title: Ammonium-induced shoot ethylene production is associated with the inhibition of lateral root formation in Arabidopsis.
abstract: Foliar NH4(+) exposure is linked to inhibition of lateral root (LR) formation. Here, the role of shoot ethylene in NH4(+)-induced inhibition of LR formation in Arabidopsis was investigated using wild-type and mutant lines that show either blocked ethylene signalling (etr1) or enhanced ethylene synthesis (eto1, xbat32). NH4(+) exposure of wild-type Arabidopsis led to pronounced inhibition of LR production chiefly in the distal root, and triggered ethylene evolution and enhanced activity of the ethylene reporter EBS:GUS in the shoot. It is shown that shoot contact with NH4(+) is necessary to stimulate shoot ethylene evolution. The ethylene antagonists Ag(+) and aminoethoxyvinylglycine (AVG) mitigated LR inhibition under NH4(+) treatment. The decrease in LR production was significantly greater for eto1-1 and xbat32 and significantly less for etr1-3. Enhanced shoot ethylene synthesis/signalling blocked recovery of LR production when auxin was applied in the presence of NH4(+) and negatively impacted shoot AUX1 expression. The findings highlight the important role of shoot ethylene evolution in NH4(+)-mediated inhibition of LR formation.
authors: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008, China.
authors: Guangjie
authors: G
authors: Li
authors: Baohai
authors: B
authors: Li
authors: Gangqiang
authors: G
authors: Dong
authors: Xiaoyu
authors: X
authors: Feng
authors: Herbert J
authors: HJ
authors: Kronzucker
authors: Weiming
authors: W
authors: Shi
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D005030:Ethylenes / Q000096:biosynthesis*; D005966:Glucuronidase / Q000378:metabolism; D007210:Indoleacetic Acids / Q000494:pharmacology; D009861:Onium Compounds / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development*; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D015398:Signal Transduction / Q000187:drug effects; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D005030:Ethylenes; D007210:Indoleacetic Acids; D009861:Onium Compounds; D000644:Quaternary Ammonium Compounds; D017382:Reactive Oxygen Species; C007517:diphenyleneiodonium; C038983:1,3-dimethylthiourea; C036216:ethylene; D005966:Glucuronidase; D013890:Thiourea