biostudies-literatureYan FKey R & D program of Yunnan Province, ChinaCigar tobacco quality control evaluation system research and applicationResearch and application of personalized cigarette productsthe National Nature Science Foundation of ChinaKey projects of Yunnan provincial natural fundMajor special projects of the Ministry of science and technology9338https://www.ebi.ac.uk/biostudies/studies/S-EPMC11039699biostudies-literatureUnknown14(1)Induced resistance is considered an eco-friendly disease control strategy, which can enhance plant disease resistance by inducing the plant's immune system to activate the defense response. In recent years, studies have shown that lactic acid can play a role in plant defense against biological stress; however, whether lactic acid can improve tobacco resistance to Phytophthora nicotianae, and its molecular mechanism remains unclear. In our study, the mycelial growth and sporangium production of P. nicotianae were inhibited by lactic acid in vitro in a dose-dependent manner. Application of lactic acid could reduce the disease index, and the contents of total phenol, salicylic acid (SA), jasmonic acid (JA), lignin and H₂O₂, catalase (CAT) and phenylalanine ammonia-lyase Scientific reportsLactic acid induced defense responses in tobacco against Phytophthora nicotianae.PMC11039699No: HYHH2021YL01202201AS070064grant no. 202103AC1000032021YFD1000202grant no. 202103AC1000032023CP02Grant No. 31860075Yang YZhou BTian SMa JChang SLiu TPeng MXi CYan FfalseLactic acid induced defense responses in tobacco against Phytophthora nicotianae.Induced resistance is considered an eco-friendly disease control strategy, which can enhance plant disease resistance by inducing the plant's immune system to activate the defense response. In recent years, studies have shown that lactic acid can play a role in plant defense against biological stress; however, whether lactic acid can improve tobacco resistance to Phytophthora nicotianae, and its molecular mechanism remains unclear. In our study, the mycelial growth and sporangium production of P. nicotianae were inhibited by lactic acid in vitro in a dose-dependent manner. Application of lactic acid could reduce the disease index, and the contents of total phenol, salicylic acid (SA), jasmonic acid (JA), lignin and H₂O₂, catalase (CAT) and phenylalanine ammonia-lyase 2024-01-01T00:00:00Z2024 Apr2025-04-22T20:40:41.255Z2025-04-06T03:16:51.707ZS-EPMC110396993865412010.1038/s41598-024-60037-2