PubMed | Mudanjiang Youbo Pharmaceutical Co., Beckman Research Institute, University of California at Riverside, University of Chinese Academy of Sciences and 5 more.
Type: Journal Article | Journal: Journal of experimental botany | Year: 2015
5-Hydroxymethylcytosine (5hmC), a modified form of cytosine that is considered the sixth nucleobase in DNA, has been detected in mammals and is believed to play an important role in gene regulation. In this study, 5hmC modification was detected in rice by employing a dot-blot assay, and its levels was further quantified in DNA from different rice tissues using liquid chromatography-multistage mass spectrometry (LC-MS/MS/MS). The results showed large intertissue variation in 5hmC levels. The genome-wide profiles of 5hmC modification in three different rice cultivars were also obtained using a sensitive chemical labelling followed by a next-generation sequencing method. Thousands of 5hmC peaks were identified, and a comparison of the distributions of 5hmC among different rice cultivars revealed the specificity and conservation of 5hmC modification. The identified 5hmC peaks were significantly enriched in heterochromatin regions, and mainly located in transposable elements (TEs), especially around retrotransposons. The correlation analysis of 5hmC and gene expression data revealed a close association between 5hmC and silent TEs. These findings provide a resource for plant DNA 5hmC epigenetic studies and expand our knowledge of 5hmC modification.
PubMed | Agricultural University of Hebei, Lixiahe Agricultural Research Institute of Jiangsu Province, CAS Institute of Genetics and Developmental Biology, CAS Institute of Subtropical Agriculture and 3 more.
Type: Journal Article | Journal: Proceedings of the National Academy of Sciences of the United States of America | Year: 2016
Hybrid rice is the dominant form of rice planted in China, and its use has extended worldwide since the 1970s. It offers great yield advantages and has contributed greatly to the worlds food security. However, the molecular mechanisms underlying heterosis have remained a mystery. In this study we integrated genetics and omics analyses to determine the candidate genes for yield heterosis in a model two-line rice hybrid system, Liang-you-pei 9 (LYP9) and its parents. Phenomics study revealed that the better parent heterosis (BPH) of yield in hybrid is not ascribed to BPH of all the yield components but is specific to the BPH of spikelet number per panicle (SPP) and paternal parent heterosis (PPH) of effective panicle number (EPN). Genetic analyses then identified multiple quantitative trait loci (QTLs) for these two components. Moreover, a number of differentially expressed genes and alleles in the hybrid were mapped by transcriptome profiling to the QTL regions as possible candidate genes. In parallel, a major QTL for yield heterosis, rice heterosis 8 (RH8), was found to be the DTH8/Ghd8/LHD1 gene. Based on the shared allelic heterozygosity of RH8 in many hybrid rice cultivars, a common mechanism for yield heterosis in the present commercial hybrid rice is proposed.
Zeng S.,University of South China |
Tang H.,Hunan Hybrid Rice Research Center |
Tang H.,Hunan Academy of Agricultural Science |
Luo X.,University of South China |
And 4 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012
According to the agronomic requirements of rice direct seeding technique with synchronous fertilizing, a precision rice hill-drop drilling machine for dry land with opening furrows, forming ridges, applying fertilizer, covering and seeding synchronously was developed. A fertilizing device was added to the 2BDH-8 type rice hill-drop drilling machine developed in South China Agricultural University. The power transmission system, fertilizing system and furrow opener were designed. The seeding and fertilizing system was both powered by the tractor engine to ensure the synchronization of seeding and fertilizing. An acute angle furrow opener was designed to open furrows with 50 mm wide, 50-70 mm deep and 100-120 mm away from seeding furrows. Fertilizers were applied into the bottom of the furrows through an external slot wheeled feeder and then covered with soil. Experimental results showed that the synchronous deep fertilizing could increase the production efficiency significantly than the manual fertilizing. With the same fertilizing level,compared with artificial fertilization seeding, synchronous fertilizing improved the rice tillering by an average of 6.9 spikes per individual plant with an increase of 25.2%, increased the average SPAD value by 8.9 with 29.8%, improved nitrogen use efficiency by 13.78% with 22.3%, improved partial productivity of nitrogen by 20.54 kg/kg·N with an increase of 46.3%, and increased rice yield by 1411.5 kg/hm 2 with an improvement of 29.5%. The results showed that this machine cancomplete opening furrows, forming ridges, applying fertilizer, covering and seeding synchronously, and the yield increased significantly than the manual fertilizing. The experimental results can provide a theoretical basis of nitrogen saving cultivation for guiding the rice hill-drop drilling machine in dry land with deep fertilization.
