中文摘要：

摘要：为鉴定ABA与小麦发育及抗寒性相关的MicroRNA（miRNA）表达和调控作用之间的关系，以东农冬麦1号为试材，对三叶期小麦幼苗喷施10。m01．L11ABA（剂量为1L·4rn。），分别于大田自然降温至4℃、0℃、-10℃和-25℃附近时取分蘖节，并对本室前期所获小RNA库中挑选的6条丰度较高且差异表达明显的miRNAs序列（miRl65、miRl66、miR319、miR5070、miR5139、miR3704）进行荧光定量PCR分析。结果表明，随着温度的降低，未经ABA处理的对照组样品中miRl65、miRl66、miR319、miR5139呈先升后降的变化趋势，miR5070呈升降升的趋势，miR3704呈上升趋势；而ABA处理的样品中miRl65、m．R166、miR5070、miR5139和miR3704表达量都呈降升降趋势，只有miR319呈先降后升的趋势，说明ABA改变了每条miRNA的表达模式。经ABA处理后的小麦样品中，各m．RNA表达量与对照相比表现为4℃和-10℃时上调，0℃时下调，-25℃时除miR5070下调外其余miRNA上调，极低温度下的这种不同改变可能与miRNA靶基因的功能相关。

英文摘要：

Winter wheat cultivar Dongnongdongmai 1 was used to identify the relationship between ABA and the expression and regulation of miRNA related with the development and cold tolerance. Leaves were sprayed with 10.5 mol· L-1 ABA when seedlings were at the 3-true-leaf stage （1 L · 4 m-2） ,tillering nodes were sampled when temperature dropped to about 4℃ ,O℃,--10℃ and --25 ℃ in the field, and the expressions of 6 higher abundance and significantly differentially expressed miRNA （miR165 ,miR166 ,miR319 ,miR5070 ,miR5139 and miR3704） selected from our previous small RNA libraries were studied by real-time quantitative PCR. The results indicated that the expressions of miR165 ,miR166 ,miR319 and miR5139 increased at first and then decreased in the control group as the temperature decreased,and the expression of miR5070 showed an increase-decrease-increase trend, and the expression of miR3704 increased; while the expression patterns of miR165,miR166 ,miR5070, miR5139 and miR3704 all appeared a decrease-increase-decrease trend, and the expression of miR319 decreased at first and increased in the ABA treated group,and it indicated that ABA could change the expression patterns of each miRNA. The expressions of the miRNAs in ABA treated samples com- pared to the control, were up-regulated at 4 ℃ and --10 ℃ ,and down-regulated at 0℃ ,and all miR- NAs were up-regulated except that miR5070 was down-regulated at --25 ℃ ,Those various changes at such low temperatures may be associated with the function of the miRNA target genes.