Microcosm study on cold adaptation and recovery of an exotic mangrove plant, Laguncularia racemosa in China. (April 2022)

• Record Type: Journal Article
• Authors: Lang, Tao; Tang, Yexun; Tam, Nora Fung-yee; Gan, Keying; Wu, Jinsong; Wu, Wenquan; Fu, Yijian; Li, Mingdang; Hu, Zhangli; Li, Fenglan; Jiang, Mingguo; Zhou, Haichao
• Is Part Of: Marine environmental research. Volume 176(2022)
• Publication Date: 2022-04
• Subjects: Exotic mangrove plant -- Laguncularia racemosa -- Cold adaptation -- MDA -- Antioxidant activity -- Photosynthesis; Marine pollution -- Environmental aspects -- Periodicals; Marine ecology -- Periodicals; Mer -- Pollution -- Aspect de l'environnement -- Périodiques; Écologie marine -- Périodiques; Electronic journals; 577.705
• DOI: 10.1016/j.marenvres.2022.105611
• Languages: English
• ISSNs: 0141-1136

Abstract

Abstract: Laguncularia racemosa (a white mangrove) is an exotic mangrove species commonly distributed in southern intertidal zones in China since it was introduced for reforestation purposes in 1999. However, the invasiveness of this exotic species and its cold adaptability have rarely been reported. The present work determined the cold resistance level of L. racemosa and its recovery from cold stress, aiming to speculate its potential invasive capability in China. Results showed that the germination of L. racemosa seeds in sand or in simulated sea field models was significantly inhibited by a series of cold treatments, with no germination at 5 °C and decreased in germination at low temperatures (15–25 °C). Low temperature also reduced net photosynthetic rate (A), water use efficiency (WUE), transpiration rate (E), and stomatal conductance (Gs) of the seedlings of L. racemosa. On the other hand, cold stress up-regulated in leaves of malondialdehyde (MDA) and antioxidant activities, including superoxide dismutase (SOD), glutathione reductase (GR), and ascorbate peroxidase (APX). Additionally, these physiological and biochemical indexes of cold-stressed L. racemosa could recover to the original levels if the plants were returned to room temperature with a few exceptions. For instance, the cold exposure duration altered seedlings' physiology, but the photosynthetic related activities could not recover if cold treatment lasted for 120 h. This study suggests that L. racemosa can tolerate low temperatures to some extent, thus settle and even invade the coast of China at high latitudes having cold winter, which poses a challenge to the conservation and management of local mangrove ecosystems. Graphical abstract: Image 1 Highlights: 5 and 10 °C of cold stress significantly inhibits the seed germination of Laguncularia racemosa . 5 and 10 °C of cold stress visibly activates antioxidant system and restrains photosynthesis in leaves of Laguncularia racemosa . Laguncularia racemosa revives when it acquires a 25 °C of recovery. Laguncularia racemosa poses a potentially invasive threat to the coast of China at high latitudes because of its cold adaptation.