TY - JOUR
T1 - Identification of a novel mutant pAMT allele responsible for low-pungency and capsinoid production in chili pepper
T2 - Accession ‘no. 4034’ (Capsicum Chinense)
AU - Tanaka, Yoshiyuki
AU - Fukuta, Shiho
AU - Koeda, Sota
AU - Goto, Tanjuro
AU - Yoshida, Yuichi
AU - Yasuba, Ken Ichiro
N1 - Funding Information:
Received; June 17, 2017. Accepted; September 20, 2017. First Published Online in J-STAGE on October 28, 2017. This study was supported by a Grant-in-Aid for Young Scientists (B) (No.(휀 5K18640), JAPAN. * Corresponding author (E-mail: yoshi-tanaka@okayama-u.ac.jp).
PY - 2018
Y1 - 2018
N2 - Capsinoids are low-pungent capsaicinoid analogues in chili pepper fruits. They exhibit various bioactivities in humans similar to capsaicinoids, but do not produce a nasty burning sensation, encouraging their application in foods and supplements. Previous reports demonstrated that loss-of-function of putative aminotransferase (pAMT) leads to low-pungency and capsinoid accumulation. Therefore, the pamt allele is a useful gene in chili pepper breeding programs to enhance health-promoting properties. Eight loss-of-function alleles have been identified in the Capsicum genus, but the variation in pamt alleles remains to be fully elucidated. In this study, we identified one novel loss-of-function allele from the analysis of low-pungent chili pepper ‘No. 4034’ (C. chinense). ‘No. 4034’ contained mainly capsinoid with an undetectable level of capsaicinoid. A genetic complementation test was conducted by crossing ‘No. 4034’ with other accessions. The results indicated that ‘No. 4034’ possessed a loss-of-function pamt allele. Sequence analysis showed that the novel mutant allele contained a 7-bp insertion (TCGGTAC) in the 16th exon region, which we designated as pamt9. The insertion caused a frameshift mutation and resulted in a truncated protein. Gene expression analysis showed that the expression level of pAMT specifically decreased among biosynthetic genes tested here in ‘No. 4034’, compared with that of pungent accession. pamt9 will be useful for low-pungency and capsinoid breeding, and will provide additional information for variations in pAMT mutants.
AB - Capsinoids are low-pungent capsaicinoid analogues in chili pepper fruits. They exhibit various bioactivities in humans similar to capsaicinoids, but do not produce a nasty burning sensation, encouraging their application in foods and supplements. Previous reports demonstrated that loss-of-function of putative aminotransferase (pAMT) leads to low-pungency and capsinoid accumulation. Therefore, the pamt allele is a useful gene in chili pepper breeding programs to enhance health-promoting properties. Eight loss-of-function alleles have been identified in the Capsicum genus, but the variation in pamt alleles remains to be fully elucidated. In this study, we identified one novel loss-of-function allele from the analysis of low-pungent chili pepper ‘No. 4034’ (C. chinense). ‘No. 4034’ contained mainly capsinoid with an undetectable level of capsaicinoid. A genetic complementation test was conducted by crossing ‘No. 4034’ with other accessions. The results indicated that ‘No. 4034’ possessed a loss-of-function pamt allele. Sequence analysis showed that the novel mutant allele contained a 7-bp insertion (TCGGTAC) in the 16th exon region, which we designated as pamt9. The insertion caused a frameshift mutation and resulted in a truncated protein. Gene expression analysis showed that the expression level of pAMT specifically decreased among biosynthetic genes tested here in ‘No. 4034’, compared with that of pungent accession. pamt9 will be useful for low-pungency and capsinoid breeding, and will provide additional information for variations in pAMT mutants.
KW - Allelic variation
KW - Capsaicinoid
KW - Frameshift mutation
KW - Health functional ingredient
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U2 - 10.2503/hortj.OKD-115
DO - 10.2503/hortj.OKD-115
M3 - Article
AN - SCOPUS:85045613813
VL - 87
SP - 222
EP - 228
JO - Horticulture Journal
JF - Horticulture Journal
SN - 2189-0102
IS - 2
ER -