Characterization of sck1, a novel Castanea mollissima mutant with the extreme short catkins and decreased gibberellin.
A novel Chinese chestnut (Castanea mollissima Bl.) mutant with extreme short catkins, here was named sck1 and has been characterized in the present study. This sck1 caused 6-fold shorter than wild-type catkins. Endogenous gibberellic acids markedly decreased in the mutant, and application of exogenous GA(3) could partially restore the sck1 phenotype to the wild-type phenotype. Paclobutrazol (PP(333)), an antagonist of GAs biosynthesis, could significantly inhibit the wild-type catkins growth, and lead to a short catkins phenotype similar to the sck1. In addition, compared to the wild-type catkins, the mRNA expression level of ent-kaurenoic acid oxidase (KAO), a gibberellin biosynthesis key gene, was significantly down-regulated (P<0.01) in the sck1. Importantly, transient over-expression of a normal CmKAO gene in short catkins also could partially restore the wild-type phenotype. Real-time PCR and semi-quantitative analysis showed that the mRNA expression level of KAO was significantly up-regulated. In addition, transient RNA interference of CmKAO in wild-type catkins led the mRNA expression level of KAO decrease significantly and inhibited the wild-type catkins elongation strongly. Taken together, our results suggest that the lower gibberellic acids content that is due to decreased CmKAO expression level may contribute to the generation of the extreme short male catkins, sck1.
Key Laboratory of New Technology in Agriculture Application of Beijing, College of Plant Science and Technology, Beijing University of Agriculture, Beijing, China.
Xian-Ping
XP
Guo
Xing-Liang
XL
Li
Xu-Wei
XW
Duan
Yuan-Yue
YY
Shen
Yu
Y
Xing
Qing-Qin
QQ
Cao
Ling
L
Qin
D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000235:genetics*; D009154:Mutation; D009754:Nuts / Q000235:genetics*; D010641:Phenotype; D018515:Plant Leaves / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic; D012313:RNA / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism
D005875:Gibberellins; D012333:RNA, Messenger; D012313:RNA; C007842:gibberellic acid; D006899:Mixed Function Oxygenases; C423619:ent-kaurenoic acid oxidase