玉米根尖淀粉对渗透胁迫的响应  

Response of Maize Root Tip Starch to Osmotic Stress

作　　者：张曼 王楠楠 周晓丽 牛靓洁 王文康 王伟[1] ZHANG Man;WANG Nannan;ZHOU Xiaoli;NIU Liangjie;WANG Wenkang;WANG Wei(College of Life Sciences,Henan Agricultural University,Zhengzhou 450046,China)

机构地区：[1]河南农业大学生命科学学院,郑州450046

出　　处：《河南科学》2024年第6期781-788,共8页Henan Science

基　　金：国家自然科学金联合基金项目(U1904107)。

摘　　要：玉米根尖淀粉的特征以及在渗透胁迫中的作用尚不清楚.本研究以玉米杂交种郑单958为材料,用15%的聚乙二醇(PEG-6000)对幼苗根系进行不同时长的渗透胁迫处理,分析根尖淀粉的形态和含量变化、淀粉酶活性及相关基因表达水平变化.结果表明,根尖淀粉粒大小为0.3~2.5μm,大部分呈球状,少数为片状或无规则形状.随着胁迫时间延长,根尖淀粉逐渐降解,淀粉酶(尤其是β淀粉酶)活性增强,导致可溶性糖含量增加;相应地,多种淀粉酶基因表达明显上调.根尖淀粉在渗透胁迫下的降解将增加根细胞的渗透调节能力,从而缓解胁迫伤害.该结果有助于认识玉米根系响应渗透胁迫的分子生理机制.Starch characteristics in maize root tips and its role in osmotic stress are unknown.In this study,the roots of 2-d-old dark-grown seedlings of maize(Zea mays cv.Zhengdan 958)were subjected to osmotic stress for different periods with 15% polyethylene glycol(PEG-6000).The changes of starch morphology and content,amylase activity and related gene expression were analyzed.The results showed that starch granules in root tips ranged from 0.3 to 2.5 μm in size,most were globular,whereas a small fraction was flaky or irregular.With the increase of stress time,starch in the root tips was gradually degraded,and the activities of amylases,especially β-amylase,were increased,leading to the increase of soluble sugar content.Correspondingly,the expression levels of several amylase genes were significantly up-regulated.The degradation of maize root tip starch under osmotic stress would increase the osmotic regulation capacity of root cells,thereby alleviating stress damage.These results contribute to understanding the molecular physiological mechanism of maize root response to osmotic stress.

关 键 词：淀粉酶 玉米 根尖 渗透胁迫 淀粉粒 

分 类 号：S513[农业科学—作物学] Q945.78[生物学—植物学]