Salicylic acid activates phenylalanine ammonia-lyase in grape berry in response to high temperature stress

Abstract

Our previous work has indicated that salicylic acid (SA) is involved in the development of pea plant thermotolerance and induces the gene expression of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), a key enzyme in phenylpropanoid metabolism of grape berry. However, the relationship between SA and PAL during high temperature stress remains obscure. The present experiment, using the technique of in vivo incubation of the grape berry (Vitis vinifera L. cv. Cabernet Sauvignon) tissue in the SA-contained medium, the effects of exogenous SA on the gene expression of PAL and the accumulation of polyphenols during high temperature stress were investigated. The results showed that SA could induce the accumulation of PAL mRNA and the synthesis of new PAL protein, and increase the activity under high temperature stress. A significant accumulation of phenolics was also observed in the SA-treated berries. But, the activation of PAL by SA could be blocked by the pretreatments of berry tissues with the protein synthesis inhibitor cycloheximide, and mRNA transcription inhibitor, actinomycin D, respectively. It is thus speculated that SA may induce the activation of PAL and the accumulation of pheonlics leading to the development of thermotolerance.

Biochemical Evaluation of Phenylalanine Ammonia Lyase (PAL) from Endemic Cyathobasis fruticulosa (Bunge) Aellen. for the Dietary Treatment of Phenylketonuria (PKU)

“…Previous reports have indicated a temperature range of 25 to 60 °C for other PAL enzymes derived from Musa sp. (34), Triticum aestivum (19), Ephedra sinica (35) and Vitis vinifera (36). Activities of (39.1±0.1) and (44.6±0.1) U/mg were recorded at 5 and 500 mM buff er concentrations, respectively.…”

Accumulation of flavanols and expression of leucoanthocyanidin reductase induced by postharvest UV-C irradiation in grape berry

“…Thus, flavanol polyphenol accumulation was regulated by UV-C irradiation at the translational level. Our previous study showed that increased PAL protein content induced an increase in PAL activity during heat stress (Wen et al, 2008) and that exogenous salicylic acid-induced increase PAL protein content, leading to increased PAL activity Wen, 2005). Hence, it can be concluded that increased LAR activity increased the LAR protein content, which was similar to temperatureinduced or salicylic acid-induced increase in PAL activity.…”

“…The protein levels of LAR1 and LAR2 were quantified by western blotting as previously described (Wen et al, 2008). Primary antibodies were provided by Prof. Qiuhong Pan (College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, China).…”

“…The biosynthesis and accumulation of polyphenols are regulated by environmental conditions such as temperature (Wen et al, 2008;Crifò et al, 2011), illumination (Wang et al, , 2012Koyama et al, 2012), and water (Acevedo-Opazo et al, 2010;Ollé et al, 2011;Quiroga et al, 2012). Numerous studies have reported that ultraviolet (UV) irradiation induces the accumulation of polyphenols Guerrero et al, 2010;Interdonato et al, 2011;Sergio et al, 2012;Zhang et al, 2012).…”

Phytohormone-Induced Resistance against <i>Xanthomonas axonopodis</i> PV. <i>citri</i> in <i>Citrus aurantifolia</i>

“…In addition, FA and NA are involved in metabolic functions such as biosynthesis of nucleic acids, amino acids and pantothenate, lignin formation and synthesis of pathogenesis-related (PR) proteins and regulated redox process [17]. So far, some studies have provided the evidence that phytohormones like SA, JA, IAN, NA and FA have the potentiality for mitigating plant disease by modulating redox balance activating enzymes [18] [19]. Above information reveals that phytohormones like SA, JA, IAN, FA and NA create a favorable condition for plant to resist pathogen by modulating physiological and molecular process.…”