Alleviating effects of exogenous salicylic acid on antioxidative physiological characters of Phalaenopsis under low temperature stress

• Published in: 浙江大学学报. 农业与生命科学版
• Main Authors: Chen Dan, Wang Dan, Sun Li, Zhang Yanyan, Huang Chongping
• Format: Article
• Language: English
• Published: Zhejiang University Press 2014-05-01
• Subjects: <italic>Phalaenopsis</italic>; salicylic acid; low temperature stress; alleviating effects
• Online Access: https://www.academax.com/doi/10.3785/j.issn.1008-9209.2013.10.302
• ISSN: 1008-9209; 2097-5155

Phalaenopsis spp. is one of the most important orchids, which has a great economic value as potted plants in China. However, growth disorders like damage to membranes, generation of reactive oxygen species (ROS), protein denaturation, and accumulation of toxic compounds due to low temperature stress have become one of the key constraints for Phalaenopsis consumption during winter season in north subtropical area of China. There are a large number of reports about using salicylic acid (SA) to alleviate the negative effects of chilling stress on plants. However there is rare report about the changes of antioxidant systems under chilling stress with exogenous plant regulators application such as SA in Phalaenopsis.The objectives of this study are to investigate the alleviating effects of exogenous SA application on Phalaenopsis under low temperature stress and in recovery growth, to determine the changes of antioxidative enzyme activities and key indicators of photosynthetic system.Five different cultivars of Phalaenopsis (“Hunyan”“Dalajiao”“Tianjiao”“Tianxianggongzhu” and “V31”) were foliar sprayed with a series of SA concentrations (0, 0.2, 0.4, 0.6, 0.8 mmol/L). After foliar application, the plants were transferred to a growth chamber treated at low temperature (LT) of 11 ℃/6 ℃(day/night) for 3 days and then to recover growth at regular temperature 27 ℃/22 ℃(day/night) for 7 days. The changes of antioxidant system and photosynthetic system in Phalaenopsis leaves were tested.The results showed that the foliar spray of SA could obviously alleviate the negative effects of LT stress. In this study, the best concentration of SA was from 0.4 to 0.6 mmol/L. Appropriate concentrations of SA could significantly increase the chlorophyll content, Fv/Fm, superoxide dismutase (SOD) activity, ascorbic acid (AsA) and glutathione (GSH) contents and improve the chilling tolerance of Phalaenopsis. The activity of ascorbate peroxidase (APX) and soluble sugar content were decreased in most of LT stress treatments. After LT stress, exogenous SA could promote the plant growth. After 7 days recovery growth, application of 0.6 mmol/L SA increased SOD and APX activities, chlorophyll content and Fv/Fm, and decreased AsA and GSH contents. The treatment enhanced the photosynthetic and antioxidant capacity of the plants.These results indicated that the application of appropriate concentration of SA can improve the LT tolerance of Phalaenopsis. Compared the different varieties of Phalaenopsis, it is concluded that the variety “Huanyan” is of strong LT tolerance and more sensitive and effective to SA application.