title: Nitric oxide and hydrogen peroxide are important signals mediating the allelopathic response of Arabidopsis to p-hydroxybenzoic acid.
abstract: Both nitric oxide (NO) and hydrogen peroxide (H2 O2 ) are important signals that mediate plant response to environmental stimulation. Their role in plants' allelopathic interactions has also been reported, but the underlying mechanism remains little understood. p-Hydroxybenzoic acid (pHBA) has been proposed to be an allelopathic chemical. Here, we found that pHBA at 0.4 mM efficiently suppressed Arabidopsis growth. Meanwhile, pHBA rapidly induced the accumulation of NO and H2 O2 , where such effect could be reversed by NO or H2 O2 metabolism inhibitors or scavengers. Also, pHBA-induced NO and H2 O2 could be compromised in NO synthesis mutants noa1, nia1 and nia2, or H2 O2 metabolism mutant rbohD/F, but suppressing NO accumulation with a NO synthesis inhibitor or using NO synthesis-related mutants did not reduce pHBA-induced H2 O2 accumulation. Furthermore, we found that the effect of pHBA on allelopathic inhibition of growth was aggravated in NO/H2 O2 metabolism-related mutants or reducing NO/H2 O2 by different inhibitors, whereas the addition of an NO/H2 O2 donor could partly relieve the inhibitory effect of pHBA on the growth of wild type. However, adding only an NO donor, but not low concentration of H2 O2 as the donor, could relieve the inhibitory effect of pHBA on root growth in NO metabolism mutants. On the basis of these results, we propose that both NO and H2 O2 are important signals that mediate Arabidopsis response to the allelopathic chemical pHBA, where during this process H2 O2 may work upstream of the NO signal.
authors: Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; Plant Germplasm and Genomics Center, the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors: Yanlong
authors: Y
authors: Guan
authors: Huaming
authors: H
authors: Lin
authors: Lan
authors: L
authors: Ma
authors: Yongping
authors: Y
authors: Yang
authors: Xiangyang
authors: X
authors: Hu
mesh_terms: D064089:Allelopathy / Q000187:drug effects*; D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D005453:Fluorescence; D006861:Hydrogen Peroxide / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009569:Nitric Oxide / Q000378:metabolism*; D009599:Nitroprusside / Q000494:pharmacology; D010226:Parabens / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D010226:Parabens; D009599:Nitroprusside; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; C038193:4-hydroxybenzoic acid