NISCAIR Online Periodicals Repository Collection: IJEB Vol.49(01) [January 2011]

Duplex-immunocapture-RT-PCR for detection and discrimination of two distinct potyviruses naturally infecting sugarcane (Saccharum spp. hybrid)

Wed, 29 Dec 2010 22:58:59 GMT

Title: Duplex-immunocapture-RT-PCR for detection and discrimination of two distinct potyviruses naturally infecting sugarcane (Saccharum spp. hybrid)

Authors: Reddy, Ch V Subba; Sreenivasulu, P; Sekhar, G

Abstract: A sensitive duplex-immunocapture-RT-PCR (D-IC-RT-PCR) technique was developed for detection and discrimination of taxonomically distinct Sugarcane streak mosaic virus (SCSMV) and Sugarcane mosaic virus (SCMV) that naturally infect sugarcane. D-IC-RT-PCR was performed using polyclonal antisera for capture of virions. Oligo 5′-d(T)₁₈(AGC)-3′ as a common reverse primer for both viruses and virus specific forward primers, 5′-aagtggttaaacgcctgtgg-3′ and 5′-ATGTC(GA)AAGAA(GA)ATGCGCTTGC-3′ were used for amplifying ~1400 and ~900 bp fragments of SCSMV and SCMV genomes, respectively from their 3′ termini. To assess the applicability of the developed technique, 67 mosaic affected sugarcane samples were initially screened by direct antigen coating-enzyme-linked immunosorbent assay (DAC-ELISA) followed by D-IC-RT-PCR. In DAC-ELISA, ~69 % of tested samples were shown to be positive for presence of SCSMV, ~28 % for SCMV and ~10 % for both viruses. In D-IC-RT-PCR both viruses were detected up to the dilution of 10^-4. In D-IC-RT-PCR, ~76 % of tested samples were found to be positive for SCSMV, ~37 % for SCMV and ~16 % for both viruses. The sequence analyses of D-IC-RT-PCR amplicons of 3 isolates of each virus revealed that the designed primers were virus-specific. The developed technique had potential application for sensitive parallel detection of two viruses in sugarcane.

Page(s): 68-73

Relationship between xanthophyll cycle and non-photochemical quenching in rice (Oryza sativa L.) plants in response to light stress

Wed, 29 Dec 2010 22:58:59 GMT

Title: Relationship between xanthophyll cycle and non-photochemical quenching in rice (Oryza sativa L.) plants in response to light stress

Authors: Vaz, Janet; Sharma, Prabhat K

Abstract: Thirty days old rice plants grown under low and moderate light conditions were transferred to full sunlight to observe the extent of photoinhibitory damage and protective mechanism, and the relationship between xanthophyll cycle and non-photochemical quenching (qN) under changing light environment. Control plants (low, moderate and sun grown) exhibited similar Fv/Fm ratio, indicating similar photosynthetic efficiency prior to light stress. On exposure to the high light treatment, low light grown plants exhibited faster and higher degree of photoinhibition compared to moderate and high light grown plants. Moderate and high light grown plants showed relatively less photoinhibition and also showed higher qN, indicating better capacity of energy dissipation. Increase in qN in moderate light and sun grown plants was accompanied by conversion of violaxanthin (V) to antheraxanthin (A) and zeaxanthin (Z) indicating operation of Z-dependent thermal dissipation. Rice plants fed with ascorbate (AsA), a stimulator of the de-epoxidation state of V to Z, showed higher Fv/Fm ratio and qN than the plants fed with dithiothreitol (DTT) an inhibitor of xanthophyll cycle. This indicated that an increased amount of energy reached PS II reaction centre, due to absence of A and Z formation, thereby causing greater damage to photosynthesis in DTT fed rice plants. The present data confirmed the relationship between qN and Z in dissipating the excess light energy, thereby protecting plants against photodamage.

Page(s): 60-67

Effect of topical phenytoin on burn wound healing in rats

Wed, 29 Dec 2010 22:58:59 GMT

Title: Effect of topical phenytoin on burn wound healing in rats

Authors: Meena, K; Mohan, A V; Sharath, B; Somayaji, S N; Bairy, K L

Abstract: To evaluate the effect of phenytoin on burn wounds and to compare the effect of the combination of topical phenytoin preparation in dexamethasone treated burn wounds in rats, partial thickness thermal burn wounds were inflicted upon five groups of six rats each. Group I was assigned as control, Group II received the standard silver sulphadiazine, Group III was given topical phenytoin and Group IV received injection dexamethasone, Group V received the combination of the phenytoin and the dexamethasone. The parameters observed were epithelialization period, percentage of wound contraction and histopathological analysis as indicative of the process of healing. Phenytoin group showed significant improvement in burn wound contraction in comparison to standard silver sulphadiazine group, the combination group of topical phenytoin and dexamethasone also showed significant contraction compared to dexamethasone group. The period of epithelialization also decreased significantly in groups II, III and V. In conclusion, phenytoin promotes burn wound healing as evidenced by decrease in period of epithelialization and faster wound contraction.

Page(s): 56-59

Effect of Bis [benzyl N'-(indol-3-ylmethylene)-hydrazinecarbodithioato]-zinc(II) derivatives on wound healing in Sprague Dawley rats

Wed, 29 Dec 2010 22:58:59 GMT

Title: Effect of Bis [benzyl N'-(indol-3-ylmethylene)-hydrazinecarbodithioato]-zinc(II) derivatives on wound healing in Sprague Dawley rats

Authors: Mughrabi, Fathi Farag; Hashim, Harita; Ameen, Mahmood; Khaledi, Hamid; Ali, Hapipah Mohd.; Ismail, Salmah

Abstract: Effects of topical application of Bis[benzyl N'-(indol-3-ylmethylene)-hydrazinecarbodithioato]-zinc(II) (BHCZ) on wound healing and histology of healed wound were assessed. Sprague Dawley rats were experimentally induced wound in the posterior neck area. Tween 20 (0.2 ml of 10%) was applied to rats in Group 1 (negative control). Intrasite gel (0.2 ml) was applied topically to rats in Group 2 as reference. BHCZ at the concentrations 0.2 ml of 25, 50 and 100 mg/ml were applied to Group 3, 4 and 5, respectively. Wound dressed with BHCZ significantly healed earlier than those treated with 10% Tween 20. Also wound dressed with 100 mg/ml BHCZ accelerated the rate of wound healing compared to those dressed with intrasite gel and, 25 mg/ml and 50 mg/ml BHCZ. Histological analysis of healed wound with BHCZ showed comparatively less scar width at wound enclosure and the healed wound contained less macrophages and large amount of collagen with angiogenesis compared to wounds dressed with 10% Tween 20. Results of this study showed that wounds dressed with 100 mg/ml of BHCZ significantly enhanced acceleration of the rate of wound healing enclosure, and histology of healed wounds showed comparatively less macrophages and more collagen with angiogenesis.

Page(s): 50-55