澳洲茶树干旱胁迫下保护酶活性及代谢产物含量变化规律

Protective Enzyme Activity and Metabolite Content of Melaleuca alternifolia under Drought Stress

为了解澳洲茶树耐旱性能,确定最适宜澳洲茶树生长的土壤相对含水量,促进澳洲茶树增产丰产,采用盆栽试验模拟干旱胁迫(土壤相对含水量20.7%～43.4%),胁迫时间15d,测定澳洲茶树(Melaleuca alternifolia)保护酶活性及关键代谢产物含量,以初步了解其应答机制。研究表明:干旱胁迫处理条件下澳洲茶树叶片中有3种保护酶活性(SOD、CAT、NR)先上升后下降,启动了保护机制,以应对逆境。另外2种保护酶(POD、GSH-PX)则未检测到活性上升。代谢产物脯氨酸和可溶性糖的含量均显著增加,出现累积,这两种物质是提高植株渗透调节能力和保水性能的重要物质。

In order to understand the drought tolerance of Melaleuca alternifolia,determining soil relative water content suitable for growth of M. alternifolia, and promoting production of M. alternifolia, effects of drought stress(soil relative water content was from 20.7% to 43.4%) on protective enzyme activity and key metabolite content of M. alternifolia were investigated for 15 days by pot experiment to understand the physiological adaptive mechanisms. Results showed that three kinds of enzymes activity(SOD,CAT,NR) firstly increased and then declined,which indicated that a protective mechanism to respond to adversity was activated,but the activity of other two kinds of protective enzymes and the soluble sugar content significantly increased and accumulated,which indicated that these two substances were important to improve the osmotic regulation and water retention of plants.