Comparative analysis of genetic effects of wheat‐Dasypyrum villosum translocations T6V#2S·6AL and T6V#4S·6DL

Wheat‐Dasypyrum villosum translocations T6V#2S·6AL and T6V#4S·6DL, carriers of Pm21 and PmV, respectively, confer high resistance to wheat powdery mildew. For better understanding of the difference in genetic effect between them, a RIL population was constructed based on the cross between “Yangmai 18” carrying T6V#2S·6AL and “Yangmai 22” carrying T6V#4S·6DL. Analysis of distribution of the translocations showed that T6V#2S·6AL is much more transmittable than T6V#4S·6DL. By comparing their effects on main agronomic traits, we firstly found that T6V#2S·6AL contributes greatly to top spikelet fecundity, but causes a decrease of 6.7%–10.5% of spike number. No stable effects of T6V#4S·6DL on agronomic traits were found, except for positive effect on plant height. Excitingly, a new recombinant, T6V#4S‐6V#2S·6AL carrying PmV, was screened and proved to have a higher transmission rate than the original translocation T6V#4S·6DL, which will greatly promote the utilization of PmV. The above conclusions of this research will provide important guidance for utilization of Pm21 and PmV more effectively, in wheat powdery mildew resistance breeding.     

乙酰羟酸合酶抑制剂类除草剂的植物抗性机制

乙酰羟酸合酶(AHAS)抑制剂类除草剂已被广泛用于农业生产,然而使用过程中可能对部分敏感农作物产生药害,因此创制对不同类别除草剂具有抗性的一系列作物新品种至关重要。本文将从AHAS抑制剂类除草剂的类别与特点、AHAS靶酶的特性及其在支链氨基酸合成中的作用、除草剂的靶标抗性与非靶标抗性机制等方面分析国内外研究现状与未来发展动态,以期为农作物除草剂抗性性状的遗传改良和开发应用提供参考。     

Spraying exogenous synthetic cytokinin 6‐benzyladenine following the waterlogging improves grain growth of waterlogged maize in the field

6‐Benzyladenine (6‐BA, a synthetic cytokinin) could improve the ability to resist adversity. However, very little attention has been given to its role in alleviating waterlogging damages on grain growth. A field experiment was performed to investigate effects of exogenous 6‐BA after waterlogging for 6 days at the third leaf stage (V3‐WL + 6‐BA) or the sixth leaf stage (V6‐WL + 6‐BA) on grain filling, and endogenous hormone of summer maize hybrids DengHai605 (DH605) and ZhengDan958 (ZD958), which were planted popularly in China. Exogenous 6‐BA alleviated waterlogging damages on grain filling by improving grain weight and volume, which was beneficial to yield increase. Grain yield of DH605 under V3‐WL + 6‐BA and V6‐WL + 6‐BA increased by 16% and 12%, respectively, compared with that of V3‐WL (waterlogging at the third leaf stage) and V6‐WL (waterlogging at the sixth leaf stage), while the corresponding values for ZD958 increased by 20% and 15%, respectively. Moreover, exogenous 6‐BA alleviated waterlogging damages on grain endogenous hormone content by increasing levels of endogenous indole‐3‐acetic acid, zeatin riboside, and gibberellic acid, and decreasing level of abscisic acid in grain of waterlogged summer maize during grain‐filling periods. Clearly, exogenous 6‐BA improved grain‐filling characteristics, and endogenous hormone, resulting in a significant yield increase of waterlogged summer maize.     

棉花蔗糖合成酶基因家族在纤维发育期时空表达模式分析

蔗糖合成酶(Sucrose Synthase)是调控植物糖类代谢的关键酶之一,在植物生长发育及渗透调节过程中起着重要的作用。该酶为多基因家族,各成员在植物不同组织及不同发育阶段发挥不同的作用。陆地棉(Gossypium hirsutum)中有15个Sus成员,本研究利用转录组高通量测序及实时定量PCR技术,检测了该基因家族的表达模式。结果表明,Gh Sus1D、Gh Sus3A、Gh Sus3D和Gh Sus6D在起始期(0~3 DPA)大量表达;GhSus7D在10 DPA的纤维中表达量快速增加,达到同期突变体胚珠的4.7倍;Gh Sus1A、Gh Sus5D在纤维伸长期(5~15 DPA)表达量显著高于胚珠,分别在10 DPA、15 DPA时达到峰值;Gh Sus3A、Gh Sus3D、和Gh Sus6D在纤维发育(15 DPA)时表达量重新上升,且在20 DPA时仍处于较高表达水平。Sus基因家族组织表达模式分析表明,它们在陆地棉品种徐州142野生型和突变体中的组织表达模式基本相同,根、茎、叶、花中没有显著差异。但不同Sus基因具有不同的组织表达特异性。     

柑橘CHS基因序列多态性及表达水平对类黄酮生物合成的影响

查尔酮的合成是类黄酮生物合成途径中的一个关键节点。从10个柑橘种质中克隆了查尔酮合成酶(chalcone synthase,CHS)基因,并对其不同时期的果实和叶片中的类黄酮含量进行了测定,分析了CHS基因的序列多态性与类黄酮含量之间的关系;同时通过qRT-PCR检测了CHS基因在不同种质之间以及同一种质的不同组织间的表达差异。结果表明,柑橘CHS基因的核苷酸序列高度保守,相似度达98%以上。聚类分析表明,CHS氨基酸序列的多态性有物种特异性,而且与类黄酮含量有一定的相关性。CHS基因的表达水平在不同种质、部位及生长发育时期有显著差异,这些差异与类黄酮的含量有显著的相关性,说明CHS基因对类黄酮的生物合成有明显影响。     

