Reference "Loss of function of OsDCL1 affects microRNA accumulation and causes developmental defects in rice"

Reference ID

11273

Title

Loss of function of OsDCL1 affects microRNA accumulation and causes developmental defects in rice

Source

Plant physiology, 2005, vol. 139, pp. 296-305

Authors (7)

Liu-B	Li-P
Li-X	Liu-C
Cao-S	Chu-C
Cao-X

Abstract

MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are two types of
noncoding RNAs involved in developmental regulation, genome maintenance, and
defense in eukaryotes. The activity of Dicer or Dicer-like (DCL) proteins is
required for the maturation of miRNAs and siRNAs. In this study, we cloned and
sequenced 66 candidate rice (Oryza sativa) miRNAs out of 1,650 small RNA
sequences (19 to approximately 25 nt), and they could be further grouped into 21
families, 12 of which are newly identified and three of which, OsmiR528,
OsmiR529, and OsmiR530, have been confirmed by northern blot. To study the
function of rice DCL proteins (OsDCLs) in the biogenesis of miRNAs and siRNAs,
we searched genome databases and identified four OsDCLs. An RNA interference
approach was applied to knock down two OsDCLs, OsDCL1 and OsDCL4, respectively.
Strong loss of function of OsDCL1IR transformants that expressed inverted
repeats of OsDCL1 resulted in developmental arrest at the seedling stage, and
weak loss of function of OsDCL1IR transformants caused pleiotropic developmental
defects. Moreover, all miRNAs tested were greatly reduced in OsDCL1IR but not
OsDCL4IR transformants, indicating that OsDCL1 plays a critical role in miRNA
processing in rice. In contrast, the production of siRNA from transgenic
inverted repeats and endogenous CentO regions were not affected in either
OsDCL1IR or OsDCL4IR transformants, suggesting that the production of miRNAs and
siRNAs is via distinct OsDCLs.