Colletotrichum lindemuthianum poses a serious threat to common bean production and impacts food security. It is essential to comprehend the intricate nature of the pathogen infection process and the underlying biochemical systems regulating plant defence to create tactics that effectively increase plant resistance. This study leveraged a stable C. lindemuthianum transformant library to examine these intrinsic mechanisms in a susceptible Phaseolus vulgaris cultivar, Jawala. Among the 57 mitotically stable transformants employed to screen for altered virulence, 51 were pathogenically similar to wild type and the remaining six transformants were either reduced or impaired. Nine transformants (three pathogenically similar and all impaired and reduced mutants) were selected for subsequent studies. These mutants exhibited an array of morpho-cultural variations. The biochemical studies of these mutants revealed free radicals as double-edged swords, exerting a pivotal influence on the infection process. The free radical (H₂O₂) elevated at an early stage (24 hpi) in the cases of reduced (CT-51) and impaired (CT-225) mutants. However, at the later stage (72 hpi), H₂O₂ was promoted in the case of R-2047 and equal to wild type (CT-101) transformant. Contrary, superoxide (O₂⁻) increased considerably at 48 hpi in the incompatible interaction of reduced (CT-51) and impaired (CT-225) mutants. The microscopic images revealed how easily the wild type (CT-101) could germinate, penetrate, and infect the leaves. The pathogenically reduced transformant (CT-51), however, had delayed germination as well as a decreased growth rate and spore production. Additionally, the pathogenicity of the impaired transformant (CT-225) was completely lost, and its conidia failed to properly germinate. This is the first account of C. lindemuthianum in planta colonization with a GFP tag. This study increased our understanding of the mechanics of the reactions triggered by C. lindemuthianum and may be used to develop novel strategies for the effective control of bean anthracnose. Additionally, identifying the genes disrupted by the insertion of Agrobacterium T-DNA will help in identifying the genes necessary for bean plant colonization.

炭疽病菌 (Colletotrichum lindemuthianum)对菜豆生产构成严重威胁并影响粮食安全。有必要了解病原体感染过程的复杂性质和调节植物防御的潜在生化系统，以制定有效增强植物抗性的策略。本研究利用稳定的 C. lindemuthianum转化体库来检查易感菜豆品种 Jawala中的这些内在机制。在用于筛选毒力改变的 57 个有丝分裂稳定的转化体中，51 个在致病性上与野生型相似，其余 6 个转化体要么降低或受损。选择九个转化体（三个致病性相似且全部受损和减少的突变体）用于后续研究。这些突变体表现出一系列形态文化变异。对这些突变体的生化研究表明，自由基是一把双刃剑，对感染过程发挥着关键影响。在减少（CT-51）和受损（CT-225）突变体的情况下，自由基（H ₂ O ₂）在早期（24 hpi）升高。然而，在后期(72 hpi)，H ₂ O ₂在R-2047的情况下得到促进并且与野生型(CT-101)转化体相同。相反，在减少的（CT-51）和受损的（CT-225）突变体的不相容相互作用中，超氧化物（O ₂ ^-）在48 hpi时显着增加。显微图像揭示了野生型（CT-101）发芽、渗透和感染叶子的容易程度。然而，致病性降低的转化体（CT-51）却延迟了发芽，并降低了生长速度和孢子产量。此外，受损转化体（CT-225）的致病性完全丧失，其分生孢子无法正常萌发。这是C. lindemuthianum在带有GFP标签的植物定植中的第一个描述。这项研究增加了我们对C. lindemuthianum引发的反应机制的理解，并可用于开发有效控制豆类炭疽病的新策略。此外，鉴定因农杆菌T-DNA插入而破坏的基因将有助于鉴定豆类植物定植所需的基因。