title: Suppressed expression of choline monooxygenase in sugar beet on the accumulation of glycine betaine.
abstract: Glycine betaine (GB) is an important osmoprotectant and synthesized by two-step oxidation of choline. Choline monooxygenase (CMO) catalyzes the first step of the pathway and is believed to be a rate limiting step for GB synthesis. Recent studies have shown the importance of choline-precursor supply for GB synthesis. In order to investigate the role of CMO for GB accumulation in sugar beet (Beta vulgaris), transgenic plants carrying the antisense BvCMO gene were developed. The antisense BvCMO plants showed the decreased activity of GB synthesis from choline compared to wild-type (WT) plants which is well related to the suppressed level of BvCMO protein. However, GB contents were similar between transgenic and WT plants with the exception of young leaves and storage roots. Transgenic plants showed enhanced susceptibility to salt stress than WT plants. These results suggest the importance of choline-precursor-supply for GB accumulation, and young leaves and storage root are sensitive sites for GB accumulation.
authors: Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, 468-8502, Japan.
authors: Nana
authors: N
authors: Yamada
authors: Hokkaido Agricultural Research Center, National Agriculture and Food Organization, Hokkaido, 082-0081, Japan.
authors: Hiroyuki
authors: H
authors: Takahashi
authors: Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, 468-8502, Japan.
authors: Kunihide
authors: K
authors: Kitou
authors: Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, 468-8502, Japan.
authors: Kosuke
authors: K
authors: Sahashi
authors: Central Agricultural Experiment Station, Agriculture Research, Department, Hokkaido Research Organization, Naganuma, Yubari, 069-1395, Japan.
authors: Hideto
authors: H
authors: Tamagake
authors: Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, 468-8502, Japan.
authors: Yoshito
authors: Y
authors: Tanaka
authors: Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, 468-8502, Japan; Research Institute, Meijo University, Nagoya, 468-8502, Japan. Electronic address: takabe@meijo-u.ac.jp.
authors: Teruhiro
authors: T
authors: Takabe
mesh_terms: D027461:Beta vulgaris / Q000201:enzymology*; D001622:Betaine / Q000378:metabolism*; D010105:Oxygenases / Q000378:metabolism*; D030821:Plants, Genetically Modified
chemical_list: D001622:Betaine; C105448:choline monooxygenase; D010105:Oxygenases
keywords: Betaine; Choline monooxgenase; Salt stress; Sugar; Sugar beet; Transgenic plants