Quantitative analysis of the isoflavone content and biological growth of soybean (Glycine max L.) at elevated temperature, CO₂ level and N application

Abstract

Effects of ambient and elevated CO 2 levels (360 and 650 µmol mol −1 respectively), ambient and high (5 • C above ambient) temperatures and their interactions with N application on soybean (Glycine max L.) were studied in 2001. Overall, total isoflavones in whole soybean seeds were highest (1383.0 µg g −1 ) in the elevated CO 2 (AE) treatment without N application and lowest (414.1 µg g −1 ) in the elevated temperature (EA) treatment with N application. Malonylgenistin (449.2 µg g −1 ) and malonyldaidzin (435.9 µg g −1 ) concentrations in the AE treatment without N application were highest among the 12 individual isoflavones, while aglycon and acetyl conjugates showed lower concentrations (below 10 µg g −1 ) than glucoside and malonyl conjugates in all treatments. Overall, N application had no effect on total isoflavone concentration, while both temperature and CO 2 level had a higher effect on increasing isoflavones, including aglycon and acetyl conjugates (P = 0.001). In the biological growth analysis, total dry weight was highest (100.9 g) in the elevated temperature and CO 2 (EE) treatment with N application, while leaf area was more affected by CO 2 than by temperature and increased with N application. There were larger numbers of pods (99) and seeds (176) per plant in the EE treatment with N application, and generally the AE treatment showed a greater increase in 100-seed weight (g per 100 seeds) and in pods and seeds per plant than other treatments. Overall, total dry weight was highly affected (P = 0.001) by three main factors, temperature, CO 2 and N application, but the interactions temperature × N and temperature × CO 2 × N did not affect total dry weight. Also, total dry weight tended to increase with increasing numbers of pods (r 2 = 0.93 * * * ) and seeds (r 2 = 0.93 * * * ) and larger leaf area (r 2 = 0.85 * * * ). In addition, numbers of pods and seeds were significantly affected (P = 0.01-0.001) by temperature, CO 2 and temperature × CO 2 . Generally, elevated CO 2 and temperature did not affect N, P and K concentrations in the seeds but did decrease the concentrations of Ca and Mg, which were increased in the AE treatment. Among the nutrients, Ca and Mg were highly correlated with temperature and CO 2 level. N concentration in the seeds increased with applied N and in particular showed a high increase with elevated temperature and ambient CO 2 (EA treatment). The variation in isoflavones was correlated with temperature (r 2 = −0.70 * * ) and CO 2 (r 2 = 0.67 * * ), while N application was not correlated with isoflavone concentration. Also, Ca (r 2 = −0.85 * * * ) and Mg (r 2 = −0.57 * ) in the seeds were correlated with variation in isoflavones. This indicated that isoflavones were in higher concentrations under conditions of low temperature and increasing CO 2 , which also resulted in low Ca and Mg concentrations in the seeds. The results of this study suggest that the long-term adaptation of the soybean to growth at elevated CO 2 level and high temperature might potentially increase its isofla...

Seeding date, row spacing, and weed effects on soybean isoflavone concentrations and other seed characteristics

“…They also reported higher isoflavone concentrations in seeds of plants grown from R6 [full seed -green bean (Fehr et al 1971)] in soil at 70% of its water-holding capacity compared with plants grown at 20% water-holding capacity. Kim et al (2005) reported greater isoflavone concentrations in seeds of soybean grown at higher CO 2 levels (i.e., 650 vs. 360 µmol mol -1 of CO 2 ). Finally, stresses such as wounding or pests may also increase soybean isoflavone concentrations (Lozovaya et al 2005;Wegulo et al 2005).…”

“…Environmental and genotype × environment effects also greatly affecting isoflavone concentrations (Lee et al 2003;Kassem et al 2004;Primomo et al 2005). Environmental factors reported to affect isoflavone concentrations in soybean include: temperature, soil moisture levels, soil fertility, CO 2 levels, light quality, and pest occurrence (Tsukamoto et al 1995;Vyn et al 2002;Bennett et al 2004;Li et al 2004;Lozovaya et al 2004Lozovaya et al , 2005Kim et al 2005). Several studies have reported temperature as being one key environmental factor affecting soybean isoflavone concentrations.…”

“…Vyn et al (2002) reported that K fertilization in low K-test soils increased isoflavone concentrations. However, Seguin and Zheng (2006) failed to observe K, P, S, or B fertilization effects in highly fertile soils, while Kim et al (2005) reported that N fertilization (40 kg N ha -1 ) could reduce soybean isoflavone concentrations. Tsukamoto et al (1995) in Japan reported soybean isoflavone concentrations that were up to 5.8 times higher when sown in July than in May.…”

Changes of Isoflavone Contents During Maturation under Different Planting Dates in Black Soybean

“…(Wang et al, 1996), 암세포에 관 여하는 tryosine-specific protein 작용을 저해하여 발암억제 효과가 있고 (Akiyama, et al, 1987), 폐경기전 여성에서는 (Kim et al, 1999), 부위별 축적 양상을 살펴보면, 아이소 플라본 함량은 등숙기간중 배축에서는 변화가 거의 없었지 만 자엽에서는 지속적으로 변화하는 것으로 볼 때 배축과 자엽은 서로 다른 합성과정을 거치는 것으로 추정하고 있다 (Berger, et al, 2008). 아이소플라본 축적에 영향하는 요인 은 품종과 재배지 (Swanson et al, 2004 ;Kim et al, 1999), 파종기 차이 (Sakai et al, 2005) 시비량 (Kim et al, 2005), 토양수분 (Lozovaya et al, 2005), 등숙기간중의 평균기온 (Mercedes et al, 1999 ;Tsukamoto et al, 1995), 유전 및 재배환경요인 (Kitamura et al, 1991 (Kim et al.,, 1999)고 한 연구결과와 같은 품종이라도 재배지역에 따라 함량 차이를 보였다(Eldrige and Kwolek, 1983)는 보고와 일치하였다. 아이소플라본 함량 간에는 glycitein은 배축에 만 존재하며 (Kim et al, 1999), 온도변화에 가장 안정적 (Akagi et al, 2007)이라고 하였고 daidzein과 genistein은 자엽에 높은 비율이 존재하며 온도에 민감하다 (Akagi, et al, 2007) …”

An in silico study of the genes for the isoflavonoid pathway enzymes in soybean reveals novel expressed homologues

“…The three key isoflavones in soybean are daidzein, genistein, and glycitein along with their glycoside forms and corresponding malonyl and acetyl derivatives. Of these 12 isoflavones, the glucoside and malonyl forms of daidzein and genistein are the most common in unprocessed soybean seeds (Lee et al 2003;Charron et al 2005;Kim et al 2005 …”