Search Advanced

Message Board

Dear readers, authors and reviewers,you can add a message on this page. We will reply to you as soon as possible!

2025 Volume 47 Issue 3
Article Contents
Previous Article Next Article

YU Ling, SHEN Shikai, WANG Jiajun, et al. Infestation of Citrus chlorotic Dwarf-Associated Virus in Eureka lemon Induced Cellular Autophagy[J]. Journal of Southwest University Natural Science Edition, 2025, 47(3): 37-45. doi: 10.13718/j.cnki.xdzk.2025.03.004
Citation: YU Ling, SHEN Shikai, WANG Jiajun, et al. Infestation of Citrus chlorotic Dwarf-Associated Virus in Eureka lemon Induced Cellular Autophagy[J]. Journal of Southwest University Natural Science Edition, 2025, 47(3): 37-45. doi: 10.13718/j.cnki.xdzk.2025.03.004
shu

Infestation of Citrus chlorotic Dwarf-Associated Virus in Eureka lemon Induced Cellular Autophagy

  • 1.

    Citrus Research Institute, Southwest University/National Citrus Engineering Research Center, Chongqing 400712, China

  • 2.

    Fruit Research Institute, Guizhou Academy of Agricultural Sciences, Guiyang 550000, China

  • 3.

    Economic Crop Development Center of Wanzhou District, Wanzhou Chongqing 404100, China

More Information
  • Corresponding author: ZHOU Yan
  • Received Date: 30/07/2024
    Available Online: 20/03/2025

  • MSC: S436.66;S666.5

  • Autophagy is an important defense mechanism of host in response to virus infection. To clarify whether the infection of Citrus chlorotic dwarf-associated virus (CCDaV) could induce autophagic response in plant, in this study, transmission electron microscope (TEM), quantitative real-time PCR, confocal microscopy analysis of enhanced green fluorescent protein-tagged Nicotiana benthamiana ATG8f (GFP-NbATG8f) and western blot were used to investigate the formation of autophagic structure, the transcript levels of autophagy related genes and ATG8 content in CCDaV-infected Eureka lemon, respectively. The results showed that the formation of autophagic structure was observed in the cytoplasm of CCDaV-infected Eureka lemon leaf cell by TEM at 15 days post inoculation (dpi). Compared with the healthy control, the expression levels of autophagy related genes (ClATG3, ClATG5, ClATG7, ClATG8a, ClATG8d, ClATG8f, ClATG8g, ClATG8i, ClBeclin1, ClPI3K and ClNBRI) in CCDaV-infected Eureka lemon leaves were significantly up-regulated, and ATG8 content was increased by 1.99 times. After co-expression of the six viral proteins encoded by CCDaV with GFP-NbATG8f in N. benthamiana for 48 h, the number of autophagosomes induced by co-expression of V3 and V4 proteins with GFP-NbATG8f was significantly higher than that of the control, and the content of free GFP was also significantly increased. These results indicated that CCDaV infection induced autophagic response in Eureka lemon, and V3 and V4 proteins may be important factors to induce autophagy.

  • 加载中
  • [1] DE DUVE C, WATTIAUX R. Functions of Lysosomes[J]. Annual Review of Physiology, 1966, 28(1): 435-492. doi: 10.1146/annurev.ph.28.030166.002251

    CrossRef Google Scholar

    [2] TSUKADA M, OHSUMI Y. Isolation and Characterization of Autophagy-Defective Mutants of Saccharomyces Cerevisiae[J]. FEBS Letters, 1993, 333(1-2): 169-174. doi: 10.1016/0014-5793(93)80398-E

    CrossRef Google Scholar

    [3] HEYDRICK S J, LARDEUX B R, MORTIMORE G E. Uptake and Degradation of Cytoplasmic RNA by Hepatic Lysosomes. Quantitative Relationship to RNA Turnover[J]. Journal of Biological Chemistry, 1991, 266(14): 8790-8796. doi: 10.1016/S0021-9258(18)31516-3

