Xiang J.-J.,CAS Shanghai Institutes for Biological Sciences |
Zhang G.-H.,China National Rice Research Institute |
Qian Q.,China National Rice Research Institute |
Xue H.-W.,CAS Shanghai Institutes for Biological Sciences
Plant Physiology | Year: 2012
Leaf rolling is an important agronomic trait in rice (Oryza sativa) breeding and moderate leaf rolling maintains the erectness of leaves and minimizes shadowing between leaves, leading to improved photosynthetic efficiency and grain yields. Although a few rolled-leaf mutants have been identified and some genes controlling leaf rolling have been isolated, the molecular mechanisms of leaf rolling still need to be elucidated. Here we report the isolation and characterization of SEMI-ROLLED LEAF1 (SRL1), a gene involved in the regulation of leaf rolling. Mutants srl1-1 (point mutation) and srl1-2 (transferred DNA insertion) exhibit adaxially rolled leaves due to the increased numbers of bulliform cells at the adaxial cell layers, which could be rescued by complementary expression of SRL1. SRL1 is expressed in various tissues and is expressed at low levels in bulliform cells. SRL1 protein is located at the plasma membrane and predicted to be a putative glycosylphosphatidylinositol-anchored protein. Moreover, analysis of the gene expression profile of cells that will become epidermal cells in wild type but probably bulliform cells in srl1-1 by laser-captured microdissection revealed that the expression of genes encoding vacuolar H+-ATPase (subunits A, B, C, and D) and H+-pyrophosphatase, which are increased during the formation of bulliform cells, were up-regulated in srl1-1. These results provide the transcript profile of rice leaf cells that will become bulliform cells and demonstrate that SRL1 regulates leaf rolling through inhibiting the formation of bulliform cells by negatively regulating the expression of genes encoding vacuolar H+-ATPase subunits and H+-pyrophosphatase, which will help to understand the mechanism regulating leaf rolling. © 2012 American Society of Plant Biologists.
News Article | September 8, 2016
(Phys.org)—A team of researchers with the Chinese Academy of Sciences and the China National Rice Research Institute has successfully mapped the genomic regions associated with yield traits in several elite rice lines as part of a study to determine the genomic architecture of heterosis. In their paper published in the journal Nature, the team describes the laborious process they used and why they believe that their work could lead to finding a universally shared genomic region that contributes to heterosis. James Birchler with the University of Missouri offers an in depth look at the work done by the team in a News & Views piece in the same journal issue. Scientists have known for some time that when two plant species are bred together, the result is often a plant that is more fertile than either of its two parents—a phenomenon known as heterosis. Plant specialists have taken advantage of this feature to produce ever higher crop yields for a wide variety of crop plants, one of which is rice. Oddly, the genetic reasons for heterosis occurrence has never been found, though researchers have put a lot of effort into understanding it, as they believe it could lead to even higher yields or the introduction of other positive features. In this new effort, the researchers embarked on an ambitious project that they hoped would finally solve the mystery. The study consisted of collecting rice plant samples that represented 17 elite lines—they subsequently bred them to produce a first generation and then over 10,000 second-generations hybrids. The researchers studied each as they grew and produced rice and cataloged their features. Next, the team performed DNA sequencing on every one of the lines, which allowed them to compare genomic regions. As they did so, they wound up splitting the hybrids into three main groups based on the strategies that had been used to breed them. The researchers report that they were unable to identify the exact genomic architecture of heterosis, but they were able to isolate and map several genomic regions with the groups that could be associated with heteroic effects on rice grain yields. While this was not the outcome they had been hoping for, the work is still considered groundbreaking, Birchler notes, because it has shed a lot of light on the types of traits that are responsible for the phenomenon. More information: Xuehui Huang et al. Genomic architecture of heterosis for yield traits in rice, Nature (2016). DOI: 10.1038/nature19760 Abstract Increasing grain yield is a long-term goal in crop breeding to meet the demand for global food security. Heterosis, when a hybrid shows higher performance for a trait than both parents, offers an important strategy for crop breeding. To examine the genetic basis of heterosis for yield in rice, here we generate, sequence and record the phenotypes of 10,074 F2 lines from 17 representative hybrid rice crosses. We classify modern hybrid rice varieties into three groups, representing different hybrid breeding systems. Although we do not find any heterosis-associated loci shared across all lines, within each group, a small number of genomic loci from female parents explain a large proportion of the yield advantage of hybrids over their male parents. For some of these loci, we find support for partial dominance of heterozygous locus for yield-related traits and better-parent heterosis for overall performance when all of the grain-yield traits are considered together. These results inform on the genomic architecture of heterosis and rice hybrid breeding.
