Screening and transcriptome analysis of low phosphorus tolerance genes in Pueraria lobata

Abstract

Abstract To explore the effects of low phosphorus stress on the root morphology, growth physiology and molecular mechanisms of Pueraria lobata, the present study utilized P. lobata from Australia and Hunan and Jiangsu Provinces in China. Three treatment levels of normal phosphorus (0.5 mmol·L− 1 KH2PO4), low phosphorus (0.05 mmol·L− 1 KH2PO4) and extremely low phosphorus (0.005 mmol·L− 1 KH2PO4) were applied by hydroponics. After 20 days of culture, the root index, proline, soluble sugar, and soluble protein contents and malondialdehyde, superoxide dismutase, peroxidase, and catalase activity levels were measured. P. lobata from Australia was tolerant to low phosphorus, while P. lobata from Jiangsu was sensitive to low phosphorus. Transcriptome sequencing was performed on the roots of P. lobata from Australia and P. lobata from Jiangsu. Gene function annotation analysis and differential expression gene screening were performed on the transcriptomes. GO enrichment and KEGG pathway enrichment analysis revealed that in the plant hormone signal transduction pathway PR1 and CTR1 were the most differentially expressed genes in Australian P. lobata, while ERF1 was the most differentially expressed gene in Jiangsu P. lobata. The transcription factor families C2H2, bZIP, MYB, and bHLH were among the most differentially expressed transcription factors under low phosphorus stress in P. lobata from Australia, while ERF was the most differentially expressed transcription factor under low phosphorus stress in P. lobata from Jiangsu. Through transcriptome sequencing, the differences in gene expression between low-phosphorus-tolerant Australian P. lobata and low-phosphorus-sensitive Jiangsu P. lobata under low phosphorus stress were preliminarily understood, providing a basis for future research on the mechanism of P. lobata stress responses.