Interspecies interaction for nitrogen use efficiency via up-regulated glutamine and glutamate synthase under wheat-faba bean intercropping
Interspecies interaction for nitrogen use efficiency via up-regulated glutamine and glutamate synthase under wheat-faba bean intercropping
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小麦-蚕豆间作下上调谷氨酰胺和谷氨酸合酶对氮利用效率的种间相互作用
DOI：
10.1016/j.fcr.2021.108324
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发表时间：
2021-10-18
影响因子：
5.8
通讯作者：
Xiao, Jingxiu
中科院分区：
文献类型：
--
作者：
Liu, Zhenyang;Zhu, Ying-An;Xiao, Jingxiu
谷氨酰胺合成酶（GS）和谷氨酸合成酶（GOGAT）循环与植物氮素的吸收、转运和再动员密切相关，但对其在间作系统中的作用关注甚少。采用两种种植模式（单作小麦和间作蚕豆）和4个氮肥水平（N0、N1、N2和N3，小麦施氮量分别为0、90、180和270 kg ha(-1)）进行了双因素田间试验。测定叶片氮素积累和分配，分析叶片中GS和GOGAT活性及其基因表达。结果表明：小麦间作蚕豆增加了小麦地上总氮积累量和籽粒氮积累量；间作小麦（IW）生殖生育期氮素转运效率（NTE）高于小麦（MW）（2018-2019年氮素水平除外）。因此，除氮素水平外，低施稻籽粒产量、氮素收获指数（NHI）和氮素表观回收率（ANR）均高于低施稻。此外，小麦间作蚕豆时，从茎伸长至灌浆期，在N0、N1和N2水平下，小麦叶片中GS、Fd-GOGAT和NADH-GOGAT总活性分别提高了27% ~ 42%、17% ~ 44%和15% ~ 25%。GS1、GS2、Fd-GOGAT和NADH-GOGAT基因在IW旗叶中的平均表达量分别是MW的1.4 ~ 4.3倍、1.2 ~ 3.6倍、1.2 ~ 2.2倍和1.4 ~ 6.7倍。通过简单的相关分析，GS和GOGAT活性及基因表达与秸秆氮素积累和NTE密切相关，而与籽粒氮素积累无关。此外，小麦成熟期全氮积累对抽穗期、开花期和灌浆期旗叶GS和GOGAT活性及基因表达更为敏感，而ANR仅与灌浆期GS和GOGAT活性相关。综上所述，间作在生殖生长期上调GS和GOGAT活性及基因表达是导致间作水稻NTE和NUE提高的主要原因。这些结果表明，种间相互作用调节了作物的GS和GOGAT，它们在间作优势中起着至关重要的作用，并为间作条件下提高氮肥利用效率的机制提供了新的认识。
Glutamine synthetase (GS) and the glutamate synthase (GOGAT) cycle are closely related to plant nitrogen (N) uptake, translocation, and remobilization, but little attention has been paid to their role in intercropping systems. A two-factor field trial involving two planting patterns (mono-cropped wheat [MW] and wheat intercropped with faba bean) and four N levels (N0, N1, N2, and N3 with respective application rates of 0, 90, 180, and 270 kg ha(-1) for wheat) were studied. Nitrogen accumulation and allocation were determined, and the GS and GOGAT activities and their gene expression in the leaves were analyzed. The results showed that wheat total aboveground N accumulation and grain N accumulation were increased when wheat was intercropped with faba bean. Intercropped wheat (IW) presented higher N translocation efficiency (NTE) than MW (except for the N3 level during 2018-2019) during the reproductive growth stage. Thus, the grain yield (except for the N3 level), N harvest index (NHI), and apparent N recovery rate (ANR) were higher in IW than in MW. In addition, total GS, Fd-GOGAT, and NADH-GOGAT activities in the wheat leaves were increased by 27 %-42 %, 17 %-44 %, and 15 %-25 %, respectively, under the N0, N1, and N2 levels from the stem elongation to filling stages when wheat was intercropped with faba bean. On average, GS1, GS2, Fd-GOGAT, and NADH-GOGAT gene expression in the IW flag leaves was 1.4-4.3 times, 1.2-3.6 times, 1.2-2.2 times, and 1.4-6.7 times higher, respectively, than that in MW. Both GS and GOGAT activity and gene expression were tightly related to straw N accumulation and NTE rather than grain N accumulation based on simple correlation analysis. In addition, wheat total N accumulation at maturity was more sensitive to GS and GOGAT activity and gene expression in the flag leaves during the heading, flowering, and filling stages, and ANR only linked with GS and GOGAT activity at the filling stage. Hence, it could be concluded that up-regulated GS and GOGAT activity and gene expression induced by intercropping during the reproductive growth stages contributed to higher NTE and NUE in intercropping. These findings suggest that interspecies interactions modulated GS and GOGAT, which play a crucial role in the intercropping advantage and provide insight into the mechanism of enhanced NUE under intercropping.