干旱胁迫及复水对杜仲苗激素含量的影响

Effects of drought stress and rehydration on hormone contents of Eucommia ulmoides seedling

以树龄2年的杜仲‘华仲6号’扦插幼苗为试验材料,研究干旱胁迫及复水对杜仲苗叶片和根系中脱落酸(ABA)、茉莉酸(JA)、水杨酸(SA)、生长素(IAA)、反式玉米素(tZ)、反式玉米素核苷(tZR)及赤霉素(GA;)含量的影响。结果表明:随着干旱胁迫时间的延长,叶片和根系ABA含量显著升高,叶片JA含量显著降低,根系JA含量显著升高,叶片和根系SA含量在胁迫后期显著升高,叶片tZ和tZR含量无显著变化,叶片IAA含量呈降低-升高的趋势,根系中的IAA、tZ、tZR和GA;含量在胁迫后期显著升高。复水后,叶片的ABA、JA含量稍降,而SA、IAA、tZ和tZR含量显著升高;根系的ABA、JA、SA、tZ、tZR、GA;含量显著降低,IAA含量稍降。叶片中GA;含量太低未检测出。综上所述,干旱胁迫下杜仲叶片通过积累ABA、SA和IAA,降低JA含量提高耐旱性;根系通过积累ABA、JA、SA、IAA、tZ、tZR和GA;提高耐旱性。复水后叶片可能通过SA、IAA、tZ、tZR的积累来促进叶片的生长,而根系复水后得到缓解,激素含量下降。

This study aimed to investigate the effects of drought stress and rehydration on the contents of ABA, JA, SA, IAA, tZ, tZR and GA;in leaves and roots of Eucommia ulmoides seedlings. Two-year-old cuttings of ‘Huazhong No.6’ were used as the experimental materials. The results showed that with the extension of drought stress time, the ABA content of leaves and roots increased significantly. The content of JA in leaves decreased significantly, while it increased significantly in roots. The SA content of leaves and roots increased significantly at the later stage of stress. The tZ and tZR contents of leaves had no significant change. The IAA content of leaves decreased first and then increased, while the IAA, tZ, tZR and GA;contents of roots increased significantly in the late stage of stress. After rehydration, ABA and JA contents in leaves decreased slightly, while SA, IAA, tZ and tZR contents increased significantly. In addition, ABA, JA,SA, tZ, tZR and GA;contents in roots decreased significantly, and IAA content decreased slightly. GA;content in leaves was too low to be detected. In summary, in face of the stress of drought, the leaves of E. ulmoides improve drought tolerance by accumulating ABA, SA and IAA contents and decreasing JA level.The roots improve drought tolerance by accumulating ABA, JA, SA, IAA, tZ, tZR and GA;. The leaves may promote leaves growth by accumulating SA, IAA, tZ and tZR after rehydration, while the roots are alleviated with the hormone content decreased after rehydration.