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Programmable design of seed coating function induces water-stress tolerance in semi-arid regions


In semi-arid regions, water stress during seed germination and early seedling growth is the highest cause of crop loss. In nature, some seeds (for example, chia and basil) produce a mucilage-based hydrogel that creates a germination-promoting microenvironment by retaining water, regulating nutrient entry and facilitating interactions with beneficial microorganisms. Inspired by this strategy, a two-layered biopolymer-based seed coating has been developed to increase germination and water-stress tolerance in semi-arid, sandy soils. Seeds are coated with a silk/trehalose inner layer containing rhizobacteria and a pectin/carboxymethylcellulose outer layer that reswells upon sowing and acts as a water jacket. Using Phaseolus vulgaris (common bean) cultured under water-stress conditions in an experimental farm in Ben Guerir, Morocco, the proposed seed coating effectively delivered rhizobacteria to form root nodules, resulted in plants with better health and mitigated water stress in drought-prone marginal lands. A programmable seed coating technology has the potential to increase seed germination and water-stress tolerance in semi-arid, sandy soils.

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Fig. 1: Material design, fabrication and selection.
Fig. 2: Mechanical characterization of P:C hydrogels.
Fig. 3: Use of P:C hydrogels as niche to grow R. tropici post rehydration.
Fig. 4: Degradation of seed coating material in soil and application to P. vulgaris to mitigate water stress.

Data availability

All relevant data are included in the article, Supplementary Information and in the Source Data files. All the other raw data are available from the authors upon request. Source data are provided with this paper.


  1. 1.

    Status of the World’s Soil Resources (FAO, 2015).

  2. 2.

    Ricciardi, V. et al. A scoping review of research funding for small-scale farmers in water scarce regions. Nat. Sustain. 3, 836–844 (2020).

    Article  Google Scholar 

  3. 3.

    The State of Food Security and Nutrition in the World 2019 (FAO, IFAD, UNICEF, WFP and WHO, 2019).

  4. 4.

    Behera, S. & Mahanwar, P. A. Superabsorbent polymers in agriculture and other applications: a review. Polym. Technol. Mater. 59, 341–356 (2020).

    CAS  Google Scholar 

  5. 5.

    Stahl, J. D., Cameron, M. D., Haselbach, J. & Aust, S. D. Biodegradation of superabsorbent polymers in soil. Environ. Sci. Pollut. Res. 7, 83–88 (2000).

    CAS  Article  Google Scholar 

  6. 6.

    Niu, X., Song, L., Xiao, Y. & Ge, W. Drought-tolerant plant growth-promoting rhizobacteria associated with foxtail millet in a semi-arid agroecosystem and their potential in alleviating drought stress. Front. Microbiol. 8, 2580 (2018).

    PubMed  PubMed Central  Article  Google Scholar 

  7. 7.

    Kuypers, M. M. M., Marchant, H. K. & Kartal, B. The microbial nitrogen-cycling network. Nat. Rev. Microbiol. 16, 263–276 (2018).

    CAS  PubMed  Article  Google Scholar 

  8. 8.

    Enebe, M. C. & Babalola, O. O. The influence of plant growth-promoting rhizobacteria in plant tolerance to abiotic stress: a survival strategy. Appl. Microbiol. Biotechnol. 102, 7821–7835 (2018).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  9. 9.

    Soumare, A. et al. Exploiting biological nitrogen fixation: a route towards a sustainable agriculture. Plants 9, 1011 (2020).

    CAS  PubMed Central  Article  PubMed  Google Scholar 

  10. 10.

    McIntyre, H. J. et al. Trehalose biosynthesis in Rhizobium leguminosarum bv. trifolii and its role in desiccation tolerance. Appl. Environ. Microbiol. 73, 3984–3992 (2007).

    CAS  PubMed  PubMed Central  Article  ADS  Google Scholar 

  11. 11.

    Vriezen, J. A., de Bruijn, F. J. & Nüsslein, K. R. Desiccation induces viable but non-culturable cells in Sinorhizobium meliloti 1021. AMB Express 2, 6 (2012).

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  12. 12.

    Geetha, S. J. & Joshi, S. J. Engineering rhizobial bioinoculants: a strategy to improve iron nutrition. Sci. World J. (2013).

  13. 13.

    Molina-Romero, D. et al. Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth. PLoS ONE 12, e0187913 (2017).

  14. 14.

    Teixeira, A., Iannetta, P., Binnie, K., Valentine, T. A. & Toorop, P. Myxospermous seed-mucilage quantity correlates with environmental gradients indicative of water-deficit stress: Plantago species as a model. Plant Soil 446, 343–356 (2020).

    CAS  Article  Google Scholar 

  15. 15.

    Western, T. L. The sticky tale of seed coat mucilages: production, genetics and role in seed germination and dispersal. Seed Sci. Res. 22, 1–25 (2012).

    CAS  Article  Google Scholar 

  16. 16.

