In recent years, great concerns have been raised about salicylic acid (SA) and its derivatives as plant regulators. Therefore, precise determination of the distribution of SAs in the living plants is necessary for not only fundamental researches but also the regulating mechanisms. In this study, a custom-made solid phase microextraction (SPME) fiber based on diallyl dimethyl ammonium chloride-assembled graphene oxide-coated C18 composite ([email protected]@PDDA) was proposed for in vivo detection of salicylic acid, acetylsalicylic acid (ASA), 4-methyl salicylic acid（4-SA）and 3-methyl salicylic acid (3-SA) in aloe plants. Under the optimized conditions, the analytical performance evaluated in homogenized aloe plant tissues exhibited low detection limits (1.8–2.8 μg g⁻¹), wide linear ranges (10–5000 μg g⁻¹), and satisfactory reproducibility (relative standard deviations less than 8.4% and 9.3% for inter-fiber and intra-fiber assays, respectively). Under cadmium stress, the developed method was applied for the in vivo tracing of four salicylic acids in aloe plants. A 48-h in vivo tracing revealed that salicylic acids were involved in the pathway of cadmium stress tolerance. To our best knowledge, it is the first effort to realize the in vivo analysis of SA and its derivatives in plants, and it has a made a great step forward in the area of plant hormone analysis.

近年来，人们对水杨酸（SA）及其衍生物作为植物调节剂引起了极大的关注。因此，准确确定SA在植物中的分布不仅是基础研究，而且是调节机制的必要条件。在这项研究中，提出了一种基于二烯丙基二甲基氯化铵组装的氧化石墨烯涂层的C18复合材料的定制固相微萃取（SPME）纤维（[email protected] @PDDA），用于体内检测水杨酸，乙酰水杨酸（ ASA），芦荟植物中的4-甲基水杨酸（4-SA）和3-甲基水杨酸（3-SA）。在最佳条件下，在均质芦荟植物组织中评估的分析性能显示出较低的检测限（1.8–2.8μgg ^-1），宽线性范围（10–5000μgg ^-1）和令人满意的重现性（纤维间和纤维内分析的相对标准偏差分别小于8.4％和9.3％）。在镉胁迫下，将开发的方法用于芦荟植物体内四种水杨酸的体内示踪。在体内进行的48小时追踪显示，水杨酸参与了镉胁迫的耐受性。据我们所知，这是在植物中实现SA及其衍生物的体内分析的第一项努力，并且在植物激素分析领域迈出了一大步。