Vitamin B6 (VB6), as an essential component involved in numerous biological activities of animals and plants, reflects the nutritional quality of cereal crops such as rice. Few studies have been conducted to mine the genes controlling the VB6 content in rice grains, and the available studies remain to be deepened. In this study, the recombinant inbred lines created from parents 'HZ' and 'Nekken2' served as the experimental materials. Based on QTL mapping, the initial screening identified ten candidate genes. The expression levels of LOC_Os01g52450, LOC_Os01g52500, LOC_Os05g09500, LOC_Os05g09440, LOC_Os05g20570, and LOC_Os05g36270 showed significant differences between the parents. According to the gene expression and parental VB6 content, we hypothesized LOC_Os05g09500 as the key gene affecting the VB6 content in rice grains, and the high expression of this gene significantly influenced the VB6 content. The results of this study fill a gap in the QTL mapping on the VB6 content of rice grains and provide theoretical support for elucidating the molecular genetic mechanisms and cloning the related genes of VB6 synthesis in rice. In addition, the findings have significant implications for identifying, screening, and breeding new rice cultivars with high VB6 content.

A novel rice mutant lmi1 showed increased resistance to bacterial blight. LMI1 encodes a DUF292 protein and regulates defense immune responses and cell death via vesicle trafficking in chloroplasts.

The CRISPR-Cas9 system is composed of a clustered regularly interspaced short palindromic repeat (CRISPR) and its associated proteins, which are widely present in bacteria and archaea, serving as a specific immune protection against viral and phage secondary infections. CRISPR-Cas9 technology is the third generation of targeted genome editing technologies following zinc finger nucleases (ZFNs) and transcription activator like effector nucleases (TALENs). The CRISPR-Cas9 technology is now widely used in various fields. Firstly, this article introduces the generation, working mechanism and advantages of CRISPR-Cas9 technology; secondly, it reviews the applications of CRISPR-Cas9 technology in gene knockout, gene knock-in, gene regulation and genome in breeding and domestication of important food crops such as rice, wheat, maize, soybean and potato. Finally, the article summarizes the current problems and challenges encountered by CRISPR-Cas9 technology and prospects future development and application of CRISPR-Cas9 technology.

The leaf inclination angle is an important agronomic rice trait and an indicator of ideal plant architecture, yield and revenue. Based on 120 recombinant inbred lines (RILs) obtained from crossing of the F1 generation of the indica rice cultivar Huazhan as the male parent and the japonica rice cultivar Nekken2 as the female parent, followed by inbreeding for 12 generations, the leaf inclination angle of the first, second and third leaves from the top of the plants were analyzed. At the same time, quantitative trait locus (QTL) mapping of the leaf inclination angle was performed using encrypted genetic maps constructed for this population. A total of 33 QTLs were detected, including two related to the first leaf inclination angle (FLIA), nine related to the second leaf inclination angle (SLIA) (highest Lod value of 5.94), and 22 related to the third leaf inclination angle (TLIA) (highest Lod value of 8.53). At the same time, candidate genes analysis were conducted on the detected QTLs’ intervals, and a total of 15 candidate genes were screened. The expression levels of candidate genes were detected by RT-qPCR, we found that LOC_Os03g46920, LOC_Os03g52630, LOC_Os04g24328, LOC_Os08g25380, LOC_Os09g23200, LOC_Os09g32080, LOC_Os09g35940, LOC_Os09g37330 and LOC_Os09g37495 displayed extremely significant differences in expression between the parents. The results showed that these genes may be the cause of the difference in leaf inclination. The present study provided substantial foundation for the further validation of the function of leaf inclination angle genes and molecular breeding practices.

植物光合作用主要依赖绿色叶片,而叶片生长发育最直观的特征是叶色.目前已克隆200多个调控水稻(Oryza sativa)叶色的基因.水稻叶色调控机制复杂多样,涉及多条调控途径,包括光合色素的生物合成与降解、核-质信号转导和血红素的合成.此外,温度和光照强度等外部环境也会影响水稻叶色的变化.该文从分子机制、叶色相关基因及环境因素等方面总结了水稻叶色遗传调控机制,并提出该领域亟待解决的科学问题,以期为水稻高光效育种及应用提供理论支撑.

