Genome-Wide Identification and Expansion Patterns of SULTR Gene Family in Gramineae Crops and Their Expression Profiles under Abiotic Stress in Oryza sativa.

Sulfate transporters (SULTRs), also known as H+/SO42- symporters, play a key role in sulfate transport, plant growth and stress responses. However, the evolutionary relationships and functional differentiation of SULTRs in Gramineae crops are rarely reported. Here, 111 SULTRs were retrieved from the genomes of 10 Gramineae species, including Brachypodium disachyon, Hordeum vulgare, Setaria italica, Sorghum bicolor, Zea mays, Oryza barthii, Oryza rufipogon, Oryza glabbermia and Oryza sativa (Oryza sativa ssp. indica and Oryza sativa ssp. japonica). The SULTRs were clustered into five clades based on a phylogenetic analysis. Syntheny analysis indicates that whole-genome duplication/segmental duplication and tandem duplication events were essential in the SULTRs family expansion. We further found that different clades and orthologous groups of SULTRs were under a strong purifying selective force. Expression analysis showed that rice SULTRs with high-affinity transporters are associated with the functions of sulfate uptake and transport during rice seedling development. Furthermore, using Oryza sativa ssp. indica as a model species, we found that OsiSULTR10 was significantly upregulated under salt stress, while OsiSULTR3 and OsiSULTR12 showed remarkable upregulation under high temperature, low-selenium and drought stresses. OsiSULTR3 and OsiSULTR9 were upregulated under both low-selenium and high-selenium stresses. This study illustrates the expression and evolutionary patterns of the SULTRs family in Gramineae species, which will facilitate further studies of SULTR in other Gramineae species.

Gene cloning of a neutral ceramidase from the sphingolipid metabolic pathway based on transcriptome analysis of Amorphophallus muelleri.

Amorphophallus is a perennial herbaceous plant species mainly distributed in the tropics or subtropics of Asia and Africa. It has been used as a traditional medicine for a long time and now is utilized for the pharmaceutical, chemical and agriculture industries as a valued economic crop. Recently, Amorphophallus has attracted tremendous interest because of its high ceramide content. However, the breeding and genome studies are severely limited by the arduous whole genome sequencing of Amorphophallus. In this study, the transcriptome data of A. muelleri was obtained by utilizing the high-throughput Illumina sequencing platform. Based on this information, the majority of the significant genes involved in the proposed sphingolipid metabolic pathway were identified. Then, the full-length neutral ceramidase cDNA was obtained with the help of its candidate transcripts, which were acquired from the transcriptome data. Furthermore, we demonstrated that this neutral ceramidase was a real ceramidase by eukaryotic expression in the yeast double knockout mutant Δypc1 Δydc1, which lacks the ceramidases-dihydroCDase (YDC1p), phytoCDase (YPC1p). In addition, the biochemical characterization of purified A. muelleri ceramidase (AmCDase) exhibited classical Michaelis-Menten kinetics with an optimal activity ranging from pH 6.5 to 8.0. Based on our knowledge, this study is the first to report the related information of the neutral ceramidase in Amorphophallus. All datasets can provide significant information for related studies, such as gene expression, genetic improvement and application on breeding in Amorphophallus.

Development of microsatellite markers by transcriptome sequencing in two species of Amorphophallus (Araceae).

