State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China.
College of Agriculture and Bioengineering, Heze University, Heze, Shandong 274015, P. R. China.
J Agric Food Chem. 2021 Jun 2;69(21):5818-5829. doi: 10.1021/acs.jafc.0c08042. Epub 2021 May 21.
Cadmium (Cd) accumulation in agricultural soils is an increasingly serious problem, as plants absorb Cd, which inhibits their growth and development. Nonetheless, the molecular mechanisms underlying Cd detoxification and accumulation in wheat ( L.) are unclear. Here, we isolated the U-box E3 ligase TaPUB1 from wheat and reported the functional characterization of 1 in Cd uptake and tolerance in wheat. Under Cd stress, 1 overexpression lines displayed higher photosynthetic rates than the wild type; opposite results were observed in the -RNAi lines. In addition, 1 overexpression lines showed reduced Cd uptake and accumulation, whereas RNAi plants exhibited a significant increase in Cd accumulation after Cd treatment. We further found that 1 enhanced the resistance of wheat to Cd stress in three ways. First, TaPUB1 interacts with and ubiquitinates TaIRT1, resulting in the inhibition of Cd uptake. Second, TaPUB1 interacts directly with and ubiquitinates TaIAA17, facilitates its degradation, and results in primary root elongation by activating the Aux signaling pathway under Cd stress. Moreover, 1 decreases ROS accumulation by regulating antioxidant-related gene expression and antioxidant enzyme activity under Cd stress. Thus, a molecular mechanism by which 1 regulates Cd uptake and tolerance by modulating the stability of TaIRT1 and TaIAA17 proteins was revealed.
镉（Cd）在农业土壤中的积累是一个日益严重的问题，因为植物会吸收 Cd，这会抑制它们的生长和发育。然而，小麦（ L.）中 Cd 解毒和积累的分子机制尚不清楚。在这里，我们从小麦中分离出 U -box E3 连接酶 TaPUB1，并报道了 1 在小麦 Cd 吸收和耐受性中的功能特征。在 Cd 胁迫下，1 过表达系的光合速率高于野生型；而在 -RNAi 系中则观察到相反的结果。此外，1 过表达系表现出 Cd 吸收和积累的减少，而 RNAi 植物在 Cd 处理后 Cd 积累显著增加。我们进一步发现 1 通过三种方式增强了小麦对 Cd 胁迫的抗性。首先，TaPUB1 与 TaIRT1 相互作用并泛素化 TaIRT1，从而抑制 Cd 的吸收。其次，TaPUB1 直接与 TaIAA17 相互作用并泛素化 TaIAA17，促进其降解，通过激活 Aux 信号通路促进 Cd 胁迫下主根伸长。此外，1 通过调节抗氧化相关基因表达和抗氧化酶活性来减少 ROS 积累。因此，揭示了 1 通过调节 TaIRT1 和 TaIAA17 蛋白的稳定性来调节 Cd 吸收和耐受性的分子机制。
