8 publications mentioning ptc-MIR172i

Open access articles that are associated with the species Populus trichocarpa and mention the gene name MIR172i. Click the [+] symbols to view sentences that include the gene name, or the word cloud on the right for a summary.

1

Consequently, we predicted 25 target genes for Pto-miR156, Pto-miR159, Pto-miR172 and Pto-miR319 that were different from the previously defined Populus miRNA targets (miRBase 19.0), and a total of 464 targets were identified for the 78 novel miRNAs (Table S3).

Target Prediction for Pto-miR156, Pto-miR159, Pto-miR172 and Pto-miR319 and Novel miRNAs in Andromonoecious P. tomentosa To understand the functions of sex-specific flower development related miRNAs, the first step is to predict and experimentally validate their targets.

In our study, miRNA172 was equally expressed in female and male flower, but two novel miRNAs, Pto-F36 and Pto-F51, were detected with female-specific expression.

miRNA172 regulates APETALA2 (AP2) and several of its homologs that share two tandem AP2 DNA -binding domains and play an important role in regulating flower development [14]– [16].

In maize, TASSELSEED 4 (TS4) and the AP2 homolog indeterminate spikelet 1 are confirmed miRNA172 targets.

miRNA172 was weakly expressed in female and male flower, with no significant difference.

Target Prediction for Pto-miR156, Pto-miR159, Pto-miR172 and Pto-miR319 and Novel miRNAs in Andromonoecious P. tomentosa.

Conserved miRNA172 has been identified as an important factor regulating AP2 transcription factors [17].

For example, three miRNA families (miR172, miR159/miR319 and miR156) are involved in flowering-time regulation [27].

miRNA156, miRNA157 and miRNA172 may be components of a regulatory pathway mediating the transition between the vegetative and reproductive phases in plants [28].

2

The ten most highly expressed miRNAs (miR156, miR157, miR159, miR164, miR167, miR172, miR393, miR396, miR414, miR2275, and miR5021) in buds and leaves are miRNAs regulating genes involved in flower and leaf development processes such as integument development, leaf morphogenesis, meristem initiation, maintenance, and growth, bilateral symmetry determination, organ morphogenesis, plant phase transition, shoot apical meristem identity, flower and fruit development, and plant architecture.

In silico expression analyses of miRNAs using DEGseq [25] identified 19 sequences belonging to eight conserved miRNA families (miR156, miR157, miR164, miR172, miR393, miR396, miR414, and miR2275) induced in winter buds versus leaves (Additional file 6: Table S6).

miR156, miR159, miR166, miR172, miR390, miR396, and miR5021 are the most expressed families in bud tissues.

miR172 was suggested to fine-tune plant development under continuously fluctuating temperature conditions [29].

Most of conserved families common to Arabidopsis and peach (miR156, miR159, miR160, miR164, miR166, miR171, miR172, miR319, miR390, miR395, and miR396) did not show significant size variation (Figure 4).

Three of these miRNA genes (miR156, miR172, and miR398) were also reported as responding to cold stress in several studies [4, 8, 10, 29, 30].

miRNA families such as miR156, miR169, miR172, miR395, and miR5021 have the largest number of members with the latter having 18 members.

3

MiR172 downregulates AP2 through transcript cleavage and translational repression in A. thaliana 41.

MiR172 is a key miRNA in flower development, regulating calyx and petal formation and developmental timing 35.

Some studies have identified targets of miR172 during abiotic stress responses.

The targets of miR172 were identified in a previous study as AP2-like transcription factor genes 36.

In recent years, some studies have shown that miR172 is also involved in abiotic stress responses 38.

4

For example, the sole target of miR1450 encoded a leucine-rich repeat transmembrane protein kinase, and five targets of miR172 encoded a homeotic protein, APETALA2, that is involved in floral development.

In total, 15 qPCR validation reactions (designed for detecting the expression of miR156, miR159, miR160, miR164, miR166, miR168, miR172, miR319, miR398, miR408, miR1448, and miR1450) for the 41 fungi-response miRNAs tested were carried out.

MiR156, miR159, miR160, miR164, miR168, miR172, and miR408 are significantly expressed in tension- and compression-stressed developing xylem of P. trichocarpa [12], and miR156, miR160, miR164, and miR168 also respond to cold stress in P. trichocarpa [4].

In addition, miR156 is considered an evolutionarily conserved regulator of vegetative phase change in both annual herbaceous plants and perennial trees [38], accompanied by miR172, where miR156 controls the transition from juvenile to adult development [39], [40].

These probes belong to 12 miRNA families (miR156, miR159, miR160, miR164, miR166, miR168, miR172, miR319, miR398, miR408, miR1448, and miR1450) and account for 17.52% of the 234 probes.

Group I included miR159, miR168, miR172, miR319 (miR319f-h), miR1450, and 13 members of miR166.

5

Wong et al. [44], predicted three wood related genes, flavonol synthase-like, xyloglucan fucosyltransferase and glucan synthase-like genes to be the targets of miR170, miR172 and miR319, respectively, and suggested that these miRNAs might be directly involved in regulation of the phenylpropanoid pathway and hemicellulose biosynthesis pathway.

6

Also, in Larix leptolepis, four miRNA families (miR159, miRNA169, miRNA171, and miRNA172) are all induced by abiotic stress and their targets regulate genes crucial to cell development, including MYB transcription factors (miR159), an NF-YA transcription factor (miR169), a scarecrow-like transcription factor (miR171) and apetala2 (miR172; Zhang et al., 2010).

7

Several Arabidopsis and rice families such as miR156/157, miR159/319, miR162, miR172, miR396, miR397, miR473, and miR475 are nearly double in size in Populus.

For families miR156/157, miR159, miR319, miR162, miR172, miR396, miR397, miR473, miR475 and miR482, the number of members identified in this study was at least twice that reported previously [3, 26] (Fig. 2).

8

In Arabidopsis, the two candidates are the miRNA* sequences of MIR172 precursors.