PubMed | International Rice Research Institute, Central South University and Hunan Hybrid Rice Research Center
Type: Journal Article | Journal: International journal of molecular sciences | Year: 2015
Rice is highly sensitive to cold stress during reproductive developmental stages, and little is known about the mechanisms of cold responses in rice anther. Using the HiSeq 2000 sequencing platform, the anther transcriptome of photo thermo sensitive genic male sterile lines (PTGMS) rice Y58S and P64S (Peiai64S) were analyzed at the fertility sensitive stage under cold stress. Approximately 243 million clean reads were obtained from four libraries and aligned against the oryza indica genome and 1497 and 5652 differentially expressed genes (DEGs) were identified in P64S and Y58S, respectively. Both gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted for these DEGs. Functional classification of DEGs was also carried out. The DEGs common to both genotypes were mainly involved in signal transduction, metabolism, transport, and transcriptional regulation. Most of the DEGs were unique for each comparison group. We observed that there were more differentially expressed MYB (Myeloblastosis) and zinc finger family transcription factors and signal transduction components such as calmodulin/calcium dependent protein kinases in the Y58S comparison group. It was also found that ribosome-related DEGs may play key roles in cold stress signal transduction. These results presented here would be particularly useful for further studies on investigating the molecular mechanisms of rice responses to cold stress.
PubMed | Food Republic and Hunan Hybrid Rice Research Center
Type: Journal Article | Journal: Current microbiology | Year: 2016
A total of five strains were isolated from two different hybrid rice seeds samples (Oryza sativa L. Shenliangyou 5814 and Yliangyou 900) in Sanya city, Hainan province, China. Sequence analysis and physiological characteristics indicated that these strains were identical and represented a novel species. Molecular phylogenetic analysis of the D1/D2 domain of the large subunit rRNA gene and the internal transcribed spacer regions revealed that this new species is located in the Microsporomyces clade, with four closely related species, namely, M. magnisporus, M. orientalis, M. bloemfonteinensis, and M. pini. The novel species differed from these four described species in ability to assimilate sorbose, cellobiose, lactose, D-arabinose, and maltose. Based on these results, the following novel yeast species is proposed: Microsporomyces hainanensis sp. nov. with the type strain of Z8(T) (CICC 33066(T)=CBS 14092(T)) belongs to phylum Basidiomycota, subphylum Pucciniomycotina, class Cystobasidiomycetes, family Microsporomycetaceae. The new species were registered in MycoBank under MB 815471.
Song L.,Nanjing Agricultural University |
Liu Z.,Hunan Agricultural University |
Liu Z.,Hunan Hybrid Rice Research Center |
Tong J.,Hunan Agricultural University |
And 4 more authors.
Proteomics | Year: 2015
Thermosensitive genic male sterile (TGMS) rice line has made great economical contributions in rice production. However, the fertility of TGMS rice line during hybrid seed production is frequently influenced by low temperature, thus leading to its fertility/sterility alteration and hybrid seed production failure. To understand the mechanism of fertility alternation under low temperature inducement, the extracted proteins from young panicles of two TGMS rice lines at the fertility alternation sensitivity stage were analyzed by 2DE. Eighty-three protein spots were found to be significantly changed in abundance, and identified by MALDI-TOF-TOF MS. The identified proteins were involved in 16 metabolic pathways and cellular processes. The young panicles of TGMS rice line Zhu 1S possessed the lower ROS-scavenging, indole-3-acetic acid level, soluble protein, and sugar contents as well as the faster anther wall disintegration than those of TGMS rice line Zhun S. All these major differences might result in that the former is more stable in fertility than the latter. Based on the majority of the 83 identified proteins, together with microstructural, physiological, and biochemical results, a possible fertile alteration mechanism in the young panicles of TGMS rice line under low temperature inducement was proposed. Such a result will help us in breeding TGMS rice lines and production of hybrid seed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PubMed | Hunan Hybrid Rice Research Center and Hunan Agricultural University
Type: Journal Article | Journal: Yi chuan = Hereditas | Year: 2016
The transcription activator-like effector nucleases (TALEN) and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) systems are two current genome editing technologies. Here, we compare and analyze the characteristics of the targeted mutations mediated by these two systems, such as efficiency, type, position, time, and genetic patterns. Both the TALEN and CRISPR/Cas9 systems can induce site-specific mutations in T0 rice plants effectively, but CRISPR/Cas9 is more effective. The major mutation type in both systems is the short insertion/deletion(InDel) mutation within 10 base pairs: deletions ranging from 1 to 10 bps are more often in TALEN, and 1bp insertions are more often in CRISPR/Cas9. Moreover, double-strand breaks (DSBs) generated by CRISPR/Cas9 are more precise than TALEN. In addition, DSBs could be repaired by the homologous recombination at a low frequency, causing DNA fragment duplication mutations. In some cases, the DNA fragments between the two close targets are deleted or inverted, and the mutation efficiency does not positively correlatewith the mutation efficiency of each target. Mutagenesis mediated by the TALEN or CRISPR/Cas9 system can occur as early as in transformed callus cells, and less frequently in somatic cells. Consequently, four different mutation types are formed, including homozygous, heterozygous, bi-allelic and chimeric mutations, with bi-allelic mutations having the highest rate and chimeric mutations having the lowest rate. All, except chimeric mutations, can descend stably into the next generation.
