Comparison of carotenoid,chlorophyll concentrations and their biosynthetic transcript levels in different coloured cauliflower

Carotenoids and chlorophylls are among the most widely distributed pigments in nature that play essential roles in the photosynthetic apparatus and confer diverse colours in plants.Among all vegetables,cauliflower(Brassica oleracea L.ssp.var.botrytis)is rich in phytochemicals and is an important crop grown all over the world.This study investigates carotenoid and chlorophyll concentrations in differently pigmented cultivars and elucidates the role of transcriptional regulation of carotenoid accumulation including lutein andβ-carotene.Here,we characterised changes in pigments by UHPLC-DAD-ToF-MS and changes in transcript levels of carotenoid metabolic genes by qRT-PCR in florets and leaves of orange(‘Jaffa'and‘Sunset'),purple(‘Di Sicilia Violetto'and‘Graffiti'),green(‘Trevi')and white(‘Clapton')cultivars.Transcript levels of all carotenoid metabolic genes showed different transcript level patterns in the leaves and florets.Compared to the other cultivars,the orange cultivars had the highest levels ofβ-carotene in the florets and lutein in the leaves resulting in changes lutein/β-carotene ratios.In the green cultivar,higher transcript levels were also found,especially for phytoene synthase and phytoene desaturase genes of the core biosynthesis pathway.However,no increased carotenoid concentrations were observed,possibly due to a higher carotenoid turnover induced by the carotenoid cleavage dioxygenase 4 in the green cultivar.In the white(‘Clapton')and purple(‘Di Sicilia Violetto'and‘Graffiti')cultivars the phytoene desaturase transcript levels as well as carotenoid concentrations were low.Chlorophyll concentrations changed in trend comparable to the carotenoid concentrations and were only significantly lower in the leaves of the orange cultivar‘Jaffa'.Also,the chlorophyll a/b ratio changed in‘Jaffa'.In florets the highest chlorophylls concentrations were observed for the green cultivar(‘Trevi')and the purple cultivar(‘Di Sicilia Violetto').Taken together,the study demonstrates the complex source-sink relationship of carotenoid accumulation in different coloured cauliflower.

Putrescine Plays a Positive Role in Salt-Tolerance Mechanisms by Reducing Oxidative Damage in Roots of Vegetable Soybean

Polyamines play important roles in plant tolerance to environmental stress. With the aim of investigating the possible involvement of putrescine （Put） in salt-tolerance mechanisms in vegetable soybean roots, exogenous Put （10 mmol L＂） and its biosynthetic inhibitor D-arginine （D-Arg） （0.5 mmol L-1） were added to nutrient solution when vegetable soybean （Glycine max L. cv. Huning 95-1） seedlings were exposed to 100 mmol L^-11 sodium chloride （NaCl）. The results showed that Put ameliorated but D-Arg aggravated the detrimental effects of NaCl on plant growth and biomass production. Under NaCl stress, levels of free, soluble conjugated and insoluble bound types of Put in roots of vegetable soybean were reduced, whereas those of free, soluble conjugated, and insoluble bound types of spermidine （Spd） and spermine （Spm） were increased. Exogenous Put eliminated the decrease in Put but promoted the increase of Spd and Spm. However, these changes could be reversed by D-Arg. Under NaCl stress, activities of arginine decarboxylase （ADC）, S-adenosylmethionine decarboxylase （SAMDC）, diamine oxidase （DAO）, and polyamine oxidase （PAO） were induced, with exogenous Put promoting and D-Arg reversing these changes. Furthermore, NaCl stress decreased activities of antioxidant enzymes. Exogenous Put alleviated but D-Arg exaggerated these effects of NaCl stress, resulting in the same changes in membrane damage and reactive oxygen species （ROS） production. These results indicated that Put plays a positive role in vegetable soybean roots by activating antioxidant enzymes and thereby attenuating oxidative damage.

