Top Read

Published in last 1 year |

In last 2 years |

In last 3 years |

All

Please wait a minute...


For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails

Select

Research Progress in the Function of Basic Leucine Zipper (bZIP) Protein Family in Rice HAN Cong, HE Yuchang, WU Lijuan, JIA Lili, WANG Lei, E Zhiguo Chinese Journal OF Rice Science    2023, 37 (4): 436-448.   DOI: 10.16819/j.1001-7216.2023.221018 Abstract （1031）   HTML （37）    PDF （1407KB）（548）       Knowledge map    Save As a large family of transcriptional regulators, basic leucine zipper (bZIP) proteins are widespread in eukaryotes. The bZIP proteins characteristically harbor a bZIP domain composed of two closely adjacent structural features: a DNA-binding basic region and the leucine zipper region. Annotations to eighty-nine bZIP transcription factor-encoding genes are available in the japonica rice genome, 45 of which are identified. They are involved in regulating rice growth and development and responses to biotic and abiotic stress, including seed dormancy and germination, floral transition, and photomorphogenesis, and stress and hormone signaling pathway, etc. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Research Progress in Molecular Mechanism and Breeding Status of Salt Tolerance in Rice WU Mingming, ZENG Wei, ZHAI Rongrong, YE Jing, ZHU Guofu, YU Faming, ZHANG Xiaoming, YE Shenghai Chinese Journal OF Rice Science    2022, 36 (6): 551-561.   DOI: 10.16819/j.1001-7216.2022.211111 Abstract （673）   HTML （3948717）    PDF （414KB）（719）       Knowledge map    Save Saline-alkali soil hinders the growth and development of rice at different stages, resulting in the decrease of rice yield. Salt-tolerant rice breeding is an effective way to increase rice yield. In this paper, the effects of salt stress on agronomic traits at different rice developmental stages were reviewed, and the recent research progress in molecular mechanism of salt tolerance in rice was summarized from four aspects: osmotic regulation, ion response, hormone regulation and active oxygen scavenging. Finally, the breeding status of salt-tolerance rice was summarized, and breeding prospects and promotion of new salt-tolerant rice varieties were discussed. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Research Progress in Alleviating Effects of Exogenous Substances on Salt Stress in Rice LIU Shuli, ZHANG Rui, Shahid HUSSAIN, WANG Yang, CHEN Yinglong, WEI Huanhe, HOU Hongyan, DAI Qigen Chinese Journal OF Rice Science    2023, 37 (1): 1-15.   DOI: 10.16819/j.1001-7216.2023.220404 Abstract （569）   HTML （40889）    PDF （424KB）（594）       Knowledge map    Save Salt stress is one of the main abiotic factors hindering rice growth, development and grain yield. By the use of exogenous substances, adverse effects can be alleviated and its growth and yield traits can be improved. This work reviews the regulation mechanism and mitigation effect of different exogenous substances (auxin, gibberellin, cytokinin, abscisic acid, ethylene, melatonin, salicylic acid, polyamine, brassinosteroid and jasmonic acid as well as calcium and silicon ionic exogenous substances) on rice salt stress. Finally, the utilization and research work of exogenous substances on salt tolerance of rice is prospected in order to lay a theoretical basis for improving rice growth, yield and quality in saline soil. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Progress in Functions, Allelic Variations and Interactions of Soluble Starch Synthases Genes SSⅡa and SSⅢa in Rice YAO Shu, ZHANG Yadong, LU Kai, WANG Cailin Chinese Journal OF Rice Science    2022, 36 (3): 227-236.   DOI: 10.16819/j.1001-7216.2022.210705 Abstract （530）   HTML （2022182613）    PDF （5007KB）（768）       Knowledge map    Save The effect of rice starch synthesis on rice quality has always been under the spotlight, which is one of the hotspots and difficult points for rice basic scientific research. The pathway of starch synthesis is regulated by many kinds of enzymes, but soluble starch synthase (SSS) is one of the most important enzymes influencing rice eating and cooking quality. Soluble starch synthase genes SSⅡa and SSⅢa are two key genes controlling rice gelatinization temperature, which are involved in biosynthesis of amylopectin of rice endosperm. We reviewed and summarized the latest research progress in the functions, allelic variations and interactions of SSⅡa and SSⅢa affecting cooking and eating quality. Meanwhile, we discussed the application perspective of SSⅡa and SSⅢa in molecular improvement and breeding of rice quality. