Aug 2026· Journal of Hazardous Materials· Vol 516, pp.
143357
· 0 citations· 49 references
Medicine
TL;DR
Preliminary evidence indicates that targeted editing of OsASY offers a promising strategy to reduce grain Cd content without adversely affecting major agronomic traits or yield, highlighting its potential as a molecular target for breeding low-Cd-accumulating rice varieties.
Abstract
Cadmium (Cd) contamination in rice threatens food security and public health. Identifying and characterizing key genes governing Cd uptake and translocation is crucial for breeding low-Cd varieties. In this study, we characterized a Cd-responsive member of major facilitator superfamily (MFS), ABNORMAL SHOOT IN YOUTH (OsASY), which shares high sequence homology with the known Cd transporter OsCd1. Functional analysis revealed that OsASY localizes to the plasma membrane and functions as an influx transporter mediating Cd uptake and translocation. OsASY is constitutively expressed in rice, and its transcript and protein levels were both downregulated by Cd stress. Loss of OsASY function significantly reduced Cd accumulation and enhanced Cd tolerance in rice, whereas overexpression produced opposite effects. The Cd influx activity of OsASY was confirmed by heterologous expression in yeast and Cd kinetic assays using osasy mutants. Alterations in OsASY function may trigger secondary regulatory effects by directly or indirectly affecting the expression of other Cd-responsive genes. Notably, OsASY interacts with OsCd1, and their co-expression in yeast increases cellular Cd concentrations. Collectively, these findings demonstrate that OsASY acts as a membrane-localized transporter that positively regulates Cd accumulation. Moreover, our preliminary evidence indicates that targeted editing of OsASY offers a promising strategy to reduce grain Cd content without adversely affecting major agronomic traits or yield, highlighting its potential as a molecular target for breeding low-Cd-accumulating rice varieties.
A novel SbWRKY6‑SbPLAC8-17 transcriptional cascade that positively regulates Cd tolerance by facilitating Cd²⁺ efflux is elucidates, providing promising genetic targets for phytoremediation and molecular breeding of safe sorghum cultivars for Cd-contaminated fields.
Shan Cao, Jiqing Zhang, Zhengyu Guo et al.· Journal of Hazardous Materia...· 0 citations
Cadmium (Cd) is a toxic metal that poses a significant threat to crop production and global food security. Transporters play a critical role in mediating the uptake of metal ions, including Cd. However, a substantial number of Cd transporters in rice remain uncharacterized. In this study, we identify OsMDR4, a member of the multidrug resistance protein family, as a mediator of Cd uptake in rice. Heterologous overexpression of OsMDR4 in yeast increased both Cd sensitivity and intracellular Cd accumulation. Consistent with this, the Cd concentrations in both roots and shoots of the mdr4 mutants were significantly lower than those in wild type. Kinetic analysis further revealed that the maximum Cd uptake rate in mdr4 mutants was markedly reduced compared with wild type. Expression analysis showed that OsMDR4 is primarily expressed in the epidermis and root hairs of rice seedlings and in floral organs during the flowering stage. Notably, OsMDR4 expression in seedling roots was upregulated in response to Cd exposure. Subcellular localization analysis revealed that OsMDR4–EGFP was predominantly localized to the plasma membrane in a heterologous Arabidopsis protoplast system. In summary, we have identified and characterized OsMDR4 as a previously uncharacterized protein that contributes to cadmium accumulation in rice.
Zijing Xie, Xiaohua Hao, Dan Zhao et al.· Plants· 0 citations
Cadmium (Cd), a highly toxic and mobile heavy metal, has emerged as a severe environmental concern in global agroecosystems, posing a substantial threat to human health. Although prior studies have established that ZAT6 and ZAT10 positively regulate Arabidopsis tolerance to Cd toxicity, the underlying molecular mechanisms remain largely elusive. The present study provides evidence that a class I TCP transcription factor, TCP9, significantly enhances Arabidopsis tolerance to Cd toxicity through the direct activation of ZAT6 and ZAT10 expression. The real-time quantitative PCR (RT-qPCR) analysis indicates that the expression of TCP9 was induced under Cd toxicity. Meanwhile, the tcp9 mutant exhibited heightened sensitivity to Cd toxicity, accompanied by elevated Cd accumulation in both shoots and roots. Notably, the complemented lines exhibited phenotypic characteristics analogous to those observed in the wild-type (WT) plants. Further physiological and biochemical analyses revealed that, in comparison to WT, the tcp9 mutant displayed elevated hydrogen peroxide (H2O2) accumulation and reduced contents of catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) under Cd toxicity. Furthermore, TCP9 directly interacted with the promoters of ZAT6 and ZAT10 in vitro, facilitating their transcription and consequently enhancing plant tolerance to Cd toxicity. Overall, our findings showed that TCP9 enhances Cd tolerance via modulating ZAT6 and ZAT10, thereby identifying TCP9 as a potential key target for improving plant tolerance to Cd toxicity.
