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.

Identification of a major quantitative trait locus and its candidate underlying genetic variation for rice stigma exsertion rate

Stigma exsertion in male sterile lines of hybrid rice is important for seed yield.In the present study, ZS616 [Oryza sativa subsp.Xian(indica)], a male sterile line with a stigma exsertion rate(SER) as high as 94.5%, was crossed to DS552, a japonica line with almost no exserted stigmas.F3 plants with extremely low and high SER were sequenced to identify SER-associated quantitative trait loci(QTL).A major QTL for SER, qSER-3.1, was identified along with other QTL on chromosome 3 in a 3.9 Mb region.A total of 307 nonsynonymous single-nucleotide polymorphisms(SNPs) and 27 frame-shift insertion/deletions(InDels)differentiating ZS616 and DS552 were identified in the region containing qSER-3.1.Most SNPs(294) and InDels(25) were excluded after further analysis because they were shared by ZS616 and low(<2.0%) SER accessions in the Huazhong Agricultural University(HAU) core rice collection.Association analysis using the full HAU collection identified a 17-bp InDel in OS03 G0689400 as the most likely causal genetic variant underlying qSER-3.1.ZS616-type accessions(n = 54, with the 17-bp insertion) in the HAU collection had minimum(16.5%)and mean(39.6%) SERs significantly greater than those(n = 424) without the insertion(with minimum and mean SERs of 0.2% and 20.6%, respectively).Thus, this study identified a major QTL for stigma exsertion and revealed the mutation in a candidate gene for the QTL.

Efficacy Evaluation of 25% Abamectin·Etoxazole SC against Red Spider (Tetranychus cinnbarinus ) in Ornamental Rose

[Objective]The paper was to understand the control effect and the optimum dosage of 25% abamectin·etoxazole SC for controlling red spider in ornamental rose. [Method] Using stem-leaf spraying method,the control effect of 25% abamectin·etoxazole SC against red spider was determined. Significance of difference was examined by Duncan's new multiple range test( DMRT). [Result] The control effect of 25% abamectin · etoxazole SC sprayed at the dose of25-31. 25 mg a. i./kg on red spider was over 82. 0% at 21 d post spraying,higher than that of 110 g/L etoxazole SC sprayed at the dose of 27. 5 mg a. i./kg and1. 8% abamectin EC sprayed at the dose of 9 mg a. i./kg. [Conclusion]25% Abamectin·etoxazole SC sprayed at the doses of 25-31. 25 mg a. i./kg could effectively control the damage of red spider in ornamental rose,and can be widely used in production.

Control Effect of Validamycin against Seedling Blight of Atractylodes macrocephala

[Objective] The paper was to explore the effective agent against seedling blight of Atractylodes macrocephala. [Method] The control effects of 60% validamycin A SP against seeding blight of A. macrocephala were studied in the field, and compared with that of control agent 20% bismerthiazol WP. [Result] At 14 d post the third spraying, the control effect of 60% validamycin A SP at the dose of 495-540 g/hm^2 was 76.9%,which was equivalent to that of control agent 20% bismerthiazol WP sprayed at the dose of 270 g/hm^2(76.7%). [Conclusion] 60% Validamycin A SP could be used as the ideal agent against seedling blight of A. macrocephala, with good prospects of application and popularization.

Field Efficacy Evaluation of 68% Metalaxyl-M·Mancozeb WDG against Dendrobium officinale Blight

The control effect of 68% Metalaxyl-M·Mancozeb WDG against Dendrobium officinale blight was studied. The results showed that the control effect of 68% Metalaxyl-M·Mancozeb WDG at the dose of 1 133-1 360 mg/kg against D. officinale blight was over 78.4% at 14 d post spraying, which was equivalent to that of control agent 72% Cymoxanil·Mancozeb WP(1 200 mg/kg) and 80% Mancozeb WP(1 143 mg/kg).Therefore, 68% Metalaxyl-M·Mancozeb WDG sprayed at the dose of 1 133-1 360 mg/kg could effectively control the damage of D. officinale blight.

New Standardized Cultivation Techniques for Tea Seed Production

The tea from tea plants,a kind of traditional leaf plant,is deeply loved by people,but the production of tea fruit and its important functional value have been seriously underestimated for a long time.To this end,the oil plant function and comprehensive utilization value of tea oil from tea fruit were introduced,and a set of new standardized cultivation technique of tea plants that could fully exert the potential of tea seed yield was put forward.The technique could increase the tea seed yield per mu from less than 50kg in traditional tea gardens to more than 200 kg,which broke through the production mode of single leaf picking in traditional tea gardens,gave play to the natural reproductive growth advantages of tea plants,achieved"leaf-seed dual harvest",and promoted the improvement of tea industry quality and efficiency,thereby creating a new path to achieve the"leaf-fruit dual use"of tea plants.

