Identification and function analysis of PP2C gene family shows that BnaA2.PP2C73 negatively regulates drought and salt stress responses in Brassica napus L.

Protein phosphatases type 2 C (PP2C) genes play a significant role in ABA signaling. Brassica napus, a pivotal industrial oilseed crop of global significance, stands at the forefront of agricultural importance. However, a comprehensive study of PP2C genes in B. napus is still missing. In this investigation, a comprehensive analysis was undertaken to identify 258 PP2C genes in B. napus, categorizing PP2C genes into 13 distinct subfamilies based on gene structural characteristics and the presence of conserved motifs. The collinearity patterns uncovered that the expansion of BnaPP2C gene family was strongly influenced by pivotal segmental duplication events with strong purifying selection. Fifty of 258 PP2C genes belonging to the subfamily E were located on 16 chromosomes. Subfamily E expansion was facilitated by segmental duplication and the promoters are rich in cis-elements. The qRT-PCR showed that subfamily E genes were transcriptionally responsive to a range of abiotic stresses, including ABA, MeJA, NaCl and drought. Additionally, the proteins encoded by selected genes from subfamily E were located in cytoplasm and BnaA2.PP2C73 negatively regulated drought and salt stress responses. These results will serve as a valuable resource for future research in understanding the fundamental characteristics and evolutionary dynamics of PP2C gene family in B. napus, providing new genetic targets to improve the abiotic stress resistance of B. napus.