Summary Phytohormones possess unique chemical structures, and their physiological effects are regulated through intricate interactions or crosstalk among multiple phytohormones. MALDI‐MSI enables the simultaneous detection and imaging of multiple hormones. However, its application for tracing phytohormones is currently restricted by low abundance of hormone in plant and suboptimal matrix selection. 2,4‐Dihydroxy‐5‐nitrobenzoic acid (DHNBA) was reported as a new MALDI matrix for the enhanced detection and imaging of multiple phytohormones in plant tissues. DHNBA demonstrates remarkable sensitivity improvement when compared to the commonly used matrix, 2,5‐dihydroxybenzoic acid (DHB), in the detection of isoprenoid cytokinins (trans‐zeatin (tZ), dihy‐drozeatin (DHZ), meta‐topolin (mT), and N6‐(Δ2‐isopentenyl) adenine (iP)), jasmonic acid (JA), abscisic acid (ABA), and 1‐aminocyclo‐propane‐1‐carboxylic acid (ACC) standards. The distinctive properties of DHNBA (i.e. robust UV absorption, uniform matrix deposition, negligible background interference, and high ionization efficiency of phytohormones) make it as an ideal matrix for enhanced detection and imaging of phytohormones, including tZ, DHZ, ABA, indole‐3‐acetic acid (IAA), and ACC, by MALDI‐MSI in various plant tissues, for example germinating seeds, primary/lateral roots, and nodules. Employing DHNBA significantly enhances our capability to concurrently track complex phytohormone biosynthesis pathways while providing precise differentiation of the specific roles played by individual phytohormones within the same category. This will propel forward the comprehensive exploration of phytohormonal functions in plant science.

中文翻译：

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使用 2,4-二羟基-5-硝基苯甲酸作为新型基质，通过 MALDI-MSI 增强植物组织中植物激素的原位检测和成像


摘要 植物激素具有独特的化学结构，其生理效应通过多种植物激素之间复杂的相互作用或串扰来调节。 MALDI-MSI 能够同时检测和成像多种激素。然而，其在追踪植物激素方面的应用目前受到植物中激素丰度低和基质选择不理想的限制。据报道，2,4-二羟基-5-硝基苯甲酸（DHNBA）是一种新的 MALDI 基质，用于增强植物组织中多种植物激素的检测和成像。与常用基质 2,5-二羟基苯甲酸 (DHB) 相比，DHNBA 在检测类异戊二烯细胞分裂素（反式玉米素 (tZ)、二氢玉米素 (DHZ)、间拓扑素 (mT)）时表现出显着的灵敏度提高和 N6-(Δ2-异戊烯基)腺嘌呤 (iP))、茉莉酸 (JA)、脱落酸 (ABA) 和 1-氨基环丙烷-1-羧酸 (ACC) 标准品。 DHNBA 的独特特性（即强大的紫外线吸收、均匀的基质沉积、可忽略的背景干扰和植物激素的高电离效率）使其成为增强植物激素检测和成像的理想基质，包括 tZ、DHZ、ABA、indole-3 ‐乙酸 (IAA) 和 ACC，通过 MALDI-MSI 在各种植物组织中检测，例如发芽种子、初生/侧根和根瘤。采用 DHNBA 显着增强了我们同时跟踪复杂的植物激素生物合成途径的能力，同时提供同一类别中各个植物激素所发挥的特定作用的精确区分。这将推动植物科学中植物激素功能的全面探索。