Transcription factor CabHLH035 promotes cold resistance and homeostasis of reactive oxygen species in pepper

Plant basic helix-loop-helix(bHLH)transcription factors(TFs)play central roles in various abiotic stresses.However,its role in plant cold resistance is largely unknown.Previously,we characterised CaNAC035 in pepper,which positively regulates tolerance to cold,salt and drought stresses tolerance.Here,we identified CabHLH035,a CaNAC035-interacting protein in pepper.To explore its functions in cold stress tolerance,we silenced the gene in pepper via virus-induced gene silencing(VIGS)and overexpressed the gene in Arabidopsis.The results showed that CabHLH035 expression was induced by cold treatment,and silencing of CabHLH035 decreased cold stress tolerance.Conversely,overexpression of CabHLH035 in Arabidopsis increased cold stress tolerance.To investigate homologs genes of C-repeat binding factor(CBF)pathway proteins and reactive oxygen species(ROS)marker gene expression blocking by CabHLH035,we performed yeast one-hybrid(Y1H),dual luciferase and electrophoretic mobility shift assay experiments.The results showed that CabHLH035 bound to the region upstream of the CaCBF1A and CaAPX promoters.Additionally,CaCBF1A bound to the CaDHN4 promoter.Taken together,our results showed that CabHLH035 plays a crucial role in cold stress tolerance and its potential as a target for breeding cold-resistant crops.The findings provide a basis for studying the functions and regulatory network of cold stress tolerance in pepper.

Melatonin mitigates cold-induced damage to pepper seedlings by promoting redox homeostasis and regulating antioxidant profiling

This study assessed the influence of exogenous ME in the mitigation of cold damage in pepper seedlings. Melatonin(ME) is a dynamic molecule that helps plants cope with stress in several ways. Cold stress(CS) is one of the most important environmental factors that restrict plant growth and yield. Pepper(Capsicum annuum L.) is a valuable commercial crop, highly sensitive to CS. Thus, identifying an efficient strategy to mitigate cold damage is critical for long-term pepper production. For this purpose, the roots of pepper seedlings were pretreated with ME(5 μmol · L^(-1)) and exposed to CS for 7 d. The results indicated that CS suppressed pepper growth, hampered photosynthetic capacity, and damaged root architecture in pepper plants. In contrast, the production of reactive oxygen species(ROS), malondialdehyde(MDA), electrolyte leakage(EL), proline, and soluble sugars were enhanced in plants under CS. ME(5 μmol · L^(-1)) pretreatment reduced the negative effects of CS by recovering plant growth, root traits, gas exchange elements, and pigment molecules compared to CS control treatment. Furthermore, ME application efficiently reduced oxidative stress markers [hydrogen peroxide(H_(2)O_(2)), superoxide ion(O_(2)^(·-)), EL, and MDA] while increasing proline and soluble sugar content in pepper leaves. ME application combined with CS further increased antioxidant enzymes and related gene expression. Collectively, our results confirmed the mitigating potential of ME supplementation for CS by maintaining pepper seedling growth,improving the photosynthesis apparatus, regulating pigments, and osmolyte content.

Variety Selection and Green Cultivation Technology of Courtyard Ornamental and Edible Peppers

In order to comply with the development trend of the multifunctional use of peppers,we conducted an investigation into the characteristics and features of varieties,potting management techniques,and the methods of extending the fruit ornamental period and other aspects of courtyard ornamental and edible peppers.A set of cultivation techniques suitable for courtyard ornamental and edible peppers has been developed,including timely sowing and seedling,nutrient soil preparation,water and fertilizer management,trimming and pruning,preservation of flowers and fruits,green prevention and control of diseases and pests,harvesting,and so on.

Fine-mapping and transcriptome analysis of the photosensitive leaf-yellowing gene CaLY1 in pepper(Capsicum annuum L.)

