A SYNTHETIC BRASSINOSTEROID ANALOGUE ENHANCES PLANT RESILIENCE

LUCIA PEREZ BORROTO; JUSTO LORENZO GONZALEZ-OLMEDO; YAMILET COLL-GARCÍA; LAILA TOUM; FRANCISCO COLL-MANCHADO; ESTEBAN MARIANO PARDO; ATILIO CASTAGNARO; BJÖRN WELIN

La Habana

Congreso; 12th International Congress on Plant Biotechnology and Agriculture; 2019

Centro de Bioplantas (CUBA)

Drought is one of the most important causes of severe yield loss in soybean worldwide, threatening food production for coming years. Phytohormones such as brassinosteroids can increase response to water deficit. However, natural brassinosteroids low stability precludes field large-scale application, challenging research and development of more stable and cost-effective analogues. Seeking functional analogues capable of improving plant drought-response, we investigated for the first time the effect of DI-31 in Arabidopsis and soybean. We found that, in A. thaliana, the DI-31 increased root growth, biomass accumulation, leaf number per plant, triggered antioxidant response and dose-dependent stomatal closure, requiring NADPH and peroxidase-dependent ROS production. In soybean, the relative water content and growth rate, biomass production and duration, root length, free proline, chlorophyll and carotenoid accumulation and enzymatic antioxidants activity were stimulated by DI-31 application after 4 and 8 days of water deficit, while lipid-peroxides content was significantly reduced. Results that were highly consistent with those obtained in the Arabidopsis trials. Additionally, our results demonstrated that DI-31 is able to alter the nodular structure to cope with drought, thickening the external cortex and extending the infection area where the N2 fixing centers are located. Also, our findings showed that i) the compound reduced the nodular senescence process triggered by water scarcity, ii) preserved Leghemoglobin integrity and iii) successfully maintain the nitrogen homeostasis through a fine tune of biological and assimilative nitrogen fixation pathways. Taken together, these findings constituted the first report of DI-31 physiological characterization as drought resilience enhancer and nitrogen homeostasis regulator, supporting its potential use as a sustainable alternative for integrative soybean resilience management under drought.