Reactions of Smooth Bromegrass Clones with Divergent Lignin or Etherified Ferulic Acid Concentration to Three Fungal Pathogens

Abstract

over, the cell walls of some plants are modified by phenolic deposits in response to infection. Papillae or cell Increased digestibility of smooth bromegrass is associated with a wall apposition formation in epidermal cells of grasses, reduction in lignin concentration or etherified ferulic acid (EthFA) rich in lignin or lignin-like compounds, have been reconcentration, either of which may reduce host resistance to fungal diseases. The objective of this study was to determine the relationship lated to mechanisms for reduced fungal penetration and of lignin and EthFA concentration with disease reaction in smooth increased resistance to fungal organisms (Sherwood and bromegrass. Host clones, divergently selected for lignin and EthFA Vance, 1976Vance, , 1980Vance and Sherwood, 1975). concentration, were challenged by three pathogenic fungi, one bio-Reductions in the concentration of lignin or ferulic troph (Puccinia coronata Corda) and two necrotrophs [Pyrenophora acid associated with increased forage digestibility may bromi (Died.) Drechs., anamorph ϭ Drechslera bromi (Died.) eliminate or impair the resistance mechanisms of plants Shoem., and Bipolaris sorokiniana (Sacc.) Shoem]. Significant posito stresses, herbivores, and parasitic organisms. This tive and negative associations were found between lignin or EthFA would be particularly true if selection acts upon the and host reaction to P. bromi or B. sorokiniana. The frequencies of these associations suggested that they arose by chance associations components responsible for these resistance mechabetween alleles, rather than tight linkages or pleiotropic (causal) efnisms and not on the components required for cell wall fects. Host reaction to P. coronata was consistently and negatively strength and structure per se (Buxton and Casler, 1993). associated with lignin, less so with EthFA. These associations, together Lower concentration of neutral and acid detergent fiber, with results from other species, suggest that lignin, and perhaps cellulose, and lignin in the stalk and leaf-sheath of maize EthFA, may be important components of rust resistance mechanisms(Zea mays L.) were related to increased feeding by in the Poaceae. If these mechanisms are real, they will cause considerthe second-generation European corn borer, Ostrinia able difficulty for breeders attempting to simultaneously improve both rust resistance and forage nutritional value.

Identification of Chlorogenic Acid as a Resistance Factor for Thrips in Chrysanthemum

“…As such it is linked to the resistance against stem borers in maize (Zea mays; Santiago et al, 2006;Mao et al, 2007) and cotton (Gossypium hirsutum;Wang et al, 2006) as well as cereal aphids (Cabrera et al, 1995;Havlickova et al, 1996) and cereal midges (Ding et al, 2000;Abdel-Aal et al, 2001). It is also involved in the resistance to fungi such as Fusarium gramineum in maize (Bily et al, 2003), Sclerotium rolfsii in chick pea (Cicer arietinum; Sarma and Singh, 2003), and Puccinia coronata in smooth bromegrass (Bromus inermis; Delgado et al, 2002). Ferulic acid, being a strong antioxidant, has shown inhibiting effects on human cancer cell lines (Kampa et al, 2003;Lee, 2005).…”

Caracterização anatômica da lâmina foliar de populações de Bromus auleticus Trin. Ex Nees (Poaceae)

“…Delgado et al (2002) destacaram que o aumento na digestibilidade de Bromus inermis foi promovido pela redução na concentração de lignina.…”

Differential responses of Oryza sativa secondary metabolism to biotic interactions with cooperative, commensal and phytopathogenic bacteria

“…Indeed, this compound has been described to be involved in maize resistance against stem borers, as well as against cereal aphids and cereal midges (Leiss et al 2009). It is also involved in the resistance of plants to fungi such as Fusarium gramineum in maize (Leiss et al 2009), Sclerotium rolfsii in chick pea (Cicer arietinum) (Sarma and Singh 2003), and Puccinia coronata in smooth bromegrass (Bromus inermis) (Delgado et al 2002). Besides ferulic acid, p-coumaric acid is one of the major phenolic acids in rice.…”