Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
Center of Plant Systems Biology and Biotechnology, 4000 Plovdiv, Bulgaria.
Plant Physiol. 2021 Dec 4;187(4):2419-2434. doi: 10.1093/plphys/kiab386.
Sulfur deficiency-induced proteins SDI1 and SDI2 play a fundamental role in sulfur homeostasis under sulfate-deprived conditions (-S) by downregulating glucosinolates. Here, we identified that besides glucosinolate regulation under -S, SDI1 downregulates another sulfur pool, the S-rich 2S seed storage proteins in Arabidopsis (Arabidopsis thaliana) seeds. We identified that MYB28 directly regulates 2S seed storage proteins by binding to the At2S4 promoter. We also showed that SDI1 downregulates 2S seed storage proteins by forming a ternary protein complex with MYB28 and MYC2, another transcription factor involved in the regulation of seed storage proteins. These findings have significant implications for the understanding of plant responses to sulfur deficiency.
在硫酸盐缺乏条件下（-S），硫缺乏诱导蛋白 SDI1 和 SDI2 通过下调硫苷来在硫稳态中发挥基本作用。在这里，我们发现除了 -S 下的硫苷调控外，SDI1 还下调另一个硫池，即拟南芥种子中的富含硫的 2S 种子贮藏蛋白。我们发现 MYB28 通过结合 At2S4 启动子直接调控 2S 种子贮藏蛋白。我们还表明，SDI1 通过与 MYB28 和另一个参与种子贮藏蛋白调控的转录因子 MYC2 形成三元蛋白复合物来下调 2S 种子贮藏蛋白。这些发现对理解植物对硫缺乏的反应具有重要意义。
