Reduced carbon availability to bacteroids and elevated ureides in nodules, but not in shoots, are involved in the nitrogen fixation response to early drought in soybean
Reduced carbon availability to bacteroids and elevated ureides in nodules, but not in shoots, are involved in the nitrogen fixation response to early drought in soybean
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DOI：
10.1104/pp.107.102491
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发表时间：
2007-10-01
期刊：
影响因子：
7.4
通讯作者：
Arrese-Igor, Cesar
中科院分区：
文献类型：
--
作者：
Ladrera, Ruben;Marino, Daniel;Arrese-Igor, Cesar
大豆（Glycine max L.）梅尔）对土壤干燥非常敏感。这种敏感性与芽或结节中氮化合物的积累以及干旱下结节状碳通量短缺有关。为了评估碳和氮状况对NF调节的相对重要性，用已知的对比耐旱性的两个大豆品种监测对干旱早期阶段的响应。在敏感品种（'Biloxi'），NF抑制发生更早，更显着比在宽容的品种（'杰克逊'）。“比洛西”对类杆菌碳通量的影响也比“杰克逊”大，这是由于前者蔗糖合成酶活性抑制较早，苹果酸浓度下降幅度较大。干旱引起酰脲积累的根瘤中的两个品种，但这种积累较高，发生在'Biloxi'。然而，在干旱的早期阶段，没有酰脲在两个品种的叶片中积累。这些结果表明，减少碳通量和氮积累的根瘤，但不是在地上部的组合，参与抑制NF在大豆早期干旱。
Nitrogen fixation (NF) in soybean (Glycine max L. Merr.) is highly sensitive to soil drying. This sensitivity has been related to an accumulation of nitrogen compounds, either in shoots or in nodules, and a nodular carbon flux shortage under drought. To assess the relative importance of carbon and nitrogen status on NF regulation, the responses to the early stages of drought were monitored with two soybean cultivars with known contrasting tolerance to drought. In the sensitive cultivar ('Biloxi'), NF inhibition occurred earlier and was more dramatic than in the tolerant cultivar ('Jackson'). The carbon flux to bacteroids was also more affected in 'Biloxi' than in 'Jackson', due to an earlier inhibition of sucrose synthase activity and a larger decrease of malate concentration in the former. Drought provoked ureide accumulation in nodules of both cultivars, but this accumulation was higher and occurred earlier in 'Biloxi'. However, at this early stage of drought, there was no accumulation of ureides in the leaves of either cultivar. These results indicate that a combination of both reduced carbon flux and nitrogen accumulation in nodules, but not in shoots, is involved in the inhibition of NF in soybean under early drought.