Abstract: In order to reveal the mechanism of osmotic adjustment and enzyme protection system of dandelion and gene expression characteristics of plasma membrane aquaporin PIP2-3 under drought stress.Using pot water control experiments to study the effects of soil drought stress(RWC=(90±5)%,RWC=(75±5)%,RWC=(50±5)% on osmoregulation substances,enzyme protection system and expression of plasma membrane hole protein gene PIP2-3 in Taraxacum mongolicum Hand.-Mazz.. Important findings:Under soil drought stress could significantly increase the dandelion leaf blade soluble sugar,soluble protein and free proline content,enhance the activity of SOD,POD and CAT,light stress show a tendency of gradually rising while severe stress showed a trend of first increase after decrease (except blade soluble sugar). Expression of plasma membrane hole protein gene PIP2-3 relative quantity increased significantly,and mild stress (MS) was higher than severe stress (SS). After restore water 7 d,the accumulation of osmotic regulation substances and the content of SOD decreased,but still significant in CK.The content of POD,CAT and plasma membrane hole protein gene PIP2-3 back to normal. This means that under drought stress,the dandelion can increase the accumulation of osmotic regulation substances and enhance the protective enzyme systems activities to improve plant resistance,increase plasma membrane hole relative expression of protein gene to strengthen water transport capacity.

Key words: Dandelion, Drought stress, Osmoregulation substances, Enzyme protection system, Plasma membrane hole protein

CLC Number: 

• S647.03