A novel soybean hairy root system for gene functional validation

• Published in: PloS one 2023-05, Vol.18 (5), p.e0285504-e0285504
• Main Authors: Pereira, Bruna Medeiros, Arraes, Fabrício, Martins, Andressa Cunha Quintana, Alves, Nayara Sabrina Freitas, Melo, Bruno Paes, Morgante, Carolina Vianna, Saraiva, Mario Alfredo Passos, Grossi-de-Sá, Maria Fátima, Guimaraes, Patricia Messenberg, Brasileiro, Ana Cristina Miranda
• Format: Article
• Language: English
• Subjects: Agrobacterium rhizogenes; Animals; Antibiotics; Bacterial infections; Biology and Life Sciences; Cell culture; Cell walls; Cloning; Cost analysis; Cultivars; Detaching; Disease resistance; Disease susceptibility; Double-stranded RNA; Engineering and Technology; Genes; Genetic aspects; Genetic engineering; Genetic transformation; Genetically modified crops; Genomes; Genotype; Genotypes; Glycerol; Glycine max; Glycine max - genetics; Glycine max - metabolism; Gram-negative bacteria; Hairy root; Health aspects; Infections; Leaves; Life sciences; Medical research; Medicine and Health Sciences; Medicine, Experimental; Meloidogyne incognita; Meloidogyne javanica; Nematoda - genetics; Plant Leaves - genetics; Plant Leaves - metabolism; Plant species; Polygalacturonase; Properties; Research and Analysis Methods; Roots; Soybean; Soybeans; Transgenes
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0285504

Agrobacterium rhizogenes-mediated transformation has long been explored as a versatile and reliable method for gene function validation in many plant species, including soybean (Glycine max). Likewise, detached-leaf assays have been widely used for rapid and mass screening of soybean genotypes for disease resistance. The present study combines these two methods to establish an efficient and practical system to generate transgenic soybean hairy roots from detached leaves and their subsequent culture under ex vitro conditions. We demonstrated that hairy roots derived from leaves of two (tropical and temperate) soybean cultivars could be successfully infected by economically important species of root-knot nematodes (Meloidogyne incognita and M. javanica). The established detached-leaf method was further explored for functional validation of two candidate genes encoding for cell wall modifying proteins (CWMPs) to promote resistance against M. incognita through distinct biotechnological strategies: the overexpression of a wild Arachis α-expansin transgene (AdEXPA24) and the dsRNA-mediated silencing of an endogenous soybean polygalacturonase gene (GmPG). AdEXPA24 overexpression in hairy roots of RKN-susceptible soybean cultivar significantly reduced nematode infection by approximately 47%, whereas GmPG downregulation caused an average decrease of 37%. This novel system of hairy root induction from detached leaves showed to be an efficient, practical, fast, and low-cost method suitable for high throughput in root analysis of candidate genes in soybean.