Msps governs acentrosomal microtubule assembly and reactivation of quiescent neural stem cells

The ability of stem cells to switch between quiescence and proliferation is crucial for tissue homeostasis and regeneration. Drosophila quiescent neural stem cells (NSCs) extend a primary cellular protrusion from the cell body prior to their reactivation. However, the structure and function of this protrusion are not well established. Here, we show that in the protrusion of quiescent NSCs, microtubules are predominantly acentrosomal and oriented plus‐end‐out toward the tip of the primary protrusion. We have identified Mini Spindles (Msps)/XMAP215 as a key microtubule regulator in quiescent NSCs that governs NSC reactivation via regulating acentrosomal microtubule growth and orientation. We show that quiescent NSCs form membrane contact with the neuropil and E‐cadherin, a cell adhesion molecule, localizes to these NSC‐neuropil junctions. Msps and a plus‐end directed motor protein Kinesin‐2 promote NSC cell cycle re‐entry and target E‐cadherin to NSC‐neuropil contact during NSC reactivation. Together, this work establishes acentrosomal microtubule organization in the primary protrusion of quiescent NSCs and the Msps‐Kinesin‐2 pathway that governs NSC reactivation, in part, by targeting E‐cad to NSC‐neuropil contact sites.     

Functional analysis of rubber tree receptor-like cytoplasmic kinase HbBIK1 in plant root development and immune response

Tree Genetics & Genomes - The correct name of the 3rd Author is presented in this paper.     

CgMFS1, a Major Facilitator Superfamily Transporter,Is Required for Sugar Transport,Oxidative Stress Resistance,and Pathogenicity of Colletotrichum gloeosporioides from Hevea brasiliensis

Colletotrichum gloeosporioides is the main causal agent of anthracnose in various plant species. Determining the molecular mechanisms underlying the pathogenicity and fungicide resistance of C. gloeosporioides could help build new strategies for disease control. The major facilitator superfamily (MFS) has multiple roles in the transport of a diverse range of substrates. In the present study, an MFS protein CgMFS1 was characterized in C. gloeosporioides. This protein contains seven transmembrane domains, and its predicted 3D structure is highly similar to the reported hexose transporters. To investigate the biological functions of CgMFS1, the gene knock-out mutant ΔCgMFS1 was constructed. A colony growth assay showed that the mutant was remarkably decreased in vegetative growth in minimal medium supplemented with monosaccharides and oligosaccharides as the sole carbon sources, whereas it showed a similar growth rate and colony morphology as wild types when using soluble starch as the carbon source. A stress assay revealed that CgMFS1 is involved in oxidative stress but not in the fungicide resistance of C. gloeosporioides. Furthermore, its pathogenicity was significantly impaired in the mutant, although its appressorium formation was not affected. Our results demonstrate that CgMFS1 is required for sugar transport, resistance to oxidative stress, and the pathogenicity of Colletotrichum gloeosporioides from Hevea brasiliensis.     

Antifungal effects of lycorine on Botrytis cinerea and possible mechanisms

Biotechnology Letters - Botrytis cinerea cause postharvest diseases on fruit and lead economic losses. Application of environment-friendly natural compounds is an alternative for synthetic...     

基于2b-RAD简化基因组测序的甜瓜遗传多样性分析

该研究利用2b-RAD(type IIB endonucleases restriction-site associated DNA)测序对28份厚皮甜瓜亲本材料的单核苷酸多态性(single nucleotide polymorphism,SNP)位点进行基因分型,分析其遗传多样性与亲缘关系,为甜瓜分子标记辅助育种提供科学依据。结果表明:(1)28份甜瓜种质SNPs数量有10318个,其发生转换与发生颠换的比值为2.15,两两种质间的遗传分化系数和遗传距离的平均值分别为0.88和2.22,说明这28份种质之间存在高度的遗传分化。(2)依据甜瓜的果皮颜色、果面网纹和果肉颜色3种性状,分别将以上28份种质分为4个群体(白皮群体、黄皮群体、青皮群体和绿皮群体)、3个群体(光皮群体、稀网群体和密网群体)以及3个群体(白肉群体、桔肉群体和绿肉群体)。(3)表型性状遗传分析结果显示,依据果皮颜色分类的各群体之间的遗传分化程度最高,其遗传分化系数在0.05~0.19之间,即均存在中度及以上程度的分化;光皮群体与密网群体之间存在中度遗传分化,但光皮群体与稀网群体之间以及稀网群体与密网群体之间均无显著分化;白肉群体与桔肉群体之间存在中度遗传分化,但白肉群体与绿肉群体之间以及桔肉群体与绿肉群体之间无明显分化。(4)分子系统进化树分析将28份甜瓜种质划分为三类,其中,第一类包含11份种质(主要为自主选育的纯合种质),第二类包含9份种质(大部分为从新疆引进或从新疆品种中选育出来的纯合种质),第三类包含8份种质(大部分为从日本引进或从日本品种中选育出来的纯合种质)。研究表明,依据甜瓜分子水平的聚类结果与地理来源具有一定关系,但其与育种者依据甜瓜的果皮颜色、果面网纹和果肉颜色对育种材料的分类结果不完全一致。     

