Role of l-Cysteine Desulfhydrase in Epibrassinolide-Induced Tolerance to Boron Toxicity in Pepper (Capsicum annuum L.) Plants

Journal of Plant Growth Regulation - Although the effect of epibrassinolide (EBL) on plants under boron (B) toxicity has been studied, the participation of l-cysteine desulfhydrase (l-DES) in...     

EMS-induced lincomycin resistance in red pepper (Capsicum annuum L.)

Summary Ethyl methane sulphonate (EMS) is a potential mutagen to induce lincomycin resistance in Capsicum annuum. Mutagenized cotyledons were cultured on shoot regenerating medium containing lincomycin (100 mgl⁻¹). Approximately 14% of regenerated shoots were chlorophyll deficient and about 4% of regenerated shoots were green from mutaganized cotyledons. The regenerated green plants were resistant to lincomycin but sensitive to chloramphenicol, kanamycin, spectinomycin, and streptomycin. Reciprocal crosses were made between resistant and sensitive plants. Inheritance of lincomycin resistance was transmitted as a non-Mendelian trait. Lincomycin resistance is a first selectable and maternally inherited organelle encoded genetic marker described in chili pepper. Such mutants should be useful in designing biochemical selection schemes to recover somatic hybrids and cybrids.     

CaMYC,A Novel Transcription Factor,Regulates Anthocyanin Biosynthesis in Color-leaved Pepper (Capsicum annuum L.)

Journal of Plant Growth Regulation - Anthocyanins are secondary metabolites derived from the general phenylpropanoid pathway and are widespread throughout the plant kingdom. Anthocyanin...     

Isolation of Yeasts from Guajillo Pepper (Capsicum annuum L.) Fermentation and Study of Some Probiotic Characteristics

Probiotics and Antimicrobial Proteins - Three yeast strains were isolated from the spontaneous fermentation of guajillo pepper: Hanseniaspora opuntiae, Pichia kudriavzevii, and Wickerhamomyces...     

Proteome analysis of bell pepper (Capsicum annuum L.) chromoplasts

We report a comprehensive proteome analysis of chromoplasts from bell pepper (Capsicum annuum L.). The combination of a novel strategy for database-independent detection of proteins from tandem mass spectrometry (MS/MS) data with standard database searches allowed us to identify 151 proteins with a high level of confidence. These include several well-known plastid proteins but also novel proteins that were not previously reported from other plastid proteome studies. The majority of the identified proteins are active in plastid carbohydrate and amino acid metabolism. Among the most abundant individual proteins are capsanthin/capsorubin synthase and fibrillin, which are involved in the synthesis and storage of carotenoids that accumulate to high levels in chromoplasts. The relative abundances of the identified chromoplast proteins differ remarkably compared with their abundances in other plastid types, suggesting a chromoplast-specific metabolic network. Our results provide an overview of the major metabolic pathways active in chromoplasts and extend existing knowledge about prevalent metabolic activities of different plastid types.     

Verticillium Wilt of Pepper (Capsicum annuum) in Morocco

Pepper crops in Morocco formerly thought to be free from attack by Verticillium were found to be susceptible to this pathogen. Verticillium wilt of pepper was observed in plots where the crop was cultivated in rotation with tomatoes. Strains of Verticillium isolated from pepper possessed different morphological and pathogenic characteristics.     

Cytomorphology of induced octoploid Chili pepper (Capsicum annuum L.)

Summary Octoploidy was induced in Chili pepper (Capsicum annuum cultivar cerasiformis) through the application of colchicine and the cytomorphological features of two octoploid plants were described. In general, the octoploids did not exhibit gigas characters when compared to the tetraploids; on the contrary they were less vigorous, suggesting that the optimum and desirable ploidy level for Capsicum is probably tetraploid. Chromosome associations such as octovalents and hexavalents, in addition to IVs, IIIs, IIs and Is, were recorded at diakinesis and metaphase I. Meiosis was highly irregular and the pollen and seed fertility was very low. Cytological features of octoploid Chili peppers are compared with octoploids of Physalis and Petunia.     

