Tree chitinases – stress‐ and developmental‐driven gene regulation

Abstract

In recent years, a considerable number of studies have harnessed the power of genomics to decipher the role of pathogenesis-related (PR) proteins in plant defence against various biotic and abiotic stresses. Chitinases are PR antifungal proteins expressed constitutively at low levels in plants and induced during biotic pressures and are demonstrated to be involved in the plant defence responses. Remarkable induction of chitinase enzymes by various abiotic agents (salicylic acid, jasmonic acid, ethylene and ozone) and biotic components (pathogens, insect pest, fungal cell wall components and oligosaccharides) is well demonstrated in plants. Several reviews on plant chitinase expression during hostpathogen interaction are available for annual species, whilst reports of their expression in tree species are limited to a few woody perennials: Populus, Pinus, Picea, Eucalyptus, Castanea and Pseudotsuga. The aim of this paper is to review the induction of chitinase during various stresses and developmental processes in forest tree species.

Immunodepletion of α‐plurivorin effector leads to loss of virulence of Phytophthora plurivora towards Fagus sylvatica

“…To elucidate the potential role of α‐plurivorin for the regulation of plant defence responses, the expression of several defence‐related genes, such as ACC‐oxidase (ACO, ethylene pathway) (Schäfer et al., ), PR1 (Mukhtar, Nishimura, & Dangl, ), PR2 (Yu, Kang, Han, Buchenauer, & Huang, ), PR3 (pathogenesis‐related proteins) (Veluthakkal, Sundari, & Dasgupta, ), PRP (proline‐rich protein of cell walls) (Yeom, Seo, Oh, Kim, & Choi, ), and the transcription factor WRKY70, which is known to be strongly up‐regulated after biotic stresses (Oh et al., ), were analysed (Figure ). All investigated defence‐related genes were consistently down‐regulated at almost all time points after P. plurivora infection, when compared to non‐infected plants.…”

Agrobacterium-mediated transformation of European chestnut somatic embryos with a Castanea sativa (Mill.) endochitinase gene

“…Genes encoding endochitinases have already been used to enhance plant resistance to fungal diseases (Wally and Punja 2010;Ceasar and Ignacimuthu 2012). Chitinase catalyzes the hydrolysis of β-1, 4 linkages of the Nacetyl-D-glucosamine (GlcNAc) polymer chitin (Veluthakkal et al 2012). There is evidence supporting the hypothesis that plant chitinases have antibiotic functions and thus probably constitute a plant defence mechanism against pathogens (Pourhosseini et al 2012).…”

Ecological interactions between herbivores and silver birch and aspen trees genetically modified for fungal disease resistance

“…Reviews concerning chitinase expression in trees are limited compared to annual plants. However, it seems that chitinase gene families are larger in trees compared to short-lived herbaceous species (Veluthakkal et al 2012). The transferred chitinase gene used in this thesis is native to sugar beets and possesses high molecular similarity with a birch-native chitinase gene identified from the birch EST-library (a library of short sub-sequences of cDNA sequences) (Lohtander et al 2008).…”

“…Chitinases are among the most frequently studied defencive products found in plants, animals, fungi and microbes (Collinge et al 1993;Lohtander et al 2008). In trees, chitinases are expressed during various abiotic and biotic agents as pathogens and insect pests (Veluthakkal et al 2012). Reviews concerning chitinase expression in trees are limited compared to annual plants.…”