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Analysis and Prospects of Extension of Main Varieties of Hybrid Rice with High Quality in China ZENG Bo, GONG Junyi, ZHANG Fang Chinese Journal OF Rice Science    2022, 36 (5): 439-446.   DOI: 10.16819/j.1001-7216.2022.220408 Abstract （518）   HTML （217072236）    PDF （13466KB）（808）       Knowledge map    Save 【Objective】The recent ten-odd years have marked an important transition when the quality of hybrid rice has been promoted under the guidance of revised and approved standards. Reviewing the breeding and extension process of high-quality hybrid rice in this period is of great significance for guiding rice breeding in the future. 【Method】 Based on rice materials and data including the extension area of main hybrid rice varieties in China from 2009 to 2020, we analyzed the extension area of male sterile lines, restorer lines and series of varieties, and reviewed the replacement process of major varieties in each rice cropping region. 【Result】 During this period, the extension area of hybrid rice varieties with high quality in China kept growing rapidly, and the high-quality-rice rate in term of planting area in main rice cropping regions increased significantly, but there was still a lack of high-grade rice varieties with high quality. The results also showed that the existing main hybrid rice varieties with high quality were derived from 15 male sterile lines and 9 restorer lines. In addition, the analysis results showed that the major hybrid rice varieties with high quality in different rice cropping regions in China had been replaced on a large scale for 1-2 times. 【Conclusion】 Over the past 12 years, driven by the innovation of rice breeding technology, the process of high-quality hybrid rice breeding in China has been significantly accelerated, a large number of high-quality hybrid rice varieties have emerged in various rice cropping regions, the planting area has increased rapidly, and the proportion of high-quality varieties applied in production has increased significantly. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Research Progress on the Effects of OsNramp5 Mutation on Important Agronomic Traits in Rice LI Xiaoxiu, LÜ Qiming, YUAN Dingyang Chinese Journal OF Rice Science    2022, 36 (6): 562-571.   DOI: 10.16819/j.1001-7216.2022.220316 Abstract （488）   HTML （476069）    PDF （425KB）（536）       Knowledge map    Save Developing low-cadmium (Cd) rice cultivars is the most economical and effective way to solve the problem of “Cadmium Rice”. Previous studies have shown that OsNramp5 is the major transport gene for Cd uptake in rice. The functional deficiency of OsNramp5 leads to a significant decrease in the content of Cd in rice grains, and the uptake of manganese (Mn) is also affected. However, in previous studies on the effect of OsNramp5 variation on rice growth and development, the conclusions were inconsistent. The systematic understanding of the effects of OsNramp5 mutation on important agronomic traits in rice will promote the development of new rice cultivars with low-Cd and high-quality. This manuscript focuses on the effects of OsNramp5 mutation on the content of metal ions, growth and development, yield and quality of rice, so as to provide scientific guidance for the breeding of new rice cultivars with low Cd accumulation by OsNramp5 mutation. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Advances in the Molecular Mechanism of Rice Plant Type LAN Jinsong, ZHUANG Hui Chinese Journal OF Rice Science    2023, 37 (5): 449-458.   DOI: 10.16819/j.1001-7216.2023.221102 Abstract （437）   HTML （57）    PDF （401KB）（464）       Knowledge map    Save The plant type of rice is one of the major factors determining rice yield. The ideotype of high-yielding rice cultivar is an important way to increase rice yield potential in rice breeding. Dwarf breeding in the 1950s and hybrid rice breeding in the 1970s are two revolutions in rice yield. However, the growth rate of rice yield has slowed down significantly in recent years. The third yield breakthrough depends on the super-high-yield breeding that combines ideotype with heterosis. We briefly reviewed the advances in the regulation mechanism of rice plant architecture, focusing on the progress achieved in leaf, panicle, grain and other aspects, and looked forward to the future research trends rice ideotype. It will lay a solid foundation for improving rice plant type and further increasing rice yield through molecular breeding. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Improvement of Herbicide Resistance in Rice by Using CRISPR/Cas9 System YIN Liying, ZHANG Yuanye, LI Rongtian, HE Mingliang, WANG Fangquan, XU Yang, LIU Xinxin, PAN Tingting, TIAN Xiaojie, BU Qingyun, LI Xiufeng Chinese Journal OF Rice Science    2022, 36 (5): 459-466.   