Genome-Wide Identification and Expression Analysis of GS and GOGAT Gene Family in Pecan (Carya illinoinensis) under Different Nitrogen Forms.

Ammonium nitrogen (NH₄⁺-N) is one of the main forms of nitrogen absorbed and utilized by plants, and mastering the regulatory mechanism of plant ammonium assimilation is a key way to improve the efficiency of plant nitrogen utilization. Glutamine synthetase (GS) and glutamate synthase (GOGAT), two key enzymes for ammonium assimilation, have rarely been studied in pecan. In this study, GS and GOGAT family members of pecan were identified and analyzed using bioinformatics methods. The results indicated that 6 GS and 4 GOGAT genes were identified. The cis-acting elements can be broadly categorized into light-responsive, hormone-responsive, and stress-responsive elements. The findings from the analysis of homologous evolution revealed that neither of the two gene families experienced tandem duplication events. Additionally, different ratios of ammonium to nitrate nitrogen were set to analyze the activities of GS and GOGAT enzymes and expression levels in pecan. The results demonstrate differences in the activities of GS and GOGAT enzymes and the gene expression levels in various tissues of pecan under different nitrogen form ratios. This study established a foundation for further mastering the molecular regulatory mechanism of nitrogen assimilation in pecan, and provided a theoretical basis for enhancing the ability of pecan to absorb and utilize nitrogen. [ABSTRACT FROM AUTHOR]