Combining Transcriptomics and Metabolomics to Uncover the Effects of High-Energy Lithium-Ion Beam Irradiation on Capsicum annuum L.

Hot pepper(Capsicum annuum L.)is consumed as one of the oldest domesticated crops all over the world.Although mutation breeding using radiation has been performed in hot peppers,little is known about the comparative analysis of mutagenic effects at the molecular level by ion beam irradiation.To comprehend the response mechanism of hot pepper to the ion beam,we used a mutant with favorable economic characteristics induced by lithium-ion beam irradiation to investigate the biological effects.The results indicated that the lithium-ion beam had a positive effect on important agronomic traits,particularly yield unit,but had a negligible effect on the photosynthetic rate of hot pepper,with a specific influence on chlorophyll b rather than chlorophyll a.By RNA-Seq analysis,671 up-regulated and 376 down-regulated genes were identified as differentially expressed genes(DEGs)between irradiated and unirradiated hot pepper.Based on GO and KEGG network analysis,the auxin metabolic process was the common pathway in these two networks.A total of 118 potential reactive oxygen species(ROS)scavenging genes and 262 signal transduction genes were identified,suggesting a balance between antioxidant enzymes and enhanced ROS transduction.The amounts of 15 metabolite,involved in GABA pathways,secondary metabolism,carbohydrate metabolism,shikimate pathways,TCA cycles,nitrogen metabolism,glycerol metabolism and acetate pathways,were significantly changed in the ion beam irradiated sample.These results highlighted that the enriched pathways could play important roles in response to ion beam irradiation in hot pepper plants.In summary,these data provide valuable information for future research on ion beam irradiation and genomic studies in hot pepper.

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.

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.

AFLP Analysis of Mitochondrial DNA from a Cytoplasmic Male Sterility Line and its Maintainer in Pepper (Capsicum annuum L.)

Cytoplasmic male sterility (CMS) is a maternally inherited trait characterized by the inability of a plant to produce functional pollen, which is widespread among higher plants. CMS system is a valuable tool for plant

Investigation of the Effects of Radio Frequency Water Treatment on Some Characteristics of Growth in Pepper (<i>Capsicum annuum</i>) Plants

The aim of the present study was to investigate the effect of electromagnetic radio frequency treatment of water on the growth of pepper (Capsicum annuum) plants. For this experiment, one hundred one-week old plants were divided into two groups. The first group of plants was watered with water subjected to radio frequency electromagnetic radiation from an internet router for one hour a day, while the other group was watered with tap water (control). The overall results showed changes of growth characters of plant watered with electromagnetic water. The length of pepper plants is significantly affected by the treated water, where the length of shoot was lower in plants grown under the effect of treated water (22.43 ± 7.17 cm) than those grown without treated water (28.11 ± 8.57 cm). The results revealed that the stem diameter of control plants (1.74 ± 0.39 cm) was significantly higher than that of the treated plants (1.66 ± 0.35 cm). In addition, the root length was lower in plants grown under the effect of treated water than those grown without treated water. Pepper plants watered with electromagnetic treated water exhibited marked decreases in health index, fresh and dry weight, relative water content, number of flowers and fruits/plant as well as number of seeds/fruit. In addition, the current experiment showed a significant decrease in the number of leaves, branch and flower per plant when watered with electromagnetic treated water. The results revealed that the first flowering time for plants in treated group was remarkably decelerated when compared to other plants in control group.

Purification and Biochemical Characterization of a Protease Inhibitor Ⅱ Family from Jalapeno Pepper(Capsicum annuum L.)

Capsicum annuum L. was initially domesticated in Mexico and northern Central America, and represented an ancient Neotropical plant food complex. The purpose of this paper is to report the isolation and purification of a novo-member of a protease inhibitor from jalape&ntildeo pepper (Capsicum annuum L.) (PIJP). The molecular weight of PIJP inhibitor is 5.95 kDa with 56 amino acids and 6 Cys residues with high inhibitory activity to trypsin with a Ki value of 95 nM. This inhibitor according to the alignment with homologous from NCBI and Pfam databases is a member of proteinase inhibitors II. It is worthwhile to mention a major compositional difference between the proteinase inhibitor II families which have 8 Cys residues. PIJP is the first purified proteinase inhibitor, member of this family with only 6 Cys residues.

