Gibberellins regulate the stem elongation rate without affecting the mature plant height of a quick development mutant of winter wheat (Triticum aestivum L.).
Gibberellin (GA) is essential for determining plant height. Alteration of GA content or GA signaling results in a dwarf or slender phenotype. Here, we characterized a novel wheat mutant, quick development (qd), in which GA regulates stem elongation but does not affect mature plant height. qd and wild-type plants did not exhibit phenotypic differences at the seedling stage. From jointing to heading stage, qd plants were taller than wild-type plants due to elongated cells. However, wild-type and qd plants were the same height at heading. Unlike wild-type plants, qd plants were sensitive to exogenous GA due to mutation of Rht-B1. With continuous GA stimulation, qd seedlings and adult plants were taller than wild-type. Thus, the GA content of qd plants might differ from that of wild-type during the growth process. Analysis of GA biosynthetic gene expression verified this hypothesis and showed that TaKAO, which is involved in catalyzing the early steps of GA biosynthesis, was differentially expressed in qd plants compared with wild-type. The bioactive GA associated gene TaGA20ox was downregulated in qd plants during the late growth stages. Measurements of endogenous GA content were consistent with the gene-expression analysis results. Consistent with the GA content variation, the first three basal internodes were longer and the last two internodes were shorter in qd than in wild-type plants. The qd mutant might be useful in dissecting the mechanism by which GA regulates stem-growing process, and it may be serve as a GA responsive semi-dwarf germplasm in breeding programs.
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Ning
N
Zhang
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Yong-Dun
YD
Xie
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Hui-Jun
HJ
Guo
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Lin-Shu
LS
Zhao
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Hong-Chun
HC
Xiong
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Jia-Yu
JY
Gu
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Jun-Hui
JH
Li
China Institute of Atomic Energy, Beijing 102413, China.
Fu-Quan
FQ
Kong
China Institute of Atomic Energy, Beijing 102413, China.
Li
L
Sui
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Zi-Wei
ZW
Zhao
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
Shi-Rong
SR
Zhao
Institute of Crop Science, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China. Electronic address: liuluxiang@caas.cn.
Lu-Xiang
LX
Liu
D001483:Base Sequence; D053898:Biosynthetic Pathways / Q000187:drug effects; D017343:Genes, Plant; D005875:Gibberellins / Q000494:pharmacology*; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000033:anatomy & histology / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D012621:Seasons; D014908:Triticum / Q000033:anatomy & histology* / Q000254:growth & development*
D005875:Gibberellins; D010940:Plant Proteins
Gibberellin; Plant height; Stem elongation rate; Winter wheat