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The present work investigated the effect of leaf extract from coastal plant Prosopis chilensis on synthesis of silver nanoparticles using AgNO 3 as a substrate and to find their antibacterial potential on pathogenic Vibrio species in the shrimp, Penaeus monodon. The leaf extract could be able to produce silver nanoparticles, as evident by gradual change in colour of the reaction mixture consisted of the extract and 1 mM AgNO 3 to dark brown. The silver nanoparticles exhibited 2h values corresponding to the presence of silver nanocrystal, as evident by X-ray diffraction spectrum. The peaks corresponding to flavanones and terpenoids were found to be stabilizing agents of the nanoparticles, as revealed by Fourier transform infrared spectroscopy. The size of silver nanoparticles ranged from 5 to 25 nm with an average of 11.3 ± 2.1 nm and was mostly of spherical in shape, as confirmed by transmission electron microscopy. The silver nanoparticles were found to inhibit Vibrio pathogens viz., Vibrio cholerae, V. harveyi, and V. parahaemolyticus and this antibacterial effect was better than that of leaf extract, as proved by disc diffusion assay. The nanoparticles were then tested in the shrimp Penaeus monodon challenged with the four species of Vibrio pathogens for 30 days. The shrimps fed with silver nanoparticles exhibited higher survival, associated with immunomodulation in terms of higher haemocyte counts, phenoloxidase and antibacterial activities of haemolymph of P. monodon which is on par with that of control. Thus, the present study proved the possibility of using silver nanoparticles produced by coastal Prosopis chilensis as antibacterial agent in controlling vibriosis.

ABSTRACT. This study was directed at the understanding of the function of CCoAOMT isolated from Acacia auriculiformis x Acacia mangium. Full length cDNA of the Acacia hybrid CCoAOMT (AhCCoAOMT) was 1024-bp long, containing 750-bp coding regions, with one major open reading frame of 249 amino acids. On the other hand, full length genomic sequence of the CCoAOMT (AhgflCCoAOMT) was 2548 bp long, containing three introns and four exons with a 5' untranslated region (5'UTR) of 391 bp in length. The 5'UTR of the characterized CCoAOMT gene contains various regulatory elements. Southern analysis revealed that the Acacia hybrid has more than three copies of the CCoAOMT gene. Real-time PCR showed that this gene was expressed in root, inner bark, leaf, flower and seed pod of the Acacia hybrid. Downregulation of the homologous CCoAOMT gene in tobacco by antisense (AS) and intron-containing hairpin (IHP) constructs containing partial AhCCoAOMT led to reduction in lignin content. Expression of the CCoAOMT in AS line (pART-HAS78-03) and IHP line (pART-HIHP78-06) was reduced respectively by 37 and 75% compared to the control, resulting in a decrease in the estimated lignin content by 24 and 56%, respectively. AhCCoAOMT was found to have altered not only S and G units but also total lignin content, which is of economic value to the pulp industry. Subsequent polymorphism analysis of this gene across eight different genetic backgrounds each of A. mangium and A. auriculiformis revealed 47 single nucleotide polymorphisms (SNPs) in A. auriculiformis CCoAOMT and 30 SNPs in A. mangium CCoAOMT.

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14 15 16 ABSTRACT 17 Aquilaria malaccensis is an agarwood-producing species in the family Thymeleaeceae.18 Agarwood is a fragrant resin used in the manufacture of incense sticks, and in 19 pharmaceutical, perfumery and cosmetic industries. In addition to the resin, hydrosol and 20 residual water by-products from agarwood woodchip distillation are also utilized. Hydrosol 21 contains water-soluble fragrant chemicals used as a tonic drink, in cooking and cosmetics 22 while the residual water is used in spas and aromatic bath treatments. The present study 23 was conducted to identify and compare compounds present in hydrosol and residual water 24 by-products of diploid and polyploid A. malaccensis. Four different four-month-old A.97 Gas Chromatography-Mass Spectrometry 98 Samples collected in the Clevenger column were heated at 60 °C for 10 minutes at a rate of 99 3 °C per minute. The temperature was gradually increased by 68-77 °C to 230 °C and held 100 at that temperature for 10 minutes. Gases that were released from samples were then 101 injected into a gas chromatography-mass spectrometry (GC-MS) instrument. Different 102 compounds vaporized at different times ('retention time', RT). GC-MS was used to analyse 103 compounds detected at their respective peaks. The mass spectrometer peaks that were 104 considered for analyses were those that at least more than 90 percent matched to the 105 library. The peaks were identified by comparing with mass spectrometer of the HPCH 106 2205.L, Wiley7 NiST05. And NIST0.5a.L. Retention times are used to calculate relative 107 retention times-dividing the retention time of a compound by the retention time of an 108 internal standard. Tables of retention indices (RI) were used by comparing experimentally 109 found retention indices with known values. The RI is given by the equation: 110 111 112 I x = 100 x [n + (N-n){(logtrU-logtrn)/(logtrN-logtrn)}] 113 x : the name of the target compound 114 n0 : n-alkane Cn0H2n0+2 directly eluting before x 115 n1 : n-alkane Cn1H2n1+2 directly eluting after x 116 RT : retention time (in any unit such as minutes, seconds, etc.) 117 RI : retention index (pure number without unit) 118 119 120 121 Statistical Analyses 122 Mean percentage values (± SD) were used to determine the compounds present in the 123 samples using solid-phase microextraction (SPME)-GCMS. Peaks were identified by 124 comparing the retention times of the samples with those from the National Institute of 125 Standards and Technology database.126 127 RESULTS AND DISCUSSION 128 Analyses of hydrosol129 Hydrosol from TC leaves showed the highest peak area for compounds with more than 10 130 fold higher than that from DC, DS, and DV (Table 1). In TC leaf samples, five important 131 compounds were detected, i.e. α-, γ-and 10-epi-γ-eudesmol, epi-α-muurolol and δ-132 selinene. Eudesmol are found in high quality agarwood essential oil (15, 16). Several 133 important compounds were detected in TC leaf samples, but in smaller amounts, i.e. α-134 and γ-muurolene, α-selinene and γ-gurjunen...