Summary Boron (B) is crucial for plant growth and development. B deficiency can impair numerous physiological and metabolic processes, particularly in root development and pollen germination, seriously impeding crop growth and yield. However, the molecular mechanism underlying boron signal perception and signal transduction is rather limited. In this study, we discovered that CPK10, a calcium‐dependent protein kinase in the CPK family, has the strongest interaction with the boron transporter BOR1. Mutations in CPK10 led to growth and root development defects under B‐deficiency conditions, while constitutively active CPK10 enhanced plant tolerance to B deficiency. Furthermore, we found that CPK10 interacted with and phosphorylated BOR1 at the Ser689 residue. Through various biochemical analyses and complementation of B transport in yeast and plants, we revealed that Ser689 of BOR1 is important for its transport activity. In summary, these findings highlight the significance of the CPK10‐BOR1 signaling pathway in maintaining B homeostasis in plants and provide targets for the genetic improvement of crop tolerance to B‐deficiency stress.

中文翻译：

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CPK10蛋白激酶通过BOR1转运蛋白的磷酸化和激活调节拟南芥对硼缺乏的耐受性

概括 硼 (B) 对于植物生长和发育至关重要。维生素 B 缺乏会损害许多生理和代谢过程，特别是根部发育和花粉萌发，严重阻碍作物生长和产量。然而，硼信号感知和信号转导的分子机制相当有限。 在这项研究中，我们发现 CPK10（CPK 家族中的一种钙依赖性蛋白激酶）与硼转运蛋白 BOR1 具有最强的相互作用。 CPK10 的突变导致 B 缺乏条件下的生长和根系发育缺陷，而组成型活性 CPK10 增强了植物对 B 缺乏的耐受性。 此外，我们发现 CPK10 与 BOR1 的 Ser689 残基相互作用并被磷酸化。通过各种生化分析以及酵母和植物中B转运的补充，我们发现BOR1的Ser689对其转运活性很重要。 总之，这些发现强调了 CPK10-BOR1 信号通路在维持植物 B 稳态中的重要性，并为作物对 B 缺乏胁迫的耐受性的遗传改良提供了目标。