    CrossRef Google Scholar

    [4] LIU Y L, SCHIFF M, CZYMMEK K, et al. Autophagy Regulates Programmed Cell Death during the Plant Innate Immune Response[J]. Cell, 2005, 121(4): 567-577. doi: 10.1016/j.cell.2005.03.007

    CrossRef Google Scholar

    [5] LI F F, ZHANG C W, LI Y Z, et al. Beclin1 Restricts RNA Virus Infection in Plants through Suppression and Degradation of the Viral Polymerase[J]. Nature Communications, 2018, 9(1): 1268. doi: 10.1038/s41467-018-03658-2

    CrossRef Google Scholar

    [6] NIU E B, LIU H, ZHOU H S, et al. Autophagy Inhibits Intercellular Transport of Citrus Leaf Blotch Virus by Targeting Viral Movement Protein[J]. Viruses, 2021, 13(11): 2189. doi: 10.3390/v13112189

    CrossRef Google Scholar

    [7] LAMB C A, YOSHIMORI T, TOOZE S A. The Autophagosome: Origins Unknown, Biogenesis Complex[J]. Nature Reviews Molecular Cell Biology, 2013, 14(12): 759-774. doi: 10.1038/nrm3696

    CrossRef Google Scholar

    [8] NIU E B, YE C Z, ZHAO W Y, et al. Coat Protein of Chinese Wheat Mosaic Virus Upregulates and Interacts with Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenase, a Negative Regulator of Plant Autophagy, to Promote Virus Infection[J]. Journal of Integrative Plant Biology, 2022, 64(8): 1631-1645. doi: 10.1111/jipb.13313

    CrossRef Google Scholar

    [9] CAO B W, GE L H, ZHANG M Z, et al. Geminiviral C2 Proteins Inhibit Active Autophagy to Facilitate Virus Infection by Impairing the Interaction of ATG7 and ATG8[J]. Journal of Integrative Plant Biology, 2023, 65(5): 1328-1343. doi: 10.1111/jipb.13452

    CrossRef Google Scholar

    [10] TONG X, ZHAO J J, FENG Y L, et al. A Selective Autophagy Receptor VISP1 Induces Symptom Recovery by Targeting Viral Silencing Suppressors[J]. Nature Communications, 2023, 14(1): 3852. doi: 10.1038/s41467-023-39426-0

    CrossRef Google Scholar

    [11] GARNSEY S M. Citrus Chlorotic dwarf, a New Whitefly-Transmitted Disease in the Eastern Mediterranean Region of Turkey[J]. International Organization of Citrus Virologists Conference Proceedings (1957-2010), 1996, 13(13): 220-225.

    Google Scholar

    [12] GUO J, LAI X P, LI J X, et al. First Report on Citrus Chlorotic dwarf Associated Virus on Lemon in Dehong Prefecture, Yunnan, China[J]. Plant Disease, 2015, 99(9): 1287.

    Google Scholar

    [13] YANG Z, ZHANG L, ZHAO J F, et al. First Report of Citrus Chlorotic dwarf-Associated Virus on Pomelo in Nakhon, Thailand[J]. Plant Disease, 2020, 104(4): 1262.

    Google Scholar

    [14] ZRACHYA A, GLICK E, LEVY Y, et al. Suppressor of RNA Silencing Encoded by Tomato Yellow Leaf Curl Virus-Israel[J]. Virology, 2007, 358(1): 159-165. doi: 10.1016/j.virol.2006.08.016

    CrossRef Google Scholar

    [15] QIN Y Y, ZHAO J F, WANG J J, et al. Regulation of Nicotiana benthamiana Cell Death Induced by Citrus Chlorotic Dwarf-Associated Virus-RepA Protein by WRKY 1[J]. Frontiers in Plant Science, 2023, 14: 1164416. doi: 10.3389/fpls.2023.1164416

    CrossRef Google Scholar

    [16] YE X, DING D D, CHEN Y, et al. Identification of RNA Silencing Suppressor Encoded by Citrus Chlorotic dwarf-Associated Virus[J]. Frontiers in Microbiology, 2024, 15: 1328289. doi: 10.3389/fmicb.2024.1328289

    CrossRef Google Scholar

    [17] KUSHWAHA N K, HAFRÉN A, HOFIUS D. Autophagy-Virus Interplay in Plants: From Antiviral Recognition to Proviral Manipulation[J]. Molecular Plant Pathology, 2019, 20(9): 1211-1216.

