Relationship between Mutations of the Pectin Methylesterase Gene in Soybean and the Hardness of Cooked Beans.
Hardness of cooked soybeans [Glycine max (L). Merr.] is an important attribute in food processing. We found one candidate gene, Glyma03g03360, to be associated with the hardness of cotyledons of cooked soybeans, based on a quantitative trait locus and fine-scale mapping analyses using a recombinant inbred line population developed from a cross between two Japanese cultivars, "Natto-shoryu" and "Hyoukei-kuro 3". Analysis of the DNA sequence of Glyma03g03360, a pectin methylesterase gene homologue, revealed three patterns of mutations, two of which result in truncated proteins and one of which results in an amino acid substitution. The truncated proteins are presumed to lack the enzymatic activity of Glyma03g03360. We classified 24 cultivars into four groups based on the sequence of Glyma03g03360. The texture analysis using the 22 cultivars grown in different locations indicated that protein truncation of Glyma03g03360 resulted in softer cotyledons of cooked soybeans, which was further confirmed by texture analysis performed using F2 populations of a cross between "Enrei" and "LD00-3309", and between "Satonohohoemi" and "Sakukei 98". A positive correlation between hardness and calcium content implies the possible effect of calcium binding to pectins on the hardness of cooked soybean cotyledons.
NARO Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan.
Kyoko
K
Toda
NARO Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan.
Kaori
K
Hirata
NARO Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan.
Ryoichi
R
Masuda
NARO Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan.
Takeshi
T
Yasui
NARO Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan.
Tetsuya
T
Yamada
NARO Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan.
Koji
K
Takahashi
NARO Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan.
Taiko
T
Nagaya
NARO Institute of Crop Science, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan.
Makita
M
Hajika
D002265:Carboxylic Ester Hydrolases / Q000235:genetics* / Q000378:metabolism; D003296:Cooking; D006244:Hardness; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012639:Seeds / Q000737:chemistry* / Q000201:enzymology / Q000235:genetics; D013025:Glycine max / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics
D010940:Plant Proteins; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase
calcium; pectin methylesterase; seed hardness; soybean