豆科植物共生结瘤的分子基础和调控研究进展

doi:10.3773/j.issn.1005-264x.2010.07.013

摘要/Abstract

摘要：

豆科植物与根瘤菌共生互作的结果导致了一个新的植物器官――根瘤的形成, 根瘤菌生活在根瘤中, 它们具有将氮气转化为能被植物同化的氨的能力。该文阐述了根瘤的形成过程和类型, 并主要以模式豆科植物蒺藜苜蓿(Medicago truncatula)和日本百脉根(Lotus japonicus)为例, 对近年来共生结瘤过程中宿主植物对根瘤菌结瘤因子的识别和信号传递、侵入线形成和固氮的分子基础, 以及宿主植物对根瘤形成的自主调控机制、环境中氮素营养对结瘤的影响研究进行了综述, 指出当前豆科植物与根瘤菌共生互作研究存在的问题, 并对今后的研究方向作了分析与展望。

关键词: 豆科植物, 根瘤形成, 结瘤素基因, 信号传递, 共生固氮

Abstract:

The symbiosis between leguminous plants and rhizobia leads to the formation of a novel root organ, the nodule. In mature nodules, rhizobia provide the host plant with ammonium, which is produced through bacterial nitrogen fixation. The symbiotic interactions involve the perception of bacterial signaling factors called Nod factors (NFs) by plant host, the NF signaling pathway, the formation of infection threads and the development of nodule in the cortex. Although this nodule formation is beneficial for host plants to secure a nitrogen resource, overproduction of nodules could deleteriously affect plant growth. Legume plants avoid this by utilizing a negative feedback regulation known as autoregulation of nodulation (AON), in which earlier formed nodules suppress further nodulation through shoot-root communication. We summarize nodule formation and types and highlight recent studies on the molecular basis underlying NF signaling cascade, AON and effects of environmental nitrogen conditions on nodulation. We also discuss current research problems and reflect on the future of this field.

Key words: legumes, nodule formation, nodulin genes, signaling, symbiotic nitrogen fixation

丑敏霞, 魏新元. 豆科植物共生结瘤的分子基础和调控研究进展. 植物生态学报, 2010, 34(7): 876-888. DOI: 10.3773/j.issn.1005-264x.2010.07.013

CHOU Min-Xia, WEI Xin-Yuan. Review of research advancements on the molecular basis and regulation of symbiotic nodulation of legumes. Chinese Journal of Plant Ecology, 2010, 34(7): 876-888. DOI: 10.3773/j.issn.1005-264x.2010.07.013

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链接本文: https://www.plant-ecology.com/CN/10.3773/j.issn.1005-264x.2010.07.013

https://www.plant-ecology.com/CN/Y2010/V34/I7/876

图/表 2

图1 定型根瘤与不定型根瘤示意图。 A, 不定型根瘤结构模式图。B, 紫云英不定型根瘤纵切图。C, 大豆定型根瘤纵切图。A和B来自Naito等(2000), C由华中农业大学农业微生物学国家重点实验室生物固氮研究室提供。

Fig. 1 Diagram of the determinate- and indeterminate-type nodule. A, Schematic representation of the five distinct regions of an indeterminate type nodule. B, The vertical dissection of an indeterminate type nodule of Astragalus sinicus. C, The vertical dissection of a determinate type nodule of soybean. A and B are derived from Naito et al., 2000; C is provided by the laboratory of Biological Nitrogen Fixation, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.

图2 共生结瘤早期结瘤因子的信号传导途径。

Fig. 2 The Nod factor signaling pathways during early sym- biotic nodulation.

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