    Google Scholar

    [18] HUANG X Q, CHEN S P, YANG X R, et al. Friend or Enemy: A Dual Role of Autophagy in Plant Virus Infection[J]. Frontiers in Microbiology, 2020, 11: 736. doi: 10.3389/fmicb.2020.00736

    CrossRef Google Scholar

    [19] 高海馨. 柑橘黄脉病毒诱导细胞自噬机制的初步研究[D]. 重庆: 西南大学, 2023.

    Google Scholar

    [20] WANG Y P, NISHIMURA M T, ZHAO T, et al. ATG2, an Autophagy-Related Protein, Negatively Affects Powdery Mildew Resistance and Mildew-Induced Cell Death in Arabidopsis[J]. The Plant Journal, 2011, 68(1): 74-87. doi: 10.1111/j.1365-313X.2011.04669.x

    CrossRef Google Scholar

    [21] LAI Z B, WANG F, ZHENG Z Y, et al. A Critical Role of Autophagy in Plant Resistance to Necrotrophic Fungal Pathogens[J]. Plant Journal, 2011, 66(6): 953-968. doi: 10.1111/j.1365-313X.2011.04553.x

    CrossRef Google Scholar

    [22] SHI J X, GONG Y N, SHI H W, et al. 'Candidatus Liberibacter Asiaticus' Secretory Protein SDE3 Inhibits Host Autophagy to Promote Huanglongbing Disease in Citrus[J]. Autophagy, 2023, 19(9): 2558-2574. doi: 10.1080/15548627.2023.2213040

    CrossRef Google Scholar

    [23] JIANG L L, LU Y W, ZHENG X Y, et al. The Plant Protein NbP3IP Directs Degradation of Rice Stripe Virus P3 Silencing Suppressor Protein to Limit Virus Infection through Interaction with the Autophagy-Related Protein NbATG8[J]. New Phytologist, 2021, 229(2): 1036-1051. doi: 10.1111/nph.16917

    CrossRef Google Scholar

    [24] NAKAHARA K S, MASUTA C, YAMADA S, et al. Tobacco Calmodulin-Like Protein Provides Secondary Defense by Binding to and Directing Degradation of Virus RNA Silencing Suppressors[J]. Proceedings of the National Academy of Sciences of the United States of America, 2012, 109(25): 10113-10118.

    Google Scholar

    [25] YANG M, ZHANG Y L, XIE X L, et al. Barley Stripe Mosaic Virus Γb Protein Subverts Autophagy to Promote Viral Infection by Disrupting the ATG7-ATG8 Interaction[J]. The Plant Cell, 2018, 30(7): 1582-1595. doi: 10.1105/tpc.18.00122

    CrossRef Google Scholar

    [26] ZHOU T T, ZHANG M Z, GONG P, et al. Selective Autophagic Receptor NbNBR1 Prevents NbRFP1-Mediated UPS-Dependent Degradation of βC1 to Promote Geminivirus Infection[J]. PLoS Pathogens, 2021, 17(9): e1009956. doi: 10.1371/journal.ppat.1009956

    CrossRef Google Scholar

    [27] YANG M, ISMAYIL A, GAO T, et al. Cotton Leaf Curl Multan Virus C4 Protein Suppresses Autophagy to Facilitate Viral Infection[J]. Plant Physiology, 2023, 193(1): 708-720. doi: 10.1093/plphys/kiad235

    CrossRef Google Scholar

    [28] LI F F, ZHANG M Z, ZHANG C W, et al. Nuclear Autophagy Degrades a Geminivirus Nuclear Protein to Restrict Viral Infection in Solanaceous Plants[J]. New Phytologist, 2020, 225(4): 1746-1761. doi: 10.1111/nph.16268

