The oil bean is a high-quality, economically valuable variety of kidney bean (Phaseolus vulgaris L.) that is widely cultivated in Northeast China. However, the prevalence of anthracnose, caused by a combination of factors, including continuous cropping over many years, has led to significant declines in both yield and quality. The mitogen-activated protein kinase (MAPK) cascade is a highly conserved plant cell signaling pathway that plays a pivotal role in plant growth and development, as well as responses to biotic stress. However, its role in the response of P. vulgaris to anthracnose infection has not previously been reported. We identified and characterized thirteen MAPK genes (PvMAPK01–PvMAPK13) in the P. vulgaris genome. These genes were found on eight of the eleven chromosomes of P. vulgaris, and phylogenetic analyses classified them into four previously established subgroups (A–D). Analysis of the cis-acting elements in their promoter regions revealed the presence of multiple elements associated with light, hormone regulation, stress responses, and growth and development. An analysis of intraspecific collinearity revealed that whole-genome and/or segmental duplication, rather than tandem duplication, has been the primary driver of PvMAPK family expansion in P. vulgaris. Transcriptome data revealed that the PvMAPKs differed in their tissue-specific expression patterns, with PvMAPK05 showing particularly high expression in stems and stem tips and PvMAPK07 and PvMAPK11 showing relatively low expression across all tissues. In general, expression of the PvMAPKs was higher in stems, stem tips, and pods than in other tissues and organs, suggesting that they may be particularly important for regulating stem and pod development. Analysis of the expression of PvMAPKs in field-grown plants infected or uninfected with anthracnose revealed that the relative expression levels of PvMAPK05, PvMAPK07, PvMAPK09, and PvMAPK11 exhibited particularly significant changes in response to anthracnose infection across different varieties, suggesting their potential involvement in the anthracnose response of Phaseolus vulgaris. This study reports the fundamental characteristics of the thirteen MAPK genes in P. vulgaris, documents their expression patterns in diverse tissues, and offers preliminary insights into their responses to anthracnose infection, establishing a foundation for subsequent functional validation.

Anthracnose has become one of the major diseases limiting common bean production, severely affecting its yield and commercial quality. Screening for resistant varieties, exploring their resistance mechanisms, and breeding new resistant cultivars have emerged as urgent issues to address. Therefore, this experiment utilized common bean germplasm resources with varying resistance levels to anthracnose as materials. By inoculating with Colletotrichum lindemuthianum, the activities of key en-zymes—including superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), glutathione S-transferase (GST), and chi-tinase (CHI)—as well as malondialdehyde (MDA) content were measured. Transcrip-tional regulation was analyzed to investigate the physiological and biochemical re-sistance mechanisms among different resistant germplasms. Additionally, differen-tially expressed genes (DEGs) and pathways associated with anthracnose resistance were screened. The results showed that, based on the analysis of physiological and biochemical changes in common bean leaves post-inoculation, the MDA content decreased in all varieties except Wuchang Dayoudou. Regarding antioxidant enzyme activities, the SOD, POD, and PPO activities in the leaves of different common bean varieties in-creased, indicating that pathogen infection could induce the upregulation of antioxi-dant enzyme activities. In contrast, GST activity decreased under pathogen stress. CHI activity increased after pathogen infection. Following pathogen challenge, PAL activi-ty increased in resistant varieties but decreased in susceptible ones. Transcriptome analysis of common bean leaves and pods revealed that the primary metabolic pathways associated with resistance were significantly enriched in phe-nylpropanoid biosynthesis, MAPK signaling pathway, and plant hormone signal transduction. Among these pathways, 13 genes were screened in phenylpropanoid bi-osynthesis, 6 genes in the MAPK signaling pathway, and 3 genes in plant hormone signal transduction. Additionally, other resistance-related pathways and transcription factors were analyzed, identifying 2 genes in the peroxisome pathway, 2 genes in the plant-pathogen interaction pathway, and 12 transcription factors (including AP2, WRKY, and ERF families). These differentially expressed genes are hypothesized to re-spond to Colletotrichum lindemuthianum stress.