title: Exogenous GA₃ Application Enhances Xylem Development and Induces the Expression of Secondary Wall Biosynthesis Related Genes in Betula platyphylla.
abstract: Gibberellin (GA) is a key signal molecule inducing differentiation of tracheary elements, fibers, and xylogenesis. However the molecular mechanisms underlying the effect of GA on xylem elongation and secondary wall development in tree species remain to be determined. In this study, Betula platyphylla (birch) seeds were treated with 300 ppm GA₃ and/or 300 ppm paclobutrazol (PAC), seed germination was recorded, and transverse sections of hypocotyls were stained with toluidine blue; the two-month-old seedlings were treated with 50 μM GA₃ and/or 50 μM PAC, transverse sections of seedling stems were stained using phloroglucinol-HCl, and secondary wall biosynthesis related genes expression was analyzed by real-time quantitative PCR. Results indicated that germination percentage, energy and time of seeds, hypocotyl height and seedling fresh weight were enhanced by GA₃, and reduced by PAC; the xylem development was wider in GA₃-treated plants than in the control; the expression of NAC and MYB transcription factors, CESA, PAL, and GA oxidase was up-regulated during GA₃ treatment, suggesting their role in GA₃-induced xylem development in the birch. Our results suggest that GA₃ induces the expression of secondary wall biosynthesis related genes to trigger xylogenesis in the birch plants.
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China. gushan0731@126.com.|Department of Life Science and Technology, Mudanjiang Normal College, Mudanjiang 157012, China. gushan0731@126.com.
authors.forename: Huiyan
authors.initials: H
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China. wangyucheng1029@126.com.
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China. LHZ249450439@126.com.
authors.forename: Huizi
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China. hupingmojiezuo@aliyun.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China. jiayuayua2015@126.com.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China. zcrlwzy@126.com.
authors.forename: Chunrui
authors.initials: C
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China. wangyucheng1029@126.com.|Forestry Science Research Institute of Heilongjiang Province, Harbin 150081, China. wangyucheng1029@126.com.
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Life Science and Technology, Mudanjiang Normal College, Mudanjiang 157012, China. gushan0731@126.com.
authors.forename: Shan
authors.initials: S
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China. yangcp@nefu.edu.cn.
authors.forename: Chuanping
authors.initials: C
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China. nefuwangchao@yahoo.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
mesh_terms: D029662:Betula / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D018525:Germination; D005875:Gibberellins / Q000378:metabolism*; D018546:Hypocotyl / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D052584:Xylem / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
chemical_list: D005875:Gibberellins; C007842:gibberellic acid
keywords: Betula platyphylla SUK; GA3; secondary wall biosynthesis related genes; seed germination; xylem development