DOI: 10.16819/j.1001-7216.2022.211004 Abstract （436）   HTML （11927647）    PDF （932KB）（596）       Knowledge map    Save 【Objective】 It is of great significance to create herbicide-resistant rice varieties. The acetyllactic acid synthase (ALS) gene was edited to create rice varieties with excellent herbicide resistance using non-herbicide-resistant japonica rice varieties with good quality as materials. 【Methods】Using CRISPR/Cas9 technology, the single-base mutant vector pH-NCas9-PBA-ALS was constructed with acyllactic acid synthase (ALS) as the target gene. Songjing 22, Longjing 46 and Suijing 18 were used as transformation materials to obtain transgenic plants through Agrobacterium-mediated genetic transformation. Genotypes and phenotypes were identified by sequencing the mutation sites of transgenic plants and herbicide spraying test. 【Results】 Ten ALSS627N mutants, one ALSS627N and 1884G-A(the 628th amino acid unchanged mutant), and one ALSS627N/G628E mutant were obtained by molecular level detection. Compared with the wild type, the three types of mutants had stronger herbicide resistance. 【Conclusion】 Using CRISPR/Cas9 gene editing technology, we obtained homozygous mutant lines which are genetically stable and herbicide-resistant, providing basic materials for herbicide-resistant rice breeding. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Development of New Low Glutelin Content japonica Rice Lines with Good Eating Quality and Fragrance by Molecular Marker-Assisted Selection CHEN Tao, ZHAO Qingyong, ZHU Zhen, ZHAO Ling, YAO Shu, ZHOU Lihui, ZHAO Chunfang, ZHANG Yadong, WANG Cailin Chinese Journal OF Rice Science    2023, 37 (1): 55-65.   DOI: 10.16819/j.1001-7216.2023.220302 Abstract （424）   HTML （20909）    PDF （3616KB）（483）       Knowledge map    Save 【Objective】 Developing new low glutelin content varieties is an important direction of functional rice breeding. It is necessary to strengthen the synchronized improvement of rice functionality and eating quality in breeding to meet the needs of nephropathic patients for rice quality and physical health. 【Method】 The good eating quality japonica rice variety Nanjing 46 with the low amylose content gene Wxmp and fragrance gene fgr was used as the parent to cross and backcross with the variety LGC-1 from Japan containing the Lgc1 gene. The molecular markers co-isolated with target genes were utilized for genotypic detection in combination with field selection and five new lines were obtained in BC2F6 generation. Taking parents Nanjing 46 and LGC-1 as control, the agronomic, yield and quality traits of these lines were analyzed. 【Result】 Compared with LGC-1, these lines has similar glutelin content and absorbable protein content, improved eating quality, excellent comprehensive characters and high yield potential. They are suitable to grow in different regions of Jiangsu Province. 【Conclusion】 As a rapid, accurate and effective method, the molecular marker-assisted selection, in combination with conventional breeding technology, can significantly improve the breeding efficiency of the low gluten rice varieties with good quality and high yield. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

OsLOX10 Positively Regulates Defense Responses of Rice to Rice Blast and Bacterial Blight ZHOU Yonglin, SHEN Xiaolei, ZHOU Lishuai, LIN Qiaoxia, WANG Zhaolu, CHEN Jing, FENG Huijie, ZHANG Zhenwen, CHEN Xiaoting, LU Guodong Chinese Journal OF Rice Science    2022, 36 (4): 348-356.   DOI: 10.16819/j.1001-7216.2022.210604 Abstract （397）   HTML （1613258775）    PDF （62674KB）（751）       Knowledge map    Save 【Objective】Rice blast caused by Magnaporthe oryzae and bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) seriously affect rice yield and quality. The transgenic materials of OsLOX10 were created to evaluate the resistance to M. oryzae and Xoo. The possible mechanism of OsLOX10 in regulating the defense responses to rice blast and bacterial blight were elucidated. 【Method】The knockout vector of OsLOX10 was constructed using CRISPR/Cas9 system, and the overexpression vector of OsLOX10 was constructed by linearizing pCXUN-HA with restriction enzyme XcmⅠ and linking with TA ligation. Transgenic rice was obtained by genetic transformation, and the homozygous transgenic lines were screened for fungal and bacterial resistance analysis. The expression dynamics of SA (salicylic acid) and JA (jasmonic acid) pathway marker genes were analyzed by qRT-PCR after infection with M. oryzae. The outbreak of reactive oxygen species (ROS) induced by chitin and flg22 in rice was also observed. 