中国农业科学 ›› 2020, Vol. 53 ›› Issue (14): 2774-2785.doi: 10.3864/j.issn.0578-1752.2020.14.002

• 专题:高粱育种与栽培 • 上一篇    下一篇

不同糯性高粱胚乳淀粉形成与积累过程的酶学调控机制及显微结构变化

柯福来(),朱凯,李志华,石永顺,邹剑秋,王艳秋()   

  1. 辽宁省农业科学院高粱研究所,沈阳 110161
  • 收稿日期:2019-07-31 接受日期:2020-01-02 出版日期:2020-07-16 发布日期:2020-08-10
  • 通讯作者: 王艳秋
  • 作者简介:柯福来,E-mail:397634262@qq.com
  • 基金资助:
    国家重点研发计划(2019YFD1001704/2019YFD1001700);国家谷子高粱产业技术体系(CARS-06-13.5-A22);中央引导地方项目(2018010035-201);辽宁省农业领域青年人才培养计划(2014019)

Formation Regulating and Micro-Structure of Sorghum Starch with Different Types of Endosperm

KE FuLai(),ZHU Kai,LI ZhiHua,SHI YongShun,ZOU JianQiu,WANG YanQiu()   

  1. Sorghum Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang 110161
  • Received:2019-07-31 Accepted:2020-01-02 Online:2020-07-16 Published:2020-08-10
  • Contact: YanQiu WANG

摘要:

【目的】高粱是酿造白酒和食醋的主要原料,其淀粉组成和结构是影响高粱酿造品质的主要指标。通过研究淀粉积累过程中相关酶活性和淀粉粒超微结构的变化动态,解析高粱淀粉合成与积累的酶学调控机制,了解不同糯性高粱胚乳淀粉的超微结构特点,以期为酿造高粱的优质育种和栽培技术研究提供理论依据。【方法】以辽粘3号、辽杂19和辽杂10号3种不同糯性的高粱品种籽粒为研究对象,利用酶学及扫描电镜技术检测淀粉积累过程中相关酶活性的变化,观测淀粉积累过程中淀粉粒的形成过程及结构特征,利用相关分析研究淀粉合成过程中相关合成酶类的调控作用。【结果】淀粉合成过程中,不同胚乳类型高粱的尿苷二磷酸葡萄糖焦磷酸化酶(UDPG)、腺苷二磷酸葡萄糖焦磷酸化酶(ADPG)、可溶性淀粉合成酶(SSS)、结合态淀粉合成酶(GBSS)、淀粉分支酶(SBE)、淀粉去分支酶(DBE)活性均呈单峰曲线变化趋势;糯高粱结合态淀粉合成酶(GBSS)活性呈单峰曲线变化趋势,粳高粱、半粳半糯高粱则表现双峰曲线变化趋势。UDPG、ADPG、SSS活性与直链淀粉、支链淀粉积累速率显著正相关,SBE、DBE活性与支链淀粉积累速率呈显著正相关,GBSS活性与粳高粱、半粳半糯高粱直链淀粉积累速率呈显著正相关,与糯高粱直链淀粉积累速率表现正相关的趋势,但相关不显著。不同胚乳类型高粱淀粉粒的充实过程表现相似变化趋势,在开花后的14—35 d充实较快。糯高粱的淀粉粒较小,直径在10 μm以内,内部有圆孔型或楔形空洞。粳高粱淀粉粒较大,呈不规则球形,内部空洞极少。半粳半糯型高粱淀粉粒粒径分布较广,多数分布楔形或星形空洞,少部分无空洞。【结论】UDPG、ADPG、SSS是调控淀粉合成的关键酶,GBSS、SBE、DBE是调控淀粉组分比例的关键酶,SBE、DBE活性高是糯高粱支链淀粉含量高的主要原因,不同淀粉组分比例可能是影响淀粉粒结构的主要因素。

关键词: 高粱, 直链淀粉, 支链淀粉, 淀粉合成关键酶, 显微结构

Abstract:

【Objective】 Sorghum is the main material for liquor-making and brewing well-aged vinegar, and its starch composition and structure are the main factors that influence the brewing quality of sorghum. In this paper, the Dynamic Changes of Key Enzymes Involved in Starch Synthesis are analyzed, the ultrastructure of starch is observed, for confirming the regulatory effect of related enzymes on sorghum starch synthesis, and revealing the ultrastructure characteristics of sorghum starch.【Method】Three sorghum cultivars(Liaonian3, Liaoza19, Liaoza10) with different endosperm types were used as experimental materials. The changes of key enzymes involved in starch synthesis were detected with enzymological technique. Scanning electron microscopy was used to observe the morphology features of starch granules. The regulation of related enzymes in starch synthesis was studied by correlation analysis. 【Result】 The activity of UDPG, ADPG, SSS, SBE, DBE enzymes of sorghum with different endosperm types showed a single peak curve during starch accumulation. The activity of GBSS enzyme of sorghum with waxy endosperm showed a single peak curve, while other types sorghum showed bimodal curves. Activities of UDPG and ADPG, SSS enzyme were significantly correlated with amylose and amylopectin accumulation rate. Activities of SBE, DBE enzyme were positively correlated with amylopectin accumulation rate. Activities of GBSS enzyme was positively and significantly correlated with amylopectin accumulation rate in non-waxy sorghum and semi-waxy sorghum, it showed a positively correlation trend, but not significant in waxy sorghum. For sorghum with different endosperms, the formation process of starch grains showed a similar tendency. The starch accumulation rate was higher during 14-35 d after flowering. The starch grains of waxy sorghum are the smallest, with a diameter within 10 μm, and carved with round-hole or wedge-shaped cavity inside. The starch grains of nonwaxy sorghum are the largest, irregularly globular, with scarcely cavity inside. The size distribution of sorghum starch granules with semi-waxy endosperm ranges widely, most of them with wedge-shaped or star-shaped cavities inside, only a few with no cave. 【Conclusion】 UDPG, ADPG, SSS play important adjustive roles in the accumulation of amylopectin and amylose. GBSS, SBE and DBE are the key enzymes to regulate the ratio of amylose/amylopectin. Higher activities of SBE and DBE are the main reason that makes waxy sorghum contains higher amylopectin. The ratio of amylose/amylopectin may be the main factor affecting the starch grain structure of sorghum.

Key words: Sorghum bicolor L., amylose, amylopectin, starch synthesis related enzymes, microstructure