Characterization of Soil Available Nitrogen in the Major Vegetable Production Areas of Pearl River Delta,China

A macro scale survey was performed to investigate the content of soil available nitrogen (N) and its spatial distribution in the main vegetable production areas of the Pearl River Delta.Preliminary enrichment-deficient index of available N was then developed,which was a base for increasing fertilizer application efficiency and vegetable yield as well as for constructing soil testing and fertilizing formula.In general,most of the vegetable growth areas in Pearl River Delta were N-deficient or medium-N-deficient.There was 30%-62% increase in yield of Chinese cabbage on the N-deficient soil after application of N; when soil available N content was less than 145 mg/kg,the yield increased with application of N fertilizer at a rate of 60-70 kg/hm2.

Mapping and validation of the epistatic D and P genes controlling anthocyanin biosynthesis in the peel of eggplant (Solanum melongena L.) fruit

Fruit color is an important trait inf luencing the commercial value of eggplant fruits.Three dominant genes(D,P and Y)cooperatively control the anthocyanin coloration in eggplant fruits,but none has been mapped.In this study,two white-fruit accessions(19141 and 19147)and their F2 progeny,with 9:7 segregation ratio of anthocyanin pigmented versus non-pigmented fruits,were used for mapping the D and P genes.A high-density genetic map was constructed with 5270 SNPs spanning 1997.98 cM.Three QTLs were identified,including two genes on chromosome 8 and one on chromosome 10.Gene expression analyses suggested that the SmANS on chromosome 8 and SmMYB1 on chromosome 10 were the putative candidate genes for P and D,respectively.We further identified(1)a SNP leading to a premature stop codon within the conserved PLN03176 domain of SmANS in 19141,(2)a G base InDel in the promoter region leading to an additional cis-regulatory element and(3)a 6-bp InDel within the R2-MYB DNA binding domain of SmMYB1,in 19147.Subsequently,these three variations were validated by PARMS technology as related to phenotypes in the F2 population.Moreover,silencing of SmANS or SmMYB1 in the purple red fruits of F1(E3316)led to inhibition of anthocyanin biosynthesis in the peels.Conversely,overexpression of SmANS or SmMYB1 restored anthocyanin biosynthesis in the calli of 19141 and 19147 respectively.Our findings demonstrated the epistatic interactions underlying the white color of eggplant fruits,which can be potentially applied to breeding of eggplant fruit peel color.

Low light intensity elongates period and defers peak time of photosynthesis: a computational approach to circadian-clock-controlled photosynthesis in tomato

Photosynthesis is involved in the essential process of transforming light energy into chemical energy.Although the interaction between photosynthesis and the circadian clock has been confirmed,the mechanism of how light intensity affects photosynthesis through the circadian clock remains unclear.Here,we propose a first computational model for circadian-clock-controlled photosynthesis,which consists of the light-sensitive protein P,the core oscillator,photosynthetic genes,and parameters involved in the process of photosynthesis.The model parameters were determined by minimizing the cost function(δ=8.56),which is defined by the errors of expression levels,periods,and phases of the clock genes(CCA1,PRR9,TOC1,ELF4,GI,and RVE8).The model recapitulates the expression pattern of the core oscillator under moderate light intensity(100μmol m^(-2) s^(-1)).Further simulation validated the dynamic behaviors of the circadian clock and photosynthetic outputs under low(62.5μmol m^(-2) s^(-1))and normal(187.5μmol m^(-2) s^(-1))intensities.When exposed to low light intensity,the peak times of clock and photosynthetic genes were shifted backward by 1–2 hours,the period was elongated by approximately the same length,and the photosynthetic parameters attained low values and showed delayed peak times,which confirmed our model predictions.Our study reveals a potential mechanism underlying the circadian regulation of photosynthesis by the clock under different light intensities in tomato.

