Based on PDX genome-wide identification and its expression analysis under waterlogging stress, transgenic Brassica napus plants overexpressing the BnaPDX1.3 gene exhibit stronger waterlogging tolerance compared to wild-type plants

Ming Yao Yao ^1,2 Bo Hong ^1,2 Hongfei Ji ^1,2 Chunyun Guan ^1,2,3* Mei Guan ^1,2,3*

• ¹ College of Agriculture, Hunan Agricultural University, Changsha, China
• ² Hunan Branch of National Oilseed Crops Improvement Center, Changsha, China
• ³ Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha, China

The PDX gene is a key gene in the vitamin B6 synthesis pathway, playing a crucial role in plant growth, development, and stress tolerance. To explore the family characteristics of the PDX gene in Brassica napus (B. napus) and its regulatory function under waterlogging stress, this study used five PDX genes from Arabidopsis thaliana as the basis for sequence analysis. Thirteen, eight, and six PDX genes were identified in B. napus, Brassica oleracea (B. oleracea), and Brassica rapa (B. rapa), respectively. Bioinformatics studies revealed a high conservation of PDX subfamily genes during evolution. Analysis of the expression pattern of PDX genes in B. napus under waterlogging stress indicated that, except for PDX1.2, which was down-regulated, all other PDX genes were up-regulated. qRT-PCR validation of the PDX1.3 gene in B. napus aligned well with RNA-seq. qRT-PCR analysis demonstrated that BnaPDX1.3 gene expression significantly and continuously increased during waterlogging stress in B. napus, maintaining an upward trend even after the stress was removed. In this study, waterlogging experiments were conducted on BnaPDX1.3-overexpressing B. napus plants. The results indicated that plants with high BnaPDX1.3 gene expression exhibited stronger antioxidant systems and hydrogen peroxide scavenging capabilities, thereby enhancing the waterlogging tolerance of B. napus.