植物生态学报 ›› 2017, Vol. 41 ›› Issue (8): 815-825.DOI: 10.17521/cjpe.2017.0018

• 研究论文 •    下一篇

丛枝菌根通过调节碳磷代谢相关基因的表达增强植物对低磷胁迫的适应性

徐丽娇1,2, 姜雪莲1,3, 郝志鹏1, 李涛1, 吴照祥1,4, 陈保冬1,2,*()   

  1. 1中国科学院生态环境研究中心城市与区域生态国家重点实验室, 北京 100085
    2中国科学院大学, 北京 100049
    3中国科学技术大学生命科学学院, 合肥 230026
    4江西省科学院生物资源研究所江西省重金属污染生态修复工程技术研究中心, 南昌 330096
  • 出版日期:2017-08-10 发布日期:2017-09-29
  • 通讯作者: 陈保冬
  • 作者简介:康璟瑶(1991-),男,江苏南京人,硕士生,主要从事旅游地理与旅游规划研究,E-mail: kangjingyao_nj@163.com
  • 基金资助:
    中国科学院战略性先导科技专项(XDB15030102)

Arbuscular mycorrhiza improves plant adaptation to phosphorus deficiency through regulating the expression of genes relevant to carbon and phosphorus metabolism

Li-Jiao XU1,2, Xue-Lian JIANG1,3, Zhi-Peng HAO1, Tao LI1, Zhao-Xiang WU1,4, Bao-Dong CHEN1,2,*()   

  1. 1State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China

    2University of Chinese Academy of Sciences, Beijing 100049, China

    3School of Life Sciences, University of Science and Technology of China, Hefei 230026, China

    4Jiangxi Engineering and Technology Research Center for Ecological Remediation of Heavy Metal Pollution, Institute of Biology and Resources, Jiangxi Academy of Sciences, Nanchang 330096, China
  • Online:2017-08-10 Published:2017-09-29
  • Contact: Bao-Dong CHEN
  • About author:KANG Jing-yao(1991-), E-mail: kangjingyao_nj@163.com

摘要:

丛枝菌根(AM)共生体系对于植物适应低磷胁迫具有重要作用。AM不仅直接调节宿主植物对低磷胁迫的响应, 还可能通过分泌物影响相邻的非菌根植物。该研究采用分室培养系统, 以玉米(Zea mays)和AM真菌Rhizophagus irregularis为试验材料, 考察低磷(10 mg·kg-1)和高磷(100 mg·kg-1)条件下, 菌根共生体系对植物生长、磷营养以及碳磷代谢相关基因表达的影响, 以揭示AM调节植物低磷胁迫响应的生理机制。分室培养系统由0.45 μm微孔滤膜分隔成供体室、缓冲室和受体室3个分室, 以供体室菌根化植物为AM分泌物来源, 通过微孔膜阻止菌根真菌对未接种受体植物的直接影响, 但允许AM分泌物在分室间的扩散。采用实时荧光定量PCR技术分析玉米以及AM真菌自身碳磷代谢相关基因的表达情况。试验结果表明, 低磷条件下接种AM真菌显著提高了供体植物干质量和磷浓度, 上调了玉米碳磷代谢相关基因的表达。AM真菌磷转运蛋白基因和碳代谢相关基因在低磷条件下的表达水平显著高于高磷水平; 对于受体植物而言, 仅高磷处理显著提高了玉米植株干质量和磷含量, 而接种处理显著上调了受体植物磷转运蛋白基因和碳代谢相关基因的表达水平。该研究表明, 低磷胁迫下AM可能通过分泌物调控植物碳磷代谢相关基因的表达, 进而调节植物对低磷胁迫的生理响应。

关键词: 分室培养系统, 丛枝菌根, 碳磷代谢, 功能基因, 缺磷胁迫

Abstract:

Aims Arbuscular mycorrhizal (AM) symbiosis plays an important role in plant adaptation to phosphorus (P) deficiency. The mycorrhizal fungi can directly regulate P stress response of the host plants, and can also indirectly influence neighbor plants via AM exudates. This study aimed to reveal the regulation mechanisms of plant response to P deficiency by AM associations. Methods In a compartmentation cultivation experiment with Zea mays ‘B73’ and AM fungus Rhizophagus irregularis ‘DAOM197198’, we investigated mycorrhizal effects on plant P nutrition and the expression of plant and fungal genes related to P and carbon (C) metabolisms under both low P (10 mg?kg-1) and high P (100 mg?kg-1) conditions. The cultivation system consisted of three compartments, namely donor compartment, buffer compartment and receiver compartment divided by two pieces of microporous filters with pore size of 0.45 μm. Maize plant in donor compartment inoculated with AM fungus served as a source of AM exudates. The microporous filters could restrict the development of extraradical mycelium of AM fungi, but allow diffusion of AM exudates. Real-time PCR was performed to quantify the gene expression levels both in maize plants and AM fungi. Important findings The experimental results indicated that under low P conditions mycorrhizal colonization increased plant dry weight and P concentration in donor plants, and up-regulated plant genes encoding P transporters Pht1;2, Pht1;6, phosphoenolpiruvate carboxylase (PEPC), inorganic pyrophosphatase (TC289), glycerol-3-phosphate transporter (G3PT) and malate synthase (MAS1). The expression of AM fungal genes encoding P transporter (GiPT), GlcNAc transporter (NGT1), GlcNAc kinase (HXK1b), GlcNAc phosphomutase (AGM1), UDP GlcNAc pyrophosphorylase (UAP1), chitin synthase (CHS1), GlcNAc-6-phosphate deacetylase (DAC1) and glucosamine-6-phosphate isomerase (NAG1) was significantly higher under low P conditions compared with high P conditions. However, for the receiver plants, plant dry mass and P concentration were only significantly increased by higher P addition, while inoculation treatment significantly up-regulated the expression of P transporter genes Pht1;2 and Pht1;6, C metabolism related genes G3PT, PEPC, TC289 and MAS1. The study proved that AM exudates could potentially stimulate plant response to P deficiency by regulating functional genes relevant to P and C metabolisms in the mycorrhizal associations.

Key words: compartment cultivation system, arbuscular mycorrhiza, carbon and phosphorus metabolism, functional gene, phosphorus deficiency