Synthetic strigolactone (rac-GR24) alleviates the adverse effects of heat stress on seed germination and photosystem II function in lupine seedlings

0538930 - ÚEB 2021 RIV FR eng J - Journal Article
Omoarelojie, L. O. - Kulkarni, M. G. - Finnie, J.F. - Pospíšil, Tomáš - Strnad, Miroslav - Van Staden, J.
Synthetic strigolactone (rac-GR24) alleviates the adverse effects of heat stress on seed germination and photosystem II function in lupine seedlings.
Plant Physiology and Biochemistry. Roč. 155, OCT (2020), s. 965-979. ISSN 0981-9428
R&D Projects: GA MŠMT(CZ) EF16_019/0000827
Institutional support: RVO:61389030
Keywords : Antioxidant enzymes * Chlorophyll a fluorescence * Germination indices * Glyoxalase system * gr24 * Heat stress tolerance * JIP-Test * PSII thermotolerance * Strigolactones
OECD category: Biochemical research methods
Impact factor: 4.270, year: 2020
Method of publishing: Open access
http://doi.org/10.1016/j.plaphy.2020.07.043

There is increasing experimental evidence that strigolactones, a class of carotenoid-derived sesquiterpenoid hormones, and their downstream signal components play a role in plant resilience to abiotic stress. Strigolactones positively influence plant coping mechanisms in response to abiotic stressors like drought and high salinity. In this study, we examined the effects of rac-GR24 (a synthetic strigolactone analog) and strigolactone inhibitors on the physiological and molecular responses associated with thermotolerance during seed germination and seedling development in Lupinus angustifolius under heat stress. Photosystem I & II functions were also evaluated via Chl a fluorescence transient analysis in heat stressed lupine seedlings. Our results suggest a putative role for GR24 in mediating tolerance to heat stress during seed germination and seedling development albeit these responses appeared independent of D14-mediated signalling. Seeds primed with GR24 had the highest of all germination indices, enhanced proline content and reduced peroxidation of lipids. GR24 also enhanced the activities of enzymes of the antioxidant and glyoxalase systems in lupine seedlings. The JIP-test indicated that GR24 conferred resistance to heat stress-induced damage to the oxygen evolution complex while also preventing the inactivation of PSII reaction centres thus ensuring PSII thermotolerance.
Permanent Link: http://hdl.handle.net/11104/0316667