Wang J.,CAS Institute of Plant Physiology and Ecology |
Hu J.,China National Rice Research Institute |
Qian Q.,China National Rice Research Institute |
Xue H.-W.,CAS Institute of Plant Physiology and Ecology
Molecular Plant | Year: 2013
Proper flowering time is essential for plant reproduction. Winter annual Arabidopsis thaliana needs vernalization before flowering, during which AtVILs (VIN3 and VRN5, components of PRC2 complex) mediate the H3K27 tri-methylation at the FLC locus (a floral repressor) to repress the FLC expression and hence to induce flowering. However, how VILs (VIL, VERNALIZATION INSENSITIVE 3-LIKE) function in rice is unknown. Here we demonstrated that rice LC2 (OsVIL3) and OsVIL2 (two OsVILs, possible components of PRC2 complex) promote rice flowering. Our results showed that expressions of LC2 and OsVIL2 are induced by SD (short-day) conditions and both lc2 mutant and OsVIL2-RNAi lines display delayed heading date, consistent with the reduced expression levels of Hd1 and Hd3a. Interestingly, LC2 binds to the promoter region of a floral repressor OsLF and represses the OsLF expression via H3K27 tri-methylation modification. In addition, OsLF directly regulates the Hd1 expression through binding to Hd1 promoter. These results first demonstrated that the putative PRC2 in rice is involved in photoperiod flowering regulation, which is different from that of Arabidopsis, and revealed that LC2 binds the promoter region of target gene, presenting a possible mechanism of the recruitment process of PRC2 complex to its target genes. The studies provide informative clues on the epigenetic control of rice flowering. © 2012 The Author.
Wang S.,CAS Institute of Genetics and Developmental Biology |
Wang S.,South China Agricultural University |
Wu K.,CAS Institute of Genetics and Developmental Biology |
Yuan Q.,CAS Institute of Genetics and Developmental Biology |
And 9 more authors.
Nature Genetics | Year: 2012
Grain size and shape are important components of grain yield and quality and have been under selection since cereals were first domesticated. Here, we show that a quantitative trait locus GW8 is synonymous with OsSPL16, which encodes a protein that is a positive regulator of cell proliferation. Higher expression of this gene promotes cell division and grain filling, with positive consequences for grain width and yield in rice. Conversely, a loss-of-function mutation in Basmati rice is associated with the formation of a more slender grain and better quality of appearance. The correlation between grain size and allelic variation at the GW8 locus suggests that mutations within the promoter region were likely selected in rice breeding programs. We also show that a marker-assisted strategy targeted at elite alleles of GS3 and OsSPL16 underlying grain size and shape can be effectively used to simultaneously improve grain quality and yield. © 2012 Nature America, Inc. All rights reserved.
Jiao Y.,CAS Institute of Genetics and Developmental Biology |
Wang Y.,CAS Institute of Genetics and Developmental Biology |
Xue D.,China National Rice Research Institute |
Xue D.,Hangzhou Normal University |
And 9 more authors.
Nature Genetics | Year: 2010
Increasing crop yield is a major challenge for modern agriculture. The development of new plant types, which is known as ideal plant architecture (IPA), has been proposed as a means to enhance rice yield potential over that of existing high-yield varieties. Here, we report the cloning and characterization of a semidominant quantitative trait locus, IPA1 (Ideal Plant Architecture 1), which profoundly changes rice plant architecture and substantially enhances rice grain yield. The IPA1 quantitative trait locus encodes OsSPL14 (SOUAMOSA PROMOTER BINDING PROTEIN-LIKE 14) and is regulated by microRNA (miRNA) OsmiR156 in vivo. We demonstrate that a point mutation in OsSPL14 perturbs OsmiR156-directed regulation of OsSPL14, generating an 'ideal' rice plant with a reduced tiller number, increased lodging resistance and enhanced grain yield. Our study suggests that OsSPL14 may help improve rice grain yield by facilitating the breeding of new elite rice varieties. © 2010 Nature America, Inc. All rights reserved.
Wu W.,China National Rice Research Institute |
Cheng S.,China National Rice Research Institute
Field Crops Research | Year: 2014
Rice is one of the most important cereal crops, feeding more than 50% population of the world. To meet the demand of increasing population, rice production has to be improved continually. As a very important part of rice plant, root system plays multiple roles in rice growth: anchorage of the plant, acquisition of water and nutrient elements, and biosynthesis of amino acids and hormones, etc. Almost all of the hot spots about rice research are associated with rice root: drought tolerance, lodging resistance, and efficient use of nutrition, the goal is to increase the grain yield with desirable seed quality. Although the understanding about rice root has been expanded in the last decades, there remain much to be done about root morphology and physiology, especially in root genetics. Rice root research is an exciting and focusing field in recent years. More and more researches on rice root genetics have been made. There is a close relation between above ground traits and underground roots, providing an alternative approach for rice genetic improvement. A number of genes associated with root architecture and physiological functions have been identified, or cloned. It provides an opportunity to further improve rice based on molecular assisted selection. Root traits improvement should be taken into account in future breeding programs in rice. However, root research is still a consuming and difficult work, because it was largely influenced by the complex underground environment. This paper reviewed the progress in rice root genetic research, and discussed its prospects. © 2014 The Authors.
