江元清等《Plant Journal》2024年

论文题目：WRKY6 transcription factor modulates root potassium acquisition through promoting expression of  AKT1  in Arabidopsis

论文作者：Niu F#, Cui X#, Yang B, Wang R, Zhao P, Zhao X, Zhang H, Fan X, Li Y, Deyholos MK*, Jiang Y-Q*

论文摘要：Potassium (K+), being an essential macronutrient in plants, plays a central role in many aspects. Root growth is highly plastic and is affected by many different abiotic stresses including nutrient deficiency. The Shaker-type K+ channel Arabidopsis (Arabidopsis thaliana) K+ Transporter 1 (AKT1) is responsible for K+ uptake under both low and high external K+ conditions. However, the upstream transcription factor of AKT1 is not clear. Here, we demonstrated that the WRKY6 transcription factor modulates root growth to low potassium (LK) stress in Arabidopsis. WRKY6 showed a quick response to LK stress and also to many other abiotic stress treatments. The two wrky6 T-DNA insertion mutants were highly sensitive to LK treatment, whose primary root lengths were much shorter, less biomass and lower K+ content in roots than those of wild-type plants, while WRKY6-overexpression lines showed opposite phenotypes. A further investigation showed that WRKY6 regulated the expression of the AKT1 gene via directly binding to the W-box elements in its promoter through EMSA and ChIP-qPCR assays. A dual luciferase reporter analysis further demonstrated that WRKY6 enhanced the transcription of AKT1. Genetic analysis further revealed that the overexpression of AKT1 greatly rescued the short root phenotype of the wrky6 mutant under LK stress, suggesting AKT1 is epistatic to WRKY6 in the control of LK response. Further transcriptome profiling suggested that WRKY6 modulates LK response through a complex regulatory network. Thus, this study unveils a transcription factor that modulates root growth under potassium deficiency conditions by affecting the potassium channel gene AKT1 expression.

钾是植物所需的大量元素之一。提高植物的钾肥利用效率至关重要。该研究通过筛选拟南芥突变体，发现WRKY6转录因子的突变体的生长对低钾高度敏感，而该基因的过表达材料呈现相反的表型。通过多种探究发现重要的调控钾离子吸收的通道蛋白AKT1的基因是WRKY6的靶标，进一步通过分子生物学试验证据以及遗传试验材料证明了上下游调控关系。转录组测序分析标明，WRKY6调节多种不同转录因子以及激酶基因的转录。该研究揭示了一个新颖的转录因子-离子通道模块调控植物钾离子吸收的基本机制。

论文链接：https://onlinelibrary.wiley.com/doi/10.1111/tpj.16703