Growing up in the midwestern United States, I’m the first to admit that I didn’t get much exposure to spicy food. .
A Perk of Our Evolution: Pleasure in Pain of Chilies
I marveled at the uncountable number of artisanal hot sauces on the market, and at the frequency with which the words “death,” “nuclear” and “devil” were used in the names.This chest-beating may be particular to the United States, where one hot sauce maker actually markets a limited edition of pure capsaicin.In places like Central America, Asia and the Indian subcontinent, hot chili peppers are an integral part of the cuisine.A recent study suggested that capsaicin is an effective defense against a fungus that attacks chili seeds.Chili pungency is not technically a taste; it is the sensation of burning, mediated by the same mechanism that would let you know that someone had set your tongue on fire. .
DNA sequence analysis tells the truth of the origin, propagation, and
The theory in question claims that Latin American chili (aji) passed through India and Japan before being introduced to Korea through the 1592 Japanese invasions.This paper aims to correct this misconception through scientific analysis and ultimately restore the truth about the history and culture of Korean fermented foods. .
How Did Hot Peppers Evolve?
Previously, I had accepted a racist intelligent-design-based hypothesis according to which God sent them to earth to torment everyone who dislikes Indian food. .
As a plant fanatic, even the simple act of cooking dinner opens the door to so many interesting questions.In the wild, Capsicum fruits are much smaller than the ones we buy at the farmers market or grocery store.The spicy effect one experiences when biting into a pepper is the result of a chemical called capsaicin.Their small size and bright coloration are vivid sign posts for their main seed dispersersal agents - birds.Capsaicin is there to deter such critters from feeding on the fruits and wasting hard earned reproductive efforts.As such, the well defended fruits can sit on the plant until they are ripe enough for birds to take them away, spreading seeds via their nutrient rich droppings.Photo Credits: Ryan Bushby, André Karwath, and Eric Hunt - Wikimedia Commons. .
Capsaicin and related compounds known as capsaicinoids are the substances giving chili peppers their intensity when ingested or applied topically. After the Columbian Exchange, many cultivars of chili pepper spread around the world, used for both food and traditional medicine.Cultivars grown in North America and Europe are believed to all derive from Capsicum annuum, and have white, yellow, red or purple to black fruits.In 2019, the world's production of raw green chili peppers amounted to 38 million tons, with China producing half. Origins of cultivating chili peppers are traced to east-central Mexico some 6,000 years ago, although according to research by the New York Botanical Garden press in 2014, chili plants were first cultivated independently across different locations in the Americas including highland Bolivia, central Mexico, and the Amazon.Production of chillies and peppers, green – 2020 Region (Millions of tons) China 16.7 Mexico 2.8 Indonesia 2.8 Turkey 2.6 Spain 1.5 World 36.1 Source: FAOSTAT of the United Nations .Capsicum chinense includes the hottest peppers such as the naga, habanero, Datil and Scotch bonnet.The substances that give chili peppers their pungency (spicy heat) when ingested or applied topically are capsaicin (8-methyl-N-vanillyl-6-nonenamide) and several related chemicals, collectively called capsaicinoids.When a habanero plant is stressed, by absorbing low water for example, the concentration of capsaicin increases in some parts of the fruit. The modern method is a quantitative analysis of SHU using high-performance liquid chromatography (HPLC) to directly measure the capsaicinoid content of a chili pepper variety.Pure capsaicin is a hydrophobic, colorless, odorless, and crystalline-to-waxy solid at room temperature, and measures 16,000,000 SHU.Capsaicin is produced by the plant as a defense against mammalian predators and microbes, in particular a fusarium fungus carried by hemipteran insects that attack certain species of chili peppers, according to one study. Peppers increased the quantity of capsaicin in proportion to the damage caused by fungal predation on the plant's seeds.Ingestion of extremely hot chili pepper varieties such as the Carolina reaper can cause a condition known as "puckerbutt".The condition is characterized by severe cramps, abdominal discomfort, and intense burning of the rectum and anus during defecation of the digested chili peppers.Chilies are sometimes used whole or in large slices, by roasting, or other means of blistering or charring the skin, so as not to entirely cook the flesh beneath.In southern Mexico, mole sauce is made with dried chiles, such as ancho and chipotle peppers.In India, most households always keep a stock of fresh hot green chilies at hand, and use them to flavor most curries and dry dishes.Some notable chili-forward dishes other than the ones mentioned elsewhere in this article include arrabbiata sauce, paprikash, chiles en nogada, jerk chicken, mole poblano, nam phrik, 'nduja, sambal, and som