receptor antagonist. Sulfakinin receptor expressed ectopically in mammalian cells CHO-K1 responds to sulfakinin stimulation with persistent calcium spikes, blockable with receptor antagonist. These data together suggest that activation of the Gq protein-coupled (i.e., calcium-mobilizing) sulfakinin receptor inhibits blood meal intake in female A. aegypti mosquitoes and could serve as a strategic node for the future control of A. aegypti mosquito reproduction/population and disease transmission.

F. cymosum, which is the most widely distributed buckwheat wild resource, represents high genetic diversity in wild population. Due to the environmental changes and human actions that result in the loss of F. cymosum wild resources, it is urgent to protect F. cymosum wild resources. In this study, based on the collected F. cymosum wild resources, we compared the differences between sexual reproduction and asexual reproduction on the off-site reproduction of F. cymosum and discussed the effects of tuber propagation on the offsite propagation of wild buckwheat in different geographical environments. These results showed that the tuber reproduction of F. cymosum was relatively better, and it was conducive to its outcrossing and fruiting after a large population was formed by off-site reproduction. The differences on the altitude of habitat, climate condition and breeding site might cause influence on the germination, growth and reproduction of wild F. cymosum. The geographical conditions and local climate at Zhaojue County of Yunnan province were suitable for the off-site reproduction of F. cymosum. Collectively, these results might provide certain reference for ex situ propagation and conservation of F. cymosum.

Abstract3,4-Dihydroxyphenylacetaldehyde synthase (DHPAAS) catalyzes the direct conversion of 3,4-dihydroxyphenylalanine to 3,4-dihydroxyphenylacetaldehyde (DHPAA), an important intermediate in the formation of flexible insect cuticle. In order to clarify the precise roles DHPAAS plays in insect development and survival, DHPAAS was characterized throughout the physiological to the molecular levels. Extensive in vivo experiments inAedes aegypticonfirm that DHPAAS is essential for blood feeding, egg development and cuticle structure formation. The crystal structure of insect DHPAAS was then solved to reveal the structural basis underlying the catalytic production of the key cuticle intermediate DHPAA. The molecular view shows a DHPAAS active site that is distinct from that of the homologous enzyme 3,4-dihydroxyphenylalanine decarboxylase. Stabilization of the flexible 320–350 region is observed to position the 350–360 loop towards the catalytic asparagine residue, and these distinct features are suggested to promote pyridoxal 5'-phosphate-dependent amine oxidation. Additional molecular dynamics simulations further support the involvement of Phe82, Tyr83 and Asn195 in substrate binding and catalysis, and also shows increased fluctuations limited to loop residues 330–345 inAedes aegyptiDHPAAS.

A new variety of Fagopyrum caudatum—Fagopyrum caudatum var. grandiflorum—is described and illustrated from Longnan City, Gansu Province, China. The new variety could be easily distinguished from F. caudatum var. caudatum mainly by its larger flower size (5.3–5.6 mm vs. 3.2–3.5 mm). The detailed description and photographs of the new variety were provided.

Common buckwheat(Fagopyrum esculentum)is an ancient crop with a world-wide distribution.Due to its excellent nutritional quality and high economic and ecological value,common buckwheat is becoming increasingly important throughout the world.The availability of a high-quality reference genome sequence and population genomic data will accelerate the breeding of common buckwheat,but the high heterozygosity due to the outcrossing nature has greatly hindered the genome assembly.Here we report the assembly of a chromosome-scale high-quality reference genome of F.esculentum var.homotropicum,a homozygous self-pollinating variant of common buckwheat.Comparative genomics re-vealed that two cultivated buckwheat species,common buckwheat(F.esculentum)and Tartary buck-wheat(F.tataricum),underwent metabolomic divergence and ecotype differentiation.The expansion of several gene families in common buckwheat,including FhFAR genes,is associated with its wider distri-bution than Tartary buckwheat.Copy number variation of genes involved in the metabolism of flavonoids is associated with the difference of rutin content between common and Tartary buckwheat.Furthermore,we present a comprehensive atlas of genomic variation based on whole-genome resequencing of 572 accessions of common buckwheat.Population and evolutionary genomics reveal genetic variation associated with environmental adaptability and floral development between Chinese and non-Chinese cultivated groups.Genome-wide association analyses of multi-year agronomic traits with the content of flavonoids revealed that Fh05G014970 is a potential major regulator of flowering period,a key agro-nomic trait controlling the yield of outcrossing crops,and that Fh06G015130 is a crucial gene underlying flavor-associated flavonoids.Intriguingly,we found that the gene translocation and sequence variation of FhS-ELF3 contribute to the homomorphic self-compatibility of common buckwheat.Collectively,our re-sults elucidate the genetic basis of speciation,ecological adaptation,fertility,and unique flavor of com-mon buckwheat,and provide new resources for future genomics-assisted breeding of this economically important crop.

Arylalkylamine N-acetyltransferase (aaNAT), considered a potential new insecticide target, catalyzes the acetylation of arylalkylamine substrates such as serotonin and dopamine and, hence, mediates diverse functions in insects. However, the origin of insect aaNATs (iaaNATs) and the evolutionary process that generates multiple aaNATs in mosquitoes remain largely unknown. Here, we have analyzed the genomes of 33 species to explore and expand our understanding of the molecular evolution of this gene family in detail. We show that aaNAT orthologs are present in Bacteria, Cephalochordata, Chondrichthyes, Cnidaria, Crustacea, Mammalia, Placozoa, and Teleoste, as well as those from a number of insects, but are absent in some species of Annelida, Echinozoa, and Mollusca as well as Arachnida. Particularly, more than 10 aaNATs were detected in the Culicinae subfamily of mosquitoes. Molecular evolutionary analysis of aaNAT/aaNAT-like genes in mosquitoes reveals that tandem duplication events led to gene expansion in the Culicinae subfamily of mosquitoes more than 190 million years ago. Further selection analysis demonstrates that mosquito aaNATs evolved under strongly positive pressures that generated functional diversity following gene duplication events. Overall, this study may provide novel insights into the molecular evolution of the aaNAT family in mosquitoes.

Template activity for histones of RNA fractions derived from Artemia salina embryos at different developmental stages were measured in a Krebs ascites cell-free system. Appreciable amounts of acid-soluble polypeptides comigrating with Hela cell histone markers on acrylamide gel electrophoresis were detected only when RNA fractions from nauplii were used. Tryptic peptide analysis by high voltage electrophoresis of the translational products had a pattern qualitatively similar to that of in vivo labeled histone markers from Hela.