【Result】qRT-PCR analysis showed that the OsLOX10 expression was up-regulated 24 h after inoculation with M. oryzae and Xoo. The OsLOX10 knockout lines were more susceptible to the rice blast than that of the wild type (Nipponbare) when inoculated with the spore suspension of M. oryzae Guy11, while the overexpressed lines had no typical disease symptoms. At 6, 12, 24 and 36 hours post inoculation, the transcriptional levels of three pathogenesis-related genes, OsPBZ1, OsPR1a and OsPR1b, and two JA pathway genes, OsAOS2 and OsLOX5, and SA pathway gene OsPAL1, were significantly down-regulated in the knockout transgenic lines. However, they were significantly up-regulated in overexpressed transgenic lines. The OsLOX10 transgenic rice was inoculated with Xoo (PXO99A), and the OsLOX10 knockout lines were more susceptible to bacterial blight. qRT-PCR analysis showed that the relative expression levels of OsPR1b, OsPAL1 and the three genes (OsAOS2, OsAOC and OsJAZ) involved in the JA synthesis pathway were up-regulated in OsLOX10 overexpression lines, significantly down-regulated in OsLOX10 knockout lines seven days after Xoo inoculation. OsLOX10 knockout also significantly reduced the ROS level induced by chitin and flg22 in rice, delayed the peaking time of ROS induced by chitin, and reduced the sensitivity of rice to chitin and flg22.【Conclusion】OsLOX10 could be induced by infection with M. oryzae and Xoo. OsLOX10 may be involved in pathogen-associated molecular patterns triggered immunity, and play a positive regulatory role in rice resistance to rice blast and bacterial blight. Moreover, the OsLOX10 may regulate rice resistance to M. oryzae and Xoo through SA and JA mediated signaling pathways. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Screening and QTL Mapping of Heat-tolerant Rice (Oryza sativa L.) Germplasm Resources at Seedling Stage LIU Jin, CUI Di, YU Liqin, ZHANG Lina, ZHOU Huiying, MA Xiaoding, HU Jiaxiao, HAN Bing, HAN Longzhi, LI Maomao Chinese Journal OF Rice Science    2022, 36 (3): 259-268.   DOI: 10.16819/j.1001-7216.2022 Abstract （365）   HTML （1980768816）    PDF （201160KB）（833）       Knowledge map    Save 【Objective】Identification of germplasm resources and genes extremely resistant to heat will provide technical support and lay a physical foundation for the breeding of new heat-tolerant rice varieties. 【Method】Heat tolerance level and survival rate are used to identify the high temperature resistance of rice at seedling stage, so as to select heat-tolerant germplasm resources and identify major QTLs. 【Results】There are obvious differences in heat tolerance among different varieties at seedling stage. Indica rice has significantly stronger tolerance to heat than japonica rice. Twenty accessions of rice germplasm resources with strong heat tolerance, such as Jiayu 253, Zhongyouzao 8, and Xiushui 09, were selected. The survival rates, growth and development of these varieties were almost immune to high temperature. Furthermore, there are significant differences in heat tolerance between the parents. Zhongyouzao 8 has strong heat resistance, while Longdao 5 is sensitive to high temperature. The phenotype followed an approximate continuous normal distribution under high temperature in the RIL populations. Twelve QTLs were detected on chromosomes 1, 3, 4, 5 and 8, and these QTLs have a significant genetic overlap for heat resistance grade(HTG) and survival rate under heat stress(HTSR). The major QTL clusters qHTS4 and qHTS8 have significant heat tolerance function. Based on the preliminary QTL mapping results, the RHL-F2 population was used to validate the stably expressed major QTL qHTS8, which was identified on the chromosome 8 between RM5808 and RM556 regions. 【Conclusion】 Twenty accessions of rice germplasm resources with strong heat tolerance were selected, twelve QTLs were identified, and then the major QTL qHTS8 was verified to have strong effects on regulating heat tolerance. These results will lay a foundation and provide abundant germplasm resources for the research on the physiological, biochemical, and molecular genetic mechanism of heat resistance and rice breeding. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Research Progress of Rice with Low Glycemic Index LI Xia, JIANG Yanjie, TAO Yajun, LI Wenqi, WANG Fangquan, CHEN Zhihui, XU Yang, WANG Jun, FAN Fangjun, ZHU Jianping, Sreenivasulu NESE, YANG Jie Chinese Journal OF Rice Science    2022, 36 (4): 336-347.   