Identification of receptor proteins of effectors from the sugarcane smut pathogen Sporisorium scitamineum

• Grant number: 17/02434-9
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): July 01, 2017
• Effective date (End): March 31, 2018
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal researcher: Claudia Barros Monteiro Vitorello
• Grantee: Patricia Dayane Carvalho Schaker
• Home Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Sugarcane is one of the crops that most contributes to sugar and ethanol of first and second generation in the world. However, the diseases that affect the culture can cause significant economic losses and therefore the importance of its study to improve control methods and to deepen the knowledge about the pathogen recognition mechanisms. The sugarcane smut disease is one of the most harmful to the crop, and its diagnosis has been increasingly frequent in the field, especially after the prohibition of burning for harvest in Brazil. Caused by the biotrophic fungus Sporisorium scitamineum, the disease is characterized by the emission of a whip-like structure in the plant meristem where fungus spores differentiate and are easily disseminated. Because it is a disease found in all cane producing regions, several research groups have studied the main mechanisms activated during the interaction that are positively related to the degree of resistance, focusing only in the plant side. However, what has been observed is that even varieties considered to be highly resistant are colonized by the fungus and may present whip emission, which demonstrates the complexity of this pathosystem and the signaling involved for the symptoms development. Studies using the dual-RNAseq technique in our research group have shown that transcriptional changes related to the identity of plant meristem occur very early in relation to whip development, while the fungus has among the most expressed genes those to candidate effectors with unknown functions. Effectors are molecules produced by pathogens that act on the apoplast or within the host cell, where they are recognized by host proteins, triggering a cell signaling that determines the compatibility or incompatibility of the interaction. To identify which plant proteins are associated with this recognition, it is necessary to study the fungus effectors. Recently, as part of my doctoral thesis, the transient expression in N. benthamiana technique of the pathogen-effector candidate genes fused to the gene coding for the fluorescent protein Citrine was used to identify the target cell compartments of these proteins. The experiments allowed determine the subcellular localization of four effectors. However, considering the complexity of the modern sugarcane varieties genome, the determination of the molecular partners of these effectors, that is, plant proteins responsible for their recognition and that contribute to the activation of a given response, would be more promising and judicious with the use of sugarcane itself in the experiments. In this way, the present project aims to transform, via Agrobacterium tumefaciens, sugarcane meristems of varieties with different levels of resistance to smut with the S. scitamineum effector's candidates more expressed during the first moments of the interaction and evaluate: 1) the phenotype of the transformed plants; 2) co-immunoprecipitate proteins that interact with the effectors, 3) sequencing, identifying and characterizing such proteins and the coding genes, and 4) validating the interaction by means of BiFc assays. With the results of this project, it is expected to understand the function of the fungus effectors in the establishment of the disease, and to characterize differences at the gene and protein level of sugarcane varieties with different degrees of resistance. In addition, the data obtained will be used to complement the transcriptomic, proteomic and metabolomic data obtained by the research group in a systems biology approach, making it possible in the future to define molecular markers related to plant susceptibility/ resistance. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BEDRE, RENESH; IRIGOYEN, SONIA; SCHAKER, PATRICIA D. C.; MONTEIRO-VITORELLO, CLAUDIA B.; DA SILVA, JORGE A.; MANDADI, KRANTHI K. Genome-wide alternative splicing landscapes modulated by biotrophic sugarcane smut pathogen. SCIENTIFIC REPORTS, v. 9, JUN 20 2019. Web of Science Citations: 1.