Leaf color is directly related to altered photosynthesis.Hence,leaf yellowing mutants can be widely used for the researching plant physiology and functional genomes,for cultivating new varieties of popular horticultural plants,and for identifying hybrid purity(as markers).Here,we constructed a^(60)Co-γF_(2)population from the leaf-yellowing mutant R24 via radiation mutation with the inbred line WT21 of pepper.Genetic analysis showed that the leaf-yellowing of the mutant was controlled by a single recessive gene.By applying the Bulk Segregation Analysis and Kompetitive Allele Specific PCR markers,the leaf-yellowing gene CaLY1(Capsicum annuum Leaf yellow 1)was mapped on chromosome 9,SNP5791587-SNP6011215,with a size of 214.5 kb.One non-synonymous mutated gene Capana09g000166 was found in the interval.The gene encoded a Psb X,which is the core complex of PSⅡ.Transcriptome analysis further showed that 2301 differentially expressed genes were identified under shading treatment for 24 h in R24.The Gene Ontology enrichment pathways were related to photosynthesis light harvesting,cell wall,activity of quercetin 3-O-glucosyltransferase and flavonoid metabolic process,which likely regulate the response of pepper leaves to different light levels.Functional enrichment analysis indicated that the most abundant pathways were photosynthesis antenna proteins and metabolic.

A novel single-base mutation in CaSGR1 confers the stay-green phenotype in pepper

The stay-green trait is of considerable importance in extending the shelf life of green pepper fruit(Capsicum annuum L.)and in enhancing the appearance of ornamental plants.The study revealed the genetic and regulatory mechanisms of the stay-green trait in pepper,which will aid in the selection of ornamental pepper varieties.In this study,a pepper mutant with stay-green fruit named TNX348 was identified from a germplasm resource bank.Two segregating populations were constructed using the stay-green mutant TNX348 and then used in bulked segregant analysis combined with RNA sequencing and linkage analyses.The causal gene of the stay-green trait was mapped to an approximately 131-kb region,and a senescence-induced chloroplast protein gene,CaSGR1(Capana01g000359),was identified as a candidate gene.Sequencing analysis revealed a G→A single-base mutation of CaSGR1 in TNX348 that led to early termination of translation.Based on the single-base mutation,a single nucleotide polymorphism(SNP)marker co-segregating with the stay-green trait was developed.Furthermore,in transcriptome analysis,expression patterns of 11 hormone transduction-related transcription factors,such as abscisic acid-insensitive(ABI),abscisic acidresponsive element-binding factor(ABF),and NAC transcription factor,were similar or opposite to that of CaSGR1.The results indicated that the transcription factors might mediate chlorophyll degradation by regulating the expression of CaSGR1.

Red light induces salicylic acid accumulation by activating CaHY5 to enhance pepper resistance against Phytophthora capsici

Pepper(Capsicum annuum L.)is frequently challenged by various pathogens,among which Phytophthora capsici is the most devastating to pepper production.Red light signal acts as a positive induction of plant resistance against multiple pathogens.However,little is known about how the red light signal affects pepper resistance to P.capsici infection(PCI).Here,we report that red light regulates salicylic acid(SA)accumulation by activating elongated hypocotyl5(CaHY5),a basic leucine zipper(bZIP)transcription factor,thereby decreasing pepper susceptibility to PCI.Exogenous SA treatment reduced pepper susceptibility to PCI,while silencing of CaPHYB(a red light photoreceptor)increased its susceptibility.PCI significantly induced CaHY5 expression,and silencing of CaHY5 reduced SA accumulation,accompanied by decreases in the expression levels of phenylalanine ammonia-lyase 3(CaPAL3),CaPAL7,pathogenesis-related 1(CaPR1),and CaPR1L,which finally resulted in higher susceptibility of pepper to PCI.Moreover,CaHY5 was found to activate the expression of CaPAL3 and CaPAL7,which are essential for SA biosynthesis,by directly binding to their promoters.Further analysis revealed that exogenous SA treatment could restore the resistance of CaHY5-silenced pepper plants to PCI.Collectively,this study reveals a critical mechanism through which red light induces SA accumulation by regulating CaHY5-mediated CaPAL3 and CaPAL7 expression,leading to enhanced resistance to PCI.Moreover,red light-induced CaHY5 regulates pepper resistance to PCI,which may have implications for PCI control in protected vegetable production.

