壳寡糖对低温胁迫下小麦幼苗的保护作用及相关代谢产物的影响

Effect of Chitooligosaccharide on Reducing Cryoinjury and Improving Metabolite of Winter Wheat Seedlings under Low Temperature Stress

为了解壳寡糖对低温胁迫下小麦的保护作用,对两个小麦品种(小偃22和西农9871)幼苗喷施100mg·L-1壳寡糖和0℃低温胁迫96h,检测叶片的损伤面积及丙二醛、脯氨酸、可溶性糖、还原糖含量,并调查复温后返青率。结果表明,与常温对照组相比,低温胁迫48h后壳寡糖处理的小麦叶片损伤面积和丙二醛含量增幅较低,其中小偃22和西农9871的损伤面积相对于低温对照分别减少了25.3%和28.8%,丙二醛含量分别降低了16.9%和33.7%;同时,两个品种叶片脯氨酸含量分别提高了15.8%和26.7%,还原糖含量分别提高了25.6和14.3%,可溶性糖含量也表现出增高的趋势。经过复温培养,壳寡糖处理下小偃22和西农9871的返青率分别提高了4.6%和5.9%。说明壳寡糖可通过促进小麦苗脯氨酸、还原糖等低温抗性相关次生代谢物的表达,提高其对低温寒害的抵抗能力。

In order to study the effects of Chitooligosaccharide （COS） on protecting wheat from low temperature stress,two cultivars,Xiaoyan 22 （XY22） and Xinong 9871 （XN9871）,were pretreated with 100 mg· L^-1 COS under 0 ℃ low temperature stress for 96 hours. The area of cold damage,thecontent of malonaldehyde （MDA）, proline, water soluble sugar （WSS）, reducing sugar and reviving rate were detected every 48 hours during the study. The results showed that COS decreased the low temperature damage area by 25.3% in XY22 and 28.8% in XN9871, respectively. Meanwhile, COS improved metabolite of the both wheat seedlings under the low temperature stress： the content of MDA was reduced by 16.9% in XY22 and aa. 7% in XN9871; proline was increased by 15. 8% in XY22 and 26.7% in XN9871; and reducing sugar was increased by 25.6% in XY22 and 14.3% in XN9871,respectively. In addition,the reviving rate raised by 4.6% in XY22 and 5.9% in XN9871, which revealed COS have remarkable effect on protecting wheat from low temperature stress. It is worth noting that the expression level of proline and reducing sugar in wheat seedling significantly ac- cumulated when pretreated with COS in 24 hours before low temperature stress, which implied that COS provide pre-protection for wheat seedlings to the upcoming low temperature stress. The study in-dicates that COS could reduce cryoinjury and increase the secondary metabolism production of winter wheat seedlings under low temperature stress.