CG hypermethylation of the bHLH39 promoter regulates its expression and Fe deficiency responses in tomato roots

Iron(Fe)is an essential micronutrient for all organisms,including plants,whose limited bioavailability restricts plant growth,yield,and nutritional quality.While the transcriptional regulation of plant responses to Fe deficiency have been extensively studied,the contribution of epigenetic modulations,such as DNA methylation,remains poorly understood.Here,we report that treatment with a DNA methylase inhibitor repressed Fe deficiency-induced responses in tomato(Solanum lycopersicum)roots,suggesting the importance of DNA methylation in regulating Fe deficiency responses.Dynamic changes in the DNA methylome in tomato roots responding to short-term(12 hours)and long-term(72 hours)Fe deficiency identified many differentially methylated regions(DMRs)and DMR-associated genes.Most DMRs occurred at CHH sites under short-term Fe deficiency,whereas they were predominant at CG sites following long-term Fe deficiency.Furthermore,no correlation was detected between the changes in DNA methylation levels and the changes in transcript levels of the affected genes under either short-term or long-term treatments.Notably,one exception was CG hypermethylation at the bHLH39 promoter,which was positively correlated with its transcriptional induction.In agreement,we detected lower CG methylation at the bHLH39 promoter and lower bHLH39 expression in MET1-RNA interference lines compared with wild-type seedlings.Virus-induced gene silencing of bHLH39 and luciferase reporter assays revealed that bHLH39 is positively involved in the modulation of Fe homeostasis.Altogether,we propose that dynamic epigenetic DNA methylation in the CG context at the bHLH39 promoter is involved in its transcriptional regulation,thus contributing to the Fe deficiency response of tomato.

Lacticaseibacillus rhamnosus Fmb14 ameliorates hyperuricemia-induced hepatocyte pyroptosis via NLRP3 inflammasome cascade inhibition

Hyperuricemia is a high-risk factor for the development of gout and renal fibrosis,but the adverse effects of hyperuricemia on the liver have been seriously neglected.This research investigated the ameliorating effect of Lacticaseibacillus rhamnosus Fmb14 on hyperuricemia induced liver dysfunction both in vitro and in vivo.Cell free extracts of high dose L.rhamnosus Fmb14 treatment reduced the death rate of HepG2 cell lines from 24.1%to 14.9%by inhibiting NLRP3 recruitment,which was mainly activated by reactive oxygen species release and mitochondrial membrane potential disorder.In purine dietary induced hyperuricemia(PDIH)mice model,liver oedema and pyroptosis were ameliorated after L.rhamnosus Fmb14 administration through downregulating the expression levels of NLRP3,caspase-1 and gasdermin-D from 1.61 to 0.86,3.15 to 1.01 and 5.63 to 2.02,respectively.L.rhamnosus Fmb14 administration restored mitochondrial inner membrane protein(MPV17)and connexin 43 from 2.83 and 0.73 to 0.80 and 0.98 respectively in PDIH mice,indicating that dysbiosis of mitochondrial membrane potential was restored in liver.Intriguingly,PDIH pyroptosis stimulates the process of apoptosis,which leads to severe leakage of hepatocytes,and both of pyroptosis and apoptosis were decreased after L.rhamnosus Fmb14 treatment.Therefore,L.rhamnosus Fmb14 is a promising biological resource to maintain homeostasis of the liver in hyperuricemia and the prevention of subsequent complications.

Genetic diversity assessment of a set of introduced mung bean accessions(Vigna radiata L.)

Genetic resources from other countries or regions play an important role in broadening the genetic background of local breeding varieties. Here we describe observations on the adaptability of mung bean germplasm obtained from the United States Department of Agriculture and their genetic diversity assessment using SSR markers. Several accessions were shown to be mixtures,based on their phenotypes for some characters. Most accessions were able to complete their lifecycles when grown in Beijing, China, making them ideal for crossbreeding without day length control. High diversity was revealed by the SSR markers, with an average of 4.2 alleles per locus and a PIC value of 0.650 per locus. STRUCTURE analysis divided the accessions into six groups.There was no obvious trend of accessions forming groups according to their geographical origin,owing mainly to germplasm exchange and an uneven distribution of accessions. The present results indicate that this germplasm would enrich the local gene pool, and provide information for the further use of germplasm in breeding programs.

