pms3 is the locus causing the original photoperiod-sensitive male sterility mutation of‘Nongken 58S'

Photoperiod-sensitive genic male sterile (PSGMS) rice is a very useful germplasm for hybrid rice development. It was first found as a spontaneous mutant in a japonica cultivar 'Nongken 58'. pms3 on chromosome 12 was determined to be the locus where the original PSGMS mutation occurred, changing the normal cultivar Nongken 58 to PSGMS Nongken 58S. Large amounts of RAPD and AFLP analyses were also conducted for the fine mapping of the pms3 genomic region, which resulted in 4 molecular markers linked to pms3. Although these markers somewhat increased the marker density of this region, the pms3 locus is still located in a marker-sparse region.     

CRISPR/Cas9-mediated disruption of TaNP1 genes results in complete male sterility in bread wheat

Male sterile genes and mutants are valuable resources in hybrid seed production for monoclinous crops.High genetic redundancy due to allohexaploidy makes it difficult to obtain the nuclear recessive male sterile mutants through spontaneous mutation or chemical or physical mutagenesis methods in wheat.The emerging effective genome editing tool,CRISPR/Cas9 system,makes it possible to achieve simultaneous mutagenesis in multiple homoeoalleles.To improve the genome modification efficiency of the CRISPR/Cas9 system in wheat,we compared four different RNA polymerase(Pol) Ⅲ promoters(TaU3 p,TaU6 p,OsU3 p,and OsU6 p) and three types of sgRNA scaffold in the protoplast system.We show that the TaU3 promoter-driven optimized sgRNA scaffold was most effective.The optimized CRISPR/Cas9 system was used to edit three TaNP1 homoeoalleles,whose orthologs,OsNP1 in rice and ZmIPE1 in maize,encode a putative glucose-methanol-choline oxidoreductase and are required for male sterility.Triple homozygous mutations in TaNP1 genes result in complete male sterility.We further demonstrated that anyone wild-type copy of the three TaNP1 genes is sufficient for maintenance of male fertility.Taken together,this study provides an optimized CRISPR/Cas9 vector for wheat genome editing and a complete male sterile mutant for development of a commercially viable hybrid wheat seed production system.     

The Rice Restorer Rf4 for Wild-Abortive Cytoplasmic Male Sterility Encodes a MitochondriaI-Localized PPR Protein that Functions in Reduction of WA352Transcripts

Dear Editor, Cytoplasmic male sterility （CMS）, the failure to produce functional male gametes, is widespread in flowering plants （Kaul, 1988）. Nuclear Restoration of Fertility （Rf） genes can make CMS lines fertile; thus, CMS provides both an ideal model system to study the interaction between mitochondrial and nuclear genomes, and a useful genetic tool for breeding to exploit hybrid vigor in crops （reviewed in Chen and Liu, 2014）. Hybrid rice, with -20%-30% higher yields, has been successfully developed with a three-line （CMS, maintainer, and restorer） system, and released for large-scale production in China in the 1970s （Lin and Yuan, 1980）. This major achievement in agriculture results mainly from the discovery and use of the Wild-Abortive type CMS （CMS-WA） cytoplasm from the wild rice （Oryza rufipogon Griff.） and its Rf genes in indica rice （0. sativa L. ssp. indica） cultivars （Lin and Yuan, 1980）.     

Long non-coding RNAs play an important role in regulating photoperiod-and temperature-sensitive male sterility in rice

正Rice(Oryza sativa L.)is a major food crop for more than half of the world’s population.Therefore,increasing rice production is of great importance.The successful development of hybrid rice in the 1970s was an important achievement for increasing yield potential,since hybrid rice varieties produce higher yields than inbred varieties(Cheng et al.,2007).In plants,male sterility refers to the inability of producing dehiscent anthers and functional pollen(Chen and Liu,2014).The     

An epi-allele of SMS causes Sanming dominant genic male sterility in rice

Male sterility is an important trait in rice for hybrid rice(Oryza sativa) breeding. However, the factors involved in dominant male sterility are largely unknown. Here, we identified a gene from Sanming dominant genic male sterile rice, named Sanming dominant male sterility(SMS), and reported that an epi-allele of this locus contributes to male sterility. Segregation analysis attributed dominant male sterility to a single locus, SMS, which we characterized using a male-sterile near isogenic line...     

