The soybean gene GmHsp22.4 is involved in the resistance response to Meloidogyne javanica in Arabidopsis thaliana

• Published in: BMC plant biology Vol. 20; no. 1; p. 535
• Main Authors: Hishinuma-Silva, Suellen Mika, Lopes-Caitar, Valéria Stefania, Nomura, Rafael Bruno Guayato, Sercero, Bruna Caroline, da Silva, Aline Garcia, da Cruz Gallo De Carvalho, Mayra Costa, de Oliveira Negrão Lopes, Ivani, Dias, Waldir Pereira, Marcelino-Guimarães, Francismar Corrêa
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 24.11.2020; BioMed Central
• Subjects: Animals; Arabidopsis - genetics; Arabidopsis thaliana; Chaperones; Disease Resistance - genetics; Disease Resistance - immunology; Diseases and pests; Functional analysis; Gene expression; Gene Knockout Techniques; Genes, Plant; Genetic aspects; Genotype; Genotype & phenotype; Genotypes; Glycine max - genetics; Glycine max - immunology; Glycine max - parasitology; Green fluorescent protein; Green Fluorescent Proteins; Health aspects; Heat shock proteins; Heat-Shock Proteins - genetics; Heat-Shock Proteins - immunology; Inoculation; Meloidogyne javanica; Multiplication; Mutants; Nematodes; Pest resistance; Physiological aspects; Plant Diseases - genetics; Plant Diseases - immunology; Plant Diseases - parasitology; Plant immunology; Plant introductions; Plant Roots - genetics; Promoter Regions, Genetic; Proteins; Root-knot; Small heat shock proteins; Soybeans; Structural analysis; Transcription; Transgenic plants; Tylenchoidea - immunology; Brazil; Reproduction factor; Root-knot nematode; HSP; Defense response
• ISSN: 1471-2229; 1471-2229
• DOI: 10.1186/s12870-020-02736-2

Small heat shock proteins (sHSPs) belong to the class of molecular chaperones that respond to biotic and abiotic stresses in plants. A previous study has showed strong induction of the gene GmHsp22.4 in response to the nematode Meloidogyne javanica in a resistant soybean genotype, while repression in a susceptible one. This study aimed to investigate the functional involvement of this small chaperone in response to M. javanica in Arabidopsis thaliana. First, it was evaluated the activation of the promoter region after the nematode inoculation, and the occurrence of polymorphisms between resistant and susceptible re-sequenced soybean accessions. Then functional analysis using A. thaliana lines overexpressing the soybean GmHsp22.4 gene, and knocked-out mutants were challenged with M. javanica infestation. High expression levels of the GFP gene marker in transformed A. thaliana plants revealed that the promoter region of GmHsp22.4 was strongly activated after nematode inoculation. Moreover, the multiplication of the nematode was significantly reduced in plants overexpressing GmHsp22.4 gene in A. thaliana compared to the wild type. Additionally, the multiplication of M. javanica in the A. thaliana mutants was significantly increased mainly in the event athsp22.0-2. This increase was not that evident in the event athsp22.0-1, the one that preserved a portion of the promoter region, including the HSEs in the region around - 83 bp. However, structural analysis at sequence level among soybean resistant and susceptible genotypes did not detect any polymorphisms in the whole gene model. The soybean chaperone GmHsp22.4 is involved in the defense response to root-knot nematode M. javanica in A. thaliana. Specifically, the promoter region covering until - 191 from the transcriptional start site (TSS) is necessary to promoter activation after nematode infection in Arabidopsis. No polymorphisms that could explain these differences in the defense response were detected in the GmHsp22.4 gene between resistant and susceptible soybean genotypes. Therefore, further investigation is needed to elucidate the triggering factor of the plant's defense mechanism, both at the sequence level of the soybean genotypes presenting contrasting reaction to root-knot nematode and by detecting cis-elements that are essential for the activation of the GmHsp22.4 gene promoter.