Symbiotic Tissue Degradation Pattern in the Ineffective Nodules of Three Nodulation Mutants of Pea (Pisum sativum L.)
Symbiotic Tissue Degradation Pattern in the Ineffective Nodules of Three Nodulation Mutants of Pea (Pisum sativum L.)
复制标题
豌豆（Pisum sativum L.）三种结瘤突变体无效结瘤中的共生组织降解模式
DOI：
10.1006/anbo.1995.1100
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发表时间：
1995
期刊：
影响因子：
4.2
通讯作者：
V. Našinec
中科院分区：
文献类型：
--
作者：
K. Novák;K. Pesina;J. Nebesářová;V. Škrdleta;L. Lisá;V. Našinec
摘要豌豆（Pisum sativum L.）使用光学和透射电子显微镜研究形成无效结节的结节结构中的畸变。根据根瘤发育块的时间对突变体进行排序。在突变体RisfixO中，共生组织发育在晚期共生区（LSZ）形成之前被阻止，而RisfixT的LSZ的感染细胞在完全分化后失去野生型结构。与RisfixO中通过电子致密阶段的类菌体降解相反，RisfixT结节中共生体内容物的裂解占主导地位。RisfixT中共生体溶解功能的增强可以用共生体-溶酶体同源性来解释。RisfixO中对共生发展的控制减弱可能是感染线大量传播和扩大的原因。来自RisfixV的LSZ的细胞在分化后经历快速塌陷，类似于防御坏死。与RisfixO和RisfixT的结节相反，RisfixV的降解结节不作为光吸收剂的汇和调节因子的来源。这表现为萎陷后淀粉不再进一步积累和过度膨胀。
Abstract Three symbiotic mutants of pea ( Pisum sativum L.) forming ineffective nodules were investigated for aberrations in nodule structure using light and transmission electron microscopy. The mutants were ordered according to the timing of the nodule development block. In the mutant RisfixO, symbiotic tissue development is arrested before the late symbiotic zone (LSZ) forms, while the infected cells of the LSZ of RisfixT lose the wild-type structure after full differentiation. In contrast to the bacteroid degradation via an electron-dense stage in RisfixO, lysis of symbiosome contents prevails in RisfixT nodules. Enhancement of the lytic function of symbiosomes in RisfixT may be interpreted in terms of the symbiosome—lysosome homology. The weakened control over symbiotic development in RisfixO may be responsible for the abundant spread of the infection threads and their enlargement. Cells from the LSZ of RisfixV undergo fast collapse, resembling defence necrosis, after differentiation. In contrast to the nodules of RisfixO and RisfixT, degraded nodules of RisfixV do not function as a sink for photosynthates and a source of the nodulation regulatory factor. This is indicated by the absence of further starch accumulation after collapse, and by hypernodulation.