Essential role of γ‐clade RNA‐dependent RNA polymerases in rice development and yield‐related traits is linked to their atypical polymerase activities regulating specific genomic regions

Autor: T N Sujith, Ashwin Nair, Padubidri V. Shivaprasad, Anushree Narjala, Kannan Pachamuthu, Debjani Basu, Swetha Chenna, Vikram Jha
Rok vydání: 2021
Předmět:
Zdroj: New Phytologist. 232:1674-1691
ISSN: 1469-8137
0028-646X
DOI: 10.1111/nph.17700
Popis: RNA-dependent RNA polymerases (RDR) generate double-stranded (ds)RNA triggers for RNA silencing across eukaryotes. Among the three clades, α-clade and β-clade members are key components of RNA silencing and mediators of stress responses across eukaryotes. However, γ-clade members are unusual in that they are represented in phylogenetically distant plants and fungi, and their functions are unknown. Using genetic, bioinformatic and biochemical methods, we show that γ-clade RDRs from Oryza sativa L. are involved in plant development as well as regulation of expression of coding and noncoding RNAs. Overexpression of γ-clade RDRs in transgenic rice and tobacco plants resulted in robust growth phenotype, whereas their silencing in rice displayed strong inhibition of growth. Small (s)RNA and RNA-seq analysis of OsRDR3 mis-expression lines suggested that it is specifically involved in the regulation of repeat-rich regions in the genome. Biochemical analysis confirmed that OsRDR3 has robust polymerase activities on both single stranded (ss)RNA and ssDNA templates similar to the activities reported for α-clade RDRs such as AtRDR6. Our results provide the first evidence of the importance of γ-clade RDRs in plant development, their atypical biochemical activities and their contribution to the regulation of gene expression.
Databáze: OpenAIRE
Externí odkaz: