BACKGROUNDCitrus huanglongbing (HLB) is a devastating disease in citrus, caused by Candidatus Liberibacter asiaticus (CLas), which primarily resides in the phloem where chemicals cannot effectively reach, posing a significant challenge in controlling HLB. To address these challenges, plant essential oils (EOs), widely used as transdermal enhancers and known for their benefits for plant tissues, were investigated for their potential to enhance chemical permeation.RESULTSIn this study, seven EOs – eugenol, carvacrol, eucalyptol, geraniol, linalool, cinnamaldehyde, and d‐limonene – were evaluated for their potential to enhance chemical penetration into citrus leaves. Preliminary screening with tracer methods revealed that geraniol provided the greatest enhancement of permeation, achieving the deepest and broadest distribution into the spongy tissue of the citrus leaf. The permeation levels of rhodamine B and crystal violet through the cuticular layer were elevated from 0.55 mg L−1 and 0.11 mg L−1 to 20.04 mg L−1 and 7.14 mg L−1, respectively, by the addition of geraniol. Further validation through high‐performance liquid chromatography–mass spectrometry (HPLC–MS) confirmed that the penetration of fludioxonil and tetracycline into citrus leaf tissues was enhanced by 15.07‐fold and 20.43‐fold, respectively. In planta experiments confirmed that adding geraniol to tetracycline and oxytetracycline via foliar application eliminated CLas bacteria in HLB‐affected citrus more efficiently than controls.CONCLUSIONOur study underscores the potential of geraniol as an effective EO‐based permeation enhancer for combating HLB. By significantly improving the delivery and efficacy of bactericidal treatments, geraniol offers a promising strategy for managing this catastrophic citrus disease, potentially transforming the approach to controlling HLB. © 2024 Society of Chemical Industry.

中文翻译：

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用香叶醇增强柑橘叶中的农用化学品递送：控制黄龙病 （HLB） 的一种有前途的策略


背景黄龙病 （HLB） 是柑橘中的一种毁灭性病害，由亚洲假丝酵母 （CLas） 引起，主要存在于化学物质无法有效到达的韧皮部中，对控制 HLB 构成重大挑战。为了应对这些挑战，研究了被广泛用作透皮增强剂并以其对植物组织有益而闻名的植物精油 （EOs） 增强化学渗透的潜力。结果在这项研究中，评估了七种 EO——丁香酚、香芹酚、桉树醇、香叶醇、芳樟醇、肉桂醛和 d-柠檬烯——它们增强化学渗透到柑橘叶中的潜力。使用示踪方法进行初步筛选后发现，香叶醇的渗透性增强最大，在柑橘叶的海绵组织中分布最深、最广。通过添加香叶醇，罗丹明 B 和结晶紫通过表皮层的渗透水平分别从 0.55 mg L-1 和 0.11 mg L-1 提高到 20.04 mg L-1 和 7.14 mg L-1。通过高效液相色谱-质谱 （HPLC-MS） 进一步验证证实，咯菌腈和四环素对柑橘叶片组织的渗透分别提高了 15.07 倍和 20.43 倍。在植物中，实验证实，通过叶面喷施将香叶醇添加到四环素和土霉素中，比对照更有效地消除了受 HLB 影响的柑橘中的 CLas 细菌。结论我们的研究强调了香叶醇作为一种有效的基于 EO 的渗透增强剂对抗 HLB 的潜力。 通过显着改善杀菌治疗的递送和疗效，香叶醇为管理这种灾难性的柑橘病害提供了一种有前途的策略，有可能改变控制 HLB 的方法。© 2024 化工学会.