A Comparison Studies on Ultrastructure and Calcium Distribution in Fertile and Sterile Anthers of a Genic Male-sterile Rapeseed （Brassica napus L.）

It‘s common understanding that plant male sterility is closely related to cell ultrastructure or cell microstructure,plant physiological and biochemical metabolism during the generation and development of anthers. The materials used for the study were fertile and sterile anthers in various stages of a genic male-sterile rapeseed     

Characterization and Use of Male Sterility in Hybrid Rice Breeding

The hybrid rice （Oryza sativa L.） breeding that was Initiated In China in the 1970s led to a great improvement in rice productivity. In general, It increases the grain yield by over 20% to the inbred rice varieties, and now hybrid rice has been widely introduced into Africa, Southern Asia and America. These hybrid varieties are generated through either three-line hybrid and two-line hybrid systems; the former is derived from cytoplasmic male sterility （CMS） and the latter derived from genlc male sterility （GMS）. There are three major types of CMS （HL, BT and WA） and two types of GMS （photoperlod-sensitlve （PGMS） and temperature-sensitive （TGMS））. The BT- and HL-type CMS genes are characterized as orf79 and orfH79, which are chimeric toxic genes derived from mltochondrial rearrangement. Rf3 for CMS-WA Is located on chromosome 1, while Rf1, Rf4, Rf5 and Rf6 correspond to CMS-BT, CMSoWA and CMS- HL, located on chromosome 10. The Rfl gene for BT-CMS has been cloned recently, and encodes a mltochondriatargeted PPR protein. PGMS Is thought to be controlled by two recessive loci on chromosomes 7 and 12, whereas nine recessive alleles have been identified for TGMS and mapped on different chromosomes. Attention Is still urgently needed to resolve the molecular complexity of male sterility to assist rice breeding.     

Understanding a key gene for thermosensitive genic male sterility in rice

<正>Recently,a joint research team led by Chuxiong Zhuang of South China Agricultural University and Xiaofeng Cao of Institute of Genetics and Development Biology,Chinese Academy of Sciences published their work on the cloning and molecular characterization of the gene thermosensitive genic male sterile 5(tms5)in rice in Nature Communications[1].This is the result of a long-term collaboration representing an important advance in male sterility research in crops.     

Structural and Expressional Variation Analyses of Mitochondrial Genomes Reveal Candidate Transcripts for the SV Cytoplasmic Male Sterility in Wheat (Triticum aestivum L.)

Common wheat (Triticum aestivum L.) is one of the most important crops,and intra-specific wheat hybrids have obvious heterosis in yield and protein quality.Therefore,utilization of hybrid wheat varieties offers an effective way to increase yield and nutrition.Cytoplasmic male sterility (CMS) systems are a useful genetic tool for hybrid crop breeding,and are ideal models for studying the genetic interaction and cooperative function of mitochondrial and nuclear genomes in plants (Schnable and Wise,1998;Hanson and Bentolila,2004).The breeding of hybrid wheat using male sterility caused by the cytoplasm of T.timopheevii has been studied since the early 1960's.But it is unsuccessful because there are some deficiencies in the practical application of this cytoplasm,including limited restoration resources,thin seeds,pre-harvest sprouting and lower germination rate (Wilson and Ross,1962).The Sv type of cytoplasmic male sterility (CMS-Sv) in wheat is general accessions for four types of CMS lines that were derived from four Aegilops species:Ae.kotschyi,Ae.variabilis,Ae.ventricosa,and Ae.bicornis.Based on the observation of alloplasmic lines produced in all possible combinations between 12 wheat nuclear genotypes and 47 cytoplasms of two related genera,Triticum (wheat) and Aegilops,Ogihara and Tsunewaki (1988) concluded that the D2-cytoplasm of Ae.crassa and its relatives,N-cytoplasm of Ae.uniaristata,and SV-cytoplasm of Ae.kotschyi and its relatives might be used as the alternative male sterile cytoplasm to replace the T.timopheevii cytoplasm for hybrid wheat breeding.Ikeguchi et al.(1999) proposed that spring-type hybrid wheat may be bred by combination of the 1BL-1RS chromosome and Ae.kotschyi cytoplasm with a new fertility-restorer gene discovered in a wheat variety Kitamiharu 48.Zhang et al.(1996) also proposed the use of CMS-Sv lines as the most effective male sterile cytoplasm.     

Impact of insect-resistant transgenic rice on target insect pests and non-target arthropods in China

Progress on the research and development of insect-resistant transgenic rice, especially expressing insecticidal proteins from Bacillus thuringiensis （Bt）, in China has been rapid in recent years. A number of insect-resistant transgenic rice lines/varieties have passed restricted and enlarged field testing, and several have been approved for productive testing since 2002 in China, although none was approved for commercial use until 2006. Extensive laboratory and field trials have been conducted for evaluation of the efficiency of transgenic rice on target lepidoteran pests and potential ecological risks on non-target arthropods. The efficacy of a number of transgenic rice lines currently tested in China was excellent for control of the major target insect pests, the rice stem borers （Chilo suppressalis, Scirpophaga incertulas, Sesamia inferens） and leaffolder （ Cnaphalocrocis medinalis）, and was better than most insecticides extensively used by millions of farmers at present in China. No significantly negative or unintended effects of transgenic rice on non-target arthropods were found compared with non-transgenic rice. In contrast, most of the current insecticides used for the control of rice stem borers and leaffolders proved harmful to natural enemies, and some insecticides may directly induce resurgence of rice planthoppers. Studies for developing a proactive insect resistance management of transgenic rice in the future are discussed to ensure the sustainable use of transgenic rice.     