五彩椒(Capsicum annuum L.)的组织培养研究

以抗寒性较强的五彩樱桃椒为试验材料,对观赏椒的组织培养进行了研究。试验表明,最佳外植体为茎尖,茎尖的最佳消毒时间为3min;最佳诱导培养基为MS+6-BA5mg·L-1+NAA1mg·L-1;最佳分化培养基为MS+6-BA5mg·L-1+NAA0.1mg·L-1,最佳生根培养基为1/2MS+IBA0.25mg·L-1。

辣椒EIL基因家族的鉴定及其在盐碱胁迫下的表达分析

EIL(Ethylene-insensitive 3-like)基因在参与植物乙烯信号通路的转导和生长发育过程中发挥着重要作用。为了解辣椒EIL基因家族成员信息,利用生物信息学手段对辣椒EIL基因家族成员的理化性质、蛋白质结构、系统进化、基因结构、保守域、启动子顺式作用元件及CaEILs基因在不同组织部位和不同非生物胁迫条件下的表达模式进行分析。同时使用实时荧光定量PCR(qRT-PCR)对辣椒叶片中CaEILs在盐碱胁迫下的表达模式进行研究。结果表明,辣椒9个CaEILs分布在6条染色体上,氨基酸数目、蛋白质理论分子质量和脂肪系数分别介于209~677、23.77~76.07 ku和63.10~87.75,且主要为酸性、亲水的不稳定性核蛋白。系统进化分析显示,CaEILs被分成了4个亚家组,9个CaEILs在根、茎、叶、花蕾、花中具有不同程度的表达,而低温、高温、高盐、干旱胁迫下均能诱导CaEILs的表达,其对以上非生物胁迫均具有不同程度的响应。此外,利用qRT-PCR对盐碱胁迫下辣椒叶片中CaEILs进行了检测,结果发现,随着处理时间的延长,CaEIL1、CaEIL2、CaEIL4、CaEIL5、CaEIL8的表达量整体呈上升趋势,而CaEIL3、CaEIL6、CaEIL7、CaEIL9的表达量整体呈下降趋势。

Molecular cloning and functional analysis of the pepper resistance gene Me3 to root-knot nematode

Root-knot nematodes(RKNs)cause severe diseases in peppers annually around the world.In pepper,the Me3 gene provides a heat-stable and broad-spectrum resistance to RKNs.In this study,several simple sequence repeat(SSR)markers and insertion/deletion(In Del)markers were developed to fine map the Me3 gene.Analysis of 2272 individuals(F2progenies)revealed that Me3 was located in a 45-kb DNA region between markers SSR784 and SSR339,in which there were three candidate genes.Among them,as a novel nucleotide binding site and leucine rich repeat(NBS-LRR)family gene,the DNA sequence of Capana09g000163 of pepper line‘HDA149’was 6348 bp in length,with a 2802-bp open reading frame encoding 933 amino acids,including NB-ARC and LRR domains.Tobacco transient expression assays demonstrated that expression of Capana09g000163 triggered a hypersensitive response(HR)in Nicotiana benthamiana leaves.Subcellular localization results showed that the Capana09g000163 protein was localized in the cell nucleus.Ectopic expression of Capana09g000163 in Arabidopsis significantly increased resistance against Meloidogyne incognita compared with the wild-type(WT)Arabidopsis.Furthermore,M.incognita was almost unable to develop in transgenic Arabidopsis expressing Capana09g000163.Taken together,we cloned the Me3 gene and verified that it induced resistance against M.incognita with the methods of map-based cloning and transgenic technology,which may be of great significance to pepper breeding for resistance against RKNs.

气孔在辣椒(Capsicum annuum L.)子叶和下胚轴上的动态变化

以辣椒幼苗(Capsicum annuum L.)为材料,研究了辣椒生长发育过程中子叶的上、下表皮和下胚轴上、下端1 cm处的气孔密度及表皮细胞密度的动态变化。结果表明:(1)辣椒的气孔由肾形保卫细胞组成,无副卫细胞;子叶的表皮细胞呈无规则形,下胚轴的表皮细胞呈长方形或椭圆形;(2)辣椒子叶上、下表皮的气孔密度和表皮细胞密度分别在辣椒种子出芽后第6天和第3天达到最大,之后随子叶的生长逐渐减小,下表皮的气孔密度和表皮细胞密度明显大于上表皮的;(3)辣椒下胚轴上、下端1 cm处的气孔密度随下胚轴的生长变化不明显,但是表皮细胞密度随下胚轴的生长逐渐减小,下胚轴上端的气孔密度和表皮细胞密度明显的大于下胚轴下端的。

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.

