MiR319 mediated salt tolerance by ethylene

Abstract

SummarySalinity‐induced accumulation of certain microRNAs accompanied by gaseous phytohormone ethylene production has been recognized as a mechanism of plant salt tolerance. MicroRNA319 (miR319) has been characterized as an important player in abiotic stress resistance in some C3 plants, such as Arabidopsis thaliana and rice. However, its role in the dedicated biomass plant switchgrass (Panicum virgatum L.), a C4 plant, has not been reported. Here, we show crosstalk between miR319 and ethylene (ET) for increasing salt tolerance. By overexpressing Osa‐MIR319b and a target mimicry form of miR319 (MIM319), we showed that miR319 positively regulated ET synthesis and salt tolerance in switchgrass. By experimental treatments, we demonstrated that ET‐mediated salt tolerance in switchgrass was dose‐dependent, and miR319 regulated the switchgrass salt response by fine‐tuning ET synthesis. Further experiments showed that the repression of a miR319 target, PvPCF5, in switchgrass also led to enhanced ethylene accumulation and salt tolerance in transgenic plants. Genome‐wide transcriptome analysis demonstrated that overexpression of miR319 (OE‐miR319) down‐regulated the expression of key genes in the methionine (Met) cycle but promoted the expression of genes in ethylene synthesis. The results enrich our understanding of the synergistic effects of the miR319‐PvPCF5 module and ethylene synthesis in the salt tolerance of switchgrass, a C4 bioenergy plant.

Exploring the miRNA-mediated response to combined stresses in melon plants

“…By means of transgenic approaches it was established 9 that miR167 acts as transcriptional regulator in response to bacterial infection (Jodder, Basak, Das & Kundu, 2017) and temperature-induced stress in tomato plants (Jodder et al, 2018). Multiple evidences obtained by both sRNA-sequencing and transgenic approaches, support the role of members of the miR319-family, an ancient miRNA conserved across plant species ranging from mosses to higher plants, as a key modulator of the plant-environment interrelation (at biotic and abiotic level) in monocotyledonous and dicotyledonous species (Bustamante et al, 2018;Liu et al, 2019;Shi et al, 2019;Wu, Qi, Meng & Jin, 2020;Fang et al, 2021;Joshi, Chauhan & Das, 2021). Finally, regarding miR398 and miR408 families, it was recently proposed that these conserved miRNAs, involved in the maintenance of the cooper homeostasis in plants, might be also involved in the systemic signaling of the response to biotic and abiotic stresses (Burkhead et al, 2009;Sanz-Carbonell, Marques, Martinez & Gomez, 2020).…”

Identification and Functional Characterization of Plant MiRNA Under Salt Stress Shed Light on Salinity Resistance Improvement Through MiRNA Manipulation in Crops

“…Over-expression of miR172c substantially increased the sensitivity of plant roots to salt stress, and the removal of miR172c would decrease the sensitivity of plant roots to salt stress, respectively (Li et al, 2016;Sahito et al, 2017). Osa-miR319a and mi319b positively regulate salt tolerance in creeping bentgrass and swithgrass, respectively (Zhou et al, 2013;Zhou and Luo, 2014;Liu et al, 2019). MiR390 increases LR growth under salt stress via the auxin pathway (He et al, 2018).…”

Emerging Connections between Small RNAs and Phytohormones

“…The cbp20 mutant is less sensitive to ethylene, while the MIR319b overexpression line shows hypersensitivity to this hormone [115]. In turn, ethylene biosynthesis and salt tolerance genes are altered in pv-miR319-overexpressing switchgrass (Panicum virgatum) upon ACC treatment, enabling enhanced salt-tolerance [116]. While no research reported direct induction of MIR transcription by ERFs, in petunia (Petunia hybrida), PhERF2 promotes RDR2/6, DCL2 and AGO1 expression to regulate siRNAs biogenesis and induce RNA silencing in response to viral infection [117] (Figure 3).…”