PeaSulf 2025

Stay-green mutants in sulfur deficiency: the role of PsSULTR4

Author

Affiliation

Corentin Maslard, PhD

INRAE

Abstract

Under prolonged sulfur deficiency (–S), sultr4 mutants display a stay-green phenotype in vegetative leaves, suggesting that vacuolar sulfate availability may influence the progression of leaf senescence and nutrient remobilization. To investigate this phenomenon, we first examined nitrogen partitioning at maturity in wild-type and sultr4 plants grown under –S. We then focused on comparing leaf responses between sultr4 and wild-type genotypes under both –S and +S conditions, monitoring chlorophyll content throughout the reproductive period, examining transcriptional regulations at key reproductive stages when nutrients are actively remobilized, and quantifying sulfate as well as a range of metabolites, including amino acids. Our findings reveal that the stay-green phenotype in sultr4 mutants under –S consistently appears in multiple experiments, indicating a direct or indirect role for vacuolar sulfate in leaf senescence. Transcriptomic analyses show that sultr4 mutants exhibit patterns distinct from the conventional sulfur deficiency response, particularly regarding the regulation of chlorophyll degradation and leaf senescence. Autophagy and photosynthetic processes remain unaffected, but the inhibition of chlorophyll catabolism and the suppression of senescence-promoting pathways characterize the mutant phenotype. Metabolic profiling further indicates that vacuolar sulfate remobilization is pivotal for maintaining cysteine levels and balancing amino acids associated with aspartate metabolism under –S. Notably, the E568K mutant accumulates OAS early in the reproductive period, representing a precocious sulfur-starvation response dependent on SULTR4, in contrast to the W78* mutant. Overall, these results underscore the crucial function of vacuolar sulfate in modulating senescence and ensuring metabolic homeostasis during sulfur-limited conditions.

Preface

Supervisor: Karine Gallardo-Guerrero

This project is an extension of the research work carried out by the FILEAS team, with several publications directly related to this subject, presented below:

• Bachelet et al. (2024)
• Bonnot et al. (2024)
• Bonnot et al. (2023)
• Henriet et al. (2021)
• Henriet et al. (2019)

Guide being written

This guide is still incomplete. The complete repository (documentation, data, script, etc.) will be available shortly at this link: https://github.com/cmaslard/PeaSulf_2025.

More informations about my work :

• Personal website
• Email
• Github
• Linkedin

• ORCID
• ResearchGate
• Google Scholar

• X (Twitter)
• HAL
• CV

Licence

This document is made available under the terms of the Licence Creative Commons Attribution - Non Commercial Use - Share Alike 4.0 International.

Bachelet, Fanélie, Myriam Sanchez, Delphine Aimé, Florence Naudé, Nadia Rossin, Alain Ourry, Chrystel Deulvot, et al. 2024. “The Vacuolar Sulfate Transporter <Span Style="font-Variant:small-Caps;">PsSULTR4</Span> Is a Key Determinant of Seed Yield and Protein Composition in Pea.” The Plant Journal 119 (6): 2919–36. https://doi.org/10.1111/tpj.16961.

Bonnot, Titouan, Fanélie Bachelet, Julie Boudet, Christine Le Signor, Emmanuelle Bancel, Vanessa Vernoud, Catherine Ravel, and Karine Gallardo. 2023. “Sulfur in Determining Seed Protein Composition: Present Understanding of Its Interaction with Abiotic Stresses and Future Directions.” Edited by Hideki Takahashi. Journal of Experimental Botany, 6.992, 74 (11): 3276–85. https://doi.org/10.1093/jxb/erad098.

Bonnot, Titouan, Charlotte Henriet, Delphine Aimé, Jonathan Kreplak, Morgane Térézol, Thierry Balliau, Alain Ourry, Michel Zivy, Vanessa Vernoud, and Karine Gallardo. 2024. “Molecular Signatures and Associated Regulators of the Pea Leaf Response to Sulfur Deficiency and Water Deficit as Revealed by Multi-Omics Analyses.” https://doi.org/10.1101/2024.03.13.582463.

Henriet, Charlotte, Delphine Aimé, Morgane Térézol, Anderson Kilandamoko, Nadia Rossin, Lucie Combes-Soia, Valerie Labas, et al. 2019. “Water Stress Combined with Sulfur Deficiency in Pea Affects Yield Components but Mitigates the Effect of Deficiency on Seed Globulin Composition.” Edited by Stanislav Kopriva. Journal of Experimental Botany, 6.992, 70 (16): 4287–4304. https://doi.org/10.1093/jxb/erz114.

Henriet, Charlotte, Thierry Balliau, Delphine Aimé, Christine Le Signor, Jonathan Kreplak, Michel Zivy, Karine Gallardo, and Vanessa Vernoud. 2021. “Proteomics of Developing Pea Seeds Reveals a Complex Antioxidant Network Underlying the Response to Sulfur Deficiency and Water Stress.” Edited by Stanislav Kopriva. Journal of Experimental Botany, 6.992, 72 (7): 2611–26. https://doi.org/10.1093/jxb/eraa571.