Soybean- Bradyrhizobium japonicum- Soybean Mosaic Virus interactions: the effects dependents on the interaction sequence

SOFIA ANDREOLA; MARIANELA RODRIGUEZ, ; RODRIGO PAROLA1 ; SERGIO ALEMANO; RAMIRO LASCANO

FUNCTIONAL PLANT BIOLOGY

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2019 p. 1036 - 1048

1445-4408

The soybean crop has a great economic importance and it´s productivity is markedly affected by (a)biotic stresses. The Soybean Mosaic Virus (SMV) compatible interaction provokes chlorotic symptom and growth impairment. Soybean-Bradyrhizobium japonicum (Bj) symbiotic interaction is a very sensitive process ending in the nodule formation where the interchanges of sugars from plant and fixed nitrogen from the bacteria occur. In addition to nitrogen provision, rhizobia also indirectly benefit plants by providing protection stimulating ?induced systemic resistance? (ISR) towards pathogens. In the present study, the effect of different interaction sequences among soybean, Bj and SMV on: biomass, photosynthesis, soluble sugar and ureides content, nodulation, salicylic acid and malondialdehyde content and pathogenesis- related defense gene expression were studied. Single SMV infections and mainly SMV-Bj sequence impair growth and changes on biomass partitioning, soluble sugar and ureide levels and hinder nodulation. Furthermore, single and combined interaction showed salicylic acid and lipid peroxidation increases associated with Gm-NPR1 and Gm-PR5OLPb transcript level increase. On the other hand, Bj inoculation previous to SMV infection ameliorate virus induced symptom, since plant growth and ΦPSII was less affected by the pathogen. In addition, Bj inoculation also altered same defense response, such as, increased GmPR-1 and GmPR-3 transcript level. Altogether, these results indicate that Bj induced systemic defense response ameliorating senescence symptom provoked by SMV, by a pathway that involve salicylic acid and potentially its interaction with cytokinins