Transcriptome and proteome analyses reveal high nitrate or ammonium applications alleviate photosynthetic decline of seedlings under elevated carbon dioxide by regulating and .

Unlabelled: The global CO concentration is predicted to reach 700 µmol·mol by the end of this century. (Hemsl.) Yang is a precious timber species and is listed as a national secondary protection plant in China. seedlings show obvious photosynthetic decline when grown long-term under an elevated CO concentration (eCO, EC). This decline can be alleviated by high nitrate or ammonium applications. However, the underlying mechanisms have not yet been elucidated. We performed transcriptomic and proteomic analyses of of seedlings grown under an ambient CO concentration (AC) and applied with either a moderate level of nitrate (N), a high level of nitrate (hN), or a moderate level of ammonium (A) and compared them with those of seedlings grown under eCO (i.e., AC_N vs EC_N, AC_hN vs EC_hN, AC_A vs EC_A) to identify differentially expressed genes (DEGs) and differentially expressed proteins (DEPs). We identified 4528 (AC_N vs EC_N), 1378 (AC_hN vs EC_hN), and 252 (AC_A vs EC_A) DEGs and 230, 514, and 234 DEPs, respectively, of which 59 specific genes and 21 specific proteins were related to the regulation of photosynthesis by nitrogen under eCO. A combined transcriptomic and proteomic analysis identified 7 correlation-DEGs-DEPs genes. These correlation-DEGs-DEPs genes revealed crucial pathways involved in glyoxylate and dicarboxylate metabolism and nitrogen metabolism. The and correlation-DEGs-DEPs genes were enriched in these two metabolisms. We propose that the and correlation-DEGs-DEPs genes play an important role in photosynthetic decline and nitrogen regulation. High nitrate or ammonium applications alleviated the downregulation of and and, hence, alleviated photosynthetic decline. The results of this study provide directions for the screening of germplasm resources and molecular breeding of , which is tolerant to elevated CO concentrations.

Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01481-2.