The miR156‐SPL9‐DFR pathway coordinates the relationship between development and abiotic stress tolerance in plants

Abstract

SUMMARYYoung organisms have relatively strong resistance to diseases and adverse conditions. When confronted with adversity, the process of development is delayed in plants. This phenomenon is thought to result from the rebalancing of energy, which helps plants to coordinate the relationship between development and stress tolerance; however, the molecular mechanism underlying this phenomenon remains mysterious. In this study, we found that miR156 integrates environmental signals to ensure timely flowering, thus enabling the completion of breeding. Under stress conditions, miR156 is induced to maintain the plant in the juvenile state for a relatively long period of time, whereas under favorable conditions, miR156 is suppressed to accelerate the developmental transition. Blocking the miR156 signaling pathway in Arabidopsis thaliana with 35S::MIM156 (via target mimicry) increased the sensitivity of the plant to stress treatment, whereas overexpression of miR156 increased stress tolerance. In fact, this mechanism is also conserved in Oryza sativa (rice). We also identified downstream genes of miR156, i.e. SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 9 (SPL9) and DIHYDROFLAVONOL-4-REDUCTASE (DFR), which take part in this process by influencing the metabolism of anthocyanin. Our results uncover a molecular mechanism for plant adaptation to the environment through the miR156-SPLs-DFR pathway, which coordinates development and abiotic stress tolerance.

Genome-Wide Characterization of Maize Small RNA Loci and Their Regulation in the required to maintain repression6-1 (rmr6-1) Mutant and Long-Term Abiotic Stresses

“…Similar observations have previously been made in maize Kong, 2010;Wang et al, 2014) and in many other plant species (Sunkar et al, 2012). In Arabidopsis, miR156 was proposed to regulate leaf cell number and size (Usami et al, 2009), and its induction under stress conditions was shown to maintain the plant in the juvenile state for a relatively longer period of time, which helps it withstand unfavorable environmental conditions (Cui et al, 2014;Stief et al, 2014). Another two miRNAs involved in the control of normal leaf growth and development were altered by the abiotic stress treatments miR166 and miR396 (Nogueira et al, 2007;Liu et al, 2009).…”

“…MiRNAs are members of multiple regulatory networks controlling plant development, and many miRNA families also play roles in stress responses and tolerance (for review, see Sunkar et al, 2012). For example, miR156, which targets SQUAMOSA PROMOTER BINDING PROTEIN-LIKE genes, coordinates the balance between development and abiotic stress tolerance and is important for heat stress memory in Arabidopsis (Cui et al, 2014;Stief et al, 2014).…”

Repression of lateral organ boundary genes by PENNYWISE and POUND-FOOLISH is essential for meristem maintenance and flowering in Arabidopsis thaliana1

“…One study shows that miR156-SPL3 delays flowering under cool ambient temperatures by regulation of FT (Kim et al, 2012). Similarly, plants overexpressing miR156 are late flowering with increased tolerance to stress linked to down-regulation of SPL9 (Cui et al, 2014). Stief et al (2014) further showed that heat stress induces miR156 isoforms linked to downregulation of SPL9-like transcripts (SPL2, SPL9, and SPL11) and delayed flowering.…”

“…The miR156-SPL-miR172 module is a core pathway for integration of flowering signals, including age, sugar, GA, and stress (Huijser and Schmid, 2011;Cho et al, 2012;Proveniers, 2013;Cui et al, 2014;Stief et al, 2014;Wang, 2014). In brief, miR156 levels decline with age, leading to a concomitant increase in abundance of SPL transcripts with products that act on distinct targets in leaves and the shoot apex to promote flowering (Wu and Poethig, 2006;Wang et al, 2009;Wu et al, 2009).…”

Constitutive Expression of Rice MicroRNA528 Alters Plant Development and Enhances Tolerance to Salinity Stress and Nitrogen Starvation in Creeping Bentgrass

“…It would be interesting to know if different miRNAs have interactions in plant responses to abiotic stress. To this end, stem-loop RT-qPCR was conducted to analyze several conserved miRNAs that are implicated in plant abiotic stress responses, including miR396, miR156, and miR172 (Wu et al, 2009a;Gao et al, 2010;Hackenberg et al, 2012;Liang et al, 2012;Bhardwaj et al, 2014;Cui et al, 2014;Gupta et al, 2014;Pandey et al, 2014;Xie et al, 2015). Figure 11, A to C, shows that miR396, miR156, and miR172 were all down-regulated in transgenic plants overexpressing Osa-miR528, suggesting a potential cross talk of miR528 with other miRNAs in the regulatory network to orchestrate the plant response to stress.…”