DOI: 10.16819/j.1001-7216.2022.210902 Abstract （358）   HTML （1225319444）    PDF （103817KB）（838）       Knowledge map    Save Milled white rice is typical starch-rich food, serves as the major daily caloric source for a majority of the world population especially for Asian. Most rice varieties are of high glycemic index, a food quality inferenced to contribute to the health problems surrounding high-calorie intake and dysregulated glucose metabolism. A lot of studies have been carried out attempting to lower glycemic index. The effects of various factors, large-scale screening methods, genetic mechanism and its related genes, starch structure and genetic improvement on low glycemic index of rice were summarized in this review. And proposal researches were put forward as well. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Breeding of Rc Function Restoration Red Rice via CRISPR/Cas9 Mediated Genome Editing ZHANG Yuanye, YIN Liying, LI Rongtian, HE Mingliang, LIU Xinxin, PAN Tingting, TIAN Xiaojie, BU Qingyun, LI Xiufeng Chinese Journal OF Rice Science    2022, 36 (6): 572-578.   DOI: 10.16819/j.1001-7216.2022.211205 Abstract （349）   HTML （1867912）    PDF （2487KB）（457）       Knowledge map    Save 【Objective】 It is of great value to restore cultivated rice varieties to red rice with good rice quality and strong stress resistance. CRISPR/Cas9 gene editing technology was used to edit the Rc gene, restoring the red seed coat, and laying a data foundation for the improvement of rice quality and resistance.【Methods】 Using CRISPR/Cas9 technology, the target gene Rc mutant vector pYLCRISPR/ Cas9-Rc-gRNA was constructed and transformed into transgenic plants with Kongyu 180 and Shangyu 453 as materials. The results were verified by sequencing and phenotypic observation. 【Results】 Two Rc mutants were obtained. For KY-1, with 4 bases deleted from 1414 bp to 1417 bp, the terminator was replaced by phenylalanine. SY-1 also lost a base at 1411 bp, which resulted in the transformation from the terminator to aspartic acid. The two kinds of editing materials restored red rice phenotype and had certain saline-alkali tolerance.【Conclusion】 Using CRISPR/Cas9 technique, we obtained homozygous lines with red seed coat, providing basic materials for the improvement of red rice. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Advances in Research on the Modification of the Heading Date Genes in Rice by Phosphorylation and Ubiquitination Pathways WANG Jingying, ZHAO Guangxin, QIU Guankai, FANG Jun Chinese Journal OF Rice Science    2022, 36 (3): 215-226.   DOI: 10.16819/j.1001-7216.2022.210707 Abstract （327）   HTML （1312821531）    PDF （1000KB）（664）       Knowledge map    Save Rice is a facultative short-day plant that is widely cultivated. Heading date (also known as flowering time) of rice is an important agronomic trait that directly affects grain yield and regional adaptability of rice varieties. Therefore, it is of great significance to study the influencing factors of this trait and make the plants bloom at appropriate time. Heading date, as a complex quantitative trait, is regulated by internal genetic network and exogenous factors such as photoperiod and temperature. At present, several key genes controlling heading date have been identified and cloned. It is found that phosphorylation and ubiquitylation play an important role in the molecular mechanism of rice heading date. This paper introduces the molecular mechanism of photoperiod pathway of heading date, and expounds the progress in research on the regulation of phosphorylation cascade and ubiquitin 26S proteasome system on flowering time, aiming at laying a theoretical basis and providing practical guidance for the new mechanism in regulating heading date, and for regional adaptability of improved varieties. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Construction of osarf7 Mutants in Rice Based on CRISPR/Cas9 Technology and Investigation on Their Agronomic Traits LI Zhaowei, SUN Congying, LING Donglan, ZENG Huiling, ZHANG Xiaomei, FAN Kai, LIN Wenxiong Chinese Journal OF Rice Science    2022, 36 (3): 237-247.   DOI: 10.16819/j.1001-7216.2022.210117 Abstract （325）   HTML （1403263445）    PDF （109895KB）（838）       Knowledge map    Save 【Objective】The purpose is to offer a deep insight into the biological function of OsARF7 and its effect on agronomic traits during the growth and development stage of rice. 【Method】CRISPR/Cas9 technology was employed to edit the gene sequence of OsARF7 and to obtain the mutants of japonica variety Zhonghua 11. The agronomic traits of the mutants were investigated in a field experiment. 