Expression of an Antisense BcMF3 Affects Microsporogenesis and Pollen Tube Growth in Arabidopsis

In an effort to provide some information relevant to the molecular mechanism of genic male sterility in plants, BcMF3 gene that encodes a pectin methylesterase was isolated from the fertile B line of Chinese cabbage-pak-choi （Brassica rapa ssp. chinensis, syn. B. campestris ssp. chinensis）. In the present paper, a 455-bp antisense cDNA fragment of BcMF3 was introduced to binary vector pB1121, and then was mobilized into Agrobacterium tumefaciens strain LBA4404. The A. tumefaciens harboring the BcMF3 antisense fragment was transformed to Arabidopsis thaliana by floral dip. Scanning electronic microscopy examination demonstrated that 47.8% of BcMF3 antisense pollen grains exhibited abnormal shape, which might lead to decreased germination of pollens, suggesting that the product of BcMF3 gene plays an important role during microsporogenesis. The evidence on burst of 45.7% of BcMF3 antisense pollen tubes in vitro and a majority of BcMF3 antisense pollens restricted within the stigmatic tissue revealed that BcMF3 is involved in aiding the growth of pollen tubes. The results suggest that BcMF3 acts at both stages of microsporogensis and pollen tube growth.

Study of Biological Effects of Low Energy Ion Implantation on Tomato and Radish Breeding

Biological effects of 30 keV low energy nitrogen ion implantation on the seeds of five types of tomato and one type of radish were investigated. Results showed that low energy ions have different effects on different vegetables. The whole dose-response curve of the germination ratio did not take on ＂the shape of saddle＂, but was a rising and falling waveform with the increase or decrease in ion implantation. In the vegetable of Solanaceae, two outstanding aberrant plants were selected from M1 of Henan No.4 tomato at a dose of 7x 1017 nitrogen ions/cm2, which had thin-leaves, long-petal and nipple tip fruit stably inherited to Mr. Furthermore the analysis of the isozyme showed that the activity of the mutant tomato seedling was distinct in quantity and color. In Raphanus sativus L., the aberrances were obvious in the mutant of radish 791 at a dose of 5×10^17 nitrogen ions/cm^2, and the weight of succulent root and the volume of growth were over twice the control＇s. At present, many species for breeding have been identified in the field and only stable species have been selected for the experiment of production. It is evident that the low energy ion implantation technology has clear effects on vegetables＇ genetic improvement.

Overexpression of SlOFP20 affects floral organ and pollen development

The OVATE gene was initially identified in tomato and serves as a key regulator of fruit shape.There are 31 OFP members in the tomato genome.However,their roles in tomato growth and reproductive development are largely unknown.Here,we cloned the OFP transcription factor SlOFP20.Tomato plants overexpressing SlOFP20 displayed several phenotypic defects,including an altered floral architecture and fruit shape and reduced male fertility.SlOFP20 overexpression altered the expression levels of some brassinosteroid(BR)-associated genes,implying that SlOFP20 may play a negative role in the BR response,similar to its ortholog OsOFP19 in rice.Moreover,the transcript accumulation of gibberellin(GA)-related genes was significantly affected in the transgenic lines.SlOFP20 may play an important role in the crosstalk between BR and GA.The pollen germination assay suggested that the pollen germination rate of SlOFP20-OE plants was distinctly lower than that of WT plants.In addition,the tomato pollen-associated genes SlCRK1,SlPMEI,LePRK3,SlPRALF,and LAT52 were all suppressed in the transgenic lines.Our data imply that SlOFP20 may affect floral organ and pollen development by modulating BR and GA signaling in tomato.