OsGCD1,a novel player in rice intine construction

<正>In angiosperms,pollen development is an intricate indispensable process for successful sexual reproduction,which involves accurately and tightly controlled regulations and requires numerous genes expressed in both sporophytic and gametophytic tissues of the anther(McCormick,2004).Understanding the molecular mechanism underlying pollen development is of great significance for the construction of male sterile lines and crop breeding.However,many critical issues concerning pollen development still need to be elucidated.Recently,targeted editing of pollen development-related genes mediated by CRISPR/Cas9 system has provided powerful tools to facilitate the relevant studies in crops to figure out these issues(Li et al., 2016,2017).     

Recent Progress on Rice Genetics in China

Through thousands of years of evolution and cultivation, tremendously rich genetic diversity has been accumulated in rice （Oryza sativa L.）, developing a large germplasm pool from which people can select varieties with morphologies of Interest and other important agronomic traits. With the development of modern genetics, scientists have paid more attention to the genetic value of these elite varieties and germplasms, and such rich rice resources provide a good foundation for genetic research in China. Approximately 100 000 accessions of radiation-, chemical- or insertion-induced mutagenesis have been generated since the 1980s, and great progress has been made on rice molecular genetics. So far at least 16 variant/mutant genes Including MOC1, BC1, SKC1, and Rfgenes have been isolated and characterized in China. These achievements greatly promote the research on functional genomics, understanding the mechanism of plant development and molecular design breeding of rice in China. Here we review the progress of three aspects of rice genetics in China： moving forward at the molecular level, genetic research on elite varieties and germplasms, and new gene screening and genetic analysis using mutants. The prospects of rice genetics are also discussed.     

Current progress of China‘s free ART program

China‘s Free ART Program was initiated in 2002 as an emergency response to save and improve the lives of AIDS patients living mainly in impoverished rural regions of central China. With little experience in HIV/AIDS treatment and care and resource limitations, China‘s efforts to provide widespread access to free antiretroviral therapy has been a process fraught with difficulty. However, the Free ART Program is progressing from an emergency response to a standardized treatment and care system. The development of national guidelines, training programs, a laboratory support network, a national patient database, programs for special populations such as children and patients living with coinfections, and operational research has improved the scope and quality of the free treatment program. As of June 30,2005, a total of 19,456 patients in 28 provinces, autonomous regions, and special municipalities had received free ART.Challenges stemming from the nature of China‘s health system and patient population persist, but with strong government support and a diverse set of resources, China has the capacity to overcome these challenges and to provide nationwide access to high quality treatment and care.     

Expression,Imprinting, and Evolution of Rice Homologs of the Polycomb Group Genes

Polycomb group proteins （PcG） play important roles in epigenetic regulation of gene expression. Some core PeG proteins, such as Enhancer of Zeste （E（z））, Suppressor of Zeste （12） （Su（z）12）, and Extra Sex Combs （ESC）, are conserved in plants. The rice genome contains two E（z）-Iike genes, OsiEZ1 and OsCLF, two homologs of Su（z）12, OsEMF2a and OsEMF2b, and two ESC-like genes, OsFIE1 and OsFIE2. OsFIE1 is expressed only in endosperm; the maternal copy is expressed while the paternal copy is not active. Other rice PcG genes are expressed in a wide range of tissues and are not imprinted in the endosperm. The two E（z）-Iike genes appear to have duplicated before the separation of the dicots and monocots; the two homologs of Su（z）12 possibly duplicated during the evolution of the Gramineae and the two ESC- like genes are likely to have duplicated in the ancestor of the grasses. No homologs of the Arabidopsis seed-expressed PcG genes MEA and FIS2 were identified in the rice genome. We have isolated T-DNA insertion lines in the rice homologs of three PcG genes. There is no autonomous endosperm development in these T-DNA insertion lines. One line with a T-DNA insertion in OsEMF2b displays pleiotropic phenotypes including altered flowering time and abnormal flower organs, suggesting important roles in rice development for this gene.     

