外源 NO 对低温胁迫下小麦幼苗果聚糖合成及 FBEs 表达的影响

摘要

采用水培的方法，研究4℃低温胁迫0，24，48，96 h后，外源NO供体硝普钠（SNP）对小麦幼苗生长、可溶性总糖含量、可溶性糖各组分含量及果聚糖合成酶（FBEs）等的影响，并采用qRT-PCR方法测定小麦幼叶中FBEs基因mRNA水平的变化。结果表明，外源NO促进小麦幼苗生长，提高低温胁迫下小麦幼叶果糖、葡萄糖、低聚果糖（DP3）、可溶性总糖等含量和果聚糖：果聚糖-1-果糖基转移酶（FFT）活性，并且在mRNA水平上调节FBEs基因表达。外源NO能够通过调控FBEs基因表达，进而影响果聚糖合成酶活性，促进果聚糖积累，提高小麦抵抗低温的能力。%The effects of exogenous NO on wheat (Triticum aestivum L.) growth,solubility sugar,fructan bio-synthesis metabolism etc.under 4 ℃chilling stress were investigated in seedlings ,subjected to different concentra-tions of sodium nitroprussiate(SNP,as nitric oxide donor) for 0,24,48,96 h.The results showed that,under chilling stress,exogenous NO could induce wheat weight ,fructose,glucose,low DP fructan,total soluble sugar content and fructan:fructan 1-fructosyltransferase(FFT) activity.Moreover,NO could regulate the gene expression at this level in following ways:sucrose:sucrose 1-fructosyltransferase (1-SST) and sucrose:fructan 6-fructosyltransferase (6-SFT) gene expression were inhibited by high concentration of SNP while 1-FFT was induced.Our report owing that exogenous NO alleviated the negative effects of non-freezing low temperatures by regulating FEBs and accumulating fructans.