Microscopic and metabolic investigations disclose the factors that lead to skin cracking in chili-type pepper fruit varieties

The hydrophobic cuticle encasing the fruit skin surface plays critical roles during fruit development and post-harvest.Skin failure often results in the fruit surface cracking and forming a wound-periderm tissue made of suberin and lignin.The factors that make the fruit skin susceptible to cracking have yet to be fully understood.Herein,we investigated two varieties of chili peppers(Capsicum annuum L.),Numex Garnet,whose fruit has intact skin,and Vezena Slatka,whose fruit has cracked skin.Microscopical observations,gas chromatography-mass spectrometry,biochemical and gene expression assays revealed that Vezena Slatka fruit form a thicker cuticle with greater levels of cutin monomers and hydroxycinnamic acids,and highly express key cutin-related genes.The skin of these fruit also had a lower epidermal cell density due to cells with very large perimeters,and highly express genes involved in epidermal cell differentiation.We demonstrate that skin cracking in the Vezena Slatka fruit is accompanied by a spatial accumulation of lignin-like polyphenolic compounds,without the formation of a typical wound-periderm tissues made of suberized cells.Lastly,we establish that skin cracking in chili-type pepper significantly affects fruit quality during post-harvest storage in a temperature-dependent manner.In conclusion,our data highlight cuticle thickness and epidermal cell density as two critical factors determining fruit skin susceptibility to cracking in chili-type pepper fruit.

Effect of Dandelion(Taraxacum mongolicum Hand.-Mazz.)Intercropping with Different Plant Spacing on Blight and Growth of Pepper(Capsicum annuum L.)

Intercropping of crops that can secrete bacteriostatic active substances can not only inhibit the occurrence of disease but also have an important effect on plant growth.However,the effects of dandelion intercropping on pepper blight control and pepper growth remain unclear.In this study,the control effect of dandelion on pepper blight was studied by inoculating the pepper leaves with Phytophthora infestans,and it also discusses the correlation of the occurrence of pepper epidemic disease with the pepper canopy environment,soil environment,pepper photo-synthesis,and yield index.The results showed that best plant distance for dandelion intercropping was 20 cm(P20),and the control effect reached 43.31%.As compared to the CK,SOD enzyme,POD enzyme,and PAL enzyme were significantly up-regulated during the growth of pepper;chlorophyll content in pepper leaves was significantly increased;photosynthetic characteristics were significantly increased;stem diameter and yield of crop pepper were effectively improved;and the quality of the pepper product was better,but intercropping dandelion resulted in a significant decrease of nutrients in the soil environment of pepper,so a reasonable intercropping distance was needed.The correlation analysis shows that the incidence of pepper blight(A)was significantly positively correlated with soil temperature(Q),intercellular carbon dioxide(L),and canopy air temperature(O).The incidence of capsicum blight(A)was significantly negatively correlated with chlorophyll content(F),net photo-synthetic rate(K),stomatal conductance(M),ww rate(N),soil sucrase activity(W),vitamin C(AB),and leaf PAL enzyme(J).Finally,it was deduced that intercropping dandelion could effectively control the occurrence of pepper blight while also demonstrating a complex interaction with the pepper growing environment.

Effects of Polygonatum odoratum Polysaccharides on the Quality of White Chili Peppers in Jars

[Objectives]This study was conducted to investigate the effects of Polygonatum odoratum polysaccharides on the quality of white chili peppers in jars.[Methods]White chili peppers were pickled by adding different concentrations of P.odoratum polysaccharides with traditional pickling technology,and its nitrite content,pH and sensory quality were analyzed and detected.[Results]The results showed that,compared with the control group without adding P.odoratum polysaccharides,the nitrite content in white chili peppers in jars decreased after adding P.odoratum polysaccharides.When the addition amount of P.odoratum polysaccharides was 0.002%,the inhibition rate of nitrite reached the maximum.Under the same fermentation time,P.odoratum polysaccharides could significantly reduce the pH value of pickles.When the addition amount of P.odoratum polysaccharide was 0.002%and the pickling time was 3 months,the sensory quality of white chili peppers in jars was the best.At this point,white chili peppers in jars had rich aroma and tasted soft and sour,and the sour and salinity were suitable.As the fermentation time continued to increase,the chili aroma of white chili peppers in jars gradually decreased,and the sour taste became more pronounced.[Conclusions]This study can provide reference for the safety and quality control of white chili peppers in jars.