Soil salinization has a serious influence on rice yield and quality. How to enhance salt tolerance in rice is a topical issue. In this study, 120 recombinant inbred line populations were generated through nonstop multi-generation selfing using a male indica rice variety Huazhan (Oryza sativa L. subsp. indica cv. ‘HZ’) and a female variety of Nekken2 (Oryza sativa L. subsp. japonica cv. ‘Nekken2’) as the parents. Germination under 80 mM NaCl conditions was measured and analyzed, and quantitative trait locus (QTL) mapping was completed using a genetic map. A total of 16 salt-tolerance QTL ranges were detected at bud stage in rice, which were situated on chromosomes 3, 4, 6, 8, 9, 10, 11, and 12. The maximum limit of detection was 4.69. Moreover, the qST12.3 was narrowed to a 192 kb region on chromosome 12 using map-based cloning strategy. Statistical analysis of the expression levels of these candidate genes under different NaCl concentrations by qRT-PCR revealed that qST12.3 (LOC_Os12g25200) was significantly down-regulated with increasing NaCl concentration, and the expression level of the chlorine-transporter-encoding gene LOC_Os12g25200 in HZ was significantly higher than that of Nekken2 under 0 mM NaCl. Sequencing analysis of LOC_Os12g25200 promoter region indicated that the gene expression difference between parents may be due to eight base differences in the promoter region. Through QTL mining and analysis, a plurality of candidate genes related to salt tolerance in rice was obtained, and the results showed that LOC_Os12g25200 might negatively regulate salt tolerance in rice. The results provide the basis for further screening and cultivation of salt-tolerant rice varieties and have laid the foundation for elucidating further molecular regulation mechanisms of salt tolerance in rice.

为发掘水稻根系性状相关基因,以籼稻品种华占(HZ)为父本、粳稻品种热研(Nekken2)为母本,杂交并衍生得到的重组自交系(recombination inbred lines,RILs)群体为实验材料,通过扫描测量重组自交系在三叶期时根系的性状.在已构建好的均匀分布于12条染色体的高密度遗传图谱基础上,对水稻根系性状的QTL进行初步定位及分析.结果表明:共检测到3个与总根长相关的QTL,分别位于水稻第2,5,10号染色体上,3个与根表面积相关的QTL,分别位于水稻第2,4,5号染色体上,6个与根平均直径相关的QTL,分别位于4,5,9,10和11号染色体上;其中总根长与根表面积QTL在第5号染色体上区间重合,根表面积与根平均直径QTL在第4号染色体上区间重合;同时对检测的QTL区间内的候选基因进行筛选、归纳和分析,并通过qRT-PCR分析,发现总根长LOC Os05g40180基因、根表面积LOC Os11g24240基因、根平均直径LOC Os04g52030基因很可能是影响水稻根系性状的新基因.以上结果为发掘根系性状、培育理想株型进而提高水稻产量及品质的影响具有一定的参考价值.

Most plant-specific TIFY proteins, the transduction hubs of jasmonic acid (JA) signals, determine transcriptional activities of JA-responsive genes, and play important regulatory roles in plant development and stress responses. In the present study, 34 TIFY genes from the highbush blueberry genome were identified, and their expression patterns during flower and fruit development and responses to exogenous JA treatment were investigated. The results showed that VcTIFY members had similar gene structures within highly conserved motifs, which were clustered into 5 main clades. Numerous phytohormone-, tissue- and development-related regulatory elements and stresses-responsive elements were widely distributed in the VcTIFY promoter regions. Gene expression analysis showed that VcTIFYs had distinct spatiotemporal expression patterns during flower enlargement and fruit development, while their expression levels were significantly different between the large-size cultivar ‘O'Neal’ and the small-size cultivar ‘Bluerain’. Under exogenous JA treatments, the weight, horizontal diameter and ripening of mature fruit were affected to different degrees, and the expression levels of VcTIFYs varied significantly in ‘O'Neal’ and ‘Bluerain’ mature fruits, indicating that VcTIFYs might be involved in regulating blueberry fruit size and development. These results should enrich our knowledge of TIFY genes and lay the groundwork for future functional research and genetic breeding of highbush blueberry.

茎腐病是金线莲人工栽培中的一种主要病害,生产上主要采用化学农药进行防控,但防治效果不理想,且易造成农药残留.本研究采用组织块培养法、 形态学观察和分子生物学鉴定,获得了金线莲茎腐病致病菌菌株.为了获得金线莲茎腐病致病菌的拮抗菌,本文采用平板对峙培养法研究了哈茨木霉、 绿色木霉和放线菌等3种生防菌对金线莲茎腐病致病菌的抑制效果.结果表明,哈茨木霉、 绿色木霉和放线菌等3种生防菌对金线莲茎腐病致病菌都具有一定的抑制作用,其中哈茨木霉抑菌作用最强,菌丝生长抑制率在第5天到达66.7％,具有较好的生物防治效果.

