MiR396‐GRF module associates with switchgrass biomass yield and feedstock quality

Abstract

Improving plant biomass yield and/or feedstock quality for highly efficient lignocellulose conversion has been the main research focus in genetic modification of switchgrass (Panicum virgatum L.), a dedicated model plant for biofuel production. Here, we proved that overexpression of miR396 (OE-miR396) leads to reduced plant height and lignin content mainly by reducing G-lignin monomer content. We identified nineteen PvGRFs in switchgrass and proved thirteen of them were cleaved by miR396. MiR396-targeted PvGRF1, PvGRF9 and PvGRF3 showed significantly higher expression in stem. By separately overexpressing rPvGRF1, 3 and 9, in which synonymous mutations abolished the miR396 target sites, and suppression of PvGRF1/3/9 activity via PvGRF1/3/9-SRDX overexpression in switchgrass, we confirmed PvGRF1 and PvGRF9 played positive roles in improving plant height and G-lignin content. Overexpression of PvGRF9 was sufficient to complement the defective phenotype of OE-miR396 plants. MiR396-PvGRF9 modulates these traits partly by interfering GA and auxin biosynthesis and signalling transduction and cell wall lignin, glucose and xylan biosynthesis pathways. Moreover, by enzymatic hydrolysis analyses, we found that overexpression of rPvGRF9 significantly enhanced per plant sugar yield. Our results suggest that PvGRF9 can be utilized as a candidate molecular tool in modifying plant biomass yield and feedstock quality.

Integrated Analysis of mRNA and Non-coding RNA Transcriptome in Pepper (Capsicum chinense) Hybrid at Seedling and Flowering Stages

“…The miR369 was reported to be involved in growth-regulating factors (GRF) silence, which may negatively regulate in disease resistance ( Chandran et al, 2018 ). The other research reported that the overexpression of miR369 has a negative influence on PH, which may be associated with biomass yield ( Liu et al, 2021 ), while in our study, miR369a-3p and miR369a-5p were downregulated in HNCy01 and HNCc22, which may have advantageous impacts on pepper growth. Based on these results, it is suggested that miRNA could play an important role in pepper heterosis.…”

Control of sucrose accumulation in sugarcane (Saccharum spp. hybrids) involves miRNA‐mediated regulation of genes and transcription factors associated with sugar metabolism

“…Among the 1102 miRNA-mRNA pairs, there were 46 TFs, belonging primarily to WRKY, SBP, AP2/ERF, GRAS, MYB, NAC and bZIP families, and they showed contrasting gene expression patterns with their paired miRNAs. TFs from the families of WRKY, NAC, GRF, MYB, bZIP and AP2/ERF have been reported to be associated with sucrose accumulation (Huang et al, 2021;Li et al, 2020;Liu et al, 2021;Ohto et al, 2005;Song et al, 2013;Sun, Zhang, et al, 2019;Sun, Gao, et al, 2019;Wei et al, 2018). In this study, the TF-associated miRNA-mRNA pairs with contrasting expression included members of WRKY (c112674.graph_c1, c120167.graph_c0, c123264.graph_c0, c132973.graph_c1, c136438.graph_c0, c140583.graph_c0, c141561.graph_c0), NAC (c131322.…”

Identification of novel drought-responsive miRNA regulatory network of drought stress response in common vetch (Vicia sativa)

“…While in pitaya, the downregulation of miR396 reached a minimum level (−37%) after 20 h [ 56 ], in common vetch, miR396 reached its highest level after 5 days, which was an upregulation by about two times. miR396 is a growth-regulating factor (GRF) [ 57 , 58 ], which causes different response degrees when plants are stressed at different growth stages.…”