Unveiling Molecular Mechanisms of Cadmium Tolerance and Accumulation in Sweet Sorghum: Role of SbYS1 and SbWRKY72 for Enhanced Phytoremediation

  • SorghumBase Team
  • 15 July 2024

Cadmium (Cd) pollution poses significant risks to both plant growth and human health. The industrialization boom in China has led to widespread Cd contamination in agricultural soils, necessitating effective remediation strategies. Phytoremediation, particularly employing hyperaccumulators like sweet sorghum, presents an economical and eco-friendly approach. Sweet sorghum, known for its high biomass production and photosynthetic efficiency, has shown promise in Cd extraction from contaminated soils. However, its potential has been hindered by limited Cd uptake and translocation capacity. Researchers from the Chinese Academy of Sciences, China National Botanical Garden and University of Chinese Academy of Sciences investigated the role of a Yellow Stripe-Like (YSL) transporter, SbYS1, and its upstream transcription factor, SbWRKY72, in Cd tolerance and accumulation in sweet sorghum.

SbYS1, induced by Cd stress, is primarily expressed in roots and exhibits both plasma membrane and endoplasmic reticulum localization. Overexpression of SbYS1 in Arabidopsis enhances Cd tolerance and reduces Cd accumulation in roots and shoots, suggesting its involvement in Cd transportation. Furthermore, SbWRKY72 negatively regulates SbYS1 expression, as demonstrated in transgenic Arabidopsis lines overexpressing SbWRKY72, which exhibit increased sensitivity to Cd stress and higher Cd accumulation in roots. These findings give insight into the molecular mechanisms underlying Cd tolerance and accumulation in sweet sorghum, providing important information about developing strategies to enhance its phytoremediation capacity in Cd-contaminated soils through genetic manipulation of key genes like SbYS1 and SbWRKY72.

SorghumBase examples: 

SbYS1 gene Sobic.004G299500 (SORBI_3004G299500, Sb04g033320) was picked up as an example to explore SorghumBase below: 

Figure 1: The location of the SbYS1 gene SORBI_3004G299500 (Sb04g033320, Sobic.004G299500
similar to Iron-phytosiderophore transporter yellow stripe 1) is displayed on Chromosome 4 (within 4:63851484-63856538) in SorghumBase.
Figure 2: This figure displays the phylogram of SbYS1 gene SORBI_3004G299500 (Sb04g033320, Sobic.004G299500 similar to Iron-phytosiderophore transporter yellow stripe 1) based on the Ensembl compara gene tree. There are 22 paralogs and 37 orthologs of this gene.
Figure 3: This figure displays the electronic fluorescent pictographic images for visualizing gene expression of the SbYS1 gene SORBI_3004G299500 (Sb04g033320, Sobic.004G299500
similar to Iron-phytosiderophore transporter yellow stripe 1 in different time points at different developmental stages. eFP browser was used to explore the anatomograms of the experimental samples used to generate the gene expression data set.
Figure 4: This figure displays the electronic fluorescent pictographic (eFP) images for visualizing gene expression of the SbYS1 gene SORBI_3004G299500 (Sb04g033320, Sobic.004G299500 similar to Iron-phytosiderophore transporter yellow stripe 1 in different nitrogen source studies at 30DAE. eFP browser was used to explore the anatomograms of the experimental samples used to generate the gene expression data set.
Figure 5: This figure displays the baseline gene expression of the SbYS1 gene SORBI_3004G299500 (Sb04g033320, Sobic.004G299500 similar to Iron-phytosiderophore transporter yellow stripe 1) in the four published sorghum BTx623 datasets curated and processed by EMBL-EBI atlas in collaboration with the SorghumBase team. The yellow highlighted shows the expression level of 790 TPM of this gene expressed in roots based on Olson et al.
Figure 6: The pathway of the SbYS1 gene SORBI_3004G299500 (Sb04g033320, Sobic.004G299500 similar to Iron-phytosiderophore transporter yellow stripe 1) shows that this gene is involved in hormone signaling, transport and metabolism especially polar Auxin transport and more specifically auxin influx transport through plasma membrane.

Reference:

Jia W, Guo Z, Lv S, Lin K, Li Y. SbYS1 and SbWRKY72 regulate Cd tolerance and accumulation in sweet sorghum. Planta. 2024 Mar 27;259(5):100. PMID: 38536457. doi: 10.1007/s00425-024-04388-0. Read more