Mutations in an AP2 transcription factor-like gene affect internode length and leaf shape in maize.
BACKGROUND
Plant height is an important agronomic trait that affects yield and tolerance to certain abiotic stresses. Understanding the genetic control of plant height is important for elucidating the regulation of maize development and has practical implications for trait improvement in plant breeding.


RESULTS
In this study, two independent, semi-dwarf maize EMS mutants, referred to as dwarf & irregular leaf (dil1), were isolated and confirmed to be allelic. In comparison to wild type plants, the mutant plants have shorter internodes, shorter, wider and wrinkled leaves, as well as smaller leaf angles. Cytological analysis indicated that the leaf epidermal cells and internode parenchyma cells are irregular in shape and are arranged in a more random fashion, and the mutants have disrupted leaf epidermal patterning. In addition, parenchyma cells in the dil1 mutants are significantly smaller than those in wild-type plants. The dil1 mutation was mapped on the long arm of chromosome 6 and a candidate gene, annotated as an AP2 transcription factor-like, was identified through positional cloning. Point mutations near exon-intron junctions were identified in both dil1 alleles, resulting in mis-spliced variants.


CONCLUSIONS
An AP2 transcription factor-like gene involved in stalk and leaf development in maize has been identified. Mutations near exon-intron junctions of the AP2 gene give mis-spliced transcript variants, which result in shorter internodes and wrinkled leaves.
National Maize Improvement Center of China, College of Agriculture and Biotechnology, China Agricultural University, Beijing, China.
Fukun
F
Jiang
Mei
M
Guo
Fang
F
Yang
Keith
K
Duncan
David
D
Jackson
Antoni
A
Rafalski
Shoucai
S
Wang
Bailin
B
Li
D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D005020:Ethyl Methanesulfonate; D017343:Genes, Plant / Q000235:genetics*; D017403:In Situ Hybridization; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D019441:Plant Epidermis / Q000166:cytology / Q000378:metabolism*; D018515:Plant Leaves / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050656:Transcription Factor AP-2 / Q000235:genetics*; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development
D017931:DNA Primers; D050656:Transcription Factor AP-2; D005020:Ethyl Methanesulfonate