Exploring Heat-Response Mechanisms of MicroRNAs Based on Microarray Data of Rice Post-meiosis Panicle

Abstract

To explore heat response mechanisms of mircoRNAs (miRNAs) in rice post-meiosis panicle, microarray analysis was performed on RNA isolated from rice post-meiosis panicles which were treated at 40°C for 0 min, 10 min, 20 min, 60 min, and 2 h. By integrating paired differentially expressed (DE) miRNAs and mRNA expression profiles, we found that the expression levels of 29 DE-miRNA families were negatively correlated to their 178 DE-target genes. Further analysis showed that the majority of miRNAs in 29 DE-miRNA families resisted the heat stress by downregulating their target genes and a time lag existed between expression of miRNAs and their target genes. Then, GO-Slim classification and functional identification of these 178 target genes showed that (1) miRNAs were mainly involved in a series of basic biological processes even under heat conditions; (2) some miRNAs might play important roles in the heat resistance (such as osa-miR164, osa-miR166, osa-miR169, osa-miR319, osa-miR390, osa-miR395, and osa-miR399); (3) osa-miR172 might play important roles in protecting the rice panicle under the heat stress, but osa-miR437, osa-miR418, osa-miR164, miR156, and miR529 might negatively affect rice fertility and panicle flower; and (4) osa-miR414 might inhibit the flowering gene expression by downregulation of LOC_Os 05g51830 to delay the heading of rice. Finally, a heat-induced miRNA-PPI (protein-protein interaction) network was constructed, and three miRNA coregulatory modules were discovered.

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

“…It was revealed that miR395a could bind and cleave the pentatricopeptide repeat (PPR) protein-coding mRNA. It was reported that pentatricopeptide (Os12t0109300-01; LOC_Os12g01850) is a high-confidence target for miR395a in rice ( Peng et al, 2020 ). PPR proteins constitute a large gene family in plants which are characterized by tandem repeats of degenerated 35-amino acid (PPR motif) sequence ( Small and Peeters, 2000 ) that forms a pair of anti-parallel alpha-helix structure which allows the binding to RNA strands and majorly involves in post-transcriptional modifications of organellar RNA ( Fujii and Small, 2011 ; Barkan et al, 2012 ; Yin et al, 2013 ; Barkan and Small, 2014 ; Wang et al, 2021 ).…”

Small RNAs: The Essential Regulators in Plant Thermotolerance

“…In addition, miR172 has also been revealed to response to high-temperature stress. In both rice post-meiosis panicle and safflower leaf tissues, miR172 was observed to be significantly downregulated, whereas its target AP2 genes were upregulated under heat stress, indicating an important role of miR172-AP2 module in plant heat stress response (Kouhi et al, 2020;Peng et al, 2020).…”

BTB/POZ proteins and their gene family in Oryza rufipogon: Novel genes and alleles from the progenitor of the domesticated japonica rice (O. sativa L.)

“…Similarly, miR5809 targets putative nger transcription factors and subtilisin (Xu et al 2014), while miR2927 targets MORE AXILLARY GROWTH1 (MAX1) genes encoding cytochrome P450 monooxygenases (Wei and Chen 2018; Marzec et al 2020). Regarding abiotic stress responses, miR414 targets DEAD-box helicases involved in salinity stress response (Macovei and Tuteja 2012) and another rice gene (LOC_Os05g51830) that regulates owering and heading delay (Peng et al 2020). These miRNA target sites in OrBTB genes suggest potential epigenetic control of certain OrBTB genes during plant development under stress.…”