Liu C.,CAS Institute of Genetics and Developmental Biology |
Mao B.,Hunan Hybrid Rice Research Center |
Ou S.,CAS Institute of Genetics and Developmental Biology |
Wang W.,CAS Institute of Genetics and Developmental Biology |
And 4 more authors.
Plant Molecular Biology | Year: 2014
The bZIP transcription factor (TF) family plays an important role in the abscisic acid (ABA) signaling pathway of abiotic stress in plants. We here report the cloning and characterization of OsbZIP71, which encodes a rice bZIP TF. Functional analysis showed that OsbZIP71 is a nuclear-localized protein that specifically binds to the G-box motif, but has no transcriptional activity both in yeast and rice protoplasts. In yeast two-hybrid assays, OsbZIP71 can form both homodimers and heterodimers with Group C members of the bZIP gene family. Expression of OsbZIP71 was strongly induced by drought, polyethylene glycol (PEG), and ABA treatments, but repressed by salt treatment. OsbZIP71 overexpressing (p35S::OsbZIP71) rice significantly improved tolerance to drought, salt and PEG osmotic stresses. In contrast, RNAi knockdown transgenic lines were much more sensitive to salt, PEG osmotic stresses, and also ABA treatment. Inducible expression (RD29A::OsbZIP71) lines were significantly improved their tolerance to PEG osmotic stresses, but hypersensitivity to salt, and insensitivity to ABA. Real-time PCR analysis revealed that the abiotic stress-related genes, OsVHA-B, OsNHX1, COR413-TM1, and OsMyb4, were up-regulated in overexpressing lines, while these same genes were down-regulated in RNAi lines. Chromatin immunoprecipitation analysis confirmed that OsbZIP71 directly binds the promoters of OsNHX1 and COR413-TM1 in vivo. These results suggest that OsbZIP71 may play an important role in ABA-mediated drought and salt tolerance in rice. © 2013 Springer Science+Business Media Dordrecht.
PubMed | Key Laboratory of Genomics, Central South University and Hunan Hybrid Rice Research Center
Type: Journal Article | Journal: Molecular genetics and genomics : MGG | Year: 2016
The future of rice breeding will likely be built on the basis of the further utilization of heterosis between elite cultivars and genetic resources from distant subspecies of rice. Previous studies have proved that exogenous genomic DNA transformation methods can be used to transfer genetic information from distant relatives (donor) into cultivated rice (recipient). However, the mechanism underlying this form of genetic transfer is poorly characterized, and the genes that cause the phenotypic changes in these variants are typically difficult to identify. This study examined YVB, a stable variant line with greatly improved grain quality traits that was derived from an indica variety (V20B) by transferring genomic DNA of O.minuta through the spike-stalk injection method (SIM). We used restriction-site associated DNA sequencing technology (RAD-seq) to evaluate a population of BC1F5 backcross lines (YVB V20B); the RAD-seq data were used to construct a genetic linkage map with high-density SNPs for use in association analysis exploring genotype-phenotype relationships at the whole-genome level. A total of 17 quantitative trait loci (QTLs) for rice quality traits were mapped to chromosomes 3, 5, 6, 8, and 9. 8 major QTLs controlling different phenotypic variations were mapped to the same region of chromosome 5. This region contained the GS5 gene for grain weight and the qSW5/GW5 gene for grain width. This study provides new resources and insights into the molecular mechanisms of grain trait phenotypic variation and the transmission of genetic information via the introduction of genomic DNA to a distantly related crop relative species.