An Insight Into Pentatricopeptide-Mediated Chloroplast Necrosis via microRNA395a During Rhizoctonia solani Infection

Abstract

Sheath blight (ShB) disease, caused by Rhizoctonia solani, is one of the major biotic stress-oriented diseases that adversely affect the rice productivity worldwide. However, the regulatory mechanisms are not understood yet comprehensively. In the current study, we had investigated the potential roles of miRNAs in economically important indica rice variety Pusa Basmati-1 upon R. solani infection by carrying out in-depth, high-throughput small RNA sequencing with a total data size of 435 million paired-end raw reads from rice leaf RNA samples collected at different time points. Detailed data analysis revealed a total of 468 known mature miRNAs and 747 putative novel miRNAs across all the libraries. Target prediction and Gene Ontology functional analysis of these miRNAs were found to be unraveling various cellular, molecular, and biological functions by targeting various plant defense-related genes. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to validate the miRNAs and their putative target genes. Out of the selected miRNA-specific putative target genes, miR395a binding and its cleavage site on pentatricopeptide were determined by 5’ RACE-PCR. It might be possible that R. solani instigated chloroplast degradation by modulating the pentatricopeptide which led to increased susceptibility to fungal infection.

Small RNAs: Efficient and miraculous effectors that play key roles in plant–microbe interactions

“…Rice lsiRNAs require OsDCL4 for biogenesis and OsAGO18 for function (Niu et al, 2017). Other studies have found that 468 known mature miRNAs and 747 putative novel miRNAs may be involved in rice– R. solani interactions (Srikakulam et al, 2022). The rice sRNA expression patterns against R. solani were screened; MITE‐derived siRNA siR109944 expression was significantly suppressed on R. solani infection.…”

Evidence of microRNAs origination from chloroplast genome and their role in regulating Photosystem II protein N (psbN) mRNA

“…Retrograde signaling from chloroplast to the nucleus has been observed to favor miRNA biogenesis in the nucleus during plant stress (Crawford et al, 2018 ). During pathogen infection, the chloroplast becomes a primary target, damaging its functions and structure more than other plant cell organelles (Bhat et al, 2013 ; Bhattacharyya et al, 2015 ; Otulak et al, 2015 ; Srikakulam et al, 2022 ). Noncoding RNAs have been reported to regulate metabolic proteins in the chloroplast (Abdel-Ghany and Pilon, 2008 ; Anand and Pandi, 2021 ).…”