Apoplastic and intracellular plant sugars regulate developmental transitions in witches’ broom disease of cacao
| Autor: | Joan Barau, Marcos Silveira Buckeridge, Gonçalo Amarante Guimarães Pereira, Gleidson Silva Teixeira, Maria Carolina Scatolin do Rio, Johana Rincones, Adriana Grandis, Vinicius M. A. Carvalho, Gustavo Henrique Alcalá Zaparoli |
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| Rok vydání: | 2014 |
| Předmět: |
Senescence
senescence Physiology Plant Science Photosynthesis Moniliophthora perniciosa hemibiotrophic Organelle Autophagy Extracellular VASSOURA-DE-BRUXA Hexoses Plant Diseases Plant Proteins Organelles Cacao biology Effector Theobroma cacao fungi starvation food and beverages biology.organism_classification Apoplast Biochemistry Agaricales Intracellular Research Paper |
| Zdroj: | Journal of Experimental Botany Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1460-2431 0022-0957 |
| Popis: | Highlight Phytopathogens can co-opt plant primary metabolism to enhance pathogenesis and pathogen nutrition. In witches’ broom disease of cacao, sensing and modulation of compartmentalized carbon availability can also temporally regulate disease development. Witches’ broom disease (WBD) of cacao differs from other typical hemibiotrophic plant diseases by its unusually long biotrophic phase. Plant carbon sources have been proposed to regulate WBD developmental transitions; however, nothing is known about their availability at the plant–fungus interface, the apoplastic fluid of cacao. Data are provided supporting a role for the dynamics of soluble carbon in the apoplastic fluid in prompting the end of the biotrophic phase of infection. Carbon depletion and the consequent fungal sensing of starvation were identified as key signalling factors at the apoplast. MpNEP2, a fungal effector of host necrosis, was found to be up-regulated in an autophagic-like response to carbon starvation in vitro. In addition, the in vivo artificial manipulation of carbon availability in the apoplastic fluid considerably modulated both its expression and plant necrosis rate. Strikingly, infected cacao tissues accumulated intracellular hexoses, and showed stunted photosynthesis and the up-regulation of senescence markers immediately prior to the transition to the necrotrophic phase. These opposite findings of carbon depletion and accumulation in different host cell compartments are discussed within the frame of WBD development. A model is suggested to explain phase transition as a synergic outcome of fungal-related factors released upon sensing of extracellular carbon starvation, and an early senescence of infected tissues probably triggered by intracellular sugar accumulation. |
| Databáze: | OpenAIRE |
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