The Effector Protein CgNLP1 of Colletotrichum gloeosporioides Affects Invasion and Disrupts Nuclear Localization of Necrosis-Induced Transcription Factor HbMYB8-Like to Suppress Plant Defense Signaling

Abstract

Fungi secrete numerous effectors to modulate host defense systems. Understanding the molecular mechanisms by which fungal effectors regulate plant defense is of great importance for the development of novel strategies for disease control. In this study, we identified necrosis- and ethylene-inducing protein 1 (Nep1)-like protein (NLP) effector gene, CgNLP1, which contributed to conidial germination, appressorium formation, invasive growth, and virulence of Colletotrichum gloeosporioides to the rubber tree. Transient expression of CgNLP1 in the leaves of Nicotiana benthamiana induced ethylene production in plants. Ectopic expression of CgNLP1 in Arabidopsis significantly enhanced the resistance to Botrytis cinerea and Alternaria brassicicola. An R2R3 type transcription factor HbMYB8-like of rubber tree was identified as the target of CgNLP1.HbMYB8-like, localized on the nucleus, and induced cell death in N. benthamiana. CgNLP1 disrupted nuclear accumulation of HbMYB8-like and suppressed HbMYB8-like induced cell death, which is mediated by the salicylic acid (SA) signal pathway. This study suggested a new strategy whereby C. gloeosporioides exploited the CgNLP1 effector to affect invasion and suppress a host defense regulator HbMYB8-like to facilitate infection.

A Novel Effector, FSE1, Regulates the Pathogenicity of Fusarium oxysporum f. sp. cubense Tropical Race 4 to Banana by Targeting the MYB Transcription Factor MaEFM-Like

“…Plant TFs play important roles in defense responses to pathogens [36][37][38]. Many studies have documented that fungal effectors directly target plant TFs to exert their functions [39][40][41]. In this study, overexpression of MaEFM-like induced typical necrosis and cell death in N. benthamiana leaves (Figure 7A), which was in accordance with the previous report that some MYB TFs are activators of the hypersensitive reaction (HR) in response to pathogen attack [42,43].…”

“…During the biotrophy stage, the pathogens could secrete effectors to inhibit host defenses and suppress cell death. For example, the Magnaporthe oryzae effector AvrPiz-t interacts with the bZIP-type transcription factor APIP5 in the cytoplasm and suppresses its transcriptional activity at the necrotrophic stage [40]; the Colletotrichum gloeosporioides effector CgNLP1 disrupts nuclear localization of necrosisinduced TF HbMYB8-Like to suppress plant HR [41]. These results strongly suggested that the pathogenicity of FSE1 was achieved through suppression of the MaEFM-mediated HR.…”

Comparative transcriptome analysis reveals the importance of phenylpropanoid biosynthesis for the induced resistance of 84K poplar to anthracnose

“…On the other hand, some genes of 84K-Cg seedlings involved in phenylpropanoid biosynthesis such as PAL were down-regulated compared to 84K-No and 84K-DCg. It was reported that the appressorium of C. gloeosporioides may release effectors during infection to inhibit plant immune responses [20,21], which may be the adaptation of C. gloeosporioides to host plants [12].…”

Characteristics, Roles and Applications of Proteinaceous Elicitors from Pathogens in Plant Immunity

“…Necrosis- and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) constitute another group of proteinaceous elicitors widely secreted by bacteria, fungi, and oomycetes. NLPs contain characteristic NPP1 domains (PF05630) and are involved in multiple processes such as virulence, conidiospore production, formation of appressoria, abiotic stresses in microbes and triggering immune responses in plants [ 11 , 13 , 58 , 74 , 75 ]. On the basis of their impacts on host plants, NLPs are classified into two forms: cytotoxic to eudicot and monocot plants and noncytotoxic [ 59 , 65 , 76 ].…”