Sly-miR398 Participates in Cadmium Stress Acclimation by Regulating Antioxidant System and Cadmium Transport in Tomato (Solanum lycopersicum)

Abstract

Cadmium (Cd) pollution is one of the major threats in agricultural production, and can cause oxidative damage and growth limitation in plants. MicroRNA398 (miR398) is involved in plant resistance to different stresses, and the post-transcriptional regulation of miR398 on CSDs plays a key role. Here, we report that miR398 was down-regulated in tomato in response to Cd stress. Simultaneously, CSD1 and SOD were up-regulated, with CSD2 unchanged, suggesting CSD1 is involved in miR398-induced regulation under Cd stress. In addition, the role of miR398 in Cd tolerance in tomato was evaluated using a transgenic line overexpressing MIR398 (miR398#OE) in which the down-expression of miR398 was disrupted. The results showed that Cd stress induced more significant growth inhibition, oxidative damage, and antioxidant enzymes disorder in miR398#OE than that in wild type (WT). Moreover, higher Cd concentration in the shoot and xylem sap, and net Cd influx rate, were observed in miR398#OE, which could be due to the increased Cd uptake genes (IRT1, IRT2, and NRAMP2) and decreased Cd compartmentalization gene HMA3. Overall, our results indicate that down-regulated miR398 plays a protective role in tomato against Cd stress by modulating the activity of antioxidant enzymes and Cd uptake and translocation.

Joint Analysis of Small RNA and mRNA Sequencing Unveils miRNA-Mediated Regulatory Network in Response to Methyl Jasmonate in Apocynum venetum L.

“…These alterations were further validated using qRT-PCR and SOD enzyme activity analyses. Similar studies showed that miR398 participated in controlling abiotic stress by targeting CSD1/CSD2 in rice [70], grapevine [71], and tomatoes [72]. Therefore, we speculate that MeJA treatment could increase the expression of CSD2 and further enhance the activity of SOD through miR398 in A. venetum, thereby enhancing the tolerance of A. venetum plants to various environmental stresses.…”

microRNAs: Key Regulators in Plant Responses to Abiotic and Biotic Stresses via Endogenous and Cross-Kingdom Mechanisms

“…Additionally, Yan et al found that growth inhibition, oxidative damage, and antioxidant enzyme disorders are more pronounced in tomato plants overexpressing miR398 under cadmium stress than in WT plants. Conversely, miR398 down-regulation exerts a protective effect against cadmium stress in tomato plants by regulating antioxidant enzyme activities alongside cadmium uptake and translocation [51].…”

MicroRNA: A Dynamic Player from Signalling to Abiotic Tolerance in Plants

“…Over the past two decades, researchers have identified a large number of plant miRNAs in major crops and model plants that act in response to abiotic stresses. Considering the continuous improvement in high-throughput and deep sequencing technologies, we can use these sequencing tools to perform genome-wide miRNA expression analysis under abiotic stresses and efficiently and rapidly identify multiple miRNA targets, including degradome sequencing, which enables the identification of the mechanisms of action of a large number of miRNAs [105]. Currently, most studies are focused on the identification of downstream target genes of miRNAs.…”