Cloning and characterization of CaGID1s and CaGAI in Capsicum annuum L.

Fruit set and development are affected by many phytohormones, including gibberellin. Little is known regarding molecular mechanism underlying gibberellin mediated fruit set and development especially in Capsicum. Three gibberellin recep- tors, CaGIDlb.1, CaGIDlb.2 and CaGIDlc, and a DELLA protein, CaGAI, have been identified in Capsicum annuum L. During the fruit development, the expression level of CaGIDlc was low, and the expression fold change is mild. However, CaGIDlb. 1 and CaGIDlb.2 were relatively higher and more acute, which indicates that CaGIDlb. 1 and CaGID1b.2 may play an important role in fruit pericarp, placenta and seed. Ectopic expressions of CaGIDlb. 1, CaGIDlb.2 and CaGIDlc in Arabidopsis double mutant gidla gidlc increased plant height, among which CaGIDlb.2 had the most significant effect; CaGAI reduced plant height in double mutant rga-24/gai-t6, having a similar function to AtGID1 and AtGAI in stem elon- gation. Yeast two-hybrid （Y2H） and bimolecular fluorescence complementation （BiFC） assays indicated that CaGIDlb.1 and CaGID1 b.2 interact with CaGAI in a GA-dependent manner, while CaGIDlc interacts with CaGAI in a GA-independent manner. Our study reveals the key elements during gibberellin signaling in Capsicum and supports the critical importance of gibberellin for Capsicum fruit set and development.

Effect of continuous negative pressure water supply on the growth, development and physiological mechanism of Capsicum annuum L.

Effects of continuous negative pressure water supply on water consumption, growth and development, as well as physiological mechanism and quality of Capsicum annuum L. were investigated in this paper. Meanwhile, the optimal negative pressure water supply conditions for growth of C. annuum L. were screened out to achieve the goals of water conservation, high yield and high quality, thus providing theoretical foundation for its field production. The pot experiment within the greenhouse was utilized; the continuous negative pressure water supply was adopted; the four treatments, artificial watering（CK）, –5 k Pa（T1）, –10 k Pa（T2）, and –15 k Pa（T3） were set; and the daily water consumption, yield, as well as the biomass, nitrate reductase, root activity, vitamin C, capsaicin, and nutrient uptakes of nitrogen（N）, phosphorus（P） and potassium（K） during various stages of its growth were determined. Compared with CK, when the water supply pressure was controlled at –5 to –15 k Pa in the experiment, the total water consumption of C. annuum L. reduced by 53.42 to 67.75%, the total water consumption intensity reduced by 54.29 to 67.14%, and the water use efficiency increased by 12.66 to 124.67%. The N accumulation in a single strain of C. annuum L. from the color turning stage to the red ripe stage increased by 15.99 to 100.55%, respectively, compared with that of CK; the P accumulation increased by 20.47 to 154.00% relative to that of CK, and the K accumulation increased by 64.92 to 144.9% compared with that of CK. Compared with CK, C. annuum L. yield was remarkably improved by 13.79% at T1, and contents of vitamin C, capsaicin as well as carotenoids at all growth stages were enhanced by 13.42–147.01%, 11.54–71.01%, and 41.1–568.06%, respectively. Nitrate reductase activity, root activity and chlorophyll（a＋b） were markedly increased by 335.78–500%, 79.6–140.68% and 114.95–676.19%, respectively, from immature stage to full ripe stage. Adopting the continuous negative pressure water supply for C. annuum L. has a significant water-saving effect, and the water supply pressure being stable at –5 k Pa contributes to its growth and development, improves yield, enhances root activity, promotes nutrient uptake, and improves its quality, thus achieving the effects of water conservation, high yield, high quality and high efficiency.