Plant lesion mimics refer to necrotic spots spontaneously produced by the plant without mechanical damage, pathogen invasion, and adversity stress. Here, we isolated and characterized two rice (Oryza sativa L) mutants, namely, spl88-1 (spotted leaf88-1) and spl88-2 (spotted leaf88-2), which were identified from an ethyl methanesulfonate-mutagenized japonica cultivar Xiushui 11 population. Physiological and biochemical experiments indicated that more ROS accumulated in spl88-1 and spl88-2 than in wild type. spl88-1 and spl88-2 displayed spontaneous cell death and enhanced their resistance to bacterial blight by affecting the expression of defense-related genes. We isolated SPL88 by map-based cloning, which encoded a highly conserved Cullin protein. A single base deletion was detected in spl88-1 and spl88-2, in which the 132nd base C of SPL88-1 and the 381th base T of SPL88-2 were deleted, causing premature termination of protein translation. SPL88 was expressed in root, stem, leaf, leaf sheath, and panicle. The Cullin protein was localized in the cytoplasm and nucleus. The aforementioned results indicate that SPL88 regulates the growth and development of rice by affecting the expression of defense-related genes.

Xanthine dehydrogenase, a member of the molybdenum enzyme family, participates in purine metabolism and catalyzes the generation of ureides from xanthine and hypoxanthine. However, the mechanisms by which xanthine dehydrogenase affects rice growth and development are poorly understood. In the present study, we identified a mutant with early leaf senescence and reduced tillering that we named early senescence and less-tillering 1 (esl1). Map-based cloning revealed that ESL1 encodes a xanthine dehydrogenase, and it was expressed in all tissues. Chlorophyll content was reduced and chloroplast maldevelopment was severe in the esl1 mutant. Mutation of ESL1 led to decreases in allantoin, allantoate, and ABA contents. Further analysis revealed that the accumulation of reactive oxygen species in esl1 resulted in decreased photosynthesis and impaired chloroplast development, along with increased sensitivity to abscisic acid and abiotic stresses. Ttranscriptome analysis showed that the ESL1 mutation altered the expression of genes involved in the photosynthesis process and reactive oxygen species metabolism. Our results suggest that ESL1 is involved in purine metabolism and the induction of leaf senescence. These findings reveal novel molecular mechanisms of ESL1 gene-mediated plant growth and leaf senescence.

[目的]早衰突变体是研究早衰机制的良好载体,对于探究早衰的遗传机理与作用机制及提高水稻的产量和品质具有重要作用.[方法]本研究利用EMS诱变获得了一个早衰突变体lps1,并对该突变体及其野生型进行表型观察、细胞学及组织化学分析、生理生化分析、遗传分析、基因定位和激素处理.[结果]lps1的叶片从3叶期开始发黄,成熟期株高、有效分蘖数、结实率、千粒重等极显著降低.电镜观察发现lps1叶表面光滑,硅质化突起和叶绿体数目减少、片层结构紊乱.生理生化分析表明lps1中有大量的活性氧积累,同时伴有蛋白质的降解、细胞膜的损伤以及大规模的细胞死亡.遗传分析表明该早衰表型受单隐性核基因控制,并且其在第5染色体上编码了一个泛素结合酶.亚细胞定位结果证明LPS1蛋白在细胞质与核中均有表达.外源激素处理发现,lps1对外源激素的处理更为敏感,且LPS1突变促进了ABA合成相关基因的表达.[结论]LPS1突变使水稻ABA合成信号途径异常,进而引发H2O2等一系列与衰老相关生理指标的异常变动,导致lps1过早衰老,最终造成水稻产量严重降低.

