콩에서 쿠니츠트립인히비터, 렉틴 및 스타키오스에 대한 열성 유전자의 집적

A Stack of Recessive Alleles of Kunitz Trypsin Inhibitor, Lectin, and Stachyose in Soybean

Abstract

성숙 콩[Glycine max (L.) Merr.] 종자에는 단백질, 지방, 탄수화물의 3대 영양소와 아이소플라본 등 다양한 기능성 성분이 함유되어 있다. 그러나, Kunitz Trypsin Inhibitor (KTI) 단백질, 렉틴 단백질, 난소화성 올리고당인 stachyose 성분이 함유되어져 있어 품질과 기능성을 저하시키고 있다. 본 연구는 콩 및 콩 제품의 품질과 기능성을 저하시키는 KTI 및 렉틴 단백질과 stachyose의 성분 함량과 관련된 유전자들이 모두 열성으로 작용하는 콩 계통(triple recessive genotype)을 선발하기 위하여 진행되었다. 3개의 모본(개척2호, PI200508, 14G20)을 이용한 육종집단으로부터 성숙 종자에서KTI 및 렉틴 단백질이 없으면서 stachyose의 함량이 일반콩보다 현저히 적은 triple recessive 유전자형(titilelers2rs2) 개체를 선발하였다. 선발된 계통의 초장은 51 cm 정도였으며 백립중은 31.0 g으로 대립이었으며 종피색 및 제색은 노란색이었다. Stachyose의 함량(g/kg)은 일반콩(13.5 g/kg)보다 훨씬 낮았다(3.8 g/kg). 본 연구를 통하여 선발된 계통은 KTI 단백질과 렉틴 단백질이 동시에 없으며 stachyose의 함량이 낮은 다양한 콩 품종 육성을 위한 중간모본으로 이용될 수 있을 것으로 사료되었다.

Soybean [Glycine max (L.) Merr.] is one of the major food sources of protein, oil, carbohydrates, isoflavones, and other nutrients for both humans and animals. However, soybean seeds contain antinutritional factors, such as lectin protein, Kunitz Trypsin Inhibitor (KTI) protein, and stachyose. The objective of this research was to stack recessive alleles for development a triple recessive genotype, titilelers2rs2, with low KTI protein, lectin protein, and stachyose contents. Three parents (Gaechuck#2, PI200508, and 14G20) were used to develop the breeding population. The presence or absence of the lectin and KTI proteins was detected by western blotting. The stachyose content in mature seeds was determined by HPLC. Agronomic traits, such as plant type, plant height, maturity date, lodging, seed quality, and 100-seed weight, were evaluated for the four $F_3$ plant strains. One $F_4$ plant strain with the desired agronomical traits was selected. One new strain with the triple recessive titilelers2rs2 genotype was developed. The plant height of the new strain was 51 cm and the 100-seed weight was 31.0 g. The new strain had a yellow seed coat and yellow hilum. The stachyose content of the new strain was 3.8 g/kg. One strain developed in this research will be used to produce improved yellow soybean cultivars that are free of lectin and KTI proteins and low in stachyose content.

Fig. 1. Scheme for development of new soybean strain with Kunitz Trypsin Inhibitor protein free, lectin protein free, and low content of stachyose (triple recessive genotype, titilelers2rs2).

Fig. 2. Confirmation of lectin protein free (A) and Kunitz trypsin inhibitor (KTI) protein free (B) in the general cultivar and new strain. C: cultivar, S: new strain (titilelers2rs2 genotype). +, -: presence and absence of lectin and KTI proteins, respectively.

Fig. 3. Plant (left) and seed (right) of new soybean strain (triple recessive genotype, titilelers2rs2) with Kunitz Trypsin Inhibitor protein free, lectin protein free, and low content of stachyose.

Table 1. Genotype for Ti (ti), Le (le), and RS2 (rs2) alleles of parents used in this experiment

Table 2. Agronomic traits of parents and new strain developed in this experiment