College of Agronomy, Northwest A&F University/State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling 712100, China.
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
Int J Mol Sci. 2019 Feb 2;20(3):652. doi: 10.3390/ijms20030652.
Melatonin (N-acetyl-5-methoxytryptamine) is involved in many developmental processes and responses to various abiotic stresses in plants. Most of the studies on melatonin focus on its functions and physiological responses in plants, while its regulation mechanism remains unknown. Caffeic acid 3-O-methyltransferase (COMT) functions at a key step of the biosynthesis process of melatonin. In this study, a COMT-like gene, (Traes_1AL_D9035D5E0.1) was identified in common wheat ( L.). Transient transformation in wheat protoplasts determined that TaCOMT is localized in cytoplasm. in wheat was induced by drought stress, gibberellin (GA)3 and 3-Indoleacetic acid (IAA), but not by ABA. In transgenic , melatonin contents were higher than that in wild type (WT) plants. Under D-Mannitol treatment, the fresh weight of the transgenic was significantly higher than WT, and transgenic lines had a stronger root system compared to WT. Drought tolerance assays in pots showed that the survival rate of -overexpression lines was significantly higher than that of WT lines. this phenotype was similar to that the WT lines treated with melatonin under drought condition. In addition, the transgenic lines had higher proline content and lower malondialdehyde (MDA) content compared to WT lines after drought treatment. These results indicated that overexpression of the wheat gene enhances drought tolerance and increases the content of melatonin in transgenic . It could be one of the potential genes for agricultural applications.
褪黑素（N-乙酰-5-甲氧基色胺）参与植物的许多发育过程和对各种非生物胁迫的反应。大多数关于褪黑素的研究都集中在其在植物中的功能和生理反应上，而其调节机制尚不清楚。咖啡酸 3-O-甲基转移酶（COMT）在褪黑素生物合成过程的关键步骤中起作用。在这项研究中，从小麦中鉴定出一个 COMT 样基因，（Traes_1AL_D9035D5E0.1）。在小麦原生质体中的瞬时转化确定 TaCOMT 定位于细胞质中。小麦中的 受到干旱胁迫、赤霉素（GA）3 和 3-吲哚乙酸（IAA）的诱导，但不受 ABA 的诱导。在 转基因 中，褪黑素含量高于野生型（WT）植物。在 D-甘露糖醇处理下，转基因 的鲜重明显高于 WT，与 WT 相比，转基因系具有更强的根系。盆栽耐旱性试验表明，过表达系的存活率明显高于 WT 系。这种表型类似于在干旱条件下用褪黑素处理的 WT 系。此外，与 WT 系相比，干旱处理后 转基因系的脯氨酸含量较高，丙二醛（MDA）含量较低。这些结果表明，小麦 基因的过表达增强了耐旱性，并增加了转基因 中褪黑素的含量。它可能是农业应用的潜在基因之一。