    Kreitschitz, A. & Gorb, S. N. The micro- and nanoscale spatial architecture of the seed mucilage–comparative study of selected plant species. PLoS ONE 13, e0200522 (2018).

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  17. 17.

    Phan, J. L. & Burton, R. A. New insights into the composition and structure of seed mucilage. Annu. Plant Rev. Online (2018).

  18. 18.

    Sun, H. & Marelli, B. Growing silk fibroin in advanced materials for food security. MRS Commun. (2021).

  19. 19.

    Zhou, Z. et al. Engineering the future of silk materials through advanced manufacturing. Adv. Mater. 30, 1706983 (2018).

    Article  CAS  Google Scholar 

  20. 20.

    Rockwood, D. N. et al. Materials fabrication from Bombyx mori silk fibroin. Nat. Protoc. 6, 1612–1631 (2011).

    CAS  PubMed  Article  Google Scholar 

  21. 21.

    Marelli, B., Brenckle, M. A., Kaplan, D. L. & Omenetto, F. G. Silk fibroin as edible coating for perishable food preservation. Sci. Rep. 6, 25263 (2016).

    CAS  PubMed  PubMed Central  Article  ADS  Google Scholar 

  22. 22.

    Marelli, B. et al. Programming function into mechanical forms by directed assembly of silk bulk materials. Proc. Natl Acad. Sci. USA 114, 451–456 (2017).

    CAS  PubMed  Article  ADS  Google Scholar 

  23. 23.

    Kim, D. et al. A microneedle technology for sampling and sensing bacteria in the food supply chain. Adv. Funct. Mater. 31, 2005370 (2021).

    CAS  Article  Google Scholar 

  24. 24.

    Cao, Y., Lim, E., Xu, M., Weng, J. K. & Marelli, B. Precision delivery of multiscale payloads to tissue-specific targets in plants. Adv. Sci. 7, 1903551 (2020).

    CAS  Article  Google Scholar 

  25. 25.

    Sun, H. & Marelli, B. Polypeptide templating for designer hierarchical materials. Nat. Commun. 11, 351 (2020).

    CAS  PubMed  PubMed Central  Article  ADS  Google Scholar 

  26. 26.

    Pritchard, E. M. & Kaplan, D. L. Silk fibroin biomaterials for controlled release drug delivery. Expert Opin. Drug Deliv. 8, 797–811 (2011).

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  27. 27.

    Crowe, J. H., Carpenter, J. F. & Crowe, L. M. The role of vitrification in anhydrobiosis. Annu. Rev. Physiol. 60, 73–103 (1998).

    CAS  PubMed  Article  Google Scholar 

  28. 28.

    Boothby, T. C. et al. Tardigrades use intrinsically disordered proteins to survive desiccation. Mol. Cell 65, 975–984.e5 (2017).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  29. 29.

    Zvinavashe, A. T., Lim, E., Sun, H. & Marelli, B. A bioinspired approach to engineer seed microenvironment to boost germination and mitigate soil salinity. Proc. Natl Acad. Sci. USA 116, 25555–25561 (2019).

    CAS  PubMed  PubMed Central  Article  ADS  Google Scholar 

  30. 30.

    Vílchez, S., Tunnacliffe, A. & Manzanera, M. Tolerance of plastic-encapsulated Pseudomonas putida KT2440 to chemical stress. Extremophiles 12, 297–299 (2008).

    PubMed  Article  CAS  Google Scholar 

  31. 31.

    Cao, Y. & Mezzenga, R. Design principles of food gels. Nat. Food 1, 106–118 (2020).

    Article  Google Scholar 

  32. 32.

    Redondo-Nieto, M., Wilmot, A. R., El-Hamdaoui, A., Bonilla, I. & Bolaños, L. Relationship between boron and calcium in the N2-fixing legume–rhizobia symbiosis. Plant. Cell Environ. 26, 1905–1915 (2003).

    CAS  Article  Google Scholar 

  33. 33.

    Yoshimura, T., Sengoku, K. & Fujioka, R. Pectin-based superabsorbent hydrogels crosslinked by some chemicals: synthesis and characterization. Polym. Bull. 55, 123–129 (2005).

    CAS  Article  Google Scholar 

  34. 34.

    Pathak, V. & Ambrose, R. P. K. Starch‐based biodegradable hydrogel as seed coating for corn to improve early growth under water shortage. J. Appl. Polym. Sci. 137, 48523 (2020).

    CAS  Article  Google Scholar 

  35. 35.

    Ahn, S. & Lee, S. J. Nano/micro natural patterns of hydrogels against water loss. ACS Appl. Bio Mater. 3, 1293–1304 (2020).

    CAS  Article  Google Scholar 

  36. 36.

    Bakholdin, B. V. & Chashchikhina, L. P. Determination of the compression modulus of soils from compression-test data for calculation of pile-foundation settlements. Soil Mech. Found. Eng. 36, 9–12 (1999).

    Article  Google Scholar 

  37. 37.

