Activities of key enzymes in the C4 pathway and anatomy of sugarcane infected by Leifsonia xyli subsp. xyli
Activities of key enzymes in the C4 pathway and anatomy of sugarcane infected by Leifsonia xyli subsp. xyli
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Leifsonia xyli subsp.感染甘蔗C4途径关键酶的活性及解剖结构。
DOI：
10.1111/jam.14444
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发表时间：
2019
影响因子：
4
通讯作者：
Zhang M Q
中科院分区：
文献类型：
--
作者：
Guo Y;Hu M;Liu L L;Yao W;Zhang M Q
目的木霉矮化病(Leifsonia xylisubsp.xyli，LXX)是长期困扰甘蔗种植国的细菌性病害。本研究主要分析了LXX在甘蔗叶片上的定位及其对甘蔗叶片的影响。方法和结果用LXX细菌接种巴迪拉。结果表明，接种后150~210天，甘蔗叶片中LXX细胞数量迅速增加。LXX侵染破坏了甘蔗叶片Kranz解剖结构中维管束鞘细胞(BSC)的完整性，导致叶片维管束鞘细胞中淀粉的异常积累。原位聚合酶链式反应表明，LXX定位于甘蔗叶片中的木质部导管、叶肉细胞和BSC中，这是甘蔗茎韧皮部寄主组织中一个新的生态位。与MI组相比，接种LXX的甘蔗植株中磷酸烯醇式丙酮酸羧化酶(PEPC)、丙酮酸、正磷酸二激酶(PPDK)和NADP-苹果酸酶(NADP-ME)的基因表达和活性均降低。结论LXX不仅破坏了甘蔗C4‘Kranz解剖’维管BSC的结构，还影响了C4循环中关键酶PEPC、PPDK和NADP-ME的活性和基因表达，表明CO2积累减少。木质素(Xyli，LXX)侵染对甘蔗光合作用生理的影响目前仅限于光合作用参数的评估。这项研究评估了LXX感染对C4循环CO2固定机制和伴随的植物解剖的影响。
AimsRatoon stunting disease caused byLeifsonia xylisubsp.xyli(Lxx) is a bacterial disease that has plagued sugarcane‐planting countries for a long time. This study mainly analysed Lxx localization and its effects on sugarcane leaf.Methods and ResultsBadila were inocultated by bacteria of Lxx. It was noted that the number of Lxx cells were rapidly enriched in sugarcane leaves from the 150th to the 210th days of post inoculation (dpi). Lxx infection disrupted the integrity of vascular bundle sheath cells (BSC) in the ‘Kranz anatomy’ of leaves, resulting in irregular accumulation of starch in vascular BSC of leaves.In situPCR showed that the Lxx localized in the xylem vessels, mesophyll cell (MC) and BSC as described before in sugarcane leaf, a new niche within the host tissues in the phloem of sugarcane stem. The gene expression and activities of phosphoenolpyruvate carboxylase (PEPC), pyruvate, orthophosphate dikinase (PPDK) and NADP‐malic enzyme (NADP‐ME) enzymes were lower in Lxx‐inoculated sugarcane plants as compared to the MI group.ConclusionLxx infection not only disrupted the structure of vascular BSC in the C4 ‘Kranz anatomy’ of sugarcane leaves, but also affected the activities and gene expression of the key enzymes PEPC, PPDK and NADP‐ME in the C4 cycle of sugarcane suggesting a reduction in CO2fixation.Significance and Impact of the StudyThe effect ofLeifsonia xylisubsp. xyli (Lxx) infection on the photosynthetic physiology of sugarcane is currently limited to the evaluation of photosynthetic parameters. This study assessed the impact of Lxx infection on the mechanism of C4 cycle CO2fixation and to accompanying plant anatomy.