Functional characterization of OsmiR396a in rice (Oryza sativa L.)

et al. 2020

IJMS

Seed plants usually undergo various developmental phase transitions throughout their lifespan, mainly including juvenile-to-adult and vegetative-to-reproductive transitions, as well as developmental transitions within organ/tissue formation. MicroRNAs (miRNAs), as a class of small endogenous non-coding RNAs, are involved in the developmental phase transitions in plants by negatively regulating the expression of their target genes at the post-transcriptional level. In recent years, cumulative evidence has revealed that five miRNAs, miR156, miR159, miR166, miR172, and miR396, are key regulators of developmental phase transitions in plants. In this review, the advanced progress of the five miRNAs and their targets in regulating plant developmental transitions, especially in storage organ formation, are summarized and discussed, combining our own findings with the literature. In general, the functions of the five miRNAs and their targets are relatively conserved, but their functional divergences also emerge to some extent. In addition, potential research directions of miRNAs in regulating plant developmental phase transitions are prospected.

Section: Mir396mentioning

confidence: 67%

The Control of Developmental Phase Transitions by microRNAs and Their Targets in Seed Plants

Zhao

et al. 2020

IJMS

“…Stem of biofuel plants contributes most of its biomass yield and had higher cellulose, hemicellulose and lignin concentration and lower ash contents, which resulted in a better fuel quality than leaves (Tubeileh et al, 2016 ). MiR396‐ GRF regulatory pathway has been found to affect the size of various organs in different species (Diao et al, 2018 ; Gao et al, 2015 ; Tang et al, 2018 ). However, the biological function of miR396 and its target genes in regulating plant stem characters for biofuel production has not been demonstrated yet.…”

Section: Discussionmentioning

confidence: 99%

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

Plant Biotechnology Journal

Yan

Wang

et al. 2021

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.

“…Previous studies have indicated that miR396 regulates plant growth and development by inhibiting the expression of multiple GRF genes (Choi et al, 2004; Liebsch & Palatnik, 2020; Liu et al, 2014). Diao et al (2018) predicted OsmiR396a targets 9 GRF genes ( OsGRF1/2/3/5/6/7/8/9/11 ) in rice, and overexpression of OsmiR396a resulted in dwarf plants with smaller leaves (Diao et al, 2018). In the Chinese cabbage, the bra‐miR396 regulates 11 GRF genes and the bra‐miR396 ‐ BrGRF4.2 regulatory module was verified to be involved in leaf development.…”

Section: Discussionmentioning

confidence: 99%

“…This result suggests that GhmiR396b_D13 has a critical role in the development of FL. OsmiR396a targets 9 GRF genes (OsGRF1/2/3/5/6/7/8/9/11) in rice, and overexpression of OsmiR396a resulted in dwarf plants with smaller leaves (Diao et al, 2018). In the Chinese cabbage, the bra-miR396 regulates 11 GRF genes and the bra-miR396-BrGRF4.2 regulatory module was verified to be involved in leaf development.…”

Section: Similar To the Expression Pattern Of Grf5 The Expression Lev...mentioning

confidence: 98%

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Analysis of the MIR396 gene family and the role of MIR396b in regulating fiber length in cotton

Zhang

Song

et al. 2022

Physiologia Plantarum

Cotton fiber is one of the most important natural raw materials in the world textile industry. Improving fiber yield and quality has always been the main goal. MicroRNAs, as typical small noncoding RNAs, could affect fiber length during different stages of fiber development. Based on differentially expressed microRNA in the two interspecific backcross inbred lines (BILs) with a significant difference in fiber length, we identified the miR396 gene family in the two tetraploid cotton genomes and found MIR396b_D13 as the functional precursor to produce mature miR396 during the fiber elongation stage. Among 46 target genes regulated by miR396b, the GROWTH‐REGULATING FACTOR 5 gene (GRF5, Gh_A10G0492) had a differential expression level in the two BILs during fiber elongation stage. The expression patterns indicated that the miR396b‐GRF5 regulatory module has a critical role in fiber development. Furthermore, virus‐induced gene silencing (VIGS) of miR396b significantly produced longer fiber than the wild type, and the expression level of GRF5 showed the reverse trends of the miR396b expression level. The analysis of co‐expression network for the GRF5 gene suggested that a cytochrome P450 gene functions as an allene oxide synthase (Gh_D06G0089, AOS), which plays a critical role in jasmonate biosynthetic pathway. In conclusion, our results revealed that the miR396b‐GRF5 module has a critical role in fiber development. These findings provide a molecular foundation for fiber quality improvement in the future.