Rh-PIP2;1, a rose aquaporin gene, is involved in ethylene-regulated petal expansion.
Aquaporins are water channel proteins that facilitate the passage of water through biological membranes and play a crucial role in plant growth. We showed that ethylene treatment significantly reduced petal size, inhibited expansion of petal abaxial subepidermal cells, and decreased petal water content in rose (Rosa hybrida 'Samantha'). Here, we report the isolation of a plasma membrane aquaporin (PIP) gene, Rh-PIP2;1, and characterized its potential role in ethylene-inhibited petal expansion. Rh-PIP2;1 is mainly localized on the plasma membrane and belongs to the class 2 subfamily of PIP proteins. We show that Rh-PIP2;1 is an active water channel. The transcripts of Rh-PIP2;1 are highly abundant in petal epidermal cells, especially in the abaxial subepidermal cells. The expression of Rh-PIP2;1 is highly correlated with petal expansion and tightly down-regulated by ethylene. Furthermore, we demonstrate that in Rh-PIP2;1-silenced flowers, petal expansion was greatly inhibited and anatomical features of the petals were similar to those of ethylene-treated flowers. We argue that Rh-PIP2;1 plays an important role in petal cell expansion and that ethylene inhibits petal expansion of roses at least partially by suppressing Rh-PIP2;1 expression.
Ma
Nan
N
Department of Ornamental Horticulture, China Agricultural University, Beijing, China.
Xue
Jingqi
J
Li
Yunhui
Y
Liu
Xiaojing
X
Dai
Fanwei
F
Jia
Wensuo
W
Luo
Yunbo
Y
Gao
Junping
J
D000595:Amino Acid Sequence; D020346:Aquaporins / Q000235:genetics* / Q000378:metabolism; D002452:Cell Count; D003001:Cloning, Molecular; D003521:Cyclopropanes / Q000494:pharmacology; D005030:Ethylenes / Q000494:pharmacology*; D035264:Flowers / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D027826:Rosa / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D016415:Sequence Alignment; D014867:Water / Q000378:metabolism
D020346:Aquaporins; D003521:Cyclopropanes; D005030:Ethylenes; D010937:Plant Growth Regulators; D010940:Plant Proteins; D018749:RNA, Plant; D014867:Water; C036216:ethylene; C412563:1-methylcyclopropene