ABSTRACT
A new phenolic acid ester, 4'-hydroxyphenylethyl 4,8(R)-dihydroxyphenylpropionate(1), was isolated from an endophytic fungus Colletotrichum capsici of Paeonia lactiflora roots, along with eight known phenolic derivatives, tyrosol(2), 2-(4-hydroxyphenyl) ethyl acetate(3), methyl p-hydroxyphenylacetate(4), methyl m-hydroxyphenylacetate(5), 4-(4-hydroxyphene-thoxy)-4-oxobutanoic acid(6), 4-hydroxyphenethyl methyl succinate(7), trichodenol B(8) and 4-hydroxyphenethyl 2-(4-hydroxyphenyl) acetate(9). Their structures were identified by a combination of high-resolution electrospray ionization mass spectrometry(HR-ESI-MS), nuclear magnetic resonance(NMR) spectroscopy, ultraviolet(UV) spectroscopy and electronic circular dichroism(ECD) spectroscopy. Compounds 2-9 were isolated from this fungus for the first time.
Subject(s)
Colletotrichum , Esters , Hydroxybenzoates , PaeoniaABSTRACT
Aims: Capsicum annuum (pepper) is one of the most important crops in the world. It contains an impressive list of phytonutrients that were found to have disease-preventing and health-promoting properties. Today, they are grown widely in many parts of the world as an important commercial crop. However, fungal infection is the main problem that leads to the common pepper disruptive disease, known as the Anthracnose, which lowers the yields of this plant. Therefore, this study was conducted to determine the growth, enzymatic antioxidant specific activities of catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (g-POD) as well as non-enzymatic antioxidants including ascorbic acid, α-tocopherol and carotenoids content in C. annuum as a response to the fungal infections by Colletotrichum capsici. Methodology and results: The assays were conducted at 0, 1, 2, 3, 4 and 5 weeks of fungal treatment periods. The results showed that plant growth (plant height, leaves number, length and width, chlorophyll content) was significantly lower in treated plants compared to controls. The CAT specific activity increased drastically at the early stages of the experiment and decreased thereafter. In contrast, the APX and g-POD specific activity were initially lower, but increased significantly at the later stages of the experiment. For the non-enzymatic antioxidants, the amount of ascorbic acid, α- tocopherol and carotenoids content were significantly higher at the first week of treatment and slowly reduced afterwards. Conclusion, significance and impact of study: This study shows that fungal infection inhibited the growth of pepper plants and the enzymatic and non-enzymatic antioxidants worked in concert to fight against the stress caused by the fungal infection, with their different specific roles in removing and reducing the reactive oxygen species in stress condition.
Subject(s)
CapsicumABSTRACT
Aims: The objectives of this study were to screen chitinolytic bacteria isolated from soil of Taman Nasional Bukit Duabelas, Jambi, Indonesia. Isolates were selected based on chitinolytic index and antagonism activity of Colletotrichum capsici. Chitinase enzyme from selected isolates was investigated for growth inhibition of C. capsici. Methodology and results: Two chitinolytic bacteria were selected based on their ability to degrade colloidal chitin and inhibit of the growth of C. capsici. Those isolates were KAHN 15.12 and SAHA 12.12, identified as Serratia marcescens and Bacillus thuringiensis respectively based on 16S rRNA gene. The chitinase maximum specific activity of isolate KAHN 15.12 was 52.03 U/mg after 36 h of incubation and SAHA 12.12 was 45.67 U/mg after 24 h of incubation. The enzyme was precipitated by ammonium sulfate 40% and 60% respectively for KAHN 15.12 and SAHA 12.12. The precipitated chitinases were active over a broad range of pH (5 to 10) and temperature (20 to 80 °C). Enzymes were stable in optimum temperature for 180 min. The precipitated of chitinase KAHN 15.12 and SAHA 12.12 had five and two protein bands respectively on SDS-PAGE gel. Chitinases exhibited an antifungal activity against C. capsici at concentration of 60 ppm. Conclusion, significance and impact of study: Isolates KAHN 15.12 and SAHA 12.12 were successfully selected by their ability to degrade colloidal chitin and inhibit the growth of C. capsici. The isolates had a broad range of pH and temperature, moreover relatively stable at the optimum temperature. Chitinase was effective as biological control for anthracnose caused by C. capsici in chilli.