Nondestructive perception of potato quality in actual online production based on cross-modal technology

Nowadays,China stands as the global leader in terms of potato planting area and total potato production.The rapid and nondestructive detection of the potato quality before processing is of great significance in promoting rural revitalization and augmenting farmers’income.However,existing potato quality sorting methods are primarily confined to theoretical research,and the market lacks an integrated intelligent detection system.Therefore,there is an urgent need for a post-harvest potato detection method adapted to the actual production needs.The study proposes a potato quality sorting method based on cross-modal technology.First,an industrial camera obtains image information for external quality detection.A model using the YOLOv5s algorithm to detect external green-skinned,germinated,rot and mechanical damage defects.VIS/NIR spectroscopy is used to obtain spectral information for internal quality detection.A convolutional neural network(CNN)algorithm is used to detect internal blackheart disease defects.The mean average precision(mAP)of the external detection model is 0.892 when intersection of union(IoU)=0.5.The accuracy of the internal detection model is 98.2%.The real-time dynamic defect detection rate for the final online detection system is 91.3%,and the average detection time is 350 ms per potato.In contrast to samples collected in an ideal laboratory setting for analysis,the dynamic detection results of this study are more applicable based on a real-time online working environment.It also provides a valuable reference for the subsequent online quality testing of similar agricultural products.

Influence of rice black streaked dwarf virus on the ecological fitness of non-vector planthopper Nilaparvata lugens （Hemiptera： Delphacidae）

瑞斯黑人条纹矮子病毒(RBSDV ) 被小棕色的 planthopper (SBPH ) 播送， Laodelphax striatellus (掉落) 。非向量大米褐 planthopper (BPH ) ， Nilaparvata lugens (St&aring;l ) ，在稻地里与 SBPH 分享一样的主人大米植物。在 RBSDV 和在感染的植物上喂的 BPH 的生态的健康感染的米饭植物的营养的作文的变化在两个人工的气候房间和领域条件下面被学习。在感染的米饭种的 RBSDV 的 16 检测氨基酸和可溶的糖的内容比在健康的那些高。在有的 diseased 植物 BPH 上，显著地更高的 nymph 的幸存评价，男性，的 nymph 的持续时间女成年人的重量，以及与 BPH 相比的鸡蛋 hatchability 在健康植物上正在被喂。然而，在女美女持续时间，长寿和肥沃没有明显的差别。防卫酶(superoxidase dismutase，草皮和过氧化氢酶，猫) 并且除去的酶(carboxylesterase， CAE 和谷胱甘肽 S-transferase， GST ) 在在 diseased 上喂的 BPH 成年人，植物举办了显著地更高的活动。结果显示 RBSDV 感染的米饭植物改进了棕色的 planthopper，一个严肃的害虫然而并非 RBSDV 病毒的一个传输器的生态的健康。

Shoot rot of Zizania latifolia and the first record of its pathogen Pantoea ananatis in China

The aquatic grass Zizania latifolia grows symbiotically with the fungus Ustilago esculenta producing swollen structures called Jiaobai,widely cultivated in China.A new disease of Z.latifolia was found in Zhejiang Province,China.Initial lesions appeared on the leaf sheaths or sometimes on the leaves near the leaf sheaths.The lesions extended along the axis of the leaf shoots and formed long brown to dark brown streaks from the leaf sheath to the leaf,causing sheath rot and death of entire leaves on young plants.The pathogen was isolated and identified as the bacterium Pantoea ananatis,based on 16 S ribosomal RNA(r RNA)gene sequencing,multilocus sequence analysis(atp D(β-subunit of ATP synthase F1),gyr B(DNA gyrase subunit B),inf B(translation initiation factor 2),and rpo B(β-subunit of RNA polymerase)genes),and pathogenicity tests.Ultrastructural observations using scanning electron microscopy revealed that the bacterial cells colonized the vascular tissues in leaf sheaths,forming biofilms on the inner surface of vessel walls,and extended between vessel elements via the perforated plates.To achieve efficient detection and diagnosis of P.ananatis,species-specific primer pairs were designed and validated by testing closely related and unrelated species and diseased tissues of Z.latifolia.This is the first report of bacterial sheath rot disease of Z.latifolia caused by P.ananatis in China.

Catalase promotes whitefly adaptation to high temperature by eliminating reactive oxygen species

Thermal stress usually leads to excessive production of reactive oxygen species(ROS)in all aerobic organisms.Catalases(CAT)are the key antioxidant enzymes,which act as the first line of defense against ROS in the antioxidant pathway.The highly invasive and widely distributed whitefly Bemisia tabaci MED damages plants by feeding as well as by transmitting many plant viruses.Previous studies have shown that strong adaptability to high temperature helps explain the spread of MED around the world.However,the mechanism underlying high temperature adaptation of this pest is not well understood.In this study,6 CAT genes were identified from the MED genome and transcriptome dataset,among which BtCAT1,BtCAT2,and BtCAT3 were found to be highly expressed in adults.The expression of BtCAT1,BtCAT2,or BtCAT3 increased with induction temperature and induction time.The MED was exposed with mean high temperature(30℃ or 35℃)and a short-term extremely high temperature(39℃ or 41℃)after the silencing of BtCAT1,BtCAT2,or BtCAT3 to significantly increased ROS levels by at least 0.5 times and significantly decreased survival rate and fecundity of MED adults.The ROS level in the treated specimens gradually returned to a normal level after 24 h at 25℃,but the survival rate still declined significantly.Taken together,our results demonstrate that CAT could help B.tabaci adapt to long-term mean high temperatures and short-term extremely high temperatures by eliminating excessive ROS.