Changes of Carbohydrates in Pepper (Capsicum annuum L.) Flowers in Relation to Their Abscission Under Different Shading Regimes

Abscission of pepper flowers is enhanced under conditions oflow light and high temperature. Our study shows that pepperflowers accumulate assimilates, particularly in the ovary, duringthe day time, and accumulate starch, which is then metabolizedin the subsequent dark period. With the exception of the petals,the ovary contains the highest total amounts of sugars and starch,compared with other flower parts and contains the highest totalactivity, as well as activity calculated on fresh mass basis,of sucrose synthase, in accordance with the role of this enzymein starch biosynthesis. Low light intensity or leaf removaldecreased sugar accumulation in the flower and subsequentlycaused flower abscission. The threshold of light intensity fordaily sugar accumulation in the sink leaves was much lower thanin flowers, resulting in higher daytime accumulation of sugarsin the sink leaves than in the adjacent flower buds under anylight intensity, suggesting a competition for assimilates betweenthese organs. Flowers of bell pepper cv. ‘Maor’and ‘899’ (sensitive to abscission) accumulatedless soluble sugars and starch under shade than the flowersof bell pepper cv. ‘Mazurka’ and of paprika cv.‘Lehava’ (less sensitive). The results suggest thatthe flower capacity to accumulate sugars and starch during theday is an important factor in determining flower retention andfruit set. Pepper; Capsicum annuum L.; abscission; shading; pepper flowers; ovary; leaves; sugars; starch; acid invertase; sucrose synthase     

高温干旱对不同品种辣椒生长及呼吸作用的影响

研究了高温干旱胁迫对不同品种辣椒生长及呼吸作用的影响。结果表明,高温胁迫对正椒13号的生长无影响,对鸡爪×吉林的生长稍有抑制;干旱及高温干旱严重地抑制了辣椒的生长。干旱导致叶片相对电导率的增加高于高温,而高温加剧了干旱伤害程度,并且对鸡爪×吉林的伤害更大。高温处理引起了辣椒总呼吸、细胞色素呼吸和交替呼吸的增加。干旱胁迫抑制了细胞色素呼吸,但诱导了交替呼吸的增强;高温干旱共同胁迫加剧了总呼吸和细胞色素呼吸的下降,交替呼吸只在胁迫第一天被促进,随后立即下降。高温、干旱和高温干旱胁迫下正椒13号表现出了较鸡爪×吉林更强的交替呼吸和总呼吸。说明高温、干旱和高温干旱胁迫下辣椒保持较高的总呼吸和交替呼吸与其抗高温和/或干旱能力相关。     

Cytokinins and leaf development in sweet pepper (Capsicum annuum L.)

Stimulation of leaf expansion by an exogenous cytokinin was studied in isolated leaf discs of sweet pepper with emphasis on the assimilate utilization of the tissue. Leaf discs were floated on solutions containing sucrose and plant growth regulators. Benzyladenine (BA) promoted the area expansion rate of the leaf discs. Sucrose at 100 mM resulted in increased area expansion rate compared with 10 mM sucrose. However, the increased sucrose concentration had no influence on the effect of BA. Over a period of 24 h, treatment with BA did not result in any change of sucrose uptake nor of the partitioning of assimilated carbon in the leaf discs. Neither did BA treatment affect the activity of acid invertase (EC 3.2.1.26) or pyrophosphate-dependent phosphofructokinase (EC 2.7.1.90) in the leaf discs. We conclude that the observed promotion of leaf area expansion by exogenous BA is not mediated through the uptake of sucrose or the carbohydrate metabolism of the leaf tissue.Abbreviations BA N⁶-benzyladenine - GA₃ gibberellic acid - PPi-PFK pyrophosphate-dependent phosphofructokinase (EC 2.7.1.90) This study was supported by grants from the Danish Research Counsil (SJVF 13-4148 and 13-4547 to P.U. SJVF 13-4146 and 13-4494 to T.H.N.) and from The Research Center for Plant Biotechnology to P.U.     

一氧化氮(NO)对采后青椒某些生理生化特性与品质的影响

不同浓度(0.1、0.5、1.0μmol·L-1)NO气体处理青椒果实的结果表明:0.5和1.0μmol·L.NO显著地抑制青椒果实的呼吸速率,延缓维生素C(VC)降解,0.5 μmol·L-1NO显著抑制多酚氧化酶(PPO)活性.各处理对果实中叶绿素和丙二醛(MDA)含量与未理的之间无显著差异.     

Androgenesis induction in microspore culture of sweet pepper (Capsicum annuum L.)