A method for the production and expedient screening of CRISPR/Cas9-mediated non-transgenic mutant plants

Developing CRISPR/Cas9-mediated non-transgenic mutants in asexually propagated perennial crop plants is challenging but highly desirable.Here,we report a highly useful method using an Agrobacterium-mediated transient CRISPR/Cas9 gene expression system to create non-transgenic mutant plants without the need for sexual segregation.We have also developed a rapid,cost-effective,and high-throughput mutant screening protocol based on Illumina sequencing followed by high-resolution melting(HRM)analysis.Using tetraploid tobacco as a model species and the phytoene desaturase(PDS)gene as a target,we successfully created and expediently identified mutant plants,which were verified as tetra-allelic mutants.We produced pds mutant shoots at a rate of 47.5%from tobacco leaf explants,without the use of antibiotic selection.Among these pds plants,17.2%were confirmed to be non-transgenic,for an overall non-transgenic mutation rate of 8.2%.Our method is reliable and effective in creating non-transgenic mutant plants without the need to segregate out transgenes through sexual reproduction.This method should be applicable to many economically important,heterozygous,perennial crop species that are more difficult to regenerate.

High Throughput Sequencing of circRNAs in Tomato Leaves Responding to Multiple Stresses of Drought and Heat

Our aim is to study the roles of a new emerging group of non-coding RNAs, circRNAs, in tomato(Solanum lycopersicum L.) plants grown at the combination of drought and heat, two of the most usual stress conditions known to frequently happen in field. Tomato seedlings from cultivar‘Jinling Meiyu’ were treated without stresses(control), at water shortage, high temperature and subjected the multiple stresses. In total, 467 circRNAs were identified with 87.82% from exon using high throughput sequencing technology. Among the circRNAs, 70 were from chr1 with the range from 23 to 49 from the other chromosomes. In detail, 156 circRNAs were shared in the four libraries, while 21, 17 and 36 circRNAs were only shown in drought, heat and multiple stresses libraries, respectively. Through a differential expression analysis, four, seven and nine circRNAs were differentially regulated in tomato at drought, heat and multiple stresses as compared with control. These circRNAs played roles on photosynthesis, starch and sucrose metabolism, RNA transport, RNA degradation, spliceosome, ribosome, etc. Our study underlined the potential role of circRNAs involved in the abiotic stress response in tomato, which might pave the way for studying biological roles of circRNAs responding to multiple stresses in plants.

Sensitivities of Phytophthora infestans to Metalaxyl, Cymoxanil, and Dimethomorph

The isolates of Phytophthora infestans on tomato in the Guangxi Zhuang Autonomous Region, China, were determined for the sensitivities to metalaxyl, cymoxanil and dimethomorph to give the basic information for integrating disease management. Sensitivities were tested by measuring the radial growth on agar medium amended with fungicide, compared with the floating-leaf-disk method. 239 isolates were collected from eight tomato growing areas during 2000-2006. The testing results indicated that the frequencies of sensitive, intermediate, and resistant isolates to metalaxyl were 42.26, 35.98, and 23.53%, respectively. Variations in sensitivities amongst isolates from different areas or different years were very high for metalaxyl. All isolates from Tianlin and Wuxuan were sensitive to metalaxyl, but the metalaxyl-resistant isolates predominated in Tianyang, with the frequency of 51.35%. The EC50 values of certain isolates from Tianyang were higher than 500 μg·mL^-1 and their resistance levels were over 100 000 folds. Cymoxanil has been used for nearly 10 years in Guangxi, and dimethomorph has been used for 5-6 years. However, there was no decrease in sensitivity of P. infestans populations and the sensitivities of the pathogen were nearly normally distributed. Hence, their mean ECs0 value [cymoxanil （0.1647 ±0.0255） μg·mL^-1, dimethomorph （0.0970 ± 0.0052） μg·mL^-1 could be used as the baseline sensitivities for monitoring the field resistance development. The comparison with the floating-leaf-disk method indicates that both the techniques provided equivalent results. These studies suggested that metalaxyl can be continuously applied in Tianlin, Wuxuan, and Nanning due to the resistant isolates that have not been found, while for those areas with resistant isolate, the use of metalaxyl should be reduced or alternated, and cymoxanil or dimethomorph was recommended for controlling late blight disease of tomato.