Effect of Low Light on the Characteristics of Photosynthesis and Chlorophyll a Fluorescence During Leaf Development of Sweet Pepper

Low light stress is one of the main limiting factors which influence the production of sweet pepper under protected cultivation in China. In this experiment, two genotypes of sweet pepper, ShY （low light-tolerant genotype） and 20078 （low light-sensitive genotype）, were used to study the effects of low light （photosynthetic photon flux density, PPFD was 75- 100 umol m-2 s-1, control 450-500 umol m-2 s-1） on photosynthesis during leaf development. The result indicated that under low light chlorophyll content, net photosynthetic rate （PN）, photosynthetic apparent quantum efficiency （Фi） and carboxylation efficiency （CE） of sweet pepper leaves increased gradually and decreased after reaching the maximum levels. The time to reach the peak values for all the above parameters was delayed, whereas the light compensation point （LCP） decreased gradually along with leaf expansion. The decrease in maximum quantum yield of PS II （Fv/Fm） was not observed at any stages of the leaf development under low light condition, but the actual PS II efficiency under irradiance （ФPS II） was lower accompanied by an increased non-photochemical quenching （NPQ） in young and/or old leaves compared with mature leaves. The antenna thermal dissipation （D） was a main way of heat dissipation when young leaves received excessive light energy, while the decline in photosynthetic function in senescence leaf was mostly owing to the decrease in carbon assimilation capacity, followed by a significantly increased allocation of excessive energy （Ex）. Compared with 20078, ShY could maintain higher PN, ФPS II and lower QA reduction state for a longer time during leaf development. Thus, in ShY photosynthetic efficiency and the activity of electron transport of PS II were not significantly affected due to low light stress.

Effects of Chlorine Dioxide Gas on Postharvest Physiology and Storage Quality of Green Bell Pepper (Capsicum frutescens L.var.Longrum)

The effects of treatment of chlorine dioxide （C1Oz） gas on postharvest physiology and preservation quality of green bell peppers were studied. Green bell peppers were collected in bags and treated with 0, 5, 10, 20, and 50 mg L^-1 ClO2 gas at 10±0.5℃ for over 40 d, and the changes in postharvest physiology and preservation quality of the peppers were evaluated during the storage. The inhibition of rot of the peppers was observed for all the tested ClO2 gas treatments. The rot rates of the treated samples were 50% lesser than those of the control after day 40 of storage. The highest inhibitory effect was obtained after 50 mg L^-1 ClO2 gas treatment, where the peppers did not decay until day 30 and showed only one-fourth of the rot rate of the control at day 40 of storage. The respiratory activity of the peppers was significantly （P〈0.05） inhibited by 20 and 50 mg L^-1 ClO2 treatments, whereas no significant effects on respiratory activity were observed with 5 and 10 mg L^-1 ClO2 treatments （P〉0.05）. Except for 50 mg L^-1 ClO2, malondialdenyde （MDA） contents in the peppers treated with 5, 10, or 20 mg L^-1 ClO2 were not significantly （P〉0.05） different from those in the control. Degradation of chlorophyll in the peppers was delayed by 5 mg L-1ClO2, but promoted by 10, 20, or 50 mg L^-1 ClO2. The vitamin C content, titratable acidity, and total soluble solids of the peppers treated by all the tested ClO2 gas did not significantly change during the storage. The results suggested that ClO2 gas treatment effectively delayed the postharvest physiological transformation of green peppers, inhibited decay and respiration, maintained some nutritional and sensory quality, and retarded MDA accumulation.