水稻（Oryzasativa）是全世界重要的经济作物之一,稻田镉（Cd）污染和镉积累问题严重威胁世界水稻的产量和品质以及人类健康,如何降低水稻中镉积累已成为热点问题。以籼稻品种华占（HZ）为父本、粳稻品种热研2号（Nekken2）为母本,连续自交多代后得到120个重组自交系群体,对其镉积累进行检测和分析,同时利用遗传图谱进行QTL作图。结果共检测到7个QTLs,分别位于水稻第2、3、9和12号染色体上,其中1个LOD值高达4.97。对这些QTL区间内与耐金属离子胁迫相关的候选基因进行定量分析,发现LOC O s02g50240、LOC O s02g52780、LOC O s09g31200、LOC O s09g35030和LOC O s09g37949这5个基因在双亲间的表达量差异显著,结合亲本对不同金属离子的浓度积累数据,推测LOC O s02g50240、LOC O s09g31200及LOC O s09g35030的高表达可能极大地提高了水稻对镉离子的吸收和胁迫耐受能力。通过QTL挖掘和分析,发现这些基因与水稻籽粒的镉积累有关,可能影响水稻耐镉胁迫的能力。研究结果为进一步筛选和培育耐镉胁迫的水稻品种创造了条件,为阐明水稻镉积累的分子调控机制奠定了基础。

为探究叶片水势（LWP）相关基因在水稻（Oryzasativa）抗旱中的作用及其遗传机制,以热研2号（Nekken2）和华占（HZ）为亲本以及构建的120个重组自交系（RILs）群体为实验材料,对水稻分蘖期叶片水势进行检测,并利用前期基于高通量测序构建的分子遗传连锁图谱进行数量性状基因座（QTL）分析。结果表明,共检测到5个与水稻分蘖期叶片水势相关的QTLs,分别位于第2、 3、 4、 11和12号染色体上,LOD值均达2.5以上,其中位于4号染色体物理距离24 066 261–30 847 136 bp内QTL的LOD值高达5.15。对这些QTL区间内与水势相关的候选基因进行定量分析,发现LOC O s02g56630、LOC O s02g57720、LOC O s02g57580、LOC O s04g43730、LOC O s04g46490、LOC O s04g44570和LOC O s04g44060这7个基因在双亲间表达量差异显著。位于4号染色体QTL区间内LOC O s04g46490基因的表达在两亲本间存在显著差异。对基因LOC O s04g46490进行测序分析,发现该基因在两亲本间共存在6处差异,从而导致氨基酸序列的改变。通过QTL挖掘及相关基因表达分析,发现这些基因与水稻叶片水势调控相关,可能间接影响水稻的抗旱性。检测到的QTL位点对水势相关基因精细定位和克隆具有重要参考价值,有助于进一步理解水稻叶片水势的遗传基础,并为培育耐旱水稻新品种提供有利的基因资源。

Rice is a key crop, and metal pollution is an important factor affecting rice yield and quality. Excavating the QTLs related to the accumulation of rice grain metal content, and analyzing its candidate genes, and then improving the ability of rice to withstand metal ion stress through genetic breeding can effectively reduce the caused by metal pollution in soil. In this study, a japonica rice variety Nekken was used as the female parent, and an indica rice variety HZ was used as the male parent. After F1 generation was obtained by cross-breeding, successive selfings were performed for 120 recombinant inbred lines (RIL population) for experimental materials. Cultured under the same and suitable conditions, routine management, then we measured the metal ion content in rice grains of each line at the maturity stage. A genetic map was constructed using the RIL population to map the QTLs resistant to metal ion stress in rice. As a result, a total of 9 QTLs related to metal ion content were detected. It contains 1 multi-effect QTL related to Cu and Hg; 3 QTLs related to As; 2 QTLs related to Fe, one of which has a LOD value as high as 5.53; 2 QTLs related to Zn accumulation, The LOD of one of them is as high as 7.29. Quantitative analysis of candidate genes related to resistance to metal ion stress in these QTL intervals found that the expression levels of the four genes LOC_Os01g14440 , LOC_Os01g18584 , LOC_Os01g20160 , LOC_Os04g34600 were significantly different between parents, Combining the results of the accumulated data of parental concentrations of different metal ions, we speculated that the high expression of LOC_Os01g14440 , LOC_Os01g18584 , and LOC_Os01g20160 may greatly improve the absorption capacity and the tolerance of rice to Zn stress, while the high expression of LOC_Os04g34600 may increase the absorption capacity and the tolerance of rice to Fe stress. Through the excavation and analysis of this QTL, it was found that these genes may affect the ability of rice to withstand metal ion stress, creating conditions for further breeding and screening of rice varieties resistant to metal ion stress.

