Magnesium (Mg(2+)) is an essential macronutrient for plant growth and development, and the CorA/MRS2/MGT-type Mg(2+) transporters play important roles in maintaining Mg(2+) homeostasis in plants. Although the MRS2/MGT genes have been identified in two model plant species, Arabidopsis and rice, a comprehensive analysis of the MRS2/MGT gene family in other plants is lacking. In this work, 12 putative MRS2/MGT genes (ZmMGT1- ZmMGT12) were identified in maize and all of them were classified into five distinct subfamilies by phylogenetic analysis. A complementation assay in the Salmonella typhimurium MM281 strain showed that five representatives of the 12 members possess Mg(2+) transport abilities. Inhibition of ZmMGT protein activity using the hexaamminecobalt (III) (Co-Hex) inhibitor indicated that the ZmMGT protein mediated both low-affinity and high-affinity Mg(2+) transport in maize. A semi-quantitative reverse transcription-PCR (RT-PCR) analysis revealed that eight genes were constitutively expressed in all of the detected tissues, with one being specifically expressed in roots and three having no detectable expression signals. A quantitative RT-PCR analysis showed that some ZmMGT members displayed differential responses to Mg(2+) deficiency and aluminum (Al) stress. Furthermore, root growth inhibition and Mg(2+) accumulation analyses in two maize inbred lines, which conferred different levels of Al tolerance, revealed that ZmMGT proteins contributed to the Al resistance of the Al tolerance genotype. We hypothesize that ZmMGT family members function as Mg(2+) transporters and may play a role in linking Mg(2+) deficiency and Al stress responses. Our results will be valuable in a further analysis of the important biological functions of ZmMGT members in maize.

Tartary buckwheat (Fagopyrum tataricum) seeds are rich in flavonoids. However, the detailed flavonoid compositions and the molecular basis of flavonoid biosynthesis in tartary buckwheat seeds remain largely unclear. Here, we performed a combined metabolite profiling and transcriptome analysis to identify flavonoid compositions and characterize genes involved in flavonoid biosynthesis in the developing tartary buckwheat seeds. In total, 234 flavonoids, including 10 isoflavones, were identified. Of these, 80 flavonoids were significantly differential accumulation during seed development. Transcriptome analysis indicated that most structural genes and some potential regulatory genes of flavonoid biosynthesis were significantly differentially expressed in the course of seed development. Correlation analysis between transcriptome and metabolite profiling shown that the expression patterns of some differentially expressed structural genes and regulatory genes were more consistent with the changes in flavonoids profiles during seed development and promoted one SG7 subgroup R2R3-MYB transcription factors (FtPinG0009153900.01) was identified as the key regulatory gene of flavonoid biosynthesis. These findings provide valuable information for understanding the mechanism of flavonoid biosynthesis in tartary buckwheat seeds and the further development of tartary buckwheat health products.

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In designing wireless sensor networks, it is important to reduce energy dissipation and prolong network lifetime. This paper presents research on the existing clustering algorithm applied in heterogeneous sensor networks and then puts forward an energy-efficient prediction clustering algorithm, which is adaptive to sensor networks with energy and objects heterogeneous. This algorithm enables the nodes to select the cluster head according to factors such as energy and communication cost, thus the nodes with higher residual energy have higher probability to become a cluster head than those with lower residual energy, so that the network energy can be dissipated uniformly. In order to reduce energy consumption when broadcasting in clustering phase and prolong network lifetime, an energy consumption prediction model is established for regular data acquisition nodes. Simulation results show that compared with current clustering algorithms, this algorithm can achieve longer sensor network lifetime, higher energy efficiency, and superior network monitoring quality.

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ZmMGT10 was specifically expressed in maize roots and induced by a deficiency of magnesium. Overexpression of ZmMGT10 restored growth deficiency of the Salmonella typhimurium MM281 strain and enhanced the tolerance in Arabidopsis to stress induced by low magnesium levels by increasing uptake of Mg via roots. CorA/MRS2/MGT-type Mg transporters play a significant role in maintaining magnesium (Mg) homeostasis in plants. Although the maize CorA/MRS2/MGT family comprises of 12 members, currently no member has been functionally characterized. Here, we report the isolation and functional characterization of ZmMGT10 from the maize MRS2/MGT gene family. ZmMGT10 has a typical structure feature which includes two conserved TMs near the C-terminal end and an altered AMN tripeptide motif. The high sequence similarity and close phylogenetic relationship indicates that ZmMGT10 is probably the counterpart of Arabidopsis AtMGT6. The complementation of the Salmonella typhimurium mutated MM281 strain indicates that ZmMGT10 possesses the ability to transport Mg. ZmMGT10 was specifically expressed in the plant roots and it can be stimulated by a deficiency of Mg. Transgenic Arabidopsis plants which overexpressed ZmMGT10 grew more vigorously than wild-type plants under low Mg conditions, exhibited by longer root length, higher plant fresh weight and chlorophyll content, suggesting ZmMGT10 was essential for plant growth and development under low Mg conditions. Further investigations found that high accumulation of Mg occurred in transgenic plants attributed to improved Mg uptake and thereby enhanced tolerance to Mg deficiency. Results from this investigation illustrate that ZmMGT10 is a Mg transporter of maize which can enhance the tolerance to Mg deficient conditions by improving Mg uptake in the transgenic plants of Arabidopsis.

Seed development is an essential and complex process, which is involved in seed size change and various nutrients accumulation, and determines crop yield and quality. Common buckwheat (Fagopyrum esculentum Moench) is a widely cultivated minor crop with excellent economic and nutritional value in temperate zones. However, little is known about the molecular mechanisms of seed development in common buckwheat (Fagopyrum esculentum). In this study, we performed RNA-Seq to investigate the transcriptional dynamics and identify the key genes involved in common buckwheat seed development at three different developmental stages. A total of 4619 differentially expressed genes (DEGs) were identified. Based on the results of Gene Ontology (GO) and KEGG analysis of DEGs, many key genes involved in the seed development, including the Ca2+ signal transduction pathway, the hormone signal transduction pathways, transcription factors (TFs), and starch biosynthesis-related genes, were identified. More importantly, 18 DEGs were identified as the key candidate genes for seed size through homologous query using the known seed size-related genes from different seed plants. Furthermore, 15 DEGs from these identified as the key genes of seed development were selected to confirm the validity of the data by using quantitative real-time PCR (qRT-PCR), and the results show high consistency with the RNA-Seq results. Taken together, our results revealed the underlying molecular mechanisms of common buckwheat seed development and could provide valuable information for further studies, especially for common buckwheat seed improvement.

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