6-苄基腺嘌呤对大豆内部水分分布及其生长状态的影响

Effects of 6-Benzylaminopurine on internal water distribution and growth state of soybean

为研究大豆发芽过程中加入不同浓度的6-苄基腺嘌呤(6-Benzylaminopurine,6-BA)后大豆内部水分的分布及对其生长状态的影响,以中黄13为研究对象,在相同环境条件下,用浓度分别为0(对照)、1、3、5、7、9 mg/L的6-BA溶液处理大豆。利用低场核磁共振技术(Low Field Nuclear Magnetic Resonance,LF-NMR)对中黄13在浸泡8 h及萌发12、24、36、48、60 h时间点的波谱信息、图像信息进行采集,同时对豆芽的生长状态进行理化指标和形态指标检测。结果显示:与其他处理组相比,浓度为3 mg/L的6-BA溶液处理的大豆的发芽周期、吸水率、平均质量、发芽率、豆芽轴长、轴径各指标表现均为最优;低浓度(1、3 mg/L)6-BA加速大豆蛋白质的水解,导致其渗透势降低,促进大豆蛋白质体吸收更多的水分,进而促使豆芽轴长变长、轴径变粗;高浓度(5、7、9 mg/L)6-BA使大豆细胞壁在细胞的渗透作用下遭到破坏,导致大豆吸水率降低,进而抑制了大豆的生长。该研究从大豆原料的预处理开始对整个加工过程进行了研究,为豆芽的生产加工提供一定的理论支持和数据参考。

Soybean sprout is one type of edible vegetable that is cultivated by sprouting soybeans.Taking Zhonghuang 13 as the research object,a series of treatments were carried out using the 6-BA solution with concentrations of 0,1,3,5,7,and 9 mg/L under the same environmental conditions.The water distribution in soybean was measured to determine the growth state under the different concentrations of 6-BA during soybean germination.The low-field nuclear magnetic resonance(LF-NMR)and magnetic resonance imaging(MRI)were selected to clarify the effect of 6-BA on the germination of soybean.Three procedures included the LF-NMR,LF-NMR/MRI imaging,and the acquirement of soybean physical,chemical,and morphological indexes.The proton density(PD)image was extracted from the nuclear magnetic signals collected by the Carr-Purcell-Meiboom-Gill(CPMG)spin echo pulse sequence.The results show that the water evolution was visually determined during soybean germination using the LF-NMR PD images.The soybean germination was divided into the imbibition(0-8 h),protrusion(8-24 h),and germination stage(24-60 h).The germination cycle from the soaking to germination varied with the concentration of 6-BA solution in the treatment groups.The germination time of soybean seeds with the 0,1,and 3 mg/L of 6-BA solution was shorter than that of the rest,where the best was the 3 mg/L concentration.The water content in various phases of soybean was quantitatively characterized by LF-NMR data.According to the relaxation time,the water content of soybean was divided into three kinds:the bound water T_(21),semi bound water T_(22),and free water T_(23).The sub peak was disappeared gradually on the left side of bound water(0.1 ms<T_(21)<10 ms)with the 6-BA concentration higher than 5 mg/L.The low 6-BA concentration accelerated the hydrolysis of soybean protein to reduce the osmotic potential,where the soybean protein body was promoted to absorb more water.By contrast,the high 6-BA concentration destroyed the soybean cell wall,due to the infiltration of soybean cells,resulting in a decrease in soybean water absorption.The low 6-BA concentration promoted the soybean water absorption for the better growth of soybean sprouts,according to the physical,chemical,and morphological indexes of soybean seeds.The high 6-BA concentration inhibited the soybean water absorption and bud growth.The water absorption of soybean soaked in the 6-BA solution with the concentration of 3 mg/L(131.8%)was the largest among the six groups,followed by that with the concentration of 1 mg/L(126.5%),and the control group in the deionized water(121.3%).The water absorption of soybean was lower than that of the control group(0 mg/L),which was 104.3%,103.6%,and 101.5%,respectively,when the solution concentration was 5,7,and 9 mg/L.The average fresh weight of soybean with the 6-BA concentration of 3 mg/L was the largest,followed by the concentration of 1,0,5,7,and 9 mg/L.Consequently,the appropriate 6-BA concentration can widely be expected to promote the germination rate of bean sprouts,indicating the longer axis length and larger diameter of bean sprouts.The LF-NMR/MRI can be a promising tool to monitor the dynamic changes of water in the growth period of bean sprouts.The finding can provide the theoretical support and data reference for the production and processing of soybean sprouts.