Brassinosteroids Mitigate Cadmium Effects in Arabidopsis Root System without Any Cooperation with Nitric Oxide

International Journal of Molecular Sciences

Camilla Betti¹  Giuseppina Falasca²  Dario Bellanima²  Nicoletta Girardi²  Diego Piacentini²  Laura Fattorini²  Federica Della Rovere²  Maria Maddalena Altamura² 

[1] Department of Biosciences, University of Milan, 20133 Milan, Italy;Department of Environmental Biology, Sapienza University of Rome, 00185 Rome, Italy;

关键词: adventitious roots;    auxin localization;    brassinazole;    CdSO₄;    epibrassinolide;    lateral roots;   

DOI  :  10.3390/ijms23020825

来源: DOAJ

【 摘 要 】

The heavy metal cadmium (Cd) affects root system development and quiescent center (QC)-definition in Arabidopsis root-apices. The brassinosteroids-(BRs)-mediated tolerance to heavy metals has been reported to occur by a modulation of nitric oxide (NO) and root auxin-localization. However, how BRs counteract Cd-action in different root types is unknown. This research aimed to find correlations between BRs and NO in response to Cd in Arabidopsis’s root system, monitoring their effects on QC-definition and auxin localization in root-apices. To this aim, root system developmental changes induced by low levels of 24-epibrassinolide (eBL) or by the BR-biosynthesis inhibitor brassinazole (Brz), combined or not with CdSO₄, and/or with the NO-donor nitroprusside (SNP), were investigated using morpho-anatomical and NO-epifluorescence analyses, and monitoring auxin-localization by the DR5::GUS system. Results show that eBL, alone or combined with Cd, enhances lateral (LR) and adventitious (AR) root formation and counteracts QC-disruption and auxin-delocalization caused by Cd in primary root/LR/AR apices. Exogenous NO enhances LR and AR formation in Cd-presence, without synergism with eBL. The NO-signal is positively affected by eBL, but not in Cd-presence, and BR-biosynthesis inhibition does not change the low NO-signal caused by Cd. Collectively, results show that BRs ameliorate Cd-effects on all root types acting independently from NO.

【 授权许可】

Unknown