« Previous AbstractSensory and analytical evaluations of paints with and without texanol    Next AbstractVOCs and PAHs emissions from creosote-treated wood in a field storage area »

Physiol Plant

Title:		Regulation by biotic stress of tannins biosynthesis in Quercus ilex: Crosstalk between defoliation and Phytophthora cinnamomi infection
Author(s):		Gallardo A; Morcuende D; Solla A; Moreno G; Pulido F; Quesada A;
Address:		"Departamento de Bioquimica, Facultad de Veterinaria, Universidad de Extremadura, 10003, Caceres, Spain. IPROCAR Research Institute, TECAL Research Group, University of Extremadura, 10003 Caceres, Spain. Institute for Dehesa Research (INDEHESA), Ingenieria Forestal y del Medio Natural, Universidad de Extremadura, 10600, Plasencia, Spain"
Journal Title:		Physiol Plant
Year:		2019
Volume:		20181115
Issue:		2
Page Number:		319 - 329
DOI:		10.1111/ppl.12848
ISSN/ISBN:		1399-3054 (Electronic) 0031-9317 (Linking)
Abstract:		"Sustainability of the Mediterranean forest is threatened by oak decline, a disease of holm oak and other Quercus species that is initiated by infection with the oomycete Phytophthora cinnamomi. Focusing on the role of tannins in the chemical defense of plants, this work investigated whether tannins content in Quercus ilex is regulated by biotic stress. Screening of published genomes allowed the identification of Quercus sequences encoding enzymes for early steps of the biosynthesis of phenolic compounds, like hydrolysable tannins and condensed tannins (CT) among others, plus genes involved in the late steps of CT biosynthesis. Four days after treatment of Q. ilex seedlings by mechanical defoliation, P. cinnamomi infection and both stressors simultaneously, mRNA concentrations for tannins biosynthesis enzymes were measured in leaves. Among the transcript amount for shikimate dehydrogenase (SDH, EC 1.1.1.25), anthocyanidin reductase (EC 1.3.1.77), anthocyanidin synthase (EC 1.14.11.19) and leucoanthocyanidine reductase (EC 1.17.1.3), defoliation induced gene expression for SDH2 isoenzyme. About 4 days after infection of roots by P. cinnamomi, this up-regulation was canceled and SDH enzyme activity decreased. Furthermore, during this late stage of biotrophic interaction the pathogen switched off the correlation engaged by defoliation between the expression of SDH1 and SDH2 encoding genes and chemical defenses corresponding to total tannins, which were down-regulated. Thus, tannins biosynthesis in seedlings of Q. ilex is induced after mechanical defoliation whereas infection by the pathogen interferes with this regulation, potentially increasing the susceptibility of plants to herbivory and aggravating the impact of biotic stress"
Keywords:		"Biosynthetic Pathways/genetics Gene Expression Regulation, Plant Genes, Plant Isoenzymes/metabolism Linear Models Phylogeny Phytophthora/*physiology Plant Diseases/genetics/*microbiology Plant Leaves/*physiology Quercus/genetics/*microbiology/*physiology;"
Notes:		"MedlineGallardo, Alejandro Morcuende, David Solla, Alejandro Moreno, Gerardo Pulido, Fernando Quesada, Alberto eng Project 956/Spanish Ministry of Agriculture, Food and Environment (Ministerio de Agricultura, Alimentacion y Medio Ambiente, Organismo Autonomo Parques Nacionales)/ Denmark 2018/10/09 Physiol Plant. 2019 Feb; 165(2):319-329. doi: 10.1111/ppl.12848. Epub 2018 Nov 15"