谷类作物中胚乳占据首要地位,而淀粉作为重要的碳水化合物是大多数粮食作物中胚乳主要的组分。本研究以自交系B73为试验材料,研究了早期施用外源乙烯对玉米胚乳淀粉合成的影响。结果显示,在玉米十展叶时期施用400 mg L-1的乙烯利水溶液会显著降低玉米产量和淀粉含量。通过对淀粉合成相关酶活性的探讨,发现ADP葡糖焦磷酸化酶、可溶性淀粉合成酶、淀粉分支酶、蔗糖合成酶的活性均在处理组中表现出显著下降。另外,运用荧光定量PCR对淀粉合成相关酶的基因进行表达量分析,发现处理组中ADP葡糖焦磷酸化酶、可溶性淀粉合成酶、蔗糖合成酶的基因表达量低于对照组。由此可以推测,乙烯处理通过调控淀粉合成相关基因的表达与酶的活性来影响玉米胚乳淀粉的发育。本研究以期揭示前期乙烯处理对籽粒的发育提供一些线索和支持。
英文摘要:
Endosperms play a predominant role in cereal seeds. Starch as available carbohydrates in the grain of most food crops especially maize is the major component of seed endosperm. To understand the role of ethylene in starch biosynthesis, inbred line B73 was used by spraying 400 mg L-1 ethephon at the ten-leaf stage. We found that the maize yield and the starch content had an obviously decrease and the activity of SSS、SBE、GBSS decreased significantly after exogenous ethylene was used. Additionally, we also performed an RT-PCR analysis of the expression pattern about endogenous genes of starch synthesis in different endosperm developmental stages. Consistent with this observation, relative expression of AGPase, SSS and SUS in treatment endosperm had a relatively low expression level during certain period of seed development. These data revealed that ethylene affect the development of starch biosynthesis by impact the activity of enzymes and relative expression level involving in starch synthesis. Our study provided some clues and support for the development of starch in maize endosperm on ethylene treatment.
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