Molecular characterization of a new type of cytoplasmic male sterile sugar beet

A line (named Cl) of cytoplasmic sterility of sugar beet whose cytoplasm derived from Betacicla Turkey was obtained by interspecific hybrid. Its cytoplasm and a spontaneous male sterile cytoplasm from wild beet Beta maritima (named M) were compared with that of Owen's sterile line (S-cms) and a common maintainer of them named N was used as control. RFLP and RAPD methods were mainly used in our experiments. The restriction fragment patterns of mtDNAs were found to be likely but for a few of specific low-lighted electrophoresis bands in Cl. The results of Southern hybridization of six heterogeneous mitochondrial genes as probes to digests of mtDNAs by six restriction enzymes showed to be analogous between S and M lines. But the Cl mtDNA was sorted out by hybridization of atpA probe. Difference of low-molecular-weight mitochondrial DNAs was found among the three sterile lines. Three RNA molecules weighing about 4.2kb stably existed in Cl mitochondria. Our results of RAPD also supported that the Cl cytoplas     

Structural and Expressional Variations of the Mitochondrial Genome Conferring the Wild Abortive Type of Cytoplasmic Male Sterility in Rice

The so-called ＂wild abortive＂ （WA） type of cytoplasmic male sterility （CMS） derived from a wild rice species Oryza rufipogon has been extensively used for hybrid rice breeding. However, extensive analysis of the structure of the related mitochondrial genome has not been reported, and the CMS-associated gene（s） remain unknown. In this study, we exploited a mitochondrial genome-wide strategy to examine the structural and expressional variations in the mitochondrial genome conferring the CMS. The entire mitochondriai genomes of a CMS-WA line and two normal fertile rice lines were amplified by Long-polymerase chain reaction into tilling fragments of up to 15.2 kb. Restriction and DNA blotting analyses of these fragments revealed that structural variations occurred in several regions in the WA mitochondrial genome, as compared to those of the fertile lines. All of the amplified fragments covering the entire mitochondrial genome were used as RNA blot probes to examine the mitochondriai expression profile among the CMS-WA and fertile lines. As a result, only two mRNAs were found to be differentially expressed between the CMS-WA and the fertile lines, which were detected by a probe containing the nad5 and orf153 genes and the other having the ribosomal protein gene rpl5, respectively. These mRNAs are proposed to be the candidates for further identification and functional studies of the CMS gene.     

Unveiling a half-century mystery of molecular bases for three-line hybrid rice breeding system

<正>Rice (Oryza sativa L.) is a staple crop for half the world’s population and an important contributor to world food security. The discovery and application of cytoplasmic male sterility (CMS) and fertility restoration (Rf) genetic materials have allowed the production of three-line hybrid rice (Kim and Zhang, 2018), successfully harnessing heterosis in crops.     

Development of Architectures for Internet Telerobotics Systems

This paper presents our experience in developing and implementing Internet telerobotics system. Internet telerobotics system refers to a robot system controlled and monitored remotely through the Internet. A robot manipulator with five degrees of freedom, called Mentor, is employed. Client-server architecture is chosen as a platform for our Internet telerobotics system. Three generations of telerobotics systems have evolved in this research. The first generation was based on CGI and two tiered architectures, where a client presents a Graphical User Interface to the user, and utilizes the user＇s data entry and actions to perform requests to robot server running on a different machine. The second generation was developed using Java. We also employ Java 3D for creating and manipulating 3D geometry of manipulator links, and for constructing the structures used in rendering that geometry, resulting in 3D robot movement simulation presented to the users （clients） through their web browser. Recent development in our Internet telerobotics includes object recognition through image captured by a camera, which poses challenging problem, giving the undeterministic latency of the Internet. The third generation is centered around the use of CORBA for development platform of distributed internet telerobotics system, aimed at distributing task of telerobotics system.     

Characterization and mapping of a novel mutant sms1 （senescence and male sterility 1） in rice

Plant senescence plays diverse important roles in development and environmental responses.However,the molecular basis of plant senescence is remained largely unknown.A rice spontaneous mutant with the character of early senescence and male sterility (sms) was found in the breeding line NT10-748.In order to identify the gene SMS1 and the underlying mechanism,we preliminarily analyzed physiological and biochemical phenotypes of the mutant.The mutant contained lower chlorophyll content compared with the wild type control and was severe male sterile with lower pollen viability.Genetic analysis showed that the mutant was controlled by a single recessive gene.By the map-based cloning approach,we fine-mapped SMS1 to a 67 kb region between the markers Z3-4 and Z1-1 on chromosome 8 using 1,074 F2 recessive plants derived from the cross between the mutant sms1 (japonica) × Zhenshan 97 (indica),where no known gene involved in senescence or male sterility has been identified.Therefore the SMS1 gene will be a novel gene that regulates the two developmental processes.The further cloning and functional analysis of the SMS1 gene is under way.