Chen Lulu, Zhang Yue, Hao Qichen, Fu Jinxiang, Bao Zhibin, Bu Yufen, Sun Na, Wu Xinyuan, Lu Liang, Kong Zhaosheng, Qin Liang, Zhou Yijun, Jing Yanping, Wang Xiaodong
State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing, 100083, China.
New Phytol. 2024 Sep;243(5):2021-2036. doi: 10.1111/nph.19964. Epub 2024 Jul 16.
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 N-(Δ-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.
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信号转导来调节。基质辅助激光解吸/电离质谱成像（MALDI-MSI）能够同时检测和成像多种激素。然而，目前其在植物激素追踪方面的应用受到植物中激素丰度低和基质选择不理想的限制。2,4-二羟基-5-硝基苯甲酸（DHNBA）被报道为一种新型MALDI基质，可增强对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）、间位托普林（mT）和N-(Δ-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）标准品时，显示出显著的灵敏度提高。DHNBA的独特性质（即强大的紫外吸收、均匀的基质沉积、可忽略的背景干扰以及植物激素的高电离效率）使其成为通过MALDI-MSI在各种植物组织（例如萌发的种子、主根/侧根和根瘤）中增强检测和成像植物激素（包括tZ、DHZ、ABA、吲哚-3-乙酸（IAA）和ACC）的理想基质。使用DHNBA显著增强了我们同时追踪复杂植物激素生物合成途径的能力，同时能够精确区分同一类别中单个植物激素所起的特定作用。这将推动植物科学中对植物激素功能的全面探索。