【Result】Twenty-two T0 transgenic lines were obtained through Agrobacterium-mediated infection of japonica rice Zhonghua 11 callus, and twenty positive transgenic lines were distinguished by screening the gene encoding hygromycin. For T2 transgenic lines, the regions of genomic DNA including two target sites were detected and identified by PCR amplifying and sequencing, and fifteen homozygous mutations were confirmed. Gene expression results displayed that the expression levels of OsARF7, OsPIN1b, OsPIN2, and OsLAX2 in the osarf7 mutants were significantly lower than those in the wild type. In comparison with the wild-type plants, osarf7 mutants showed a significant decrease in the productive panicle percentage. Among them, the osarf7 mutants with more tillers than the wild type showed a similar effective panicle number to the wild type, and the osarf7 mutants with the same tiller number as the wild type presented a decrease in the effective panicle number per plant in paddy field conditions, resulting in increased non-productive tillers and decreased effective panicle percentage. 【Conclusion】OsARF7 was involved in the emergence and development of tiller bud dominated by auxin, and the successful construction of osarf7 mutants plays a positive role in revealing the biological function of OsARF7 and the mechanism of tiller formation and development dominated by auxin. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Comparison of Grain Quality Profiles of japonica Soft Rice Varieties with Different Amylose Contents SHI Yuliang, YANG Yong, LI Xuefei, LI Qianfeng, HUANG Lichun, ZHANG Changquan, SONG Xuetang, LIU Qiaoquan Chinese Journal OF Rice Science    2022, 36 (6): 601-610.   DOI: 10.16819/j.1001-7216.2022.211212 Abstract （320）   HTML （688665）    PDF （2217KB）（567）       Knowledge map    Save 【Objective】 Soft rice with low amylose content (5%−12%) usually has a good taste and is very popular in the domestic rice market. However, soft rice varieties differ greatly in the grain quality profiles, which has not been well understood yet. Thus, it is necessary to characterize the difference in grain quality profiles of different soft rice types in detail. 【Method】 Eight japonica rice varieties, including four soft rice, two normal ones, and two glutinous ones released in Jiangsu Province were selected for systematic grain quality analysis. 【Result】 Sequencing results showed that the soft rice varieties Nanjing 5055 and Nanjing 9108 carry the Wxmp alleles, while the other two soft rice varieties, Xiangruanyu and Wuxianjing 113, carry the same Wxb allele as that in two normal japonica rice varieties. Rice grain quality analysis showed that both Xiangruanyu and Wuxiangjing 113 have lower amylose content and more opaque endosperm than those of the other two soft rice varieties Nanjing 5055 and Nanjing 9108. There were obvious cavities within the single starch granule in all the four soft rice. Amylose content had a negative correlation with the level of rice endosperm transparency. Rice taste quality analysis showed that the soft rice with lower amylose content had a better taste value, because rice with lower amylose content tended to have lower cool paste viscosity, setback value, and higher breakdown value. Starch fine structure analysis showed that endosperm starch from soft rice contains less amylose and more short-chain amylopectin as compared with the two normal rice varieties. 【Conclusion】 There were significant differences in genetics and grain quality among the selected four soft rice varieties in Jiangsu Province. It provides important information for the breeding of new soft rice varieties as well as cloning of novel genes related to rice grain quality. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Analysis of Agrobacterium-Mediated Genetic Transformation System of indica Rice 9311 and Huazhan ZHANG Jia, WANG Huijie, HE Zhengquan, LIU Wenzhen Chinese Journal OF Rice Science    2023, 37 (2): 213-224.   DOI: 10.16819/j.1001-7216.2023.220305 Abstract （313）   HTML （93）    PDF （2866KB）（413）       Knowledge map    Save 【Objective】 The rice transgenic technology is an important tool to promote rice molecular biology research and precision breeding. Agrobacterium-mediated transgenic technology has become the mainstream method for rice genetic transformation. Nevertheless, due to its genotype, the genetic transformation efficiency of typical indica rice is still quite low. It is urgent to improve its transformation efficiency. 【Method】 The effects of medium composition and photoperiod on genetic transformation efficiency of recalcitrated indica rice varieties 9311 and Huazhan were investigated. 