Selection for high quality pepper seeds by machine vision and classifiers

This research aimed to improve selection of pepper seeds for separating high-quality seeds from low-quality seeds. Past research has shown that seed vigor is significantly related to the seed color and size, thus several physical features were identified as candidate predictors of high seed quality. Image recognition software was used to automate recognition of seed feature quality using 400 kernels of pepper cultivar 101. In addition, binary logistic regression and a neural network were applied to determine models with high predictive value of seed germination. Single-kernel germination tests were conducted to validate the predictive value of the identified features. The best predictors of seed vigor were determined by the highest correlation observed between the physical features and the subsequent fresh weight of seedlings that germinated from the 400 seeds. Correlation analysis showed that fresh weight was significantly positively correlated with eight physical features： three color features （R, a＊, brightness）, width, length, projected area, and single-kernel density, and weight. In contrast, fresh weight significantly negatively correlated with the feature of hue. In analyses of two of the highest correlating single features,＇ germination percentage increased from 59.3 to 71.8% when a＊〉3, and selection rate peaked at 57.8%. Germination percentage increased from 59.3 to 79.4%, and the selection rate reached 76.8%, when single-kernel weight 〉0.0064 g. The most effective model was based on a multilayer perceptron （MLP） neural network, consisting of 15 physical traits as variables, and a stability calculated as 99.4%. Germination percentage in a calibration set of seeds was 79.1% and the selection rate was 90.0%. These results indicated that the model was effective in predicting seed germination based on physical features and could be used as a guide for quality control in seed selection. Automated systems based on machine vision and model classifiers can contribute to reducing the costs and labor required in the selection of pepper seeds.

Chemical composition,sensory properties and application of Sichuan pepper(Zanthoxylum genus)

This review summarized the composition of volatile and nonvolatile compounds,the sensory mechanism and the application of Sichuan pepper(Zanthoxylum genus)as a spice and multifunctional food,such as antibacterial,inhibition of inflammation,and antioxidant among others.The aim is to provide a better understanding and potential future in-depth research and application of Sichuan pepper.

Genomic analysis reveals the genetic diversity,population structure,evolutionary history and relationships of Chinese pepper

Chinese pepper,mainly including Zanthoxylum bungeanum and Zanthoxylum armatum,is an economically important crop popular in Asian countries due to its unique taste characteristics and potential medical uses.Numerous cultivars of Chinese pepper have been developed in China through long-term domestication.To better understand the population structure,demographic history,and speciation of Chinese pepper,we performed a comprehensive analysis at a genome-wide level by analyzing 38,395 genomic SNPs that were identified in 112 cultivated and wild accessions using a high-throughput genomewide genotyping-by-sequencing(GBS)approach.Our analysis provides genetic evidence of multiple splitting events occurring between and within species,resulting in at least four clades in Z.bungeanum and two clades in Z.armatum.Despite no evidence of recent admixture between species,we detected substantial gene flow within species.Estimates of demographic dynamics and species distribution modeling suggest that climatic oscillations during the Pleistocene(including the Penultimate Glaciation and the Last Glacial Maximum)and recent domestication events together shaped the demography and evolution of Chinese pepper.Our analyses also suggest that southeastern Gansu province is the most likely origin of Z.bungeanum in China.These findings provide comprehensive insights into genetic diversity,population structure,demography,and adaptation in Zanthoxylum.

Study on Agrobacterium-Mediated Transformation of Pepper with Barnase and Cre Gene

