title: Glycine increases cold tolerance in rice via the regulation of N uptake, physiological characteristics, and photosynthesis.
abstract: To investigate the response of rice growth and photosynthesis to different nitrogen (N) sources under cold stress, hydroponic cultivation of rice was done in greenhouse, with glycine, ammonium, and nitrate as the sole N sources. The results demonstrate that exposure to low temperature reduced the rice biomass and leaf chlorophyll content, but their values in the glycine-treated plants were significantly higher than in the ammonium- and nitrate-treated plants. This might be attributed to the higher N uptake rate and root area and activity in the glycine-treated plants. The glycine-treated plants also maintained high contents of soluble proteins, soluble sugars, and proline as well as enhanced antioxidant enzyme activities to protect themselves against chilling injury. Under cold stress, reduced stomatal conductance (gs) and effective quantum efficiency of PSII (ΦPSII) significantly inhibited the leaf photosynthesis; however, glycine treatment alleviated these effects compared to the ammonium and nitrate treatments. The high non-photochemical quenching (qN) and excess energy dissipative energy (Ex) in the glycine-treated plants were beneficial for the release of extra energy, thereby, strengthening their photochemical efficiency. We, therefore, conclude that the strengthened cold tolerance of glycine-treated rice plants was closely associated with the higher accumulation of dry matter and photosynthesis through the up-regulation of N-uptake, and increase in the content of osmoprotectants, activities of the antioxidant defense enzymes, and photochemical efficiency. The results of the present study provide new ideas for improving the plant tolerance to extreme temperatures by nutrient resource management in the cold regions.
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China.
authors.forename: Cao
authors.initials: C
authors.lastname: Xiaochuang
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Lianfeng
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Junhua
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China.
authors.forename: Sajid
authors.initials: S
authors.lastname: Hussain
authors.affiliation: Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058 China.
authors.forename: Wu
authors.initials: W
authors.lastname: Lianghuan
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China. Electronic address: caoxiaochuang@126.com.
authors.forename: Jin
authors.initials: J
authors.lastname: Qianyu
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D018533:Biomass; D002338:Carotenoids / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003080:Cold Temperature; D004553:Electric Conductivity; D005453:Fluorescence; D005998:Glycine / Q000494:pharmacology*; D008315:Malondialdehyde / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D009587:Nitrogen Isotopes; D012275:Oryza / Q000187:drug effects / Q000502:physiology*; D009195:Peroxidase / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects*; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D054046:Plant Stomata / Q000187:drug effects / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000502:physiology; D012995:Solubility; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D009587:Nitrogen Isotopes; D002734:Chlorophyll; D002338:Carotenoids; D008315:Malondialdehyde; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D009584:Nitrogen; D005998:Glycine
keywords: Amino acids; Cold stress; Nitrogen form; Photosynthesis; Physiological trait; Rice