稻瘟病菌重复顺序PoR6和稻瘟病菌的分型

POR6是一具有高度多态性的稻瘟病菌(Pyricularia oryzae)重复顺序。利用脉冲电泳技术和Southern分析,表明它是非均匀地散布于基因组中的。经测定POR6的拷贝数约为30—40,序列测定未发现在内部有更小的重复单位。用POR6作探针对44株稻瘟病菌进行DNA指纹分析,分析的中国北方地区的22个菌株可根据相似率归并成8个谱系。对一些转管培养中致病型发生变化的菌株用POR6进行指纹分析,发现这些菌株在转管过程中基因组DNA是有变化的。     

LncRNA ZNF667-AS1靶向 miR-31-5p对食管癌细胞增殖、迁移和凋亡的机制研究

目的探究长链非编码RNA(lncRNA)ZNF667-AS1通过靶向miR-31-5p对食管癌细胞增殖和迁移的影响及潜在的机制。方法采用实时荧光定量PCR(qPCR)技术检测ZNF667-AS1在食管癌细胞Eca109、EC1、TE1和正常食管上皮细胞Het-1A的表达水平,并选择表达差异最大的细胞株进行后续实验。采用脂质体转染技术将pcDNA3.1-ZNF667-AS1过表达重组载体质粒转染至人食管癌Eca109细胞,实验分为对照组(未行转染的Eca109细胞)、pcDNA3.1组(转染空载体质粒的Eca109细胞)和ZNF667-AS1组(转染pcDNA3.1-ZNF667-AS1质粒的Eca109细胞),qPCR技术检测pcDNA3.1-ZNF667-AS1的转染效果,噻唑蓝比色法(MTT)和平板克隆实验检测过表达ZNF667-AS1对Eca109细胞增殖能力的影响,Transwell实验检测Eca109细胞迁移能力,流式细胞术检测Eca109细胞凋亡率,Western blot检测Eca109细胞中G1/S-特异性周期蛋白-D1(Cyclin D1)、细胞周期依赖性激酶抑制因子(p21)、上皮标志物上皮型钙黏蛋白(E-cadherin)、间充质标志物神经型钙黏蛋白(N-cadherin)、波形蛋白(Vimentin)、B细胞淋巴瘤/白血病-2相关蛋白X(Bax)和B细胞淋巴瘤/白血病-2(Bcl-2)的表达水平,生物信息学预测ZNF667-AS1与miR-31-5p的互补配对关系,荧光素酶报告实验和qPCR技术验证ZNF667-AS1和miR-31-5p的靶向调控关系。多组间比较采用单因素方差分析,组间两两比较采用SNK-q检验。结果与Het-1A细胞相比,食管癌Eca109、EC1和TE1细胞中ZNF667-AS1的表达水平均降低(1.00±0.08比0.29±0.04,0.36±0.05,0.33±0.06),差异有统计学意义(P<0.001)。与ZNF667-AS1组相比,对照组及pcDNA3.1组中ZNF667-AS1的表达水平(3.14±0.32比1.00±0.10,0.94±0.09),细胞活力[(63.42±3.75)%比100.00±4.85、(97.69±4.57)%],细胞克隆形成数[(34.26±3.52)个比(95.64±10.22)个、(92.80±10.04、个],Cyclin D1表达水平(0.26±0.05比0.75±0.08、0.71±0.07),迁移细胞数[(20.24±2.35)个比(63.55±6.04)个、(60.02±6.12)个],细胞中E-cadherin表达水平(0.19±0.02比0.48±0.05,0.49±0.05)和miR-31-5p的表达水平(0.30±0.03比1.00±0.10,0.95±0.09)均升高,p21表达水平(0.79±0.09比0.24±0.05,0.26±0.06),细胞凋亡率[(29.17±1.26)%比(3.41±0.73)%,(3.72±0.78)%],细胞中N-cadherin(0.87±0.09比0.42±0.04,0.40±0.04)、Vimentin表达水平(0.82±0.08比0.44±0.04,0.44±0.04)均降低,差异有统计学意义(P均<0.001),与对照组比较,pcDNA3.1组ZNF667-AS1的表达水平,细胞活力,细胞克隆形成数,Cyclin D1和p21表达水平,迁移细胞数,细胞中E-cadherin、N-cadherin、Vimentin和miR-31-5p表达水平,细胞凋亡率差异无统计学意义(P均>0.05)。生物信息学预测发现ZNF667-AS1和miR-31-5p存在靶向结合位点;荧光素酶报告实验结果显示,与空载转染组比较,miR-31-5p组ZNF667-AS1-Wt相对荧光素酶活性(1.00±0.10比0.19±0.02)降低(P<0.05),ZNF667-AS1-Mut相对荧光素酶活性比较,差异无统计学意义(P>0.05)。结论过表达ZNF667-AS1能抑制食管癌Eca109细胞的增殖、迁移并诱导其凋亡,其机制可能与ZNF667-AS1靶向调控miR-31-5p有关。     

DELAYED HEADING DATE1 interacts with OsHAP5C/D,delays flowering time and enhances yield in rice

Heading date is an important agronomic trait affecting crop yield. The GRAS protein family is a plant‐specific super family extensively involved in plant growth and signal transduction. However, GRAS proteins are rarely reported have a role in regulating rice heading date. Here, we report a GRAS protein DHD1 (Delayed Heading Date1) delays heading and enhances yield in rice. Biochemical assays showed DHD1 physically interacts with OsHAP5C/D both in vitro and in vivo. DHD1 and OsHAP5C/D located in the nucleus and showed that rhythmic expression. Both DHD1 and OsHAP5C/D affect heading date by regulating expression of Ehd1. We propose that DHD1 interacts with OsHAP5C/D to delay heading date by inhibiting expression of Ehd1.     