This study was designed to control plant fertility by cell lethal gene Barnase expressing at specific developmental stage and in specific tissue of male organ under the control of Cre/lox system, for heterosis breeding of chili pepper （Capsicum annuum L.）. Chili pepper inbred lines （A, D, E, and I） were transformed with Cre gene and Barnase gene situated between loxp, separately, by means of Agrobacterium co-culture. In this study, we had established a high transformation system by extensive study of affecting factors including genotype, selection of marker, and lethal dose. Cotyledon with petiole from 9-11-day-old seeding was pre-cultured on media MR[MB（MS mineral＋vitamine B5）＋BA（6-Benzyladenine） 5.0 mg·L^-1 ＋IAA（indoleacetic acid） 1.0 mg·L^-1＋GA3（gibberellic acid） 1.0mg·L^-1＋sucrose 3%＋agar 6.5g·L^-1] for 2d. The explants were infected by Agrobacterium tumefaciens when their OD600（optical density at 600 nm）reached 0.6-0.9. After co-cultured for 4-5 d on media MC [MB＋BA5.0 mg·L^-1＋IAA 1.0 mg·L^-1 ＋GA3 1.0 mg·L^-1＋sucrose 3% ＋agar 6.5 g·L^-1＋AS （acetosyringone） 200μmol·L^-1, these cotyledons with petiole were cultured on selective differentiation medium in the media MT[MB medium supplemented with BA [5.0 mg·L^-1＋ IAA 1.0 mg·L^-1＋ GA3 1.0 mg·L^-1＋ AgNO3 5.0 mg·L^-1＋ CW （coconut water） 5% ＋ Km （kanamycin） 65 mg·L^-1＋ Cb （carbenicillin） 500 mg·L^-1＋ 3% sucrose ＋ agar 6.5 g·L^-1].The Kmr （kanamycin resistant） bud rosettes were elongated on selective elongation medium and rooted on rooting medium. PCR and Southern blotting analysis of Kmr plantlet indicated that the foreign genes had been integrated into the genome of pepper. The transgenic plants with Cre gene developed well, blossomed out, and set fruit normally. The transgenic plants with Barnase gene grew well with normal appearance of flower, but they showed different fertility from complete sterility, partial sterility to complete fertility, and similar results were obtained from in vitro pollen germination experiments.

Acid Soil Is Associated with Reduced Yield, Root Growth and Nutrient Uptake in Black Pepper (<i>Piper nigrum</i>L.)

Low pH is a major limiting factor for the production of black pepper (Piper nigrum L.) in Hainan province. Black pepper gardens often exhibit a decrease in soil pH (to 5.5 - 5.0) on orchards with a multi-year production history. An exploratory hydroponic experiment was conducted to examine the effects of increasingly acid nutrient solution pH (7.0, 5.5, 4.0, and 3.5) on seedling growth, tissue nutrient concentrations and root morphological traits. The results indicated that low pH may directly inhibit root development and function, limit K, Ca and Mg absorption and reduce seedling growth. At pH 5.5, black pepper attained maximum growth, while the minimum growth occurred at pH 3.5. It can be concluded that low pH reduces plant growth and is associated with low root nutrient concentrations of Ca and Mg, which may explain the decline of the yield in the seven pepper gardens of the Institute.

Combining Ability Analyses of Net Photosynthesis Rate in Pepper (Capsicum annuum L.)

In perspective of breeding high-yield hybrid pepper varieties, combining ability analysis of net photosynthesis rate at different phases of flowering and fruit setting in pepper was made with 15 cross combinations from 6 parents by （1/2） n （n- 1） diallel crosses. There are relatively large differences not only in general combining ability （GCA） effect among different parents and at different phases of flowering and fruit setting, but also in specific combining ability （SCA） effect among different hybrids. There are relatively large GCA effects in late parents but relatively less GCA effects in early parents. No obvious laws have been found in the relationship between SCA effects and maturity of hybrids. Variances of SCA are larger than those of GCA. Heritability is less but influence of environment is larger. Correlation analysis of combining ability between net photosynthesis rate and agronomic character or resistances to main diseases has showed that correlation coefficients of GCA are relatively large at the medium phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and fruit characters. Correlation coefficients of SCA are relatively large at the early phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and plant characters at the early phase but to plant characters and fruit characters at the late phase. Correlation coefficients of SCA between net photosynthesis rate and resistances to main diseases are larger than those of GCA. The combining abilities of net photosynthesis rate at different phases of flowering and fruit setting are positively correlated with those of yield per plant. The combining ability is an important parameter of breeding of high photosynthesis hybrid pepper varieties.