    CrossRef Google Scholar

    [29] GONG P, TAN H, ZHAO S W, et al. Geminiviruses Encode Additional Small Proteins with Specific Subcellular Localizations and Virulence Function[J]. Nature Communications, 2021, 12(1): 4278. doi: 10.1038/s41467-021-24617-4

    CrossRef Google Scholar

    [30] GONG P, ZHAO S W, LIU H, et al. Tomato Yellow Leaf Curl Virus V3 Protein Traffics along Microfilaments to Plasmodesmata to Promote Virus Cell-to-Cell Movement[J]. Science China Life Sciences, 2022, 65(5): 1046-1049.

    Google Scholar

  • 加载中
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

Figures(5)

Export Citation
PDF
XML

Article Metrics

Article views(296) PDF downloads(52) Cited by(0)

Access History

Other Articles By Authors

Infestation of Citrus chlorotic Dwarf-Associated Virus in Eureka lemon Induced Cellular Autophagy

    Corresponding author: ZHOU Yan
  • Received Date: 30/07/2024
  • Available Online: 20/03/2025

Abstract: 

Autophagy is an important defense mechanism of host in response to virus infection. To clarify whether the infection of Citrus chlorotic dwarf-associated virus (CCDaV) could induce autophagic response in plant, in this study, transmission electron microscope (TEM), quantitative real-time PCR, confocal microscopy analysis of enhanced green fluorescent protein-tagged Nicotiana benthamiana ATG8f (GFP-NbATG8f) and western blot were used to investigate the formation of autophagic structure, the transcript levels of autophagy related genes and ATG8 content in CCDaV-infected Eureka lemon, respectively. The results showed that the formation of autophagic structure was observed in the cytoplasm of CCDaV-infected Eureka lemon leaf cell by TEM at 15 days post inoculation (dpi). Compared with the healthy control, the expression levels of autophagy related genes (ClATG3, ClATG5, ClATG7, ClATG8a, ClATG8d, ClATG8f, ClATG8g, ClATG8i, ClBeclin1, ClPI3K and ClNBRI) in CCDaV-infected Eureka lemon leaves were significantly up-regulated, and ATG8 content was increased by 1.99 times. After co-expression of the six viral proteins encoded by CCDaV with GFP-NbATG8f in N. benthamiana for 48 h, the number of autophagosomes induced by co-expression of V3 and V4 proteins with GFP-NbATG8f was significantly higher than that of the control, and the content of free GFP was also significantly increased. These results indicated that CCDaV infection induced autophagic response in Eureka lemon, and V3 and V4 proteins may be important factors to induce autophagy.

    HTML

  • 开放科学（资源服务）标识码（OSID）：

  • 自噬最早于1963年由De Duve等首次提出，用来描述细胞自身物质的溶酶体降解途径[1]。随后，Tsukada等在酵母上鉴定出第一个自噬基因APG[2]，之后陆续在酵母、动物和植物中鉴定出40多个自噬相关蛋白(ATGs)。早期对自噬的研究主要集中于其在癌症、神经退行性疾病等人类疾病中的功能[3]。Liu等[4]首次发现烟草花叶病毒(Tobacco mosaic virus，TMV)的侵染能够诱导自噬基因的表达。随后，越来越多的研究表明，自噬反应在植物应对多种植物病毒感染时被激活，不仅能够限制病毒的积累，还能促进病毒的感染，是植物响应病毒侵染的重要调控机制[5-6]。在发生自噬反应的植物细胞中可以观察到自噬相关基因(ATGs)表达量显著上调，以及自噬小体和自噬标记物ATG8的大量积累[7]。

