MYB3 plays an important role in lignin and anthocyanin biosynthesis under salt stress condition in Arabidopsis
MYB3 plays an important role in lignin and anthocyanin biosynthesis under salt stress condition in Arabidopsis
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DOI：
10.1007/s00299-022-02878-7
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发表时间：
2022-05-13
影响因子：
6.2
通讯作者：
Kim, Sewon
中科院分区：
文献类型：
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作者：
Kim, Daewon;Jeon, Su Jeong;Kim, Sewon
关键信息 核定位的拟南芥 MYB3 作为转录阻遏蛋白发挥作用，在高盐条件下调节木质素和花青素的生物合成。盐胁迫是全球范围内降低植物生长和作物产量的主要因素。为了改善高盐环境下作物的生长，必须严格控制植物对盐胁迫的反应。在这里，为了进一步了解高盐条件下植物反应的调节，研究了MYB3转录因子作为阻遏物在盐胁迫条件下控制木质素和花青素积累的功能。核定位的 MYB3 形成同源二聚体。它普遍表达，特别是在维管组织中，在根、叶、茎和花等组织中，氯化钠高度诱导表达。 myb3 突变体植物在高 NaCl 条件下比野生型植物表现出更长的根生长。然而，与野生型相比，myb3 中的几个 NaCl 响应基因没有显着改变。有趣的是，在 NaCl 处理下，myb3 中木质素和花青素的大量积累，以及参与木质素和花青素生物合成的基因表达增加，如苯丙氨酸解氨酶 1 (PAL1)、肉桂酸 4-羟化酶 (C4H)、儿茶酚-O-甲基转移酶 (COMT)、4-香豆酸-CoA 连接酶 (4CL3)、二氢黄酮醇还原酶（DFR）和无色花青素双加氧酶（LDOX）。根据酵母双杂交筛选，分离出多种转录因子作为MYB3相互作用蛋白，包括花青素调节剂Transparent Testa 8 (TT8)和Enhancer of Glabra 3 (EGL3)。 MYB3 被定性为转录阻遏蛋白，其阻遏结构域位于 C 末端。总体而言，这些结果表明核定位的 MYB3 作为转录阻遏蛋白发挥作用，在盐度胁迫条件下控制木质素和花青素的积累。
Key message Nuclear-localized Arabidopsis MYB3 functions as a transcriptional repressor for regulation of lignin and anthocyanin biosynthesis under high salt conditions. Salinity stress is a major factor which reduces plant growth and crop yield worldwide. To improve growth of crops in high salinity environments, plant responses to salinity stress must be tightly controlled. Here, to further understand the regulation of plant responses under high salinity conditions, the function of the MYB3 transcription factor was studied as a repressor to control accumulation of lignin and anthocyanin under salt stress conditions. Nuclear-localized MYB3 forms a homodimer. It is ubiquitously expressed, especially in vascular tissues, with expression highly induced by NaCl in tissues such as roots, leaves, stems, and flowers. myb3 mutant plants exhibited longer root growth in high NaCl conditions than wild-type plants. However, several NaCl responsive genes were not significantly altered in myb3 compared to wild-type. Interestingly, high accumulation of lignin and anthocyanin occurred in myb3 under NaCl treatment, as well as increased expression of genes involved in lignin and anthocyanin biosynthesis, such as phenylalanine ammonia lyase 1 (PAL1), cinnamate 4-hydroxylase (C4H), catechol-O-methyltransferase (COMT), 4-coumaric acid-CoA ligase (4CL3), dihydroflavonol reductase (DFR), and leucoanthocyanidin dioxygenase (LDOX). According to yeast two-hybrid screenings, various transcription factors, including anthocyanin regulators Transparent Testa 8 (TT8) and Enhancer of Glabra 3 (EGL3), were isolated as MYB3 interacting proteins. MYB3 was characterized as a transcriptional repressor, with its repressor domain located in the C-terminus. Overall, these results suggest that nuclear-localized MYB3 functions as a transcriptional repressor to control lignin and anthocyanin accumulation under salinity stress conditions.