tam.Fresh or dried chilies are often used to make hot sauce, a liquid condiment—usually bottled when commercially available—that adds spice to other dishes.Hot sauces are found in many cuisines including harissa from North Africa, chili oil from China (known as rāyu in Japan), and sriracha from Thailand.This method lets people experience extreme feelings without any significant risk of bodily harm.Capsaicin, the pungent chemical in chili peppers, is used as an analgesic in topical ointments, nasal sprays, and dermal patches to relieve pain. A 2022 review of preliminary research indicated that regular consumption of chili peppers was associated with weak evidence for a lower risk of death from cardiovascular diseases and cancer.Capsaicin extracted from chilies is used in pepper sprays and some tear gas formulations as a chemical irritant, for use as less-lethal weapons for control of unruly individuals or crowds.Because the elephants have a large and sensitive olfactory and nasal system, the smell of the chili causes them discomfort and deters them from feeding on the crops.By planting a few rows of the fruit around valuable crops, farmers create a buffer zone through which the elephants are reluctant to pass.They are bricks made of mixing dung and chili, and are burned, creating a noxious smoke that keeps hungry elephants out of farmers' fields.Chile is the most common Spanish spelling in Mexico and several other Latin American countries,  as well as some parts of the United States  and Canada, which refers specifically to this plant and its fruit.is the most common Spanish spelling in Mexico and several other Latin American countries, as well as some parts of the United States and Canada, which refers specifically to this plant and its fruit.Chilli was the original Romanization of the Náhuatl language word for the fruit (chīlli) and is the preferred British spelling according to the Oxford English Dictionary, although it also lists chile and chili as variants.Certain Spanish-speaking countries in South America and the Caribbean, including Chile, Colombia, Ecuador, Panama, Peru, Dominican Republic, Venezuela and Puerto Rico, call the peppers as ají, a word of Taíno origin. The word pepper is also commonly used in the botanical and culinary fields in the names of different types of pungent plants and their fruits. .
Genome sequence of the hot pepper provides insights into the
CM334 (hereafter, CM334) by Illumina sequencing of genomic libraries with insert sizes ranging from 180 bp to 20 kb (Supplementary Figs.For each library, we confirmed that raw data were unbiased by measuring the distribution of insert sizes (Supplementary Fig.To construct pseudomolecules, we established a high-density genetic map with 6,281 markers using 120 recombinant inbred lines derived from C. annuum cv.We performed resequencing of two pepper cultivars (Perennial and Dempsey) and de novo sequencing of a wild species (C.
chinense PI159236; hereafter, C. chinense) to provide a comprehensive overview of genetic variation and differences in genome structure among pepper cultivars (Supplementary Figs.The number of low-coverage blocks (190 with 500-kb windows) that were divergent between C.
annuum and C. chinense shows the genomic variation in the two species (Fig.Density of matched blocks is presented for C.
chinense, Dempsey and Perennial (left to right) for 500-kb windows.The predominant type of TE was long terminal repeat (LTR) elements, which represented approximately 1.7 Gb (more than 70%) of the total number of TEs in the two genomes.A large number of Caulimoviridae elements were unique to either pepper genome (Supplementary Table 20).The TEs were widely dispersed throughout the pepper genome and often led to the conversion of euchromatin into heterochromatin.A total of 34,903 protein-coding genes were predicted in the PGA pipeline (Pepper Genome Annotation v. 1.5) (Supplementary Figs.We evaluated consensus gene models using 19.8 Gb of Illumina RNA sequencing (RNA-seq) data.The distribution of small RNAs correlated well with gene density in the hot pepper genome (Supplementary Fig.We estimated the total number of LTR retrotransposons by counting the reverse-transcriptase (RT) domains encoded by the hot pepper and tomato genomes (Fig.Hot pepper and corresponding tomato chromosomes are represented by red and blue bars, respectively.Common elements and those existing in only one species are depicted by filled and empty triangles, respectively.Del elements are known to selectively accumulate in heterochromatic regions owing to the function of the encoded chromodomain24.However, we often found these Del elements in the collinear regions of the hot pepper genome that correlated with tomato euchromatin, with the insertion of these elements resulting in the formation of heterochromatic gene islands in the hot pepper genome (Fig.We also observed that the Tat subgroup of the Gypsy family had selectively accumulated in euchromatic regions (Fig.We estimated the times of insertion for Gypsy and Copia elements using the method described by SanMiguel et al.25 (Fig.Speciation time can be estimated from the peak value in frequency analysis of the synonymous substitution rate (K s ) of orthologous gene sets27.The