Screening of lentiviral vectors carrying effective siRNA targeting S1P2 gene

AIM:To screen the lentiviral vector carrying siRNA with higher efficiency of suppressing the sphingosine-1-phosphate receptor 2(S1P2) gene expression in the primarily cultured corpus cavernosum smooth muscle cells of spontaneously hypertensive rats (SHR).METHODS:SHR and SD rats (n=5 each) were used for primarily culturing corpus cavernosum smooth muscle cells.The cells were randomly divided into 6 groups:SHR siRNA-1,SHR siRNA-2,SHR siRNA-3,SHR GFP,SHR control (SHR non-transfection group),and SD control (SD rat control group).Each group had 5 samples with 1.0×10⁵ cells of each sample.At 72 h after transfection (MOI=60) with lentiviral vectors carrying S1P2 siRNA into the SHR corpus cavernosum smooth muscle cells,the expression of GFP was observed under fluorescence microscope.The protein expression of S1P2,ROCK1,ROCK2 and eNOS in the corpus cavernosum smooth muscle cells,and the mRNA expression of S1P2,ROCK1 and ROCK2 were determined by by Western blot and RT-PCR.RESULTS:The transfection efficiency of the corpus cavernosum smooth muscle cells in SHR siRNA-1,SHR siRNA-2,SHR siRNA-3 and SHR GFP groups were>80%.Compared with SHR control group,the mRNA levels and the protein expression of S1P2,ROCK1 and ROCK2 in SHR GFP group showed no remarkable changes,while those in SHR siRNA-1,SHR siRNA-2,SHR siRNA-3 and SD control groups were significantly lower than those in SHR control group (P<0.05).The protein expression of eNOS in SHR siRNA-1,SHR siRNA-2,SHR siRNA-3 and SHR GFP groups were not significantly changed as compared with SHR control group,but that in SD control group was significantly higher than that in SHR control group.CONCLUSION:Three groups of siRNA lentiviral vectors targeting S1P2 inhibit the expression of S1P2 in the corpus cavernosum smooth muscle cells of SHR,and by silencing the S1P2 expression,the expression of ROCK1 and ROCK2 is inhibited.Among them,siRNA-1 has the highest inhibitory efficiency.     

茶树咖啡碱合成酶CRISPR/Cas9基因组编辑载体的构建

CRISPR/Cas9技术是一门新兴的基因组定点编辑技术,具有操作简单、高效的优点,可轻松实现对目标基因的敲除、替换和定点突变等操作。该技术刚诞生,就受到了全球生命科学领域研究者的关注,不到3年的时间就已经成功应用于多种动、植物当中。然而CRISPR/Cas9技术在茶树中的应用面临载体构建问题,本文以茶树咖啡碱合成酶为例,联合采用常规PCR、Overlapping PCR和Golden Gate Cloning技术,构建了包含茶树咖啡碱合成酶双靶点的CRISPR/Cas9基因编辑载体,为CRISPR/Cas9介导的基因组编辑技术在茶树中的应用奠定了坚实基础。     

广藿香中PTS基因不同时间点的表达分析

利用荧光定量PCR技术,分析1天中8个时间点广藿香叶片百秋李醇合成酶基因的表达情况。结果表明,6∶00,9∶00,12∶00和15∶00时间点的PTS基因表达量较低,0∶00,3∶00,18∶00和21∶00的表达量均显著高于前4个时间点,其中,时间点3∶00的表达量最高,表明PTS基因的转录从夜间开始积累,黎明前达到最高峰,之后转录水平逐渐下降。     

Effect of dietary fish meal and fish oil replacement on lipogenic and lipoprotein lipase activities and plasma insulin in gilthead sea bream (Sparus aurata)

The effects of a double replacement of fish oil (FO) and fish meal (FM) by dietary vegetable ingredients in juvenile gilthead sea bream (Sparus aurata L. 1758) on some indices of lipid metabolism and plasma insulin levels were analysed. Four experimental diets with a replacement of 75% of FM by plant proteins (PP) were administered. Added oil was either FO (75PP/FO diet), or a vegetable oil mix (VO), replacing 33%, 66% or 100% of FO (75PP/33VO, 75PP/66VO, 75PP/100VO diets). Another diet with 50% of substitution of FM by PP and with 100% of VO was also tested (50PP/100VO diet). Final body weight was similar in all diet groups, except for the 75PP/100VO group, which presented lower values. Circulating insulin levels increased with feed administration in all groups and no differences between diets were observed, with the exception of the 75PP/FO group, which presented higher plasma insulin values. In adipose tissue, glucose‐6‐phosphate dehydrogenase and malic enzyme activities decreased with the inclusion of vegetable oil, especially 5 h after feeding. Diet had no significant effect on the hepatic activity of either enzyme. Lipoprotein lipase activity decreased in white muscle and adipose tissue with the replacement of fish oil in 75PP diets, 5 h after feeding. In conclusion, the use of a combined replacement of fish oil and fish meal by vegetable ingredients in gilthead sea bream permits satisfactory growth, with moderate changes in tissue lipogenesis and lipid uptake.