Role of exogenous abscisic acid in freezing tolerance of mangrove Kandelia obovata under natural frost condition at near 32oN

Mangrove Kandelia obovata, an important coastal shelterbelt and landscape tree, is distributed in tropical and subtropical shores and likely delimited in the latitudinal range by varying sensitivity to cold. Here, we explored the temporal variations in physiological status and transcriptome profiling of K. obovata under natural frost conditions at ~32oN, as well as the positive role of exogenous abscisic acid (ABA) in cold resistance. Overall design: Five different concentrations of ABA (0, 5, 25, 50, and 100 mg L-1) were set to treat K. obovata with a hand-held sprayer until run off. Each treatment was set up with three subplots for a total of 9 replicate seedlings.

秋茄（Kandelia obovata）是重要的海岸防护林与景观树种，分布于热带及亚热带沿岸区域，其纬度分布范围或受低温敏感性差异的限制。本研究探究了北纬约32°处自然霜冻条件下，秋茄生理状态与转录组分析（transcriptome profiling）的时间动态变化，以及外源脱落酸（abscisic acid, ABA）在其抗寒过程中的积极作用。实验设计：设置5种不同浓度的脱落酸处理（0、5、25、50及100 mg·L⁻¹），采用手持喷雾器对秋茄幼苗进行喷施，直至药液从叶面流下。每个处理设置3个重复样区，总计9株重复幼苗。