Research progress on gut health of farmers teleost fish: a viewpoint concerning the intestinal mucosal barrier and the impact of its damage

Reviews in Fish Biology and Fisheries - The intestinal mucosal barrier plays a critical role in the maintenance of host health. In farmed teleost fish, the intestinal epithelium is challenged by a...     

Overexpression of the persimmon abscisic acid β‐glucosidase gene (DkBG1) alters fruit ripening in transgenic tomato

β‐Glucosidases (BG) are present in many plant tissues. Among these, abscisic acid (ABA) β‐glucosidases are thought to take part in the adjustment of cellular ABA levels, however the role of ABA‐BG in fruits is still unclear. In this study, through RNA‐seq analysis of persimmon fruit, 10 full‐length DkBG genes were isolated and were all found to be expressed. In particular, DkBG1 was highly expressed in persimmon fruits with a maximum expression 95 days after full bloom (DAFD). We verified that, in vitro, DkBG1 protein can hydrolyze ABA‐glucose ester (ABA‐GE) to release free ABA. Compared with wild‐type, tomato plants that overexpressed DkBG1 significantly upregulated the expression of ABA receptor PYL3/7 genes and showed typical symptoms of ABA hypersensitivity in fruits. DkBG1 overexpression (DkBG1‐OE) accelerated fruit ripening onset by 3–4 days by increasing ABA levels at the pre‐breaker stage and induced early ethylene release compared with wild‐type fruits. DkBG1‐OE altered the expression of ripening regulator NON‐RIPENING (NOR) and its target genes; this in turn altered fruit quality traits such as coloration. Our results demonstrated that DkBG1 plays an important role in fruit ripening and quality by adjusting ABA levels via hydrolysis of ABA‐GE.     

A biotechnology‐based male‐sterility system for hybrid seed production in tomato

Incorporating male sterility into hybrid seed production reduces its cost and ensures high varietal purity. Despite these advantages, male‐sterile lines have not been widely used to produce tomato (Solanum lycopersicum) hybrid seeds. We describe the development of a biotechnology‐based breeding platform that utilized genic male sterility to produce hybrid seeds. In this platform, we generated a novel male‐sterile tomato line by clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR‐associated protein 9 (Cas9)‐mediated mutagenesis of a stamen‐specific gene SlSTR1 and devised a transgenic maintainer by transforming male‐sterile plants with a fertility‐restoration gene linked to a seedling‐colour gene. Offspring of crosses between a hemizygous maintainer and the homozygous male‐sterile plant segregated into 50% non‐transgenic male‐sterile plants and 50% male‐fertile maintainer plants, which could be easily distinguished by seedling colour. This system has great practical potential for hybrid seed breeding and production as it overcomes the problems intrinsic to other male‐sterility systems and can be easily adapted for a range of tomato cultivars and diverse vegetable crops.     

古DNA捕获新技术与中国南方早期人群遗传研究新格局

古DNA捕获技术目前已获得极大的发展,能够从骨骼和环境沉积物等多种材料中获取到目的DNA片段,而且对于保存环境较差的低纬度地区,同样能够获取有效的内源DNA片段,极大地丰富了古DNA研究的材料来源。本文围绕这一新技术开展总结和讨论,主要分为两个方面：1）总结并介绍该技术应用前景;2）应用这一技术打开了中国南方早期人群研究的新局面,梳理该新技术的应用对史前中国南方人群古基因组研究所获得的新认识,并对中国南方早期人群古基因组深入分析;另外,利用古DNA捕获技术成功获取云南3446~3180 BP的大阴洞遗址4例高质量线粒体基因组信息,并开展了人群遗传历史的研究。     

灌木斑块格局对产流及产沙过程的影响

研究景观斑块盖度和连通方式影响下坡面径流、输沙及其水动力学参量的变化规律,对于揭示坡面土壤侵蚀过程的水动力机制和水文连通性具有重要意义。本研究采用野外人工模拟降雨试验,分析灌木样地不同覆盖度水平(0%、20%、40%、60%、90%)和不同连通方式(竖路径、横路径、S路径、随机斑块路径)下坡面径流、输沙及其水动力学参量的变化。结果表明: 随灌木覆盖度增加,产流量和产沙量均呈指数递减趋势;覆盖度增加到60%以上时,灌木减水减沙能力趋于稳定。随灌木覆盖度增加,流速、径流深、雷诺数、弗劳德数、径流功率和径流剪切力显著降低,曼宁糙率系数和Darcy-Weisbach阻力系数显著增大;但当灌木覆盖度增加到60%以上时,水力学参数特征值变化无显著差异。4种连通方式的产流率大小依次为竖路径>S路径>横路径>随机斑块;产沙率表现为竖路径最大,S路径次之,横路径与随机斑块无显著差异。连通性差的路径(横路径、随机斑块路径)与连通性好的路径(竖路径、S路径)相比,表现出较强的水力传输阻力和较差的水力挟沙能力。研究灌木斑块不同覆盖度和不同组合方式对坡面产流产沙量和水动力参量的作用,阐明植被减水减沙的临界盖度和合理配置方式,可为黄土高原水土流失治理和黄河流域高质量发展提供重要的理论依据。     

赤松枯梢病叶内生真菌多样性研究

在微生物层面研究枯梢病与植物针叶内生微生物的互作关系,分析内生真菌的多样性差异,为松枯梢病的防控提供基础数据。利用高通量测序技术测定赤松(Pinus densiflora)不同染病程度的针叶内生真菌的多样性。结果显示,随着病害的加重,P. densiflora针叶内生真菌丰富度呈现出上升的趋势,多样性指数表现为先下降后上升的趋势。无病斑针叶内生真菌中,子囊菌门(Ascomycota)与担子菌门(Basidiomycota)相对丰度最高,优势属为Lapidomyces和Selenophoma,病害导致优势菌相对丰度的降低。通过对不同染病情况的P. densiflora针叶内生真菌的测定,明确了枯梢病不同发病程度的P. densiflora针叶内生真菌的多样性及群落结构组成。     

三裂叶薯NBS-LRR类抗病基因的筛选鉴定与结构分析

为发掘甘薯近缘野生种三裂叶薯(Ipomoea triloba)的NBS-LRR类抗病基因,从基因数据库中对三裂叶薯基因组序列进行了筛选、鉴定和分析。结果表明,从三裂叶薯的98 025个基因中,筛选到282个编码NBS-LRR类蛋白的基因,其中N型80个,NL型83个,CN型28个,CNL型57个,TN型10个,TNL型23个,RN型1个。三裂叶薯的16条染色体上均含有NBS-LRR家族基因,数量最多的染色体含有65个,最少的只有1个。三裂叶薯基因组共有55个基因簇,包含了63.5%的NBS-LRR家族基因。在NBS-LRR抗病基因家族中,CNL和TNL亚家族分别对应到7和11个保守结构域。这为三裂叶薯抗性资源的利用提供了科学参考。