    双生病毒(Geminiviruses)是一类在世界范围内广泛发生的单链环状DNA病毒，其寄主范围广泛，主要通过烟粉虱、叶蝉和蚜虫传播，每年造成的经济损失达数百亿美元。自噬现象在双生病毒上也较为普遍，棉花木尔坦曲叶病毒(Cotton leaf curl Multan virus，CLCuMuV)编码的βC1蛋白是第一个被鉴定的植物病毒自噬激活剂，通过阻止自噬相关蛋白3(ATG3)与胞质自噬负调控因子3-磷酸甘油醛脱氢酶(GAPC)互作，从而激活植株的自噬反应，抑制CLCuMuV侵染[8]。随后发现云南番茄曲叶病毒(Tomato leaf curl Yunnan virus，TLCYnV)、印度绿豆黄化花叶病毒(Mungbean yellow mosaic India virus，MYMIV)、甜菜严重曲顶病毒(Beet severe curly top virus，BSCTV)等多种双生病毒都能激活细胞自噬途径，上调自噬相关基因mRNA的表达[9-10]。

    柑橘褪绿矮缩病毒(Citrus chlorotic dwarf-associated virus，CCDaV)是近年来柑橘生产上出现的一种新病毒，自19世纪80年代在土耳其东部以及地中海地区默辛省被首次发现[11]，目前在中国和泰国都有发生[12-13]。CCDaV在柠檬、红宝石柚等敏感品种上引起叶片褪绿、斑驳和扭曲(图 1a和1b)。CCDaV基因组为约3.64 kb的环状单链DNA分子，可能含有6个开放阅读框(Open reading frames，ORFs)，分别是V1、V2、V3、V4、RepA、Rep。其中，V1被认为是外壳蛋白(CP)；V2含有双生病毒V2蛋白的保守结构域，具有保守的半胱氨酸残基，该残基对抑制番茄黄化曲叶病毒(Tomato yellow leaf curl virus，TYLCV)诱导的基因沉默至关重要[14]。近来研究发现WRKY1正向调控CCDaV复制相关蛋白RepA在本生烟(Nicotiana benthamiana)中诱导细胞死亡[15]。CCDaV编码的V2蛋白可抑制GFP RNA引发的局部和系统RNA沉默，但不影响16c本生烟中RNA沉默信号的短距离移动[16]。目前国内外尚未开展关于CCDaV诱导寄主自噬的相关研究。

    本研究以感染CCDaV的尤力克柠檬作为研究材料，探究CCDaV是否能诱导尤力克柠檬的自噬反应，以及诱导自噬的病毒蛋白种类，以期为今后研究细胞自噬在CCDaV侵染寄主中的调控作用提供参考。

1.   材料与方法

    1.1.   供试材料

  • 无病毒一年生尤力克柠檬实生苗和CCDaV毒株均保存于国家柑桔苗木脱毒中心。本生烟生长条件为25 ℃，16 h光照，8 h黑暗处理。统一采用生长至40 d的四至六叶期烟苗为试验材料。

    • 1.2.   主要试剂

  • 植物蛋白提取试剂盒购自北京索莱宝生物科技有限公司；IsoPlus、Prime STAR Max DNA Polymerase购自宝生物工程(大连)有限公司；氯仿、乙醇、异丙醇等购自北京鼎国昌盛生物技术有限责任公司；反转录一步法试剂购自ABM公司；实时荧光定量SYBR Prime qPCR Mix试剂购自重庆葆光生物科技有限公司；Anti-Actin抗体、羊抗鼠二抗和羊抗兔二抗购买于翌圣生物科技(上海)股份有限公司；GFP单克隆抗体、ATG8单克隆抗体购自成都AlpVHHs有限公司。

    • 1.3.   透射电子显微镜检测自噬

  • 使用直径5 mm打孔器在感染CCDaV 15 d后的尤力克柠檬嫩叶上取样，使用透射电镜观察自噬结构。统计超过50个细胞内自噬小体的平均值，进行3次重复试验。使用GraphPad Prism 8软件进行统计学分析。

    • 1.4.   实时荧光定量检测

  • 称取0.1 g感染CCDaV 15 d后的尤力克柠檬嫩叶，IsoPlus提取总RNA反转录为cDNA。使用SYBR Prime qPCR Mix进行qRT-PCR反应。以尤力克柠檬的ClActin作为内参基因。采用2-ΔΔct法分析相对表达量，GraphPad Prism 8软件进行t检验分析。