Jianju She, Feng Chen, Jia-Yi Liu et al.· Plants· 0 citations
Water-saving cultivation practices, such as intermittent irrigation, are essential for sustainable rice production but often exacerbate grain cadmium (Cd) accumulation due to aerobic-soil-induced increases in Cd bioavailability. Uncoupling this trade-off is a critical challenge for global food safety. Here, we identify the transcription factor OsNAC4 as a key positive regulator of Cd uptake. Loss-of-function osnac4 mutants significantly reduce grain Cd accumulation by 30%-50% across diverse genetic backgrounds without compromising grain yield or agronomic traits. Mechanistically, we reveal that the drought/abscisic acid (ABA)-activated kinase OsSAPK2 interacts with and phosphorylates OsNAC4, thereby stabilizing the protein and enhancing its transcriptional activation of the Cd transporter gene OsNRAMP1. This signaling cascade establishes a direct molecular link whereby environmental water stress signaling cascades effectively "hijack" the basal Cd uptake machinery. Crucially, multi-location field trials demonstrate that osnac4 mutation effectively suppresses the aerobic-induced Cd elevation typically observed under water-saving regimes. Our findings elucidate the molecular mechanism underlying the conflict between water conservation and Cd accumulation, providing a robust genetic resource for breeding safe, climate-resilient rice varieties suitable for water-limited agriculture.
Xiao-Fang Zhu, Fangwei Yu, Changzhao Chen et al.· Current Biology· 0 citations
It is demonstrated that PlPAT1 functions as a positive regulator of salt stress tolerance, likely through modulating osmotic balance and enhancing reactive oxygen species scavenging capacity.
Jian Cai, Xuemei Zhang, Cong Yan et al.· BMC Genomics· 0 citations
Background: Drought tolerance in wheat is a complex trait controlled by multiple regulatory networks, among which calcium-dependent protein kinases (CDPKs) act as important components linking stress perception with downstream cellular responses. However, the functional contribution of individual CDPK members to drought adaptation in wheat remains largely unclear. This study aimed to identify and functionally characterize drought-responsive CDPK genes associated with differential drought responses in wheat. Methods: Two wheat lines derived from the same breeding background exhibiting contrasting drought adaption, 23B1 and 23B39, were subjected to PEG6000-induced osmotic stress. Growth traits, osmotic adjustment-related metabolites, membrane damage indicators, and antioxidant enzyme activity were evaluated. Transcriptomic analysis was performed at early drought-response stages, followed by differential expression analysis, functional enrichment, CDPK family screening, and qRT-PCR validation. The role of TaCDPK22-5A was further investigated using barley stripe mosaic virus (BSMV)-mediated virus-induced gene silencing (VIGS). Results: The drought-responsive line 23B1 maintained stronger growth, accumulated higher levels of proline and soluble sugars, exhibited enhanced peroxidase activity, and showed reduced membrane lipid peroxidation compared with 23B39. Transcriptome analysis revealed extensive transcriptional reprogramming under drought stress, with differentially expressed genes mainly associated with metabolic adjustment, transport regulation, secondary metabolism, and stress-responsive pathways. Among the identified CDPK members, TaCDPK22-5A showed a strong drought-responsive expression pattern in the line exhibiting stronger drought tolerance (23B1). Virus-induced gene silencing of TaCDPK22-5A significantly impaired drought tolerance, resulting in reduced growth, biomass accumulation, and chlorophyll retention under drought conditions. Conclusions: These findings demonstrate that TaCDPK22-5A contributes positively to drought adaptation in wheat and highlight CDPK-mediated calcium signaling as an important regulatory component of drought responses. The identified gene provides a potential target for improving drought resilience in wheat breeding.
Bo Liu, Yu Li, Hui-Na Li et al.· Genes· 0 citations