Direct determination of glyphosate and its major metabolite, aminomethylphosphonic acid, In fruits and vegetables by mixed-mode hydrophilic interaction/weak anion-exchange liquid chromatography coupled with electrospray tandem mass spectrometry
Chen M.-X.,China National Rice Research Institute |
Cao Z.-Y.,China National Rice Research Institute |
Jiang Y.,China National Rice Research Institute |
Zhu Z.-W.,China National Rice Research Institute
Journal of Chromatography A | Year: 2013
A novel method was developed for the direct, sensitive, and rapid determination of glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), in fruit and vegetable samples by mixed-mode hydrophilic interaction/weak anion-exchange liquid chromatography (HILIC/WAX) coupled with electrospray tandem mass spectrometry (ESI-MS/MS). Homogenized samples were extracted with water, without derivatization or further clean-up, and the extracts were injected directly onto the Asahipak NH2P-50 4E column (250mm×4.6mm i.d., 5μm). The best results were obtained when the column was operated under mixed-mode HILIC/WAX elution conditions. An initial 10-min washing step with acetonitrile/water (10:90, v/v) in HILIC mode was used to remove potentially interfering compounds, and then the analytes were eluted in WAX mode with acetonitrile and water containing 0.1molL-1 ammonium hydroxide under gradient elution for the ESI analysis in negative ion mode. Limits of quantification of glyphosate and AMPA were 5μgkg-1 and 50μgkg-1, respectively, with limits of detection as low as 1.2μgkg-1 for glyphosate and 15μgkg-1 for AMPA. The linearity was satisfactory, with correlation coefficients (r)>0.9966. Recovery studies were carried out on spiked matrices (6 vegetables, 3 fruits) with glyphosate at four concentrations and AMPA at three concentrations. The mean recoveries for glyphosate and AMPA were 75.3-110% and 76.1-110%, respectively, with relative standard deviations in the range of 1.1-13.8%. The intra-day precision (n=7) for glyphosate and AMPA in vegetable and fruit samples spiked at an intermediate level between 5.9% and 7.5%, and the inter-day precision over 11 days (n=11) was between 7.0% and 13%. © 2012 Elsevier B.V.
Gao Z.Q.,China National Rice Research Institute
Yi chuan = Hereditas / Zhongguo yi chuan xue hui bian ji | Year: 2011
Increase of crop production is the primary goal of crop breeding. Rice grain shape is a quantitative trait that is directly related to yield traits and has a close relationship with quality traits. The evaluation of grain shape is mainly grain length, grain width, grain thickness, length/width, and length/thickness. In recent years, the quantitative genetic research on rice grain shape has made a significant progress and a number of important genes associated with rice grain shape have been cloned. This paper reviews the classic genetic analysis on rice grain traits, QTL mapping, grain shape gene cloning and functional analysis, and their application in rice breeding for super high yield.
China National Rice Research Institute | Date: 2013-09-24
A noninvasive method of source-sink regulation in rice belongs to the technical field of rice production. In this method, the source-sink relationship is regulated by a rice sterile line and its identical type of maintaining line being subjected to mixed-planting and insulated pollination, or sowing and transplanting at different times and insulated pollination, so as to construct rice plant samples with gradient difference of source-sink levels. The present invention is a kind of native, natural noninvasive method of source-sink regulation, which could broaden the traditional thinking of source-sink theoretical research, especially overcome the deficiency in conventional methods such as leaf-cutting, spikelet-thinning that lead to physical injury or physiological interference. The method provides a brand new approach and solution for thoroughly investigating source-sink relationship in rice, wheat, maize and other crops, and will play an important role in enriching crop source-sink theory and also promoting the development of the related disciplines.
China National Rice Research Institute | Date: 2013-07-24
The present invention provides a soil heavy metal curing agent for controlling accumulation of heavy metals of crops and its preparation method. The curing agent is made from the following parts of raw materials by weight: 60140 parts of substance containing carbon-carbon double bond; 1400 parts of sulfo-compound by sulfur; 50500 parts of organic matter by 10% water content; 0400 parts of water; 0100 parts of an initiator; 0200 parts of a reducer; and 0200 parts of a strong base. The curing agent for heavy metals in the soil according to the present invention can reduce the cadmium, lead and mercury content in the soil and further greatly reduce the roots absorption of these heavy metals.