Cleistogamous flowering in barley arises from the suppression of microRNA-guided HvAP2 mRNA cleavage.
The cleistogamous flower sheds its pollen before opening, forcing plants with this habit to be almost entirely autogamous. Cleistogamy also provides a means of escape from cereal head blight infection and minimizes pollen-mediated gene flow. The lodicule in cleistogamous barley is atrophied. We have isolated cleistogamy 1 (Cly1) by positional cloning and show that it encodes a transcription factor containing two AP2 domains and a putative microRNA miR172 targeting site, which is an ortholog of Arabidopsis thaliana AP2. The expression of Cly1 was concentrated within the lodicule primordia. We established a perfect association between a synonymous nucleotide substitution at the miR172 targeting site and cleistogamy. Cleavage of mRNA directed by miR172 was detectable only in a noncleistogamous background. We conclude that the miR172-derived down-regulation of Cly1 promotes the development of the lodicules, thereby ensuring noncleistogamy, although the single nucleotide change at the miR172 targeting site results in the failure of the lodicules to develop properly, producing the cleistogamous phenotype.
Nair
Sudha K
SK
National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan.
Wang
Ning
N
Turuspekov
Yerlan
Y
Pourkheirandish
Mohammad
M
Sinsuwongwat
Suphawat
S
Chen
Guoxiong
G
Sameri
Mohammad
M
Tagiri
Akemi
A
Honda
Ichiro
I
Watanabe
Yoshiaki
Y
Kanamori
Hiroyuki
H
Wicker
Thomas
T
Stein
Nils
N
Nagamura
Yoshiaki
Y
Matsumoto
Takashi
T
Komatsuda
Takao
T
D001483:Base Sequence; D035264:Flowers / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D001467:Hordeum / Q000033:anatomy & histology / Q000235:genetics / Q000502:physiology*; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011110:Polymorphism, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D035683:MicroRNAs; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D014157:Transcription Factors