Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

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.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

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

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

  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. 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).

    Article  CAS  Google Scholar 

  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).

    Article  PubMed  PubMed Central  Google Scholar 

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

    Article  CAS  PubMed  Google Scholar 

  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).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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

    Article  CAS  PubMed Central  Google Scholar 

  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).

    Article  CAS  PubMed  PubMed Central  ADS  Google Scholar 

  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).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

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

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

  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).

    Article  CAS  Google Scholar 

  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).

    Article  CAS  Google Scholar 

  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).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

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

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

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

    Article  CAS  Google Scholar 

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

    Article  CAS  PubMed  Google Scholar 

  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).

    Article  CAS  PubMed  PubMed Central  ADS  Google Scholar 

  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).

    Article  CAS  PubMed  ADS  Google Scholar 

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

    Article  CAS  Google Scholar 

  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).

    Article  CAS  Google Scholar 

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

    Article  CAS  PubMed  PubMed Central  ADS  Google Scholar 

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

    Article  CAS  PubMed  Google Scholar 

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

    Article  CAS  PubMed  Google Scholar 

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

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  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).

    Article  CAS  PubMed  PubMed Central  ADS  Google Scholar 

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

    Article  PubMed  CAS  Google Scholar 

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

    Article  Google Scholar 

  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).

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  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).

    Article  CAS  Google Scholar 

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

    Article  CAS  PubMed  Google Scholar 

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

    Article  CAS  Google Scholar 

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

    Article  ADS  Google Scholar 

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

    Article  CAS  PubMed  PubMed Central  ADS  Google Scholar 

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

    Article  PubMed  PubMed Central  ADS  CAS  Google Scholar 

  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).

    Article  CAS  PubMed  Google Scholar 

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

    Article  PubMed  PubMed Central  ADS  CAS  Google Scholar 

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

    Article  PubMed  PubMed Central  ADS  CAS  Google Scholar 

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

    Article  CAS  PubMed  Google Scholar 

  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. 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. 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).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  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).

    Article  CAS  PubMed  Google Scholar 

Download references


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

Authors and Affiliations



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.

Ethics declarations

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.

Reporting Summary

Source data

Source Data Fig. 1

Statistical Source Data.

Source Data Fig. 2

Statistical Source Data.

Source Data Fig. 3

Statistical Source Data.

Source Data Fig. 4

Statistical Source Data.

Rights and permissions

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

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).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing