Li Wan-Ting, Ning Peng, Wang Fei, Cheng Xiao-Mao, Huang Xiao-Xia
College of Landscape Architecture and Horticulture/Southwest Landscape Architecture Engineering Research Center of National Forestry and Grassland Administration, Southwest Forestry University, Kunming 650224, China.
Ying Yong Sheng Tai Xue Bao. 2020 May;31(5):1543-1550. doi: 10.13287/j.1001-9332.202005.009.
In this study, the effects of exogenous abscisic acid (ABA) on the growth and physiolo-gical characteristics of Machilus yunnanensis seedlings were examined under well water supply conditions (70%-75% field capacity, FC) and different drought stress conditions, i.e., light drought stress (50%-55% FC) and severe drought stress (30%-35% FC), respectively. The results showed that drought stress reduced leaf relative water content, plant height, and total biomass of seedlings significantly decreased, as well as net photosynthetic rate and maximal photochemistry efficiency (F/F), but enhanced root/shoot and malondialdehyde contents (MDA). Exogenous ABA improved the adaptability of seedlings under drought stress, especially under severe drought stress, with leaf relative water content being improved 21.0%. Plant height and biomass allocation were improved by exogenous ABA under drought, while root/shoot was improved by 1.1 times compared with the well watered plants. The accumulation of MDA was decreased, the activities of CAT and SOD were significantly increased, and the proline content was increased 6.7 times by exogenous ABA under drought. Exogenous ABA application alleviated the negative effect of drought on photosynthetic organs, reduced the decrease of net photosynthetic rate and stomatal conductance under drought, and enhanced F/F value. The results suggested that exogenous ABA treatment could enhance the resistance of M. yunnanensis to drought stress.
本研究分别在充分供水条件（田间持水量的70%-75%，FC）以及不同干旱胁迫条件下，即轻度干旱胁迫（50%-55% FC）和重度干旱胁迫（30%-35% FC），研究了外源脱落酸（ABA）对滇楠幼苗生长和生理特性的影响。结果表明，干旱胁迫显著降低了叶片相对含水量、株高，幼苗总生物量以及净光合速率和最大光化学效率（F/F）均显著下降，但根冠比和丙二醛含量（MDA）增加。外源ABA提高了幼苗在干旱胁迫下的适应性，尤其是在重度干旱胁迫下，叶片相对含水量提高了21.0%。干旱条件下，外源ABA改善了株高和生物量分配，根冠比比充分供水的植株提高了1.1倍。干旱条件下，外源ABA降低了MDA的积累，显著提高了CAT和SOD的活性，脯氨酸含量增加了6.7倍。外源ABA处理减轻了干旱对光合器官的负面影响，减少了干旱条件下净光合速率和气孔导度的下降，并提高了F/F值。结果表明，外源ABA处理可增强滇楠对干旱胁迫的抗性。
