title: A GmRAV ortholog is involved in photoperiod and sucrose control of flowering time in soybean.
abstract: Photoperiod and sucrose levels play a key role in the control of flowering. GmRAV reflected a diurnal rhythm with the highest expression at 4 h after the beginning of a dark period in soybean leaves, and was highly up-regulated under short-day (SD) conditions, despite of not following a diurnal pattern under long-day (LD) conditions. GmRAV-i (GmRAV-inhibition) transgenic soybean exhibited early flowering phenotype. Two of the FT Arabidopsis homologs, GmFT2a and GmFT5a, were highly expressed in the leaves of soybeans with inhibition (-i) of GmRAV under SD conditions. Moreover, the transcript levels of the two FT homologs in GmRAV-i soybeans were more sensitive to SD conditions than LD conditions compared to the WT plant. GmRAV-i soybeans and Arabidopsis rav mutants showed more sensitive hypocotyl elongation responses when compared with wild-type seedlings, and GmRAV-ox overevpressed in tobacco revealed no sensitive changes in hypocotyl length. These indicated that GmRAV was a novel negative regulator of SD-mediated flowering and hypocotyl elongation. Although sucrose has been suggested to promote flowering induction in many plant species, high concentration of sucrose (4% [w/v]) applied into media defer flowering time in Arabidopsis wild-type and rav mutant. This delayed flowering stage might be caused by reduction of LEAFY expression. Furthermore, Arabidopsis rav mutants and GmRAV-i soybean plants were less sensitive to sucrose by the inhibition assays of hypocotyls and roots growth. In contrast, transgenic GmRAV overexpressing (-ox) tobacco plants displayed more sensitivity to sucrose. In conclusion, GmRAV was inferred to have a fundamental function in photoperiod, darkness, and sucrose signaling responses to regulate plant development and flowering induction.
authors.affiliation: Key Laboratory of Soybean Biology of Chinese Education Ministry (Key Laboratory of Biology and Genetics & Breeding for Soybean in Northeast China, Ministry of Agriculture), Northeast Agriculture University, Harbin, China.
authors.forename: Qingyao
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Key Laboratory of Soybean Biology of Chinese Education Ministry (Key Laboratory of Biology and Genetics & Breeding for Soybean in Northeast China, Ministry of Agriculture), Northeast Agriculture University, Harbin, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Soybean Biology of Chinese Education Ministry (Key Laboratory of Biology and Genetics & Breeding for Soybean in Northeast China, Ministry of Agriculture), Northeast Agriculture University, Harbin, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Li
authors.affiliation: Key Laboratory of Soybean Biology of Chinese Education Ministry (Key Laboratory of Biology and Genetics & Breeding for Soybean in Northeast China, Ministry of Agriculture), Northeast Agriculture University, Harbin, China.
authors.forename: Diqiu
authors.initials: D
authors.lastname: Hao
authors.affiliation: Agricultural Academy of Shi He Zi, Xinjiang Province, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: Key Laboratory of Soybean Biology of Chinese Education Ministry (Key Laboratory of Biology and Genetics & Breeding for Soybean in Northeast China, Ministry of Agriculture), Northeast Agriculture University, Harbin, China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Li
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D035264:Flowers / Q000187:drug effects / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018546:Hypocotyl / Q000187:drug effects / Q000254:growth & development; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D017440:Photoperiod; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D036226:Seedlings / Q000187:drug effects / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D013025:Glycine max / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D013395:Sucrose / Q000494:pharmacology*; D013997:Time Factors; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D013395:Sucrose