The Phoebe genome sheds light on the evolution of magnoliids

Lauraceae includes the genus Phoebe,and the family is linked to the evolution of magnoliids.We sequenced the genome of Phoebe bournei Nanmu.The assembled genome size was 989.19 Mb,with a contig N50 value of 2.05 Mb.A total of 28,198 protein-coding genes were annotated in P.bournei.Whole-genome duplication(WGD)analysis showed that Lauraceae has experienced two WGD events;the older WGD event occurred just before the divergence of Lauraceae and Magnoliales,and the more recent WGD was shared by all lineages of Lauraceae.The phylogenetic tree showed that magnoliids form a sister clade to monocots and eudicots.We also identified 63 MADS-box genes,including AGL12-like genes that may be related to the regulation of P.bournei roots and FIN219-like genes encoding GH3 proteins,which are involved in photomorphogenesis.SAUR50-like genes involved in light signal-mediated pedicel or stem development were also identified.Four ATMYB46-and three PtrEPSP-homologous genes related to lignin biosynthesis were identified.These genes may be associated with the formation of straight trunks in P.bournei.Overall,the P.bournei reference genome provides insight into the origin,evolution,and diversification of Phoebe and other magnoliids.

Whole-genome sequencing provides insights into the genetic diversity and domestication of bitter gourd(Momordica spp.)

Bitter gourd(Momordica charantia)is a popular cultivated vegetable in Asian and African countries.To reveal the characteristics of the genomic structure,evolutionary trajectory,and genetic basis underlying the domestication of bitter gourd,we performed whole-genome sequencing of the cultivar Dali-11 and the wild small-fruited line TR and resequencing of 187 bitter gourd germplasms from 16 countries.The major gene clusters(Bi clusters)for the biosynthesis of cucurbitane triterpenoids,which confer a bitter taste,are highly conserved in cucumber,melon,and watermelon.Comparative analysis among cucurbit genomes revealed that the Bi cluster involved in cucurbitane triterpenoid biosynthesis is absent in bitter gourd.Phylogenetic analysis revealed that the TR group,including 21 bitter gourd germplasms,may belong to a new species or subspecies independent from M.charantia.Furthermore,we found that the remaining 166 M.charantia germplasms are geographically differentiated,and we identified 710,412,and 290 candidate domestication genes in the South Asia,Southeast Asia,and China populations,respectively.This study provides new insights into bitter gourd genetic diversity and domestication and will facilitate the future genomics-enabled improvement of bitter gourd.

Identification of MAM1s in Regulation of 3C Glucosinolates Accumulation in Allopolyploid Brassica juncea

Allopolyploid Brassica juncea is particularly enriched in sinigrin,a kind of 3C aliphatic glucosinolates(GSLs),giving rise to characteristic taste after picking.However,the molecular mechanism underlying 3C aliphatic GSLs biosynthesis in this species remains unknown.In this study,we genome-widely identified GSLs metabolic genes,indicating different evolutionary rate of GSLs metabolic genes between subgenomes of B.juncea.Eight methythioalkylmalate synthase(MAMs)homologs were identified from B.juncea,in which six MAM1s were located in chloroplast and the other two were not detected with any expression.Furthermore,BjMAM1-4,BjMAM1-5,and BjMAM1-6 displayed higher expression levels in leaves than other tissues.Silenced expression analysis revealed that BjMAM1-4 and BjMAM1-6 function in 3C and 4C aliphatic GSLs accumulation.The specificity of the substrate selection for the second cycle reaction is much lower than that of the first cycle,suggesting these genes may preferentially catalyze 3C aliphatic GSLs biosynthesis.Our study provides insights into the molecular mechanism underlying the accumulation of 3C aliphatic GSLs,thereby facilitating the manipulation of aliphatic GSLs content in B.juncea.