甜瓜幼苗叶片内源一氧化氮和蔗糖代谢对低温胁迫的响应

以低温敏感型甜瓜品种‘XL-1’和耐低温型品种‘红优’为试材,采用6℃低温处理0、1、3、6、12、24h及3d、5d和7d,研究低温胁迫下甜瓜幼苗叶片中NO合成和蔗糖代谢的变化特征。结果表明:(1)低温胁迫能提高甜瓜幼苗叶片中硝酸还原酶(NR)活性,诱导促进NO生成,其中耐低温型甜瓜‘红优’中NO对低温的响应时间更早,变化幅度更大。(2)与对照相比,低温胁迫处理提高了2种甜瓜幼苗叶片中蔗糖、果糖和葡萄糖含量,增加了蔗糖磷酸合成酶(SPS)、蔗糖合成酶(SS)、酸性转化酶(AI)和中性转化酶(NI)活性,降低了淀粉含量。(3)低温胁迫处理使2种甜瓜叶片中渗透调节物质可溶性糖、可溶性蛋白、脯氨酸的含量上升。研究发现,低温胁迫通过增加甜瓜体内NO合成酶的活性刺激体内NO合成,通过促进蔗糖代谢相关酶的活性,提高蔗糖、果糖和葡萄糖的含量,从而响应低温胁迫,且低温胁迫诱导的糖分物质积累时间晚于NO的产生时间。     

木质素在海洋中的生物转化及其对海洋碳循环的影响

微型生物参与的海洋碳汇是海洋重要的储碳途径,可调节全球气候变化。木质素是地球上第二大光合而成的碳库,其在海洋中的生物地球化学过程与海洋碳循环密切相关。异养微生物所主导的代谢活动是木质素生物转化的主要途径。近年来,迅速发展的高通量测序技术与传统微生物技术相结合,在探索自然生境中木质素代谢菌群,发现木质素代谢新物种,挖掘相关功能基因等方面已取得一系列成果。然而绝大多数的研究主要集中于陆地生态系统,对于海洋生态系统的研究仍较少。陆源有机碳在海洋中的转化过程仍是一个"谜",故解析海洋木质素碳转化是海洋碳循环研究的重要任务。本文综述了参与海洋木质素转化的功能微生物、木质素代谢机理以及微生物碳代谢活动与海洋碳汇过程的内在联系,为今后的研究提供参考。     

The fertilization effect of global dimming on crop yields is not attributed to an improved light interception

Global dimming, a decadal decrease in incident global radiation, is often accompanied with an increase in the diffuse radiation fraction, and, therefore, the impact of global dimming on crop production is hard to predict. A popular approach to quantify this impact is the statistical analysis of historical climate and crop data, or use of dynamic crop simulation modelling approach. Here, we show that statistical analysis of historical data did not provide plausible values for the effect of diffuse radiation versus direct radiation on rice or wheat yield. In contrast, our field experimental study of 3 years demonstrated a fertilization effect of increased diffuse radiation fraction, which partly offset yield losses caused by decreased global radiation, in both crops. The fertilization effect was not attributed to any improved canopy light interception but mainly to the increased radiation use efficiency (RUE). The increased RUE was explained not only by the saturating shape of photosynthetic light response curves but also by plant acclimation to dimming that gradually increased leaf nitrogen concentration. Crop harvest index slightly decreased under dimming, thereby discounting the fertilization effect on crop yields. These results challenge existing modelling paradigms, which assume that the fertilization effect on crop yields is mainly attributed to an improved light interception. Further studies on the physiological mechanism of plant acclimation are required to better quantify the global dimming impact on agroecosystem productivity under future climate change.     

MiR‐30a‐5p inhibits proliferation and metastasis of hydatidiform mole by regulating B3GNT5 through ERK/AKT pathways

Hydatidiform moles are gestational trophoblastic disease. They are abnormal proliferations of trophoblast cells that have the potential to become cancerous. miR‐miR30a‐5p is a tumour suppressor that participates in the development of numerous diseases. However, the role of miR‐30a in hydatidiform moles and the mechanisms underlying its effects are presently unclear. This study explored the levels of miR‐30a and B3GNT5 expression in human hydatidiform mole tissue. The results showed that miR‐30a and B3GNT5 were differentially expressed in normal placenta and hydatidiform mole, and miR‐30a decreased cell proliferation, invasion and migration in trophoblast cell lines. Upon further examination, it was confirmed that miR‐30a directly targeted the 3’untranslated region of B3GNT5 using a dual‐luciferase assay. The results of the present study also revealed that miR‐30a reduced the proliferation, invasion and migration ability in JAR and BeWo cells by regulating B3GNT5, which may inactivate the ERK and AKT signalling pathways. This study demonstrated that miR‐30a was a novel target B3GNT5 that serves an important role in the development of hydatidiform moles, suggesting that miR‐30a may serve as a novel potential biomarker or useful diagnostic and therapeutic tool for hydatidiform moles in clinical settings.