Isolated microspore culture experiments were carried out in sweet pepper (Capsicum annuum L.) F₁ hybrid genotypes. In the first experiment, four culture media (W14, B5, MS and NLN) were compared to test their effectiveness in inducing the formation of microspore-derived structures in two genotypes. The experiments revealed the superiority of B5 medium. In the second experiment, the effects of different ratios of 2,4-dichlorophenoxyacetic acid (2,4-D) (0, 0.1, 0.2 and 0.5 mg l⁻¹) and kinetin (0, 0.2 and 0.5 mg l⁻¹) were also investigated in B5 medium with two genotypes. The effect of growth regulators were investigated on the production of microspore-derived calli and embryo-like structures (ELSs), the ratio of the two and plant regeneration (number of regenerated plantlets) in microspore culture. The histological experiments revealed the differences between the microspore-derived ELSs and calli. The most promising results were obtained on the investigated parameters in the presence of 0.1 mg l⁻¹ 2,4-D and 0.2 mg l⁻¹ kinetin producing the highest number of plantlets in both genotypes tested. In the response of 11 genotypes, the androgenesis induction was successful in each sweet pepper genotypes tested using the best basic medium and growth regulators combination. In case of 11 genotypes, the number of ELSs ranged from 20 to 100/Petri dish (an average of 48.1 ELS/Petri dish), while the number of green plantlets varied from 0 to 8 plantlets/Petri dish (an average of 1.5 plantlets/Petri dish) depending on the genotype. The spontaneous rediploidization rate obtained was 25% in isolated microspore.     

Plant regeneration from sweet pepper (Capsicum annuum L.) hypocotyl explants

Morphogenetic potential of hypocotyl and cotyledon explants of the three Polish Capsicum annuum L. cultivars (Kujawianka, Passat and Zorza) was studied to develop a reliable plant regeneration protocol. Out of 8 and 15 combinations of growth regulators used in the first and second series respectively, the best medium contained BAP (5 mg·l⁻¹) and IAA (1 mg·l⁻¹). Media containing thidiazuron (TDZ) and IAA proved to be worse than those with BAP and IAA. Additionally, it was indicated that hypocotyl explants placed upside-down developed more adventious buds. ‘Passat’ was the most responsive variety (approximately 40 % of both types of explants produced buds). In the second part of experiment the aim was to stimulate shoot induction in the conditions most adapted to Agrobacterium transformation. ‘Bryza’ replaced cv ‘Kujawianka’ and proved to be better than ‘Passat’, previously distinguished as a highly responsive cultivar. The experiments confirmed a significant effect of the hypocotyl explant length and induction period on shoot regeneration. Finally, the optimum concentration of carbenicillin and kanamycin was determined.     

Suppression of ethylene levels promotes morphogenesis in pepper (Capsicum annuum L.)

Ethylene and polyamines (PAs) are two phytohormones that play important roles during in vitro morphogenesis of several plant species. The interaction between ethylene and PAs has been of interest because both have S-adenosylmethionine as a precursor. To study the influence of ethylene and PAs on in vitro morphogenesis of an ornamental pepper, we added an ethylene scavenger, PAs, a PA inhibitor, and compounds that affect ethylene biosynthesis and activity to the regeneration medium. Regeneration frequencies increased in response to treatment with ethylene inhibitors (aminoethoxyvinylglycine and silver thiosulfate) and an ethylene scavenger (mercury perchlorate). Treatment with the ethylene precursor 1-aminocyclopropane-1-carboxylic acid reduced the regeneration frequency, increased callus formation, and increased ethylene levels; similar results were obtained in response to treatment with the PA inhibitor methylglyoxal-bis(guanylhydrazone). By contrast, treatment with PAs (particularly spermidine and spermine) decreased ethylene levels, increased the regeneration frequency, and increased shoot bud formation. These results suggest a coordinated regulation of ethylene and polyamines because the suppression of ethylene levels using ethylene inhibitors, polyamines, or mercury perchlorate increased the in vitro regeneration frequency and morphogenic responses of Capsicum annuum L.     

Increased capsaicin content in PFP-resistant cells of chili pepper (Capsicum annuum L.)

Cell suspensions of chili pepper (Capsicum annuum L.) were subjected to a selection process on semisolid medium containing the amino acid analog p-fluorophenylalanine (PFP). Four cell lines with different degrees of resistance were selected and suspension cultures were established from each of them. Resistance was retained even after 75 days of culture in the absence of PFP. PFP-resistant cell lines accumu lated higher levels of capsaicin than sensitive lines even after prolonged culture in PFP-free medium. Capsaicin production in non-selected cells was only 26.8% of that found in one cell line resistant to 500 M PFP. The capsaicin content in the non-selected cell suspension and in one of the resis tant cell lines was 6.7% and 24.9% respectively, that of fruits.Abbreviations BA benzyladenine - 2,4-D 2,4-dichlorophenoxyacetic acid - PFP p-fluorophenylalanine - d. wt. dry weight - f. wt. fresh weight