Functional characterization and allelic mining of genes for potential uses in rice improvement.

Glutamate-like receptor (GLR) genes are a group of regulatory genes involved in many physiological processes of plants. With 26 members in the rice genome, the functionalities of most rice GLR genes remain unknown. To facilitate their potential uses in rice improvement, an integrated strategy involving CRISPR-Cas9 mediated knockouts, deep mining and analyses of transcriptomic responses to different abiotic stresses/hormone treatments and gene CDS haplotype (gcHap) diversity in 3,010 rice genomes was taken to understand the functionalities of the 26 rice GLR genes, which led us to two conclusions.

Genetic Dissection of Salt Tolerance and Yield Traits of () Rice by Selective Subspecific Introgression.

Salinity is a major factor limiting rice productivity, and developing salt-tolerant (ST) varieties is the most efficient approach. Seventy-eight ST introgression lines (ILs), including nine promising lines with improved ST and yield potential (YP), were developed from four BCF populations from inter-subspecific crosses between an elite () recipient and four () donors at the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences. Genome-wide characterization of donor introgression identified 35 ST QTLs, 25 of which harbor 38 cloned ST genes as the most likely QTL candidates.

Simultaneous improvement and genetic dissection of drought and submergence tolerances in rice ( L.) by selective introgression.

Introduction: Drought and submergence are contrasting abiotic stresses that often occur in the same rice crop season and cause complete crop failure in many rain-fed lowland areas of Asia.

Methods: To develop rice varieties with good tolerances to drought and submergence, 260 introgression lines (ILs) selected for drought tolerance (DT) from nine BC populations were screened for submergence tolerance (ST), resulting in 124 ILs with significantly improved ST.

Results: Genetic characterization of the 260 ILs with DNA markers identified 59 DT quantitative trait loci (QTLs) and 68 ST QTLs with an average 55% of the identified QTLs associated with both DT and ST.

Genome-Wide Association Study of Rice Grain Shape and Chalkiness in a Worldwide Collection of Xian Accessions.

Rice ( L.) appearance quality, which is mainly defined by grain shape and chalkiness, is an important target in rice breeding. In this study, we first re-sequenced 137 indica accessions and then conducted a genome-wide association study (GWAS) for six agronomic traits with the 2,998,034 derived single nucleotide polymorphisms (SNPs) by using the best linear unbiased prediction (BLUP) values for each trait.

Genome-Wide Association Study Reveals Candidate Genes for Root-Related Traits in Rice.

Root architecture is a determinant factor of drought resistance in rice and plays essential roles in the absorption of water and nutrients for the survival of rice plants. Dissection of the genetic basis for root structure can help to improve stress-resistance and grain yield in rice breeding. In this study, a total of 391 rice ( L.

Fine Mapping of Two Interacting Loci for Transmission Ratio Distortion in Rice ( L.).

Transmission ratio distortion (TRD) denotes the observed allelic or genotypic frequency deviation from the expected Mendelian segregation ratios in the offspring of a heterozygote. TRD can severely hamper gene flow between and within rice species. Here, we report the fine mapping and characterization of two loci ( and ) for TRD using large F segregating populations, which are derived from rice chromosome segment substitution lines, each containing a particular genomic segment introduced from the cultivar Nipponbare (NIP) into the cultivar Zhenshan (ZS97).

From Green Super Rice to green agriculture: Reaping the promise of functional genomics research.

Producing sufficient food with finite resources to feed the growing global population while having a smaller impact on the environment has always been a great challenge. Here, we review the concept and practices of Green Super Rice (GSR) that have led to a paradigm shift in goals for crop genetic improvement and models of food production for promoting sustainable agriculture. The momentous achievements and global deliveries of GSR have been fueled by the integration of abundant genetic resources, functional gene discoveries, and innovative breeding techniques with precise gene and whole-genome selection and efficient agronomic management to promote resource-saving, environmentally friendly crop production systems.

Identification of Heterotic Loci with Desirable Allelic Interaction to Increase Yield in Rice.

Heterosis denotes the superiority of a hybrid plant over its parents. The use of heterosis has contributed significantly to yield improvement in crops. However, the genetic and molecular bases on heterosis are not fully understood.

Identification of QTLs for Salt Tolerance at the Germination and Seedling Stages in Rice.

Rice is highly sensitive to salinity stress during the seedling establishment phase. Salt stress is widely occurring in cultivated areas and severely affects seed germination ability and seedling establishment, which may result in a complete crop failure. The objective of the present study is to identify quantitative trait loci (QTLs) related to salt tolerance of the germination and seedling stages in a rice backcross inbred line (BIL) population that was derived from a backcross of an Africa rice ACC9 as donor and cultivar Zhenshan97 (ZS97) as the recurrent parent.

OsGRETCHENHAGEN3-2 modulates rice seed storability via accumulation of abscisic acid and protective substances.

Seed storability largely determines the vigor of seeds during storage and is significant in agriculture and ecology. However, the underlying genetic basis remains unclear. In the present study, we report the cloning and characterization of the rice (Oryza sativa) indole-3-acetic acid (IAA)-amido synthetase gene GRETCHEN HAGEN3-2 (OsGH3-2) associated with seed storability.

