Calcium-Regulated Phosphorylation Systems Controlling Uptake and Balance of Plant Nutrients
Calcium-Regulated Phosphorylation Systems Controlling Uptake and Balance of Plant Nutrients
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DOI：
10.3389/fpls.2020.00044
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发表时间：
2020-02
影响因子：
5.6
通讯作者：
Shunya Saito;N. Uozumi
中科院分区：
文献类型：
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作者：
Shunya Saito;N. Uozumi
从土壤中吸收并分布在整个植物中的必需元素在不同的组织中发挥着不同的作用。阳离子和阴离子有助于维持细胞内渗透压和膜电位的形成，而硝酸盐、铵和硫酸盐被结合到氨基酸和其他有机化合物中。与这些离子物种相比，钙离子通常在胞质中保持较低的浓度，并且钙作为胞质信号分子表现出独特的行为。各种环境应激刺激细胞内钙离子浓度升高，导致钙调节蛋白激酶和下游信号通路的激活。本文综述了两种钙调节的磷酸化系统：CPK和CBL-CIPK对养分吸收和平衡的胁迫响应调节。CPK是一类被钙激活的蛋白激酶家族。CBL是一组钙感受器蛋白，与CIPK激酶相互作用，使其下游靶标磷酸化。在拟南芥中，相当多的离子转运系统受CPK或CBL-CIPK复合体的调控，包括介导钾(KAT1、KAT2、Gork、AKT1、AKT2、Hak5、Spik)、钠(SOS1)、铵(AMT1；1、AMT1；2)、硝酸盐和氯(SLAC1、SLAH2、SLAH3、NRT1.1、NRT2.4、NRT2.5)和质子(AHA2、V-ATPase)的通道/转运体。CPK和CBL-CIPK也在C/N营养响应和镁和铁的获取中发挥作用。这种钙依赖的磷酸化系统的功能调节确保了植物的生长，并使它们获得了对各种环境胁迫的耐受性。钙是调节膜转运系统的关键因素。
Essential elements taken up from the soil and distributed throughout the whole plant play diverse roles in different tissues. Cations and anions contribute to maintenance of intracellular osmolarity and the formation of membrane potential, while nitrate, ammonium, and sulfate are incorporated into amino acids and other organic compounds. In contrast to these ion species, calcium concentrations are usually kept low in the cytosol and calcium displays unique behavior as a cytosolic signaling molecule. Various environmental stresses stimulate increases in the cytosolic calcium concentration, leading to activation of calcium-regulated protein kinases and downstream signaling pathways. In this review, we summarize the stress responsive regulation of nutrient uptake and balancing by two types of calcium-regulated phosphorylation systems: CPK and CBL-CIPK. CPK is a family of protein kinases activated by calcium. CBL is a group of calcium sensor proteins that interact with CIPK kinases, which phosphorylate their downstream targets. In Arabidopsis, quite a few ion transport systems are regulated by CPKs or CBL-CIPK complexes, including channels/transporters that mediate transport of potassium (KAT1, KAT2, GORK, AKT1, AKT2, HAK5, SPIK), sodium (SOS1), ammonium (AMT1;1, AMT1;2), nitrate and chloride (SLAC1, SLAH2, SLAH3, NRT1.1, NRT2.4, NRT2.5), and proton (AHA2, V-ATPase). CPKs and CBL-CIPKs also play a role in C/N nutrient response and in acquisition of magnesium and iron. This functional regulation by calcium-dependent phosphorylation systems ensures the growth of plants and enables them to acquire tolerance against various environmental stresses. Calcium serves as the key factor for the regulation of membrane transport systems.