根系作为水稻(Oryza sativa)植株的重要组成部分,在水稻生长发育过程中发挥多种作用,包括植物的固定、水分和营养物质的获取以及氨基酸和激素的生物合成等,其形态结构和生理功能与水稻产量和稻米品质以及抗性等密切相关.目前,通过遗传及生化等诸多手段,已挖掘到较多水稻根系QTLs与控制基因.该文综述了水稻根系QTL和基因的研究进展,并对未来根系研究进行展望,以期为进一步克隆水稻根系基因和完善水稻理想株型模型提供参考.

BACKGROUND: DNA methylation balance is an important regulatory mechanism for mammalian and plant development. The fruit ripening and anthocyanin accumulation of Vaccinium corymbosum are complex developmental processes that involve numerous physiological, biochemical, and structural alterations. OBJECTIVE: This study aimed to investigate the correlation of DNA methylation balance, DNA methylation and demethylation-related gene expression models and anthocyanin accumulation during blueberry fruit ripening. METHODS: The anthocyanin contents during V. corymbosum ‘O’Neal’ fruit development were evaluated. The V. corymbosum DNA methylation- and anthocyanin accumulation-related genes were isolated, and their relative expression patterns were detected during flower bud enlargement and fruit development. Moreover, the relative expression patterns of anthocyanin biosynthetic genes and the dynamic changes in the DNA methylation of the promoter sequences of key anthocyanin biosynthetic genes were evaluated. RESULTS: The results showed that the DNA methylation level of V. corymbosum fruit was consistent with anthocyanin accumulation during ripening, and the expression levels of anthocyanin biosynthetic and DNA methylation-related genes. CONCLUSIONS: During V. corymbosum fruit ripening, anthocyanin accumulation is regulated partially by DNA methylation balance of VcCHS and VcANS promoters.

BACKGROUND: DNA methylation balance is an important regulatory mechanism for mammalian and plant development. The fruit ripening and anthocyanin accumulation of Vaccinium corymbosum are complex developmental processes that involve numerous physiological, biochemical, and structural alterations. OBJECTIVE: This study aimed to investigate the correlation of DNA methylation balance, DNA methylation and demethylation-related gene expression models and anthocyanin accumulation during blueberry fruit ripening. METHODS: The anthocyanin contents during V. corymbosum ‘O’Neal’ fruit development were evaluated. The V. corymbosum DNA methylation- and anthocyanin accumulation-related genes were isolated, and their relative expression patterns were detected during flower bud enlargement and fruit development. Moreover, the relative expression patterns of anthocyanin biosynthetic genes and the dynamic changes in the DNA methylation of the promoter sequences of key anthocyanin biosynthetic genes were evaluated. RESULTS: The results showed that the DNA methylation level of V. corymbosum fruit was consistent with anthocyanin accumulation during ripening, and the expression levels of anthocyanin biosynthetic and DNA methylation-related genes. CONCLUSIONS: During V. corymbosum fruit ripening, anthocyanin accumulation is regulated partially by DNA methylation balance of VcCHS and VcANS promoters. Keywords DNA methylation , anthocyanin accumulation , blueberry , , , fruit development

为明确引起蓝莓枝干溃疡病的病原菌,为该病害的田间诊断及综合防治提供参考,采用组织分离法和单孢分离法对引起蓝莓枝干溃疡病的病原菌进行了分离纯化,利用柯赫氏法则、菌落形态特征及核糖体DNA内转录间隔区序列(rDNA-ITS)对菌株进行了分类鉴定,采用活体接种病原菌和病斑长度测量的方法检测了5种蓝莓品种的抗病性.从病枝分离得到疑似病原菌菌株15株(JA1～JA8、JB1～JB7),菌株JA4和JB2均可导致蓝莓枝干溃疡病.rDNA-ITS序列分析和菌落形态学鉴定发现,JA4为拟茎点霉菌(Phomopsis sp.),JB2为葡萄座腔菌(Botryosphaeria dothidea).接种试验表明,布里吉塔、蓝丰和蓝美人对枝干溃疡病的抗性没有显著差异.拟茎点霉菌(Phomopsis sp.)和葡萄座腔菌(Botryosphaeria dothidea)均可以引起蓝莓枝干溃疡病,拟茎点霉菌在春天条件适宜情况下可由花芽侵入,而葡萄座腔菌必须从伤口侵染,两种病原菌也可以产生复合侵染.蓝莓品种布里吉塔、蓝美人和蓝丰等品种抗性强;夏普蓝易受病原菌侵染,抗病性差.