Identification of a novel QTL and candidate gene associated with grain size using chromosome segment substitution lines in rice.

Rice is one of the staple crops in the world. Grain size is an important determinant of rice grain yield, but the genetic basis of the grain size remains unclear. Here, we report a set of chromosome segment substitution lines (CSSL) developed in the genetic background of the genome-sequenced indica cultivar Zhenshan 97.

Genetic Dissection and Validation of Chromosomal Regions for Transmission Ratio Distortion in Intersubspecific Crosses of Rice.

Transmission ratio distortion (TRD) refers to a widespread phenomenon in which one allele is transmitted by heterozygotes more frequently to the progeny than the opposite allele. TRD is considered as a mark suggesting the presence of a reproductive barrier. However, the genetic and molecular mechanisms underlying TRD in rice remain largely unknown.

Genetic Dissection of Seed Dormancy in Rice (Oryza sativa L.) by Using Two Mapping Populations Derived from Common Parents.

Background: Seed dormancy, a quality characteristic that plays a role in seed germination, seedling establishment and grain yield, is affected by multiple genes and environmental factors. The genetic and molecular mechanisms underlying seed dormancy in rice remain largely unknown.

Results: Quantitative trait loci (QTLs) for seed dormancy were identified in two different mapping populations, a chromosome segment substitution line (CSSL) and backcross inbred line (BIL) population, both derived from the same parents Nipponbare, a japonica cultivar with seed dormancy, and 9311, an indica cultivar lacking seed dormancy.

Genetic Dissection of Seed Dormancy using Chromosome Segment Substitution Lines in Rice ( L.).

Timing of germination determines whether a new plant life cycle can be initiated; therefore, appropriate dormancy and rapid germination under diverse environmental conditions are the most important features for a seed. However, the genetic architecture of seed dormancy and germination behavior remains largely elusive. In the present study, a linkage analysis for seed dormancy and germination behavior was conducted using a set of 146 chromosome segment substitution lines (CSSLs), of which each carries a single or a few chromosomal segments of Nipponbare (NIP) in the background of Zhenshan 97 (ZS97).

Correction to: Genomic Breeding of Green Super Rice Varieties and Their Deployment in Asia and Africa.

The article Genomic Breeding of Green Super Rice Varieties and Their Deployment in Asia and Africa.

Genomic Breeding of Green Super Rice Varieties and Their Deployment in Asia and Africa.

The "Green Super Rice" (GSR) project aims to fundamentally transform crop production techniques and promote the development of green agriculture based on functional genomics and breeding of GSR varieties by whole-genome breeding platforms. Rice (Oryza sativa L.) is one of the leading food crops of the world, and the safe production of rice plays a central role in ensuring food security.

Genetic dissection and validation of candidate genes for flag leaf size in rice (Oryza sativa L.).

Two major loci with functional candidate genes were identified and validated affecting flag leaf size, which offer desirable genes to improve leaf architecture and photosynthetic capacity in rice. Leaf size is a major determinant of plant architecture and yield potential in crops. However, the genetic and molecular mechanisms regulating leaf size remain largely elusive.

Polysaccharide purified from Lycium barbarum protects differentiated PC12 cells against L‑Glu‑induced toxicity via the mitochondria‑associated pathway.

The present study successfully demonstrated the neuroprotective effects of purified Lycium barbarum polysaccharide (LBPS02) against glutamate (L‑Glu)‑induced differentiated PC12 (DPC12) cell apoptosis. Purified polysaccharide was obtained by using a diethylaminoethyl‑52 cellulose anion exchange column and a Sepharose G‑100 column. During identification and characterization, LBPS02 was validated to be a fraction with 68 kDa molecular weight, and with a structure containing 1→3, 1→4 and 1→6 linkages.

The Hypoglycemic, Hypolipidemic, and Anti-Diabetic Nephritic Activities of Zeaxanthin in Diet-Streptozotocin-Induced Diabetic Sprague Dawley Rats.

Zeaxanthin (ZA), an important compound found in Lycium barbarum, shows various pharmacodynamic effects. In our present study, a high-fat, high-sucrose diet and streptozotocin (STZ)-induced diabetic rat model was used to investigate the antidiabetic activities of ZA. After a 4-week administration of 200 and 400 mg/kg of ZA and 100 mg/kg of metformin hydrochloride, various blood biochemical indexes were detected.

Lycium barbarum Polysaccharide Mediated the Antidiabetic and Antinephritic Effects in Diet-Streptozotocin-Induced Diabetic Sprague Dawley Rats via Regulation of NF-κB.

Lycium barbarum, extensively utilized as a medicinal plant in China for years, exhibits antitumor, immunoregulative, hepatoprotective, and neuroprotective properties. The present study aims to investigate the hyperglycemic and antidiabetic nephritic effects of polysaccharide which is separated from Lycium barbarum (LBPS) in high-fat diet-streptozotocin- (STZ-) induced rat models. The reduced bodyweight and enhanced blood glucose concentration in serum were observed in diabetic rats, and they were significantly normalized to the healthy level by 100 mg/kg of metformin (Met) and LBPS at doses of 100, 250, and 500 mg/kg.