MicroRNA171c-targeted SCL6-II, SCL6-III, and SCL6-IV genes regulate shoot branching in arabidopsis

National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Molecular Plant (Impact Factor: 6.34). 09/2010; 3(5):794-806. DOI: 10.1093/mp/ssq042
Source: PubMed


MicroRNAs (miRNAs) are ∼21-nucleotide noncoding RNAs that play critical roles in regulating plant growth and development through directing the degradation of target mRNAs. Axillary meristem activity, and hence shoot branching, is influenced by a complicated network that involves phytohormones such as auxin, cytokinin, and strigolactone. GAI, RGA, and SCR (GRAS) family members take part in a variety of developmental processes, including axillary bud growth. Here, we show that the Arabidopsis thaliana microRNA171c (miR171c) acts to negatively regulate shoot branching through targeting GRAS gene family members SCARECROW-LIKE6-II (SCL6-II), SCL6-III, and SCL6-IV for cleavage. Transgenic plants overexpressing MIR171c (35Spro-MIR171c) and scl6-II scl6-III scl6-IV triple mutant plants exhibit a similar reduced shoot branching phenotype. Expression of any one of the miR171c-resistant versions of SCL6-II, SCL6-III, and SCL6-IV in 35Spro-MIR171c plants rescues the reduced shoot branching phenotype. Scl6-II scl6-III scl6-IV mutant plants exhibit pleiotropic phenotypes such as increased chlorophyll accumulation, decreased primary root elongation, and abnormal leaf and flower patterning. SCL6-II, SCL6-III, and SCL6-IV are located to the nucleus, and show transcriptional activation activity. Our results suggest that miR171c-targeted SCL6-II, SCL6-III, and SCL6-IV play an important role in the regulation of shoot branch production.

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    • "Du et al. (2014) demonstated induction of miR159 during viral disease symptom development. miR171 acts mainly by down-regulating SCL6 genes to control a wide range of developmental processes during shoot development, including altered shoot branching, plant height, primary root elongation, flower structure, leaf shape and patterning (Curaba et al. 2013; Wang et al. 2010). It is very interesting that the expression patterns of miR159ab and 171g were contrary in RBSDV-infected leaves and roots. "
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    ABSTRACT: MicroRNAs (miRNAs) are small, non-coding RNAs which typically function by guiding cleavage of target mRNAs. They play important roles in development, abiotic stress, and responses to pathogens. Four small RNA libraries and four degradome libraries were constructed from the leaves and roots of healthy rice and plants infected with rice black streaked dwarf virus (RBSDV). Analysis of the deep sequencing results showed that the expression patterns of 14 miRNAs in leaves and 16 miRNAs in roots changed significantly in response to RBSDV infection. Some responses were similar in roots and leaves but many miRNAs responded differently in different tissues. The results were confirmed for selected miRNAs by quantitative real-time PCR. By using degradome sequencing, a total of 104 target transcripts for 17 conserved and 16 non-conserved miRNAs were shown to be responsive to RBSDV infection. 15 novel miRNAs were also identified by small RNA and degradome sequencing. The results provide new insights into the regulatory networks of miRNAs and their targets in different plant tissues in response to virus infection. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail:
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    • "The GRAS gene family, which contains the DELLA domain, displays activity in the repression of the GA response (Dill et al., 2004; Itoh et al., 2005). Control of plant height is one biological function of GA, and overexpression of miR171 in Arabidopsis resulted in taller plants; there was post-transcriptional regulation of members of the GRAS gene family by miR171, including SCARECROW-LIKE6-II (SCL6), SCL6-III, and SCL6-IV (Wang et al., 2010), indicating that miR171 might participate in GA signal transduction. In our work, miR171 was upregulated in 4m-SlAGO1A plants compared to the wild type and SlAGO1A-3# (Fig. 7), showing that miR171 is a potential candidate of parthenocarpy in 4m-SlAGO1A and 4m-SlAGO1B plants. "
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    • "Reinitiation of bud growth is determined mainly by the plant's genetic programme, which probably includes small RNAs (sRNAs). Interestingly, several members of gene families associated with shoot development are targets for regulation by sRNAs (Chuck et al., 2007; Koyama et al., 2007; Schwarz et al., 2008; Jiao et al., 2010; Wang et al., 2010). sRNAs (19–25 nt) are classified into two major categories: small interfering RNAs (siRNAs) and microRNAs (miR- NAs). "
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