peak value of the K s frequency used to determined the speciation time point was observed at 0.3 (19.1 million years ago) (Supplementary Fig.Gypsy elements in the hot pepper genome were gradually accumulated before speciation and peaked in frequency at a substitution value of 0.2 (12.7 million years ago) (Fig.Thus, the unequal accumulation of Gypsy elements in heterochromatic regions of the progenitor species may have had a role in the speciation of hot pepper.Caulimoviridae is a DNA pararetrovirus of ∼8-kb unit length that evolved from a Gypsy element and replicates via an RNA intermediate without LTR sequences29.So far, Caulimoviridae elements have not been reported in repeat classification in other plant genome sequences, except for a small copy number in the banana genome30.This finding indicates that the proliferation of Petuvirus and Caulimovirus elements resulted in the high abundance of Caulimoviridae in the hot pepper genome with random distribution (Fig.Therefore, the accumulation of these elements might also have had a role in the expansion of the hot pepper genome in both heterochromatic and euchromatic regions.Capsaicinoids are synthesized by capsaicin synthase (CS and Pun1), which condenses vanillylamine from the phenylpropanoid pathway with 8-methyl-6-nonenoyl-CoA from the branched-chain fatty-acid pathway31,32 (Fig.Although the biosynthetic genes have been partly elucidated33,34,35, the biochemical reactions, evolution and regulation of capsaicinoid biosynthesis are still largely unknown.PAL, phenylalanine ammonia-lyase; C4H, cinnamate 4-hydroxylase; 4CL, 4-coumaroyl-CoA ligase; HCT, hydroxycinnamoyl transferase; C3H, p-coumaroyl shikimate/quinate 3-hydroxylase; COMT, caffeoyl-CoA 3-O-methyltransferase; HCHL, hydroxycinnamoyl-CoA hydratase lyase; AMT, aminotransferase; BCAT, branched-chain amino acid aminotransferase; Kas, ketoacyl-ACP synthase; ACL, acyl carrier protein; FatA, acyl-ACP thioesterase; CS, capsaicin synthase.Using homology, microsynteny and previous reports35, we identified all orthologous genes of the capsaicinoid pathway in the tomato genome (Supplementary Fig.In a comparative transcriptome analysis, several genes in the pathway clearly showed differential expression in pepper and tomato fruits (Fig.Fruit-specific expression of CS, encoding a homolog of acyltransferase, primarily occurred during pepper placenta development (at 16 d.p.a., 25 d.p.a.In contrast, the orthologous genes in the tomato pathway (BCAT, Kas and CS) were rarely expressed at this stage, and we obtained a similar result for the potato genome (Supplementary Fig.These results may indicate that changes in the gene expression of BCAT, Kas and CS enabled capsaicinoid synthesis in hot pepper fruits.All other genes in the capsaicinoid biosynthetic pathway showed similar expression, except for BCAT, COMT and FatA at 6 d.p.a.The distribution of orthologous gene families in hot pepper, tomato, potato, Arabidopsis, grape and rice was defined using OrthoMCL38.The hot pepper genome shared 27, 51 and 20 gene families with Arabidopsis, grape and rice, respectively.Some transcription factors included Solanaceae-specific subclasses, specifically in the ARF, AP2/ERF, WRKY and NAC families.The number of TIR-type proteins in the hot pepper genome (48) was similar to that in potato (47) (Supplementary Table 39).This expansion might be a consequence of evolutionary events of tandem duplication resulting in preferential clustering of the genes on chromosome 9 (Supplementary Fig.Climacteric fruits such as tomato and banana display increases in respiration rate and ethylene synthesis during ripening.Non-climacteric fruits such as pepper and strawberry exhibit neither a respiratory burst nor elevated ethylene production during ripening42.Thus, pepper and tomato provide suitable models for comparisons of fruit ripening processes.Thus, the conservation and divergence of the transcription of these genes and their interactions may lead to qualitative and quantitative differences in the physiological phenomena underlying ripening.(a) Heat map of normalized RNA-seq data prepared from three biological replicates for genes involved in fruit ripening.Blue and red boxes represent genes that are downregulated and upregulated in pepper, respectively.The major pigments in pepper fruits are capsanthin and capsorubin, which are pepper-specific carotenoids synthesized by capsanthin-capsorubin synthase (CCS)54.4 and Supplementary Table 22), which suggests that ethylene-dependent regulation may be preserved in both types of fruit ripening and lead to distinct outcomes.Therefore, these developmental and hormonal regulatory networks might be the main components that distinguish different ripening patterns.One of the ripening characteristics distinguishing pepper and tomato is fruit softening, in which polygalacturonase (PG) has a central role.In comparative sequencing analysis of PG (CA10g18920) from wild-type pepper and the Soft flesh56 mutant, we found that a point mutation in the 3′ splice acceptor site at intron VIII generated a premature stop codon in the PG gene from wild-type pepper.Most of the pepper genes in the L-galactose pathway showed expression similar to or higher than in tomato (Supplementary Table 56). .