Whole-genome identification and expression analysis of K^+ efflux antiporter(KEA) and Na^+/H^+ antiporter(NHX) families under abiotic stress in soybean

Sodium toxicity and potassium insufficient are important factors affecting the growth and development of soybean in saline soil. As the capacity of plants to maintain a high cytosolic, K^＋/Na^＋ ratio is the key determinant of tolerance under salt stress. The aims of the present study were to identify and analyse expression patterns of the soybean K^＋ efflux antiporter（KEA） gene and Na^＋/H^＋ antiporter（NHX） gene family, and to explore their roles under abiotic stress. As a result, 12 soybean Gm KEAs genes and 10 soybean Gm NHXs genes were identified and analyzed from soybean genome. Interestingly, the novel soybean KEA gene Glyma16g32821 which encodes 11 transmembrane domains were extremely up-regulated and remained high level until 48 h in root after the excessive potassium treatment and lack of potassium treatment, respectively. The novel soybean NHX gene Glyma09g02130 which encodes 10 transmembrane domains were extremely up-regulated and remained high level until 48 h in root with Na Cl stress. Imaging of subcellular locations of the two new Glyma16g32821-GFP and Glyma09g02130-GFP fusion proteins indicated all plasma membrane localizations of the two novel soybean genes. The 3D structures indicated that the two soybean novel proteins Glyma09g02130（NHX） and Glyma16g32821（KEA） all belong to the cation/hydrogen antiporter family.

Integrated proteomic and metabolomic analyses reveal the importance of aroma precursor accumulation and storage in methyl jasmonate-primed tea leaves

In response to preharvest priming with exogenous methyl jasmonate(MeJA),tea plants adjust their physiological behavior at the molecular level.The whole-organism reconfiguration of aroma formation from the precursor to storage is poorly understood.In this study,we performed iTRAQ proteomic analysis and identified 337,246,and 413 differentially expressed proteins in tea leaves primed with MeJA for 12 h,24h,and 48 h,respectively.Furthermore,a total of 266 nonvolatile and 100 volatile differential metabolites were identified by utilizing MS-based metabolomics.A novel approach that incorporated the integration of extended self-organizing map-based dimensionality was applied.The vivid time-scale changes tracing physiological responses in MeJA-primed tea leaves are marked in these maps.Jasmonates responded quickly to the activation of the jasmonic acid pathway in tea leaves,while hydroxyl and glycosyl jasmonates were biosynthesized simultaneously on a massive scale to compensate for the exhausted defense.The levels ofα-linolenic acid,geranyl diphosphate,farnesyl diphosphate,geranylgeranyl diphosphate,and phenylalanine,which are crucial aroma precursors,were found to be significantly changed in MeJA-primed tea leaves.Green leaf volatiles,volatile terpenoids,and volatile phenylpropanoids/benzenoids were spontaneously biosynthesized from responding precursors and subsequently converted to their corresponding glycosidic forms,which can be stably stored in tea leaves.This study elucidated the physiological response of tea leaves primed with exogenous methyl jasmonate and revealed the molecular basis of source and sink changes on tea aroma biosynthesis and catabolism in response to exogenous stimuli.The results significantly enhance our comprehensive understanding of tea plant responses to exogenous treatment and will lead to the development of promising biotechnologies to improve fresh tea leaf quality.

Diallel Crossing Analyses of Resistance to Main Diseases in Pepper(Capsicum annuum L.)

Fifteen capsicum combinations were made with 6 parents by （1/2）n（n-1） diallel crossing. Genetic parameters in the resistance to TMV, CMV, phytophthora blight, bacterial spot of these combinations were studied by Hayman. The results indicated that the resistance to TMV, CMV and bacterial spot conformed genetically to the “additive-dominant” model but the resistance to phytophthora blight did not and significant epistatic dominance effect existed in it. F1 hybrid＇s resistance to CMV was controlled by homozygous dominant gene （s）, but resistance to bacterial spot by heterozygous one （s）. There were little, or no sum of dominant effect and genomes controlling the dominant expression of F1 hybrids in its phytophthora blight resistance.