title: Mycelial development preceding basidioma formation in Moniliophthora perniciosa is associated to chitin, sugar and nutrient metabolism alterations involving autophagy.
abstract: We identified and characterized two chitinases, named MpCHIT1 and MpCHIT2, from the fungus Moniliophthora perniciosa - the etiologic agent of witches' broom disease in cacao tree (Theobroma cacao L.) - during its development, mainly in the mycelia phases preceding the basidioma formation. The expression of MpCHIT1 and MpCHIT2, together with MpCHS and MpATG8 (chitin synthase and autophagy genes, respectively), was analyzed during the M. perniciosa growth and development on bran-based solid medium as well as in liquid medium containing H2O2 or rapamycin (oxidative and nutritional related-autophagy stress agents, respectively). In order to link the expression of chitin metabolism-related genes to nutritional composition influencing fungus development, we also quantified total and reduced sugars, as well as macro- and micronutrients in the bran-based solid medium. The expression analysis showed that the MpCHS expression increased through mycelial development and then decreased in the primordium and basidioma phases, while the expression of MpCHIT1 and MpCHIT2 was higher in basidioma and primordium phases, respectively. Moreover, the expression pattern of MpCHIT1 and MpCHIT2 is distinct, the second correlated with the MpATG8 expression pattern and possibly with autophagy process, while the first may be related to the basidioma formation. The quantification of total and reduced sugars, as well as macro- and micronutrients supported the idea that the cell wall restructuration due to MpCHS, MpCHIT1 and MpCHIT2 is related to stress and fungal nutrient reallocation, allowing the formation and development of the basidioma. Experiments involving M. perniciosa growth on liquid medium containing H2O2 or rapamycin showed that MpCHIT1 and MpCHIT2 were over-expressed in response to oxidative but also to nutritional related-autophagy stresses. Interestingly, the expression level of MpCHS, MpCHIT1 and MpCHIT2 in presence of rapamycin is similar to the one observed in the primordium and basidioma from bran-based solid medium. The analysis of the overall data allowed designing a general scheme of chitin metabolism and autophagy during M. perniciosa development, focusing on the mycelium phases as crucial and environmentally influenced steps preceding the primordium and basidioma formation. These data support the idea that the nutritional environment of M. perniciosa influences its development and life cycle.
authors.affiliation: Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Rodovia Ilhéus-Itabuna, km 16, 45662-900 Ilhéus, BA, Brazil.
authors.forename: Dayane Santos
authors.initials: DS
authors.lastname: Gomes
authors.affiliation: Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Rodovia Ilhéus-Itabuna, km 16, 45662-900 Ilhéus, BA, Brazil; Universidade Estadual de Feira de Santana (UEFS), Departamento de Ciências Biológicas (DCBio), Av. Transnordestina, s/n°, 44036-900 Feira de Santana, BA, Brazil.
authors.forename: Maíza Alves
authors.initials: MA
authors.lastname: Lopes
authors.affiliation: Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Rodovia Ilhéus-Itabuna, km 16, 45662-900 Ilhéus, BA, Brazil.
authors.forename: Sara Pereira
authors.initials: SP
authors.lastname: Menezes
authors.affiliation: Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Rodovia Ilhéus-Itabuna, km 16, 45662-900 Ilhéus, BA, Brazil.
authors.forename: Lidiane Figueredo
authors.initials: LF
authors.lastname: Ribeiro
authors.affiliation: Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Rodovia Ilhéus-Itabuna, km 16, 45662-900 Ilhéus, BA, Brazil.
authors.forename: Cristiano Villela
authors.initials: CV
authors.lastname: Dias
authors.affiliation: Universidade Estadual do Sudoeste da Bahia (UESB), Av. José Moreira Sobrinho, 45206-190 Jequié, BA, Brazil.
authors.forename: Bruno Silva
authors.initials: BS
authors.lastname: Andrade
authors.affiliation: Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Exatas e Tecnológicas (DCET), Rodovia Ilhéus-Itabuna, km 16, 45662-900 Ilhéus, BA, Brazil.
authors.forename: Raildo Mota
authors.initials: RM
authors.lastname: de Jesus
authors.affiliation: Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Rodovia Ilhéus-Itabuna, km 16, 45662-900 Ilhéus, BA, Brazil.
authors.forename: Acassia Benjamin Leal
authors.initials: ABL
authors.lastname: Pires
authors.affiliation: Universidade Estadual de Feira de Santana (UEFS), Departamento de Ciências Biológicas (DCBio), Av. Transnordestina, s/n°, 44036-900 Feira de Santana, BA, Brazil.
authors.forename: Aristóteles
authors.initials: A
authors.lastname: Goes-Neto
authors.affiliation: Universidade Estadual de Santa Cruz (UESC), Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Rodovia Ilhéus-Itabuna, km 16, 45662-900 Ilhéus, BA, Brazil; CIRAD, UMR AGAP, F-34398 Montpellier, France. Electronic address: fabienne.micheli@cirad.fr.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Micheli
mesh_terms: D000363:Agaricales / Q000145:classification / Q000201:enzymology / Q000254:growth & development*; D001343:Autophagy; D002099:Cacao / Q000382:microbiology; D050260:Carbohydrate Metabolism; D002241:Carbohydrates; D002686:Chitin / Q000378:metabolism; D002688:Chitinases / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D005800:Genes, Fungal; D025282:Mycelium / Q000254:growth & development*; D010802:Phylogeny
chemical_list: D002241:Carbohydrates; D005656:Fungal Proteins; D002686:Chitin; D002688:Chitinases
keywords: Autolysis; Cell wall; Chitin synthase; Chitinase; Fungal development