The contrasting N management of two oilseed rape genotypes reveals the mechanisms of proteolysis associated with leaf N remobilization and the respective contributions of leaves and stems to N storage and remobilization during seed filling.
The contrasting N management of two oilseed rape genotypes reveals the mechanisms of proteolysis associated with leaf N remobilization and the respective contributions of leaves and stems to N storage and remobilization during seed filling.
复制标题
DOI：
10.1186/s12870-015-0437-1
复制
发表时间：
2015-02-21
影响因子：
5.3
通讯作者：
Avice JC
中科院分区：
文献类型：
--
作者：
Girondé A;Etienne P;Trouverie J;Bouchereau A;Le Cahérec F;Leport L;Orsel M;Niogret MF;Nesi N;Carole D;Soulay F;Masclaux-Daubresse C;Avice JC
油菜是世界上第三大含油作物，但需要高水平的氮肥，其中只有50%在种子中回收。这种弱的N利用效率与低的叶面N再动员，导致显着的N返回到土壤和污染的风险。相反，在营养阶段的衰老过程中观察到的，从茎和叶的N再动员被认为是有效的在一次结实衰老。然而，茎对氮素管理的贡献和参与叶片再动员的细胞机制仍然在很大程度上未知。为了达到这一目标，氮通量在整个植物水平上从抽薹成熟种子和叶氮再动员和蛋白质水解的过程中所涉及的两个对比基因型（Aviso和Oase）充足或限制硝酸盐供应下栽培进行了研究。在这两种氮素条件下的种子灌浆过程中，Oase有效地分配了从吸收到种子的N，而Aviso有利于更好地从茎和叶向种子的N再动员。硝态氮限制降低了两种基因型的种子产量和油品质，但Aviso的种子氮填充最好。在氮素限制条件下，Aviso在籽粒灌浆开始前有较好的氮素从叶片向茎的转移。之后，较高的氮从茎和叶的转移导致较高的最终氮在种子中的量。这种高叶N再动员与不溶性蛋白质、寡肽、硝酸盐和/或氨的更好的降解/输出相关。通过使用基于在蛋白酶抑制剂的存在下测定Rubisco降解的原始方法，将与半胱氨酸蛋白酶和蛋白酶体活性相关的有效蛋白水解确定为N再活化的机制。结果证实了叶片氮再动员后，抽薹，以满足种子灌浆的重要性，并强调，一个有效的蛋白水解主要是与（i）半胱氨酸蛋白酶和蛋白酶体活性和（ii）之间的蛋白水解和输出机制的良好协调。此外，茎可能充当暂时的存储器官的情况下，叶片N再动员和氮需求的种子填充。本文的在线版本（doi：10.1186/s12870-015-0437-1）包含补充材料，可供授权用户使用。
Oilseed rape is the third largest oleaginous crop in the world but requires high levels of N fertilizer of which only 50% is recovered in seeds. This weak N use efficiency is associated with a low foliar N remobilization, leading to a significant return of N to the soil and a risk of pollution. Contrary to what is observed during senescence in the vegetative stages, N remobilization from stems and leaves is considered efficient during monocarpic senescence. However, the contribution of stems towards N management and the cellular mechanisms involved in foliar remobilization remain largely unknown. To reach this goal, the N fluxes at the whole plant level from bolting to mature seeds and the processes involved in leaf N remobilization and proteolysis were investigated in two contrasting genotypes (Aviso and Oase) cultivated under ample or restricted nitrate supply. During seed filling in both N conditions, Oase efficiently allocated the N from uptake to seeds while Aviso favoured a better N remobilization from stems and leaves towards seeds. Nitrate restriction decreased seed yield and oil quality for both genotypes but Aviso had the best seed N filling. Under N limitation, Aviso had a better N remobilization from leaves to stems before the onset of seed filling. Afterwards, the higher N remobilization from stems and leaves of Aviso led to a higher final N amount in seeds. This high leaf N remobilization is associated with a better degradation/export of insoluble proteins, oligopeptides, nitrate and/or ammonia. By using an original method based on the determination of Rubisco degradation in the presence of inhibitors of proteases, efficient proteolysis associated with cysteine proteases and proteasome activities was identified as the mechanism of N remobilization. The results confirm the importance of foliar N remobilization after bolting to satisfy seed filling and highlight that an efficient proteolysis is mainly associated with (i) cysteine proteases and proteasome activities and (ii) a fine coordination between proteolysis and export mechanisms. In addition, the stem may act as transient storage organs in the case of an asynchronism between leaf N remobilization and N demand for seed filling. The online version of this article (doi:10.1186/s12870-015-0437-1) contains supplementary material, which is available to authorized users.
登录
查看更多内容
影响因子：
6.4
作者：
Erley, Gunda Schulte auf'm;Wijaya, Ketut-Anom;Horst, Walter J.
通讯作者：
Horst, Walter J.
影响因子：
5.8
作者：
Berry, P. M.;Spink, J.;White, P. J.
通讯作者：
White, P. J.
影响因子：
4.9
作者：
Dreccer, MF;Schapendonk, AHCM;Rabbinge, R
通讯作者：
Rabbinge, R
影响因子：
3.4
作者：
Desclos, Marie;Etienne, Philippe;Avice, Jean-Christophe
通讯作者：
Avice, Jean-Christophe
影响因子：
6.9
作者：
Dubousset L;Etienne P;Avice JC
通讯作者：
Avice JC