RT Journal Article
SR Electronic
T1 An Essential Role for miRNA167 in Maternal Control of Embryonic and Seed Development
JF Plant Physiology
JO Plant Physiol.
FD American Society of Plant Biologists
SP 453
OP 464
DO 10.1104/pp.19.00127
VO 180
IS 1
A1 Yao, Xiaozhen
A1 Chen, Jilin
A1 Zhou, Jie
A1 Yu, Hanchuanzhi
A1 Ge, Chennan
A1 Zhang, Min
A1 Gao, Xiuhua
A1 Dai, Xinhua
A1 Yang, Zhong-Nan
A1 Zhao, Yunde
YR 2019
UL http://www.plantphysiol.org/content/180/1/453.abstract
AB Maternal cells play a critical role in ensuring the normal development of embryos, endosperms, and seeds. Mutations that disrupt the maternal control of embryogenesis and seed development are difficult to identify. Here, we completely deleted four MICRORNA167 (MIR167) genes in Arabidopsis (Arabidopsis thaliana) using a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein9 (Cas9) genome-editing technology. We found that plants with a deletion of MIR167A phenocopied plants overexpressing miRNA167-resistant versions of Auxin Response Factor6 (ARF6) or ARF8, two miRNA167 targets. Both the mir167a mutant and the ARF overexpression lines were defective in anther dehiscence and ovule development. Serendipitously, we found that the mir167a (♀) × wild type (♂) crosses failed to produce normal embryos and endosperms, despite the findings that embryos with either mir167a+/− or mir167a−/− genotypes developed normally when mir167a+/− plants were self-pollinated, revealing a central role of MIR167A in maternal control of seed development. The mir167a phenotype is 100% penetrant, providing a great genetic tool for studying the roles of miRNAs and auxin in maternal control. Moreover, we found that mir167a mutants flowered significantly later than wild-type plants, a phenotype that was not observed in the ARF overexpression lines. We show that the reproductive defects of mir167a mutants were suppressed by a decrease of activities of ARF6, ARF8, or both. Our results clearly demonstrate that MIR167A is the predominant MIR167 member in regulating Arabidopsis reproduction and that MIR167A acts as a maternal gene that functions largely through ARF6 and ARF8.