The pink ear rot is one of the most damaging maize diseases, caused by the mycotoxigenic fungal pathogen, Fusarium verticillioides. The application of biological control agents, like antagonistic and/or resistance inducer microorganisms, is an option to reduce fungal infection and kernel contamination in a sustainable and environmentally friendly way. It is well known that Trichoderma species are non-pathogenic fungi able to antagonize plant pathogens and to induce systemic resistance in plants. The present work aimed to verify if Trichoderma spp., applied to maize kernels, affect the plant growth and induce systemic responses to F. verticillioides. Besides, the capability to reduce fumonisin concentration in liquid cultures was investigated. Two T. gamsii (IMO5 and B21), and one T. afroharzianum (B75) isolates, selected both for antagonism and for the ability to reduce root infections, significantly reduced the endophytic development of the stem-inoculated pathogen, compared to the control. The mechanisms of action appeared to be strain-specific, with IMO5 enhancing transcript levels of marker genes of Induced Systemic Resistance (ZmLOX10, ZmAOS, and ZmHPL) while B21 enhancing marker genes of Systemic Acquired Resistance (ZmPR1 and ZmPR5), as evinced by measuring their expression profiles in the leaves. Moreover, IMO5 promoted plant growth, while B21 was able to significantly reduce the fumonisin content in a liquid medium. The results of this work give new evidence that the seed application of T. gamsii is a promising tool for controlling F. verticillioides to be integrated with breeding and the adoption of good agricultural practices.

粉色穗腐病是最损坏玉米疾病，引起mycotoxigenic真菌病原体的一个串珠镰刀菌。诸如拮抗和/或抗性诱导微生物等生物防治剂的应用是一种以可持续和环境友好的方式减少真菌感染和籽粒污染的选择。众所周知，木霉属种是非病原性真菌，能够拮抗植物病原体并诱导植物的系统抗性。目前的工作旨在验证木霉属种是否适用于玉米粒，是否影响植物生长并诱导对网状拟南芥的系统性反应。。此外，还研究了降低液体培养物中伏马毒素浓度的能力。与对照相比，为对抗性和减少根部感染的能力而选择的两种T. gamsii（IMO5和B21）和一种T. afroharzianum（B75）分离株与对照相比显着降低了干接种病原体的内生发育。作用机制似乎是菌株特异性的，IMO5增强了诱导的系统抗性的标记基因（ZmLOX10，ZmAOS和ZmHPL）的转录水平，而B21增强了系统获得性抗性的标记基因（ZmPR1和ZmPR5）），如通过测量它们在叶片中的表达谱所证实的。此外，IMO5促进了植物的生长，而B21则能够显着降低液体培养基中的伏马毒素含量。这项工作的结果给出了新的证据表明，种子应用T. gamsii是控制一个行之有效的手段F.轮枝与繁殖和采用良好农业规范进行整合。