作物营养创新科研平台： 赤霉素在调节玉米N吸收及其生理特性中的作用

研究使用平台：NMT作物营养创新科研平台
期刊：International Journal of Molecular Sciences

主题：赤霉素在调节玉米N吸收及其生理特性中的作用

标题：The Role of Gibberellins in Regulation of Nitrogen  Uptake and Physiological Traits in Maize Responding to Nitrogen  Availability
影响因子：4.183
检测指标：NO3-流速

检测样品：玉米幼苗

NO3-流实验处理方法：

低氮/正常氮处理5天后检测根系，检测位置为根上距离根冠700微米的点。
NO3-流实验测试液成份：
0.1 mM NH4NO3、0.1mMKCl，0.1mMCaCl2、0.3mMMES，pH 6.0

作者：中国农业大学张明才、王玉斌

中文摘要（谷歌机翻）

修饰的赤霉素（GA）信号导致作物中的低氮（N）使用效率（NUE）低的半侏儒症。GA介导的N摄取的理解对于NUE改善的农作物的发展至关重要。

在低（LN）和充足（SN）N条件下生长的GA合成缺陷型突变体zmga3ox中，分析了GA在调节氮吸收能力和**盐（NO3-）转运蛋白（NRT）中的功能。LN显着抑制了GA1，GA3和GA4的产生，而zmga3ox植物对芽和LN胁迫显示出更高的敏感性。

此外，还记录了较高的花青素积累和叶绿素含量的降低。在LN和SN条件下，zmga3ox植物的净NO3-通量和15N含量均降低。外源GA3可以恢复zmga3ox植物的NO3-吸收，但烯康唑则抑制NO3-的吸收。

此外，ZmNRT2.1 / 2.2的转录水平在zmga3ox植物中被下调，而GA3的应用提高了表达水平。此外，RNA-seq分析鉴定了一些转录因子，这些转录因子与GA介导的NRT相关基因的转录操作有关。

这些发现表明，GAs影响了NRTs的转录调控和玉米对氮素供应的生理反应中N的吸收。

Nitrateuptake and allocation in zmga3ox plants under LN and SN conditions. (a–b) The net NO3- flux (a), and the mean NO3- flux (b) along the maturation zone of wild-typeandzmga3ox primary root. Values werethe means ± SD (n =7). (c) The 15N content after 10 min15Ntracing assay in wildtype and zmga3ox plants; (d) total N content per plantin shoots and roots of wild-type and zmga3ox plants; (e) the 15N content in wild-type and zmga3oxseedlings treated with GA3 and/or uniconazole (Ucz). (c–e) Values were the means ±SD (n = 3). Different lettersindicated significant difference calculated by Fisher’s LSD (p < 0.05).

英文摘要

Modified gibberellin (GA) signaling leads to  semi-dwarfism with low nitrogen (N) use effciency (NUE) in crops.  Anunderstanding of GA mediatedNuptake is essential for the development  of crops with improved NUE.

The function of GA in modulating N  uptake capacity and nitrate (NO3-) transporters (NRTs) was analyzed in  the GA synthesis-deficient mutant zmga3ox grown under low (LN) and  suffcient (SN) N conditions. LN significantly suppressed the production  of GA1, GA3, and GA4, and the zmga3ox plants showed more sensitivity in  shoots as well as LN stress.

Moreover, the higher anthocyanin  accumulation and the decrease of chlorophyll content were also recorded.  The net NO3- fluxes and 15N content were decreased in zmga3ox plants  under both LN and SN conditions. Exogenous GA3 could restore the NO3-  uptake in zmga3ox plants, but uniconazole repressed NO3- uptake.

Moreover,  the transcript levels of ZmNRT2.1/2.2 were downregulated in zmga3ox  plants, while the GA3 application enhanced the expression level.  Furthermore, the RNA-seq analyses identified several transcription  factors that are involved in the GA-mediated transcriptional operation  of NRTs related genes.

These findings revealed that GAs  influenced N uptake involved in the transcriptional regulation of NRTs  and physiological responses in maize responding to nitrogen supply.