Coexpression network analysis reveals an MYB transcriptional activator involved in capsaicinoid biosynthesis in hot peppers

Plant biosynthesis involves numerous specialized metabolites with diverse chemical natures and biological activities.The biosynthesis of metabolites often exclusively occurs in response to tissue-specific combinatorial developmental cues that are controlled at the transcriptional level.Capsaicinoids are a group of specialized metabolites that confer a pungent flavor to pepper fruits.Capsaicinoid biosynthesis occurs in the fruit placenta and combines its developmental cues.Although the capsaicinoid biosynthetic pathway has been largely characterized,the regulatory mechanisms that control capsaicinoid metabolism have not been fully elucidated.In this study,we combined fruit placenta transcriptome data with weighted gene coexpression network analysis(WGCNA)to generate coexpression networks.A capsaicinoid-related gene module was identified in which the MYB transcription factor CaMYB48 plays a critical role in regulating capsaicinoid in pepper.Capsaicinoid biosynthetic gene(CBG)and CaMYB48 expression primarily occurs in the placenta and is consistent with capsaicinoid biosynthesis.CaMYB48 encodes a nucleus-localized protein that primarily functions as a transcriptional activator through its C-terminal activation motif.CaMYB48 regulates capsaicinoid biosynthesis by directly regulating the expression of CBGs,including AT3a and KasIa.Taken together,the results of this study indicate ways to generate robust networks optimized for the mining of CBG-related regulators,establishing a foundation for future research elucidating capsaicinoid regulation.

INTEGRATED RISK ASSESSMENT OF MAJOR METEOROLOGICAL DISASTERS WITH PAPRIKA PEPPER IN HAINAN PROVINCE

Paprika pepper, as one of the main vegetable crops, is originated in the tropics and now widely planted in the world for its dietary therapy and medicinal functions. For its typical physiological properties referring to low tolerances to flood, drought and cold, paprika pepper often suffers from one or several disasters during its growing period,especially under tropical climate. Paprika pepper in Hainan, as a typical region of tropical climate in China, sustains flood, chilling and drought disaster risks induced by varied weather systems. This study was to develop and employ appropriate indices to assess hazard, sensitivity, vulnerability and prevention capability for major disasters during paprika pepper growth period, using long-term meteorological data from 1998 to 2011, actual disasters record from 1999 to 2011, production and socioeconomic statistics from 2002 to 2011 at 18 weather stations. Based on the Analytic Hierarchy Process and Entropy method, the combined weight was given to each disaster factor, thus an integrated disaster risk assessment model was developed and applied at regional level. High flood hazard mainly occurred in eastern Hainan, high chilling hazard in north and central mountain areas, and high drought hazard in the western part of Hainan. Drought and chilling sensitivity had a similar spatial distribution which decreased from central to coastal regions while flood sensitivity was the opposite. High vulnerability of the disasters mainly occurred in central regions,similar to low prevention capability. Eastern Hainan suffered from high integrated damage risk. The predicted damage occurrence showed a good agreement with the occurrence of actual disasters. We concluded that an integrated damage risk assessment model could provide a new tool to assess major meteorological disasters and help farmers and policy makers to alleviate the risks of major meteorological disasters for paprika pepper, which seems also suitable for other crops.

Robust molecular detection of the new Tomato brown rugose fruit virus in infected tomato and pepper plants from Turkey

Tomato brown rugose fruit virus(ToBRFV)causes severe fruit loss in tomato(Solanum lycopersicum)and pepper(Capsicum annuum)plants.It is an emerging Tobamovirus that is spreading globally.The major challenge is to develop a reliable method for the detection of the virus,and to better characterize the symptoms it causes.The aims of this study,therefore,were to characterize the symptom development on tomato and pepper plants,and to establish a reliable detection method for the virus.Following infection of the tomato and pepper plants with ToBRFV,the leaves turned chlorotic,mosaic or mottled,while the fruit became rugose,necrotic and marbled,and showed discoloration with yellow or brown spots.Transmission electron microscopy(TEM)revealed single rod-like virus particles characteristic of the Tobamoviruses.Classical reverse transcription PCR(RT-PCR)and quantitative PCR(qPCR)with specific primers and probes confirmed that the virus is ToBRFV.We found that the resistance genes from tomato,Tm-2^(2),and pepper,L1,L2,L3 and L4,did not confer resistance to ToBRFV.Here,we present a PCR-based method as a diagnostic test for detecting ToBRFV in infected seeds.This method will help to prevent further spread of the virus in commercial seeds.