2000年来吕梁连片贫困区植被净初级生产力时空变化特征

多年来吕梁连片贫困区实施的生态恢复措施对其生态环境产生了较大影响,为掌握该区域在生态恢复措施实施(2000年)以来植被净初级生产力的变化状况,利用2000—2018年时序的遥感数据和基于光能利用率的CASA模型对其进行了模拟,并分析了导致其变化的主要控制因素,结果显示:(1)2000年以来吕梁连片贫困区NPP整体上升,其中93.46%的区域NPP呈增长状态,6.54%的区域呈减少状态,2010—2015年区域NPP出现下降。(2)受人类活动影响,过去18年来区域土地利用类型变化较为显著,耕地面积缩减,草地面积基本保持稳定,林地与城镇面积增加且城镇面积扩张迅速,不同土地利用下的NPP特征差异显著,耕地NPP年均值增长最为迅速,为5.9 gC m^-2 a^-1,林地最为平稳,为1.32 gC m^-2 a^-1。(3)研究区降水量波动对区域NPP的变化影响显著,未来气候变化中降水量的变化可能对区域NPP产生直接影响。研究结果将为区域生态恢复、精准扶贫及黄河中游地区的经济发展提供重要的理论支撑。     

Identification of a stable quantitative trait locus for percentage grains with white chalkiness in rice (Oryza sativa)

High chalkiness is a major problem in many rice-producing areas of the world, especially in hybrid rice (Oryza sativa L.) in China. We previously showed a major quantitative trait locus for the percentage of grains with white chalkiness (QTLqPGWC-8) in the interval G1149-R727 on chromosome 8 using a chromosome segment substitution line (CSSL). Here, we selected the line-CSSL50 harboring the QTLqPGWC-8 allele from the CSSLs derived from a cross between Asominori (as a recurrent parent) and IR24 (as a donor parent), which had higher percentage chalkiness, markedly different from that of Asominori. There were also significant differences in starch granules, appearance of amylose content (AAC) and milling qualities between Asominori and CSSL50, but not in grain size or thousand grain weight (TGW). The BC(4) F(2) and BC(4) F(3) populations from a cross between CSSL50 and Asominori were used for fine mapping of qPGWC-8. We narrowed down the location of this QTL to a 142 kb region between Indel markers 8G-7 and 8G-9. QTLqPGWC-8 accounted for 50.9% of the difference in PGWC between the parents. The markers tightly linked to qPGWC-8 should facilitate cloning of the gene underlying this QTL and will be of value for marker-assisted selection in breeding rice varieties with better grain quality.     

The failure to express a protein disulphide isomerase-like protein results in a floury endosperm and an endoplasmic reticulum stress response in rice

The rice somaclonal mutant T3612 produces small grains with a floury endosperm, caused by the loose packing of starch granules. The positional cloning of the mutation revealed a deletion in a gene encoding a protein disulphide isomerase-like enzyme (PDIL1-1). In the wild type, PDIL1-1 was expressed throughout the plant, but most intensely in the developing grain. In T3612, its expression was abolished, resulting in a decrease in the activity of plastidial phosphorylase and pullulanase, and an increase in that of soluble starch synthase I and ADP-glucose pyrophosphorylase. The amylopectin in the T3612 endosperm showed an increase in chains with a degree of polymerization 8-13 compared with the wild type. The expression in the mutant's endosperm of certain endoplasmic reticulum stress-responsive genes was noticeably elevated. PDIL1-1 appears to play an important role in starch synthesis. Its absence is associated with endoplasmic reticulum stress in the endosperm, which is likely to underlie the formation of the floury endosperm in the T3612 mutant.     

Young Seedling Stripe1 encodes a chloroplast nucleoid-associated protein required for chloroplast development in rice seedlings

Planta - Young Seedling Stripe1 (YSS1) was characterized as an important regulator of plastid-encoded plastid RNA polymerase (PEP) activity essential for chloroplast development at rice seedling...     

Albino midrib 1, encoding a putative potassium efflux antiporter,affects chloroplast development and drought tolerance in rice

Key message

Mutation of the AM1 gene causes an albino midrib phenotype and enhances tolerance to drought in rice

Abstract

K⁺ efflux antiporter (KEA) genes encode putative potassium efflux antiporters that are mainly located in plastid-containing organisms, ranging from lower green algae to higher flowering plants. However, little genetic evidence has been provided on the functions of KEA in chloroplast development. In this study, we isolated a rice mutant, albino midrib 1 (am1), with green- and white-variegation in the first few leaves, and albino midrib phenotype in older tissues. We found that AM1 encoded a putative KEA in chloroplast. AM1 was highly expressed in leaves, while lowly in roots. Chloroplast gene expression and proteins accumulation were affected during chlorophyll biosynthesis and photosynthesis in am1 mutants. Interestingly, AM1 was induced by salt and PEG, and am1 showed enhanced sensitivity to salinity in seed germination and increased tolerance to drought. Taken together, we concluded that KEAs were involved in chloroplast development and played important roles in drought tolerance.