【Result】 The results showed that MS macro element, B5 micro element, N6 organic matter and maltose were the best combination for 9311 tissue culture. MS macro element, MS micro element, MS organic matter and maltose were the best combination for Huazhan tissue culture. Adding 0.5 mg/L BAP or 1.5 mg/L KT into the induction medium could significantly improve the regeneration rate of 9311 and Huazhan tissue culture, up to more than 70.0%. The transformation efficiency with 100 μmol/L AS in the infection solution was higher than that with 200 μmol/L AS. Photoperiod experiments suggested that different photoperiod strategies should be adopted for 9311 and Huazhan transformation. 9311 transformation efficiency peaked, 6.0%?6.4%, under continuous darkness at the induction and selection stages and continuous light at the differentiation stage. Huazhan transformation efficiency reached the highest, 5.0%?7.5%, under 12 h photoperiod at all stages. 【Conclusion】 Collectively, the present study optimized tissue culture and genetic transformation system of recalcitrant indica rice varieties 9311 and Huazhan. Our methods could also be applied to the genetic transformation of other related indica rice genotypes. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Directed Knockout of SD1 Gene Improves Lodging Resistance and Blast Resistance of Rice LI Gang, GAO Qingsong, LI Wei, ZHANG Wenxia, WANG Jian, CHEN Baoshan, WANG Di, GAO Hao, XU Weijun, CHEN Hongqi, JI Jianhui Chinese Journal OF Rice Science    2023, 37 (4): 359-367.   DOI: 10.16819/j.1001-7216.2023.221113 Abstract （305）   HTML （23）    PDF （1390KB）（374）       Knowledge map    Save 【Objective】 Huai 119 is a high-yielding japonica rice variety. To improve its unfavorable traits, especially high plant height and poor resistance to rice blast, we used the CRISPR/Cas9 gene editing technology to knock out its ‘Green Revolution’ gene SD1.【Method】 We selected the SD1 gene as the target to construct the CRISPR/Cas9 gene knockout vector, which was then transformed into Huai 119 by Agrobacterium-mediated transformation method, and the homozygous sd1 knockout line without transgenic insertion was obtained. Subsequently, we compared and analyzed the plant height, rice blast resistance, and nitrogen uptake and utilization efficiency of the sd1 and wild-type lines.【Result】 We successfully isolated a homozygous sd1 knockout line without transgenic insertion in the background of Huai 119. In field paddy, it was found that over 60% of the planting area of wild-type Huai 119 was lodging, while the sd1 homozygous mutant population effectively avoided lodging in the later stages of growth due to its shorter plant height. In addition, after treatment with different concentrations of GA (0.01-1.00 μmol/L), the plant height increase of wild-type plants was significantly greater than that of the sd1 line, indicating that the sensitivity of sd1 line to exogenous GA treatment was reduced. The identification of rice blast resistance shows that knocking out SD1 also contributed to the improvement of rice blast resistance of Huai 119. However, the absorption and utilization efficiency of nitrogen decreased due to the knockout of SD1. 【Conclusion】 The knockout of SD1 gene in the rice variety Huai 119 not only improves lodging resistance by reducing plant height, but also enhances the resistance to rice blast. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Evaluation of New japonica Rice Lines with Low Cadmium Accumulation and Good Quality Generated by Knocking Out OsNramp5 PEI Feng, WANG Guangda, GAO Peng, FENG Zhiming, HU Keming, CHEN Zongxiang, CHEN Hongqi, CUI Ao, ZUO Shimin Chinese Journal OF Rice Science    2023, 37 (1): 16-28.   DOI: 10.16819/j.1001-7216.2023.220503 Abstract （298）   HTML （28826）    PDF （1649KB）（460）       Knowledge map    Save 【Objective】 It is crucial to elucidate the effects of OsNramp5 gene knockout on cadmium and other metal elements accumulation, yield and quality in japonica rice, which can provide new materials and theoretical references for scientific and efficient production of high-quality and green japonica rice.【Methods】 Using CRISPR/Cas9 technology, the OsNramp5 was knocked out under the background of Nanjing 46 (NJ46), a japonica rice variety with good taste and high yield. Combined with molecular marker-assisted selection, some OsNramp5 knockout lines without exogenous genes were obtained. The changes in yield and quality traits and seven metal elements contents such as cadmium, manganese and selenium in grains after spraying zinc fertilizer or selenium fertilizer and cultivated in soils with different cadmium content were investigated. 