title: Nitric oxide mediates alginate oligosaccharides-induced root development in wheat (Triticum aestivum L.).
abstract: Alginate oligosaccharides (AOS), which are marine oligosaccharides, are involved in regulating plant root growth, but the promotion mechanism for AOS remains unclear. Here, AOS (10-80 mg L(-1)) were found to induce the generation of nitric oxide (NO) in the root system of wheat (Triticum aestivum L.), which promoted the formation and elongation of wheat roots in a dose-dependent manner. NO inhibitors suggested that nitrate reductase (NR), rather than nitric oxide synthase (NOS), was essential for AOS-induced root development. Further studies confirmed that AOS-induced NO generation in wheat roots by up-regulating the gene expression and enzyme activity of NR at the post-transcriptional level. The anatomy and RT-PCR results showed that AOS accelerated the division and growth of stele cells, leading to an increase in the ratio of stele area to root transverse area. This could be inhibited by the NR inhibitor, sodium tungstate, which indicated that NO catalyzed by the NR was involved in AOS regulation of root development. Taken together, in the early stage of AOS-induced root development, NO generation was a novel mechanism by which AOS regulated plant growth. The results also showed that this marine resource could be widely used for crop development.
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Liaoning Provincial Key Laboratory of Carbohydrates, 457 Zhongshan Road, Dalian 116023, Liaoning, PR China.
authors.forename: Yunhong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hang
authors.initials: H
authors.lastname: Liu
authors.forename: Heng
authors.initials: H
authors.lastname: Yin
authors.forename: Wenxia
authors.initials: W
authors.lastname: Wang
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhao
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Du
mesh_terms: D000464:Alginates / Q000494:pharmacology*; D020723:Glucuronic Acid / Q000494:pharmacology; D006603:Hexuronic Acids / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D009844:Oligosaccharides / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development*; D014908:Triticum / Q000187:drug effects* / Q000254:growth & development*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D009844:Oligosaccharides; D009569:Nitric Oxide; D020723:Glucuronic Acid
keywords: 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazo-line-1-oxyl-3-oxide; 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate; AOS; Alginate oligosaccharides; Arg; DAF-FM DA; Hepes; IBA; LR; MAPK; NG-nitro-l-Arg-methyl ester; NO; NOS; NR; Nitric oxide; Root development; SNP; Triticum aestivum L.; Tu; alginate oligosaccharides; cPTIO; indole-3-butytric acid; l-NAME; l-arginine; lateral root; mitogen-activated protein kinase; nitrate reductase; nitric oxide; nitric oxide synthase; sodium nitroprusside; sodium tungstate