Plasma membrane-associated calcium signaling regulates arsenate tolerance in Arabidopsis

Abstract

Arsenate [As(V)] is a metalloid with heavy metal properties and is widespread in many environments. Dietary intake of food derived from arsenate-contaminated plants constitutes a major fraction of the potentially health-threatening human exposure to arsenic. However, the mechanisms underlying how plants respond to arsenate stress and regulate the function of relevant transporters are poorly understood. Here, we observed that As(V) stress induces a significant Ca2+ signal in Arabidopsis (Arabidopsis thaliana) roots. We then identified a calcium-dependent protein kinase, CALCIUM-DEPENDENT PROTEIN KINASE 23 (CPK23), that interacts with the plasma membrane As(V)/Pi transporter PHOSPHATE TRANSPORTER 1; 1 (PHT1; 1) in vitro and in vivo. cpk23 mutants displayed a sensitive phenotype under As(V) stress, while transgenic Arabidopsis plants with constitutively active CPK23 showed a tolerant phenotype. Furthermore, CPK23 phosphorylated the C-terminal domain of PHT1; 1, primarily at Ser514 and Ser520. Multiple experiments on PHT1; 1 variants demonstrated that PHT1; 1S514 phosphorylation is essential for PHT1; 1 function and localization under As(V) stress. In summary, we revealed that plasma-membrane-associated calcium signaling regulates As(V) tolerance. These results provide insight for crop bioengineering to specifically address arsenate pollution in soils.

CPK10 protein kinase regulates Arabidopsis tolerance to boron deficiency through phosphorylation and activation of BOR1 transporter

“…Luciferase complementation imaging was based on the previously published method (Liu et al ., 2023). To summarize, Agrobacterium tumefaciens strains carrying CPK10‐nLUC and BOR1‐cLUC, CPK30‐nLUC and BOR1‐cLUC, CPK10‐nLUC and GUS‐cLUC, CPK30‐nLUC and GUS‐cLUC, BOR1‐cLUC and GUS‐nLUC, GUS‐cLUC and GUS‐nLUC were co‐injected into Nicotiana benthamiana leaves.…”

Glycine‐serine‐rich effector PstGSRE4 in Puccinia striiformis f. sp. tritici targets and stabilizes TaGAPDH2 that promotes stripe rust disease

“…The extracted total protein of N. benthamiana PstGSRE4‐GFP and GFP lines was extracted with IP buffer, and enriched with anti‐GFP agarose beads (ChromoTek, gta‐20). Purified proteins were subjected to SDS‐PAGE gel electrophoresis and further assays were performed as previously described (Liu et al, 2023). Then, MS raw output data were obtained and imported into Proteome Discoverer (version 2.4) for software analysis, and N. benthamiana database was used for the qualitative analysis of proteins.…”

From genes to ecosystems: Decoding plant tolerance mechanisms to arsenic stress

“…Moreover, calcium signaling represents another cascade in the As stress response. In Arabidopsis , As(V) can induce a significant calcium signal [ 18 ]. Calcium-dependent protein Kinase 23 ( CPK23 ) plays a crucial role in this process, as it interacts with PHT1 (phosphate transporter), leading to the subsequent phosphorylation of PHT1 .…”

“…Calcium-dependent protein Kinase 23 ( CPK23 ) plays a crucial role in this process, as it interacts with PHT1 (phosphate transporter), leading to the subsequent phosphorylation of PHT1 . This regulation governs the perception and entry of As into the root cell [ 18 ]. On the other hand, CPK31 interacts with NIP1;1 to control As transport [ 85 ].…”

“…The plant response to As is not merely passive; it activates a network of defensive mechanisms, including the detoxification and sequestration strategies seen in As hyperaccumulators like Pteris vittata and the signaling pathways involving calcium and MAPKs, integral for initiating a cascade of protective responses [ [16] , [17] , [18] ]. Plant adaptation and survival in As-polluted environments rely on these responses to modulate oxidative stress and enhance the resilience of plant systems [ 19 ].…”