The PILNCR1-miR399 Regulatory Module Is Important for Low Phosphate Tolerance in Maize

Abstract

The regulation of adaptive responses to phosphorus (P) deficiency by the ()/ () pathway has been well studied in Arabidopsis () but not in maize (). Here, we show that miR399 transcripts are strongly induced in maize by phosphate (Pi) deficiency. Transgenic maize plants that overexpressed accumulated excessive amounts of P in their shoots and displayed typical Pi-toxicity phenotypes. We reannotated with an additional 1,165 bp of the 5' untranslated region. miR399-guided posttranscriptional repression of was mainly observed in the P-efficient lines. We identified Pi-deficiency-induced long-noncoding RNA1 () from our strand-specific RNA libraries. Transient expression assays in and maize leaf protoplasts demonstrated that inhibits ZmmiR399-guided cleavage of The abundance of was significantly higher in P-inefficient lines than in P-efficient lines, which is consistent with the abundance of ZmmiR399 transcripts. These results indicate that the interaction between and miR399 is important for tolerance to low Pi in maize.

Transcriptome-wide identification of novel circular RNAs in soybean in response to low-phosphorus stress

“…By acting as miRNA sponges and competing for endogenous mRNAs, circRNAs play crucial roles in regulating functional gene expression and transcription [46]. Many miRNAs have been reported to participate in the response to P deficiency in various plant species by regulating the expression of target genes, including miR399 [47][48][49][50], miR319 [51], miR156 [52], and miR159 [53]. For example, a recent study in maize revealed that the PILNCR1-miR399 regulatory module is important for LP tolerance [47].…”

MiR399d and epigenetic modification comodulate anthocyanin accumulation in Malus leaves suffering from phosphorus deficiency

“…Although the induction of miR399 , PHO2 , and PHT1s by Pi deficiency has been well studied in Arabidopsis , rice, and maize (Bari et al, ; Du et al, ; X. Wang et al, ), the current study demonstrates that miR399d and epigenetic modification comodulation model provides a pathway for transmission of Pi deficiency signaling to the nucleus and that this pathway causes the indicator trait of the anthocyanin accumulation phenotype. We observed that when exposed to Pi starvation, the treated lines showed increased anthocyanin levels and that the genes miR399d , McPHT1;4 , McMYB10 , McCHS , and McANS were significantly upregulated.…”

“…In maize, miR399‐guided cleavage of PHO2 is inhibited by identified Pi‐deficiency‐induced long noncoding RNA 1 ( PILNCR1 ) (Du et al, ). In rice, phosphoproteomic profiling reveals the importance of CK2, MAPKs, and CDPKs in response to phosphate starvation (Yang et al, ).…”

Dynamic architecture and regulatory implications of the miRNA network underlying the response to stress in melon

“…Narrow-response miRNAs include miR395, miR894 or miR394, which have been previously associated to diverse biotic and/or abiotic stress responses (Kawashima et al, 2011;Yuan et al, 2016;Du et al, 2018;Xie et al, 2014;Song et al, 2013). On the other hand, broad-response miRNAs regulate genes involved in the responses to various biotic and abiotic stresses in different species and include miR396, miR156, miR166 and miR167.…”

“…Regarding the functional aspects of the miRNAs playing a more generalist or specialist role in the regulation of the stress response (defined by the biological role of their targets), it was evident that miRNAs with a narrow response-range are mainly characterized as regulators of transcripts associated to stress response and basic cell functions such as metabolism (of metals, carbohydrates, and carotenoids), reproduction, RNA silencing and photosynthesis (Table S7). Although further studies are needed in order to elucidate the roles played by miRNAs with narrow responserange in melon, the observation that miRNAs such as miR395 (Du et al, 2018), miR894 (Xie et al, 2014) or miR394 (Song et al, 2013) -for example-have been previously associated to diverse biotic and/or abiotic stress responses allow us to speculate about a potential selective stress-related regulatory activity. In contrast, miRNAs that exhibit a broad response-range seem to be master regulators of central hubs in the control of the gene expression, targeting predominantly (70% of the identified targets) TFs related with plant development (Table S7).…”