BACKGROUND: Amorphophallus is a genus of perennial plants widely distributed in the tropics or subtropics of West Africa and South Asia. Its corms contain a high level of water-soluble glucomannan; therefore, it has long been used as a medicinal herb and food source. Genetic studies of Amorphophallus have been hindered by a lack of genetic markers. A large number of molecular markers are required for genetic diversity study and improving disease resistance in Amorphophallus. Here, we report large scale of transcriptome sequencing of two species: Amorphophallus konjac and Amorphophallus bulbifer using deep sequencing technology, and microsatellite (SSR) markers were identified based on these transcriptome sequences. RESULTS: cDNAs of A. konjac and A. bulbifer were sequenced using Illumina HiSeq™ 2000 sequencing technology. A total of 135,822 non-redundant unigenes were assembled from about 9.66 gigabases, and 19,596 SSRs were identified in 16,027 non-redundant unigenes. Di-nucleotide SSRs were the most abundant motif (61.6%), followed by tri- (30.3%), tetra- (5.6%), penta- (1.5%), and hexa-nucleotides (1%) repeats. The top di- and tri-nucleotide repeat motifs included AG/CT (45.2%) and AGG/CCT (7.1%), respectively. A total of 10,754 primer pairs were designed for marker development. Of these, 320 primers were synthesized and used for validation of amplification and assessment of polymorphisms in 25 individual plants. The total of 275 primer pairs yielded PCR amplification products, of which 205 were polymorphic. The number of alleles ranged from 2 to 14 and the polymorphism information content valued ranged from 0.10 to 0.90. Genetic diversity analysis was done using 177 highly polymorphic SSR markers. A phenogram based on Jaccard's similarity coefficients was constructed, which showed a distinct cluster of 25 Amorphophallus individuals. CONCLUSION: A total of 10,754 SSR markers have been identified in Amorphophallus using transcriptome sequencing. One hundred and seventy-seven polymorphic markers were successfully validated in 25 individuals. The large number of genetic markers developed in the present study should contribute greatly to research into genetic diversity and germplasm characterization in Amorphophallus.

Molecular cloning and expression of two cytosolic copper-zinc superoxide dismutases genes from Nelumbo nucifera.

Two cytosolic copper-zinc superoxide dismutase (cytCuZnSOD) complementary deoxyribonucleic acid were achieved in Nelumbo nucifera (Elian). The active sites and common characteristics of cytCuZnSOD family were showed by homology modeling. The two recombinant proteins expressed by PET-32a vector showed the similar SOD activity (89.94 ± 0.54 U/mg) and could maintain more than 90% activity after incubation at 65°C. The subcellular location by green fluorescent protein revealed that these two isoforms were all located in cytosol and nucleus. The cytCuZnSODs were expressed in various parts of N. nucifera, which were expressed highest in the leafstalks and young leaves and lowest in the roots. The cytCuZnSOD messenger ribonucleic acids isolated from wounded leaves significantly increased at 1.5 h after treatment (HAT) with the highest expression at 3 HAT, after which the level decreased.

Authentication of Panax ginseng from its adulterants by PCR-RFLP and ARMS.

As a widely used and expensive herbal medicine, Panax ginseng has many adulterants in the commercial market. PCR-restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation system (ARMS) based on 5S rDNA sequence analysis were applied to identify two common adulterants of P. ginseng. The sizes of 5S rRNA gene non-transcribed spacers (NTS) sequences in P. ginseng and its adulterants were determined, ranging from 143 to 424 bp. The PCR product of P. ginseng only could be digested among the tested specimens because of its specific SpeI restriction site found in the 5S rDNA sequence. In addition, P. ginseng was successfully identified from compound medicinal preparations and from the Single-Taste medicines. These results suggest that the methods are able to authenticate P. ginseng.

Molecular cloning and expression analysis of an Mn-SOD gene from Nelumbo nucifera.

A rapid amplification cDNA end (RACE) assay was established to achieve the complete sequence of mitochondrial manganese-superoxide dismutase (Mn-SOD) cDNA in Nelumbo nucifera. The obtained full-length cDNA of Mn-SOD was 926 bp and contained a 699-bp open reading frame encoding an Mn-SOD precursor of 233 amino acids. The recombinant of Mn-SOD expressed by PET-32a vector in Escherichia coli BL21 was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting assays. A 3D structural model of the Mn-SOD was constructed by homology modeling. Real-time polymerase chain reaction analysis revealed that Mn-SOD mRNA was expressed in young leaves, blossom, stems, and terminal buds during reproductive stage but with the highest expression in young leaves. This significant difference demonstrated the differential expression of Mn-SOD in various organs of N. nucifera.