【Results】 Five transgenic plants with different mutations of OsNramp5 were obtained in the T0 generation, and specific molecular markers of three of them were designed. Then, combined with marker-assisted selection, homozygous knockout lines without hygromycin selective marker gene and CAS9 protein gene were obtained in the T2 generation of each plant. Compared with the wild type, the cadmium content in the whole plant including the grain of the knockout lines and the manganese content in shoots were significantly lower than those of the wild type in both high and low concentrations of cadmium soil. The plant height and grain number per panicle of the knockout lines decreased slightly, and the yield per plant decreased significantly in the knockout lines at high and medium tillering fertilizer levels while no changes were observed at the low tillering fertilizer level. The appearance of the knockout lines was better than that of the control, and the contents of protein and amylose were significantly higher than those of the control. The contents of copper, manganese and selenium in grains of knockout lines were significantly lower than those of the control NJ46, but zinc and selenium fertilizer could significantly increase the contents of zinc and selenium, and further reduce the content of cadmium in grains. Application of selenium was beneficial to rice appearance quality, but application of zinc was contrary. Spraying both fertilizers reduced the edible value of rice, worsening taste quality. The change of seed setting rate of the knockout lines under extreme high and low temperature conditions was the same as that of the control, but the resistance level to rice sheath blight was significantly reduced.【Conclusion】 We obtained marker-free OsNramp5 knockout lines under the background of japonica variety with high quality and yield, and proved that OsNramp5 was of great value in the production of low-cadmium, Se- and zinc-rich, though their yield and eating quality were decreased to different extents. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Transcriptome Analysis of Young Rice Panicles in Early Response to Exposure to Mycotoxin of Ustilaginoidea virens FU Rongtao, WANG Jian, CHEN Cheng, ZHAO Liyu, CHEN Xuejuan, LU Daihua Chinese Journal OF Rice Science    2022, 36 (5): 447-458.   DOI: 10.16819/j.1001-7216.2022.210714 Abstract （298）   HTML （19792004）    PDF （28637KB）（483）       Knowledge map    Save 【Objective】 Rice false smut caused by Ustilaginoidea virens not only leads to rice yield loss, but also produces mycotoxins which is toxic to animals and plants. In order to elucidate the molecular mechanism behind the response to exposure to mycotoxin the young panicles of rice were mycotoxin-treated with U. virens mycotoxin, which may provide a new idea for exploring rice false smut resistance genes and molecular breeding for disease resistance. 【Method】Transcriptome sequencing was performed with mycotoxin-treated young panicles as materials. The genome of 9311 was used as the reference genome to align the sequences. The expression level of genes was calculated by the term of Transcripts Per Million (TPM). According to the database, the differentially expressed genes were screened by parameters (|LOG2 fold change|≥1 and q-value≤0.05). Combined with differential expression analysis and function annotation, the key genes in response to mycotoxin were identified in rice panicles. The differentially expressed genes were verified by qRT-PCR. 【Result】2526 differentially expressed genes (DEG) were identified in young panicles of rice after 12 h treated with mycotoxin. Through GO enrichment, KEGG metabolic pathway and KOG function analysis, the DEGs were divided into 64 terms under GO function, 32 metabolic pathways and 23 categories under KOG function, including starch and sucrose metabolism, phenylpropyl biosynthesis, carbon metabolism, glycolysis/gluconeogenesis, amino sugar and nucleoside sugar metabolism and other biological processes. There were 66 plant transcription factors in DEGs, which belonged to 7 family of plant transcription factors, including WRKY and Myb. The expression levels of OsCPS2, OSKSL4 and cytochrome P450 were up-regulated, while the expression levels of amylase, beta-fructofuranosidase and UGPase were down-regulated when we analyzed genes involved in diterpenoid biosynthesis and starch and sucrose metabolism pathways. Therefore, it is speculated that these genes play an important role in rice response to mycotoxin of U. virens stress. 【Conclusion】As an abiotic stress factor, mycotoxin of U. virens had a toxic effect on young panicles of rice. It affects the synthesis of nutrients in seeds by interfering with metabolism of starch and sucrose, and thus reduces the resistance of rice to pathogen infection. Table and Figures | Reference | Related Articles | Metrics | Comments（0）