    • 1.5.   诱导自噬的病毒蛋白种类鉴定

  • 利用Prime STAR Max DNA Polymerase，以CCDaV毒株为模板扩增CCDaV的V1、V2、V3、V4、C1和C2基因，并将其分别构建到pART27-Myc中。测序验证后，分别与GFP-NbATG8f转化农杆菌GV3101，并共注射于本生烟；48 h后使用Olympus FV3000进行观察；488 nm观察绿色荧光(GFP)，543 nm观察红色叶绿体自发光；浸润pART27-Myc-GUS的本生烟作为对照。

    • 1.6.   Western Blot检测自噬

  • 称取0.2 g感染CCDaV 15 d后的尤力克柠檬嫩叶，使用植物组织蛋白提取试剂盒提取总蛋白，并进行12.5% SDS-PAGE。分别使用CCDaV CP单克隆抗体和ATG8单克隆抗体作为一抗室温孵育2 h，再分别以羊抗鼠二抗和羊抗兔二抗室温孵育2 h，Myc直标抗体室温孵育2 h。使用IMAGEJ软件分析蛋白条带灰度值。

2.   结果与分析

    2.1.   透射电镜观察细胞自噬

  • CCDaV侵染尤力克柠檬15 d后，在透射电子显微镜下观察到有双层膜囊泡状结构的自噬小体(图 2a)。经统计分析，感病尤力克柠檬叶片中自噬结构数量显著高于无病毒尤力克柠檬(图 2b)。结果表明，CCDaV可能诱导尤力克柠檬叶片细胞内的自噬反应。

    • 2.2.   CCDaV侵染激活自噬相关基因的表达

  • 进一步qRT-PCR检测尤力克柠檬嫩叶中自噬相关基因的表达量发现，感染CCDaV 15 d后，自噬相关基因ClBeclin1、ClPI3K、ClNBR1、ClATG3、ClATG5、ClATG7、ClATG8a、ClATG8d、ClATG8f、ClATG8i和ClATG8g的表达量与对照组相比均显著上调。其中ClATG5、ClATG8g、ClNBR1、ClATG8i、ClPI3K的mRNA表达水平增长最明显，为对照组的6.64~10.52倍，另外ClBeclin1、ClATG3、ClATG7、ClATG8a、ClATG8d、ClATG8f的mRNA表达水平为对照组的2.64~5.24倍(图 3)。结果表明CCDaV侵染尤力克柠檬激活了自噬相关基因的表达。

    • 2.3.   CCDaV侵染诱导自噬体标志蛋白ATG8-PE表达

  • 尤力克柠檬接种CCDaV 15 d后，蛋白印迹检测发现ATG8和ATG8-PE的积累量均显著增加(图 4)。与对照组相比，感病叶片细胞内ATG8-PE的积累增加了1.99倍。结果进一步表明CCDaV侵染激活了尤力克柠檬中的细胞自噬反应。

    • 2.4.   CCDaV编码蛋白诱导细胞自噬能力鉴定

  • 通过PCR扩增分别得到CCDaV编码的6个ORFs全长序列：C1(810 bp)、C2(243 bp)、V1(765 bp)、V2(420 bp)、V3(300 bp)和V4(251 bp)。

    将CCDaV编码的各个蛋白分别与GFP-NbATG8f共表于本生烟48 h后，通过共聚焦观察发现，V3和V4蛋白，分别与GFP-NbATG8f共表达时，自噬小体数量迅速增加。CCDaV编码的其他蛋白分别与GFP-NbATG8f共表达时，本生烟中的自噬小体数量与对照(pART27-Myc-GUS)相似(图 5a、5b)。蛋白印迹分析的结果进一步显示，与对照组相比，V3和V4分别与GFP-NbATG8f共表达时，游离GFP的积累量分别增加了8.80倍和10.16倍(图 5c)。上述结果表明，V3、V4蛋白可能是CCDaV诱导自噬的重要因子。