Mutation in the Agrobacterium his I gene enhances transient expression in pepper

Agrobacterium-mediated plant transformation is widely used in plant genetic engineering.However,its efficiency is limited by plant immunity against Agrobacterium.Chili pepper(Capsicum annuum L.)is an important vegetable that is recalcitrant to Agrobacterium-mediated transformation.In this work,Agrobacterium was found to induce a strong immune response in pepper,which might be the reason for T-DNA being difficult to express in pepper.An Agrobacterium mutant screen was conducted and a point mutation in the hisI gene was identified due to a weak immune response and enhanced transient expression mediated by this Agrobacterium mutant in pepper leaves.Further genetic analysis revealed that histidine biosynthesis deficiency caused by mutations in many genes of this pathway led to reduced pepper cell death,presumably due to reduced bacterial growth.However,mutation analysis of threonine and tryptophan biosynthesis genes showed that the biosynthesis of different amino acids may play different roles in Agrobacterium growth and stimulating the pepper immune response.The possible application of Agrobacterium amino acid biosynthesis mutations in plant biology was discussed.

辣椒(Capsicum annuum L.)果实发育及品质相关新microRNA的鉴定与分析

MicroRNA(miRNA)是一种非编码的小RNA,在各种生物过程中起着重要的调节作用。前人研究表明,模式植物中miRNA与果实发育相关。然而,人们对辣椒(Capsicum annuum L.)果实品质及发育相关的miRNA了解尚不清楚。本研究利用二代测序技术(Next-generation sequencing technology)比较了不同品种辣椒果实在不同发育时期的小RNA。利用miRDeep2软件从4个样本中共鉴定出了59个已知miRNA和310个新miRNA。预测了新miRNA的靶基因,共656个,并对其中402个靶基因进行了注释。GO分析和KEGG途径表明,某些靶基因与淀粉糖、氨基糖以及核糖代谢相关。qPCR表明一些miRNA的表达模式与其靶向基因相反,该结果为今后研究miRNA调控果实发育和品质形成提供了重要基础。

Processing of Snack of Goat Chub Chili(Capsicum annuum L.)with Formulations of Tomato and Tomato-Marjoram

The cultivation of goat chili has potentially increased in Chile, due to different varieties of gourmet products made with it;for this reason, new industrial projects are sought to the growing volume to adapt them to the new trends in consumption habits, mainly focused on achieving an attractive meal, a fast preparation and consumption, while nutrients are provided to offer some benefits for human health. The “snacks” products that include the use of fruit satisfactorily respond to these requirements, in addition to providing marketing alternatives to the surplus of fruit exports. For this reason, the present test, consisting of the processing of snacks based on goat chub chili with the addition of tomato and marjoram, was carried out to increase the palatability and the sensorial quality of the final product. The following formulations were used: only chili (T1);chili and tomato (T2);chili, tomato and marjoram (T3). The latter one was characterized by a good flavor and aroma. A large amount of the fruit water content had been removed by drying it with forced hot air. A product without chemical preserves was obtained, with physical and chemical parameters similar to those required by similar foods existing on the market today. In sensorial terms, the formulation to which marjoram was added showed good sensorial and acceptability attributes, highlighting them from the rest of the treatments. The snack color was maintained after the dehydration process, according to panelists.

膜透气性参数对朝天椒(Capsicum annuum var.conoides)自发气调包装冷藏效果的影响

以红熟期朝天椒为材料,结合自发气调包装(modified atmosphere packaging,MAP)和(9±0. 5)℃低温贮藏技术,研究了不同透气性参数的聚乙烯包装膜对朝天椒低温贮藏保鲜效果的影响。结果表明,MAP处理可有效降低朝天椒贮藏过程中的失重率,包装膜透气性参数对包装后朝天椒的贮藏品质影响具有明显差异。MAP处理中除E处理[包装膜O2和CO2透过率分别为1 865 cm3/(m2·24 h·0.1 MPa)和7 214 cm3/(m2·24 h·0.1 MPa)]加速了朝天椒的腐烂外,其他4个处理均能不同程度抑制朝天椒贮藏过程中组织相对电导率的升高,减少腐烂的发生,延缓外观品质的劣变。其中,C处理[包装膜O2和CO2透过率分别为8 087 cm3/(m2·24 h·0. 1 MPa)和31 520 cm3/(m2·24 h·0. 1 MPa)]在贮藏30 d时朝天椒商品性最好。

