A nodule-specific plant cysteine proteinase, AsNODF32, is involved in nodule senescence and nitrogen fixation activity of the green manure legume Astragalus sinicus
A nodule-specific plant cysteine proteinase, AsNODF32, is involved in nodule senescence and nitrogen fixation activity of the green manure legume Astragalus sinicus
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DOI：
10.1111/j.1469-8137.2008.02562.x
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发表时间：
2008-10-01
期刊：
影响因子：
9.4
通讯作者：
Zhou, Junchu
中科院分区：
文献类型：
--
作者：
Li, Yixing;Zhou, Lei;Zhou, Junchu
Asnodf32编码紫云英中的根瘤特异性半胱氨酸蛋白酶，可能与根瘤衰老有关。为了获得其在根瘤衰老中的作用的直接证据，将发根农杆菌介导的RNA干扰应用于中华农杆菌毛状根。使用实时qRT-PCR来估计抑制效率。采用石蜡包埋玻片、TUNEL（TdT介导的dUTP缺口末端标记）实验和透射电镜检测转基因根瘤的衰老表型，并测定菌体固氮活性。结果发现，沉默Asnodf32可延缓根瘤和菌体衰老。菌体主动固氮时间显着延长。有趣的是，在Asnodf32沉默的毛状根上也观察到了长度增大的根瘤。本文报道的结果表明Asnodf32在根瘤衰老的调节中发挥着重要作用。
Asnodf32, encoding a nodule-specific cysteine proteinase in Astragalus sinicus, is probably involved in nodule senescence. To obtain direct evidence of its role in nodule senescence, Agrobacterium rhizogenes-mediated RNA interference was applied to A. sinicus hairy roots.Real-time qRT-PCR was used to estimate the efficiency of suppression. The senescent phenotype of transgenic nodules was examined with paraffin-embedded slides, TUNEL (TdT-mediated dUTP nick-end labeling) assay, and transmission electron microscopy, and the bacteroid nitrogen fixation activity was also measured.It was found that silencing of Asnodf32 delayed root nodule and bacteroid senescence. The period of bacteroid active nitrogen fixation was significantly extended. Interestingly, nodules enlarged in length were also observed on Asnodf32-silenced hairy roots.The results reported here indicate that Asnodf32 plays an important role in the regulation of root nodule senescence.