3.   讨论与结论

    3.1.   讨论

  • 自噬是一种真核生物中的重要保护过程，当植物受到特定信号刺激，如营养匮乏、温度胁迫、渗透胁迫或病原物侵染时，自噬会被大量诱导以清除受损细胞器或异常蛋白[17-18]。前期研究显示，柑橘黄化脉明病毒(Citrus yellow vein clearing virus，CYVCV)编码的病毒蛋白TGB2、TGB3和CP分别与GFP-ATG8f共表于本生烟48 h后自噬相关基因表达显著上调[19]。本研究发现，与对照相比，CCDaV侵染尤力克柠檬15 d后，在叶肉细胞中出现了明显的双层膜囊泡结构，液泡中也出现了类似自噬小体的结构。此时，ClATG3、ClATG5、ClATG7、ClATG8a、ClATG8d、ClATG8f、ClATG8g、ClATG8i、ClBeclin1、ClPI3K和ClNBR1等自噬相关基因的表达量显著上调。由此证明CCDaV可诱导植株发生细胞自噬反应。

    自噬在植物响应病原菌侵染中发挥了重要作用。例如，自噬相关蛋白ATG2负调控拟南芥对白粉病的抗性和白粉菌诱导的细胞死亡[20]。灰霉菌(Botrytis cinerea)诱导拟南芥自噬基因ATG18a的表达和自噬体的形成[21]。柑橘黄龙病菌(Candidatus liberibacter asiaticus)分泌蛋白SDE3抑制寄主自噬促进黄龙病菌侵染[22]。此外，自噬在植物抵御病毒侵染中也发挥了重要的作用。Jiang等[23]研究发现水稻条纹病毒(Rice stripe virus，RSV)的P3蛋白可以与本生烟中的NbPI3P相互作用，从而抑制P3作为沉默抑制子的活性，并诱导P3被自噬降解，进而提高植株对RSV的抗性。此外，烟草钙调蛋白样蛋白rgs-Ca可通过与烟草蚀纹病毒(Tobacco etch virus，TEV)编码的HC-Pro，以及黄瓜花叶病毒(Cucumber mosaic virus，CMV)和番茄不孕病毒(Tomato aspermy virus，TAV)编码的2b蛋白结合，从而诱导自噬，限制病毒侵染。为成功侵染植物，病毒也进化出多种手段来抑制植物的自噬反应[24]。Yang等[25]发现，大麦条纹花叶病毒(Barley stripe mosaic virus，BSMV)的γb蛋白可以通过阻止ATG7与ATG8的互作，从而抑制自噬体的形成。此外，CLCuMuV、TLCYnV、中国番茄黄化曲叶病毒(Tomato yellow leaf curl China virus，TYLCCNV)等双生病毒编码的βC1、C4、C1蛋白也可诱导自噬反应[26-28]。虽然前期研究显示，TYLCV的V3蛋白参与了病毒的移动，并具有沉默抑制子的功能[29-30]，但关于双生病毒V3和V4蛋白功能的研究较少，也尚无其参与细胞自噬反应的报道。本研究发现，CCDaV编码的V3和V4蛋白能够诱导细胞自噬的发生，但V3和V4蛋白如何与寄主蛋白互作，从而调控寄主的抗/感病反应的机理还不清楚，今后将进一步开展相关研究。

    • 3.2.   结论

  • 本研究首次证实CCDaV侵染的尤力克柠檬能诱导产生细胞自噬反应，其编码的V3、V4蛋白可能是引起细胞自噬的关键因子。本研究结果为今后深入研究CCDaV与寄主的互作机制提供了重要参考。

Figure (5)  Reference (30)

Catalog

    Copyright Journal of Southwest University Natural Science Edition

    Address： Tel：023-68254576, 68252540, 68366165,68366917 E-mail：lkxb@swu.edu.cn

    Supported by:Beijing Renhe Information Technology Co. Ltd

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return