An NAC transcription factor controls ethylene-regulated cell expansion in flower petals.
Cell expansion is crucial for plant growth. It is well known that the phytohormone ethylene functions in plant development as a key modulator of cell expansion. However, the role of ethylene in the regulation of this process remains unclear. In this study, 2,189 ethylene-responsive transcripts were identified in rose (Rosa hybrida) petals using transcriptome sequencing and microarray analysis. Among these transcripts, an NAC (for no apical meristem [NAM], Arabidopsis transcription activation factor [ATAF], and cup-shaped cotyledon [CUC])-domain transcription factor gene, RhNAC100, was rapidly and dramatically induced by ethylene in the petals. Interestingly, accumulation of the RhNAC100 transcript was modulated by ethylene via microRNA164-dependent posttranscriptional regulation. Overexpression of RhNAC100 in Arabidopsis (Arabidopsis thaliana) substantially reduced the petal size by repressing petal cell expansion. By contrast, silencing of RhNAC100 in rose petals using virus-induced gene silencing significantly increased petal size and promoted cell expansion in the petal abaxial subepidermis (P < 0.05). Expression analysis showed that 22 out of the 29 cell expansion-related genes tested exhibited changes in expression in RhNAC100-silenced rose petals. Moreover, of those genes, one cellulose synthase and two aquaporin genes (Rosa hybrida Cellulose Synthase2 and R. hybrida Plasma Membrane Intrinsic Protein1;1/2;1) were identified as targets of RhNAC100. Our results suggest that ethylene regulates cell expansion by fine-tuning the microRNA164/RhNAC100 module and also provide new insights into the function of NAC transcription factors.
Department of Ornamental Horticulture, China Agricultural University, Beijing 100193, China.
Haixia
H
Pei
Nan
N
Ma
Ji
J
Tian
Jing
J
Luo
Jiwei
J
Chen
Jing
J
Li
Yi
Y
Zheng
Xiang
X
Chen
Zhangjun
Z
Fei
Junping
J
Gao
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics; D001483:Base Sequence; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D005030:Ethylenes / Q000494:pharmacology*; D035264:Flowers / Q000166:cytology* / Q000187:drug effects* / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D017434:Protein Structure, Tertiary; D027826:Rosa / Q000166:cytology* / Q000187:drug effects* / Q000235:genetics; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome / Q000235:genetics
D005030:Ethylenes; D035683:MicroRNAs; D010940:Plant Proteins; D014157:Transcription Factors; C036216:ethylene