Wheat nitrogen metabolism during grain filling: comparative role of glumes and the flag leaf
Wheat nitrogen metabolism during grain filling: comparative role of glumes and the flag leaf
复制标题
DOI：
10.1007/s00425-006-0338-5
复制
发表时间：
2006-12-01
期刊：
影响因子：
4.3
通讯作者：
Araus, Jose L.
中科院分区：
文献类型：
--
作者：
Lopes, Marta S.;Cortadellas, Nuria;Araus, Jose L.
研究了面包小麦籽粒灌浆过程中氮素化合物的转移以及颖壳和旗叶的作用。CV.佛罗里达）在田间条件下生长。颖壳损失的总氮含量是旗叶在乳熟期和面团早期损失的总氮含量的两倍。在剑叶、颖壳和籽粒中，Glu、Asp、Ser和Ala占游离氨基酸库总减少量的85%。游离氨基酸库的主成分分析分离的颖片和旗叶的粮食，建议粮食的具体规定在蛋白质合成中使用的游离氨基酸。在所有三个器官中，没有检测到谷氨酰胺的减少，可能是由于稳定的谷氨酰胺合成酶（GS; EC 6.3.1.2）的活动，每个可溶性蛋白在旗叶和颖。与旗叶相比，颖壳中叶绿体GS同工酶的含量相对较少。我们表明，这是由于较低的相对数量的叶肉细胞在颖片的不同解剖结构和GS免疫定位的细胞模式的支持。我们认为，细胞分布起着关键作用，支持代谢，使颖片组织承担的各种功能。
The mobilization of nitrogen (N) compounds and the roles played by glumes and the flag leaf during grain filling were studied in bread wheat (Triticum aestivum L. cv. Florida) grown under field conditions. Glumes lost twice as much of their total N content as that lost by the flag leaf between the milk and early dough stages. In the flag leaf, glumes and grains, Glu, Asp, Ser and Ala accounted for 85% of all the reductions in the free amino acid pool. Principal component analysis of free amino acid pools separated grains from the glumes and the flag leaf, suggesting grain specific regulations in the use of free amino acids in protein synthesis. In all three organs, no decrease in Gln was detected, probably due to steady glutamine synthetase (GS; EC 6.3.1.2) activities per soluble protein in both the flag leaf and glumes. Compared with the flag leaf, glumes presented relatively smaller amounts of the chloroplast GS associated isoform. This we show is due to a lower relative number of mesophyll cells in glumes as supported by the different anatomy and the cellular pattern of the GS immunolocalization. We argue that cellular distribution plays a key role in supporting metabolism to enable the various functions undertaken by glume tissue.