Genetics of Fertility Restoration in Cytoplasmic Male Sterile Pepper

Pepper hybrid seeds production using male sterility could lower cost by reducing time and labour, and increase the genetic purity of the F1 seeds. To investigate the genetics of fertility restoration of the Peterson cytoplasmic sterility in pepper, a doubled haploid population of 115 pepper lines obtained from anther culture of the F1 hybrid between Yolo Wonder （sterility maintainer line） and Perennial （fertility restorer line） and the parental lines were test-crossed by 77013A （a strict cytoplasmic-genic male sterile line）. The fertility of the test-crossed lines was assessed in greenhouse and open field with the following three criteria： pollen index （PI, visual estimation of pollen amount per flower）, pollen number （PN, pollen counting under microscope）, and seed number （SN, the number of seeds per fruit in open pollination）. Correlations between the each couple of criteria within, as well as between the cultivation methods ranged from 0.55 to 0.84. Analysis of variance showed that the genotype （DH line） and environment were the significant sources of variation of the fertility. Narrow sense of heritance of fertility restoration ranged from 0.38 to 0.92, depending on the criteria and environment. The distribution of the progeny was continuous between the parental genotypes indicating the quantitative inheritance of fertility restoration. Inferred from segregation according to Snape et al.（1984）, the number of segregating genes was estimated to be that three to four genetic factors were involved in pollen traits （PI and PN） and five to eight genetic factors in seed production （SN）. The heredity analysis of the CMS will be helpful for understanding of the genetic mechanism of the fertility restoration and the exploitation of the CMS in hybrid seed production.

Comparative Transcriptome Analysis between Cytoplasmic Male-sterile Line and Its Maintainer During the Floral Bud Development of Pepper

The male-sterile line has been largely used in the hybrid seed production of pepper, which can effectively improve the efficiency of hybrid seed production. However, the formation mechanism of male sterility in pepper remains unclear. In the present study, we compared the gene expression patterns between pepper cytoplasmic male sterile line 9704 A and its maintainer 9704 B during floral bud development using RNA sequencing technology. A total of 547 976 and 2 416 Differentially Expressed Genes(DEGs) were identified in the stage S1, S2 and S3, respectively,and more than 70% of the DEGs were down-regulated in the sterile line. Gene Ontology(GO), and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses were performed to further understand the functions of these identified DEGs. The results showed that the DEGs were mainly enriched in pathways of starch and sucrose metabolism, pentose and glucuronate interconversions. A number of genes, such as MS1, PME5, ATPB, and lots of transcription factors were found down-regulated in the sterile line, and we also identified a series of genes with large differences in expression patterns between sterile line and maintainer line. Collectively, our findings laid a foundation for further molecular breeding in pepper and provided new insights into its mechanism underlying the male sterility.

Growth and Production of Hydroponic Pepper under Salt Stress and Plant Density

The viability of the use of brackish water in the hydroponic cultivation of vegetables cannot dispense with auxiliary techniques such as water mixing and the use of plant densities. In this sense, the objective of the present work was to analyze the growth and production of sweet pepper, cv. All Big, under hydroponic conditions, under different levels of electrical conductivity of the nutrient solution (1.7, 3.7, 5.7, 7.7, 9.7 and 11.7 dS&middotm-1) in plants spaced every 0.2 m and 0.3 m. These treatments were distributed in a completely randomized experimental design, analyzed in a 6 × 2 factorial scheme, with five replications. The growth variables were evaluated at 60, 75 and 90 days after sowing and the production variables at the time of harvest;however, the results were submitted to analysis of variance, at a 0.05 probability level. The interaction between the electrical conductivity of the nutrient solution and the density of plants influenced the behavior of the growth and production variables of pepper (All Big). It was verified that the pepper plants had better performance of the biometric variables plant height, stem diameter and number of leaves when cultivated every 30 cm. At the time, in the analysis by plant, the production of pepper fruits was more expressive when spacing of 30 cm was adopted, however, in the tube of six meters, when 20 cm of spacing was used, the number of fruits was on average, 26.38% and 16.40% higher than lower density, in the electrical conductivities 1.7 and 11.7 dS&middotm-1.