Conservation and diversification of the miR166 family in soybean and potential roles of newly identified miR166s

Identity between pre-miR166s in soybean. (TIF 5906 kb

Reabilitação protética da disfunção velofaríngea: prótese de palato e obturador faríngeo

The seed maturation program only occurs during late embryogenesis, and repression of the program is pivotal for seedling development. However, the mechanism through which this repression is achieved in vegetative tissues is poorly understood. Here we report a microRNA (miRNA)-mediated repression mechanism operating in leaves. To understand the repression of the embryonic program in seedlings, we have conducted a genetic screen using a seed maturation gene reporter transgenic line in Arabidopsis (Arabidopsis thaliana) for the isolation of mutants that ectopically express seed maturation genes in leaves. One of the mutants identified from the screen is a weak allele of ARGONAUTE1 (AGO1) that encodes an effector protein for small RNAs. We first show that it is the defect in the accumulation of miRNAs rather than other small RNAs that causes the ectopic seed gene expression in ago1. We then demonstrate that overexpression of miR166 suppresses the derepression of the seed gene reporter in ago1 and that, conversely, the specific loss of miR166 causes ectopic expression of seed maturation genes. Further, we show that ectopic expression of miR166 targets, type III homeodomain-leucine zipper (HD-ZIPIII) genes PHABULOSA (PHB) and PHAVOLUTA (PHV), is sufficient to activate seed maturation genes in vegetative tissues. Lastly, we show that PHB binds the promoter of LEAFY COTYLEDON2 (LEC2), which encodes a master regulator of seed maturation. Therefore, this study establishes a core module composed of a miRNA, its target genes (PHB and PHV), and the direct target of PHB (LEC2) as an underlying mechanism that keeps the seed maturation program off during vegetative development

Identification of 14-3-3 Family in Common Bean and Their Response to Abiotic Stress.

14-3-3s are a class of conserved regulatory proteins ubiquitously found in eukaryotes, which play important roles in a variety of cellular processes including response to diverse stresses. Although much has been learned about 14-3-3s in several plant species, it remains unknown in common bean. In this study, 9 common bean 14-3-3s (PvGF14s) were identified by exhaustive data mining against the publicly available common bean genomic database. A phylogenetic analysis revealed that each predicted PvGF14 was clustered with two GmSGF14 paralogs from soybean. Both epsilon-like and non-epsilon classes of PvGF14s were found in common bean, and the PvGF14s belonging to each class exhibited similar gene structure. Among 9 PvGF14s, only 8 are transcribed in common bean. Expression patterns of PvGF14s varied depending on tissue type, developmental stage and exposure of plants to stress. A protein-protein interaction study revealed that PvGF14a forms dimer with itself and with other PvGF14 isoforms. This study provides a first comprehensive look at common bean 14-3-3 proteins, a family of proteins with diverse functions in many cellular processes, especially in response to stresses

Subcellular localization of Gm08DWD.

<p><i>A</i>. <i>tumefaciens</i> GV3101 carrying the plasmid with Gm08DWD-YFP fusion construct was infiltrated in <i>N</i>. <i>benthamiana</i> leaves and visualized by confocal microscopy. Scale bar is shown in μm.</p

The miR156/SPL12 module orchestrates fruit colour change through directly regulating ethylene production pathway in blueberry

Colour change is an important event during fruit ripening in blueberry. It is well known that miR156/SPLs act as regulatory modules mediating anthocyanin biosynthesis and ethylene plays critical roles during colour change, but the intrinsic connections between the two pathways remain poorly understood. Previously, we demonstrated that blueberry VcMIR156a/VcSPL12 affects the accumulation of anthocyanins and chlorophylls in tomato and Arabidopsis. In this study, we first showed that VcMIR156a overexpression in blueberry led to enhanced anthocyanin biosynthesis, decreased chlorophyll accumulation, and, intriguingly, concomitant elevation in the expression of ethylene biosynthesis genes and the level of the ethylene precursor ACC. Conversely, VcSPL12 enhanced chlorophyll accumulation and suppressed anthocyanin biosynthesis and ACC synthesis in fruits. Moreover, the treatment with ethylene substitutes and inhibitors attenuated the effects of VcMIR156a and VcSPL12 on pigment accumulation. Protein-DNA interaction assays indicated that VcSPL12 could specifically bind to the promoters and inhibit the activities of the ethylene biosynthetic genes VcACS1 and VcACO6. Collectively, our results show that VcMIR156a/VcSPL12 alters ethylene production through targeting VcACS1 and VcACO6, therefore governing fruit colour change. Additionally, VcSPL12 may directly interact with the promoter region of the chlorophyll biosynthetic gene VcDVR, thereby activating its expression. These findings established an intrinsic connection between the miR156/SPL regulatory module and ethylene pathway

Expression analysis of soybean <i>DWD</i> genes.

<p>The transcript profiling data of soybean tissues were extracted from Phytozome database (<a href="http://www.phytozome.net/" target="_blank">http://www.phytozome.net</a>) for heatmap generation. The color scale above the heat map indicates gene expression levels, low transcript abundance indicated by green color and high transcript abundance indicated by red color. SAM, shoot apical meristem.</p

Multiple sequence alignment of deduced amino acid sequence of Gm08DWD with its homologs in different species.

<p>Amino acid sequences of Gm05DWD (Glyma05G187400), Gm08DWD (Glyma08G145700), Cca-MORG1 (<i>Cajanus cajan</i>, KYP67816), Mtr-MORG1 (<i>Medicago truncatula</i>, XP_013446856), Zma-MORG1 (<i>Zea mays</i>, NP_001141954), <a target="_blank">AT5G64730</a> (Arabidopsis WD40 repeat-like superfamily protein) Cyc-Gbeta1 G-protein beta 1 in <i>Cynara cardunculus</i>, KVI09821), Has-MORG1 (<i>Homo sapiens</i>, NP_001093207) were aligned by ClustalW, and imported in Genedoc for shading. Identical amino acid residues are shown in black. If the conserved percent was up to 80% and 60%, the amino acid residues were shaded with gray and light gray colors, respectively. The WD40 domains of candidate GmDWDs are indicated by lines and numbered. The DWD signature sequences of GmDWDs are marked with stars.</p