Low Red to Far-Red Light Environment Alters Nitrogen Assimilation in Corn (Zea mays)

In the absence of direct resource competition, far-red light reflected from neighbouring weeds compromises light quality (red to far-red ratio; R/FR) which inactivates phytochrome (Phy) resulting in the regulation of various physiological processes. The main objective of this research was to investigate the effects of low R/FR light on nitrogen assimilation in corn. To explore this, changes to the nitrogen assimilation pathway were measured in corn seedlings nine days post-emergence under low R/FR and control light conditions. The observed results indicate that nitrate levels increased and ferredoxin-dependent glutamine:2-oxoglutarate aminotransferase activities decreased under low R/FR light, however, no other pathway enzymes were affected. Changes in the pathway appear to be PhyB-independent, as Arabidopsis phyB mutant did not change the nitrate levels compared to wild-type Arabidopsis. The research indicates the importance of mitigating early-season weed competition and offers insight into the early physiological mechanisms involved in nitrogen utilization under resource-independent competition.This data was collected as part of William Kramer's MSc research work (see Related Publication).

在无直接资源竞争的情境下，邻近杂草反射的远红光会降低光质，也就是红光与远红光比值（R/FR），进而使光敏色素（Phytochrome, Phy）失活，调控多种生理过程。本研究的核心目标为探究低R/FR光照对玉米氮同化过程的影响。为验证该科学问题，本研究在低R/FR光照与对照光照条件下，对出苗9天的玉米幼苗体内氮同化通路的变化进行了检测。观测结果显示，低R/FR光照下玉米幼苗的硝酸盐含量上升，而铁氧还蛋白依赖型谷氨酰胺:2-氧代戊二酸转氨酶（ferredoxin-dependent glutamine:2-oxoglutarate aminotransferase）活性下降，但该通路其余酶类未受影响。该通路的变化似乎不依赖光敏色素B（PhyB），与野生型拟南芥（Arabidopsis）相比，phyB突变体拟南芥的硝酸盐水平未发生显著改变。本研究证实了缓解作物生育早期杂草竞争的重要性，并为理解资源非直接竞争下氮利用相关的早期生理机制提供了新的研究视角。本数据集采集自William Kramer的硕士研究工作（详见相关出版物）。