Recognised Research Group AGROBIOTECH, Department of Plant Production and Forest Resources, Higher Technical School of Agricultural Engineering of Palencia, University Institute for Research in Sustainable Forest Management (iuFOR), University of Valladolid, Avda. Madrid 57, 34004 Palencia, Spain.
Group of Genetics, Breeding and Biochemistry of Brassicas, Mision Biologica de Galicia (MBG-CSIC), 36143 Pontevedra, Spain.
Plant Sci. 2023 May;330:111664. doi: 10.1016/j.plantsci.2023.111664. Epub 2023 Feb 27.
Trichoderma is a genus of filamentous fungi widely studied and used as a biological control agent in agriculture. However, its ability to form fungal networks for inter-plant communication by means of the so-called inter-plant "wired communication" has not yet been addressed. In our study we used the model plant Arabidopsis thaliana, the fungus Trichoderma hamatum (isolated from Brassicaceae plants) and the pathogens Sclerotinia sclerotiorum and Xanthomonas campestris (necrotrophic fungus and hemibiotrophic bacteria, respectively). We performed different combinations of isolated/neighboring plants and root colonization/non-colonization by T. hamatum, as well as foliar infections with the pathogens. In this way, we were able to determine how, in the absence of T. hamatum, there is an inter-plant communication that induces systemic resistance in neighboring plants of plants infected by the pathogens. On the other hand, the plants colonized by T. hamatum roots show a greater systemic resistance against the pathogens. Regarding the role of T. hamatum as an inter-plant communicator, it is the result of an increase in foliar signaling by jasmonic acid (increased expression of LOX1 and VSP2 genes and decreased expression of ICS1 and PR-1 genes), antagonistically increasing root signaling by salicylic acid (increased expression of ICS1 and PR-1 genes and decreased expression of LOX1 and VSP2). This situation prevents root colonization by T. hamatum of the foliarly infected plant and leads to massive colonization of the neighboring plant, where jasmonic acid-mediated systemic defenses are induced.
木霉是一种广泛研究并用作农业生物防治剂的丝状真菌。然而，其通过所谓的植物间“有线通讯”形成植物间通讯的能力尚未得到解决。在我们的研究中，我们使用了模式植物拟南芥、木霉（从十字花科植物中分离得到）以及病原菌核盘菌和野油菜黄单胞菌（分别为坏死真菌和兼性寄生细菌）。我们进行了不同的组合，包括孤立/邻近植物以及木霉对根的定殖/非定殖，同时还进行了病原菌的叶面感染。通过这种方式，我们能够确定在没有木霉的情况下，植物间通讯如何诱导受病原菌感染的植物的邻近植物产生系统抗性。另一方面，木霉根定殖的植物对病原菌表现出更强的系统抗性。关于木霉作为植物间通讯者的作用，它是由于茉莉酸（LOX1 和 VSP2 基因表达增加和 ICS1 和 PR-1 基因表达减少）的叶面信号增加所致，而水杨酸的根信号拮抗增加（ICS1 和 PR-1 基因表达增加和 LOX1 和 VSP2 基因表达减少）。这种情况阻止了木霉对叶面感染植物的根定殖，并导致邻近植物大量定殖，从而诱导了茉莉酸介导的系统防御。