    Nataraj, M. S. & McManis, K. L. Strength and deformation properties of soils reinforced with fibrillated fibers. Geosynth. Int. 4, 65–79 (1997).

    CAS  Article  Google Scholar 

  38. 38.

    Taylor, A. G. et al. Seed enhancements. Seed Sci. Res. 8, 245–256 (1998).

    Article  ADS  Google Scholar 

  39. 39.

    Li, J. & Mooney, D. J. Designing hydrogels for controlled drug delivery. Nat. Rev. Mater. 1, 16071 (2016).

    CAS  PubMed  PubMed Central  Article  ADS  Google Scholar 

  40. 40.

    Samateh, M. et al. Unravelling the secret of seed-based gels in water: the nanoscale 3D network formation. Sci. Rep. 8, 7315 (2018).

    PubMed  PubMed Central  Article  ADS  CAS  Google Scholar 

  41. 41.

    Nanjareddy, K. et al. Nitrate regulates rhizobial and mycorrhizal symbiosis in common bean (Phaseolus vulgaris L.). J. Integr. Plant Biol. 56, 281–298 (2014).

    CAS  PubMed  Article  Google Scholar 

  42. 42.

    Yin, N. et al. Bacterial cellulose as a substrate for microbial cell culture. Appl. Environ. Microbiol. 80, 1926–1932 (2014).

    PubMed  PubMed Central  Article  ADS  CAS  Google Scholar 

  43. 43.

    Kandemir, N., Vollmer, W., Jakubovics, N. S. & Chen, J. Mechanical interactions between bacteria and hydrogels. Sci. Rep. 8, 10893 (2018).

    PubMed  PubMed Central  Article  ADS  CAS  Google Scholar 

  44. 44.

    Lichter, J. A. et al. Substrata mechanical stiffness can regulate adhesion of viable bacteria. Biomacromolecules 9, 1571–1578 (2008).

    CAS  PubMed  Article  Google Scholar 

  45. 45.

    Restricting the Use of Intentionally Added Microplastic Particles to Consumer or Professional Use Products of Any Kind Annex XV Restriction Report (ECHA, 2019).

  46. 46.

    Mansori, M. et al. Seaweed extract effect on water deficit and antioxidative mechanisms in bean plants (Phaseolus vulgaris L.). J. Appl. Phycol. 27, 1689–1698 (2015).

    Article  Google Scholar 

  47. 47.

    Beebe, S. E., Rao, I. M., Blair, M. W. & Acosta-Gallegos, J. A. Phenotyping common beans for adaptation to drought. Front. Physiol. 4, 35 (2013).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  48. 48.

    Trevors, J. T. Sterilisation and inhibition of microbial activity in soil. J. Microbiol. Methods 26, 53–59 (1996).

    CAS  Article  Google Scholar 

  49. 49.

    Deaker, R., Roughley, R. J. & Kennedy, I. R. Legume seed inoculation technology—a review. Soil Biol. Biochem. 36, 1275–1288 (2004).

    CAS  Article  Google Scholar 

  50. 50.

    Mukhtar, S., Shahid, I., Mehnaz, S. & Malik, K. A. Assessment of two carrier materials for phosphate solubilising biofertilizers and their effect on growth of wheat (Triticum aestivum L.). Microbiol. Res. 205, 107–117 (2017).

    CAS  PubMed  Article  Google Scholar 

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We acknowledge M. Lara for R. tropici CIAT 899-GFP from Universidad Nacional Autonoma de Mexico, OCP S.A. and the Université Mohammed VI Polytechnique–MIT Research Program. This work was partially supported by the Office of Naval Research (Award No. N000141812258), the National Science Foundation (Award No. CMMI‐1752172) and the MIT Paul M. Cook Career Development Professorship. Schematics in Fig. 1a,b were created with

Author information




A.T.Z., J.L., M.M., B.M. and L.K. designed the study. A.T.Z., J.L., M.M., H.S., S.M., D.K. and H.M.E.F. collected and analysed the data. All authors contributed to the discussion and interpretation of the results. The manuscript was drafted by A.T.Z., J.L., H.S., M.M, L.K and B.M. and reviewed and approved by the other authors.

Corresponding author

Correspondence to Benedetto Marelli.

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Competing interests

B.M. and A.T.Z. are co-inventors in a patent application (US Patent application no. 63/036,088) that describes the coating technology reported in this study. B.M. is co-founder of Mori, Inc., a company that develops silk-based edible coatings to extend the shelf life of food. All other authors have no competing interests.

Additional information

Peer review information Nature Food thanks David Britt, Haihua Xiao and Maximino Manzanera for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figs. 1–7, Table 1 and Methods.

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Statistical Source Data.

Source Data Fig. 2

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Source Data Fig. 3

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Source Data Fig. 4

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Zvinavashe, A.T., Laurent, J., Mhada, M. et al. Programmable design of seed coating function induces water-stress tolerance in semi-arid regions. Nat Food 2, 485–493 (2021).

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