RESUMO
Fusarium wilt caused byFusarium udumButler(Fud) is a constant threat to pigeonpea productivity in several parts of the world. Understanding the molecular basis of pigeonpea-Fudinteraction is necessary to improve resistance to Fudand thereby the productivity of pigeonpea. Temporal and spatial changes were studied in defense enzymes namely catalase, peroxidase (PO), polyphenol oxidase (PPO), Phenylalanine ammonia lyase (PAL), ?-1,3-glucanase and chitinase at pre-initiation (S1), disease initiation (S2) and severe diseased (S3) stages in root, stem and leaf tissues of 2 susceptible and 2 resistant cultivars of pigeonpea inoculated with Fud. Comparison of various treatment combinations revealed that all the defence enzymes showed temporal and spatial variation in activity/expression pattern. PO increased in all the tissues of all the varieties from S1 to S2 and declined thereafter in S3 stage, and induction was higher in resistant cultivars. Catalase and PPO were induced highly in resistant cultivars inoculated with Fud, and the pattern was stage-specific and tissue-specific in nature. Catalase induction occurred at S2 in uninoculatedplants whereas it started at S1 in Fudinoculatedplants. PPO level diminished from S2 to S3 stage, and in susceptible varieties, it reached even below the control. PAL, ?-1,3-glucanase and chitinase activity were induced at S1, and S2 and values at S3 decreased progressively. Induction of chitinase was significantly high in leaves whereas ?-1,3-glucanase activity was high in stem tissues. Both control and challenged plants had a higher level of ?-1,3-glucanase activity at later stages of disease development, but the proportionate increase was much higherin resistant cultivars. The activity/expression pattern of these defence enzymes reveals their use as biochemical markers for resistance and provides scope for manipulating their expression and development of wilt-resistant transgenic pigeonpea
RESUMO
Aims: The purpose of the present study was to evaluate and compare the clinical outcome of infrabony defects following reconstructive surgery with the use of tricalcium phosphate (TCP) alone; TCP and citric acid (CA) root conditioning; and TCP, CA, and oxidized regenerated cellulose (ORC) membrane. Materials and Methods: Thirty-nine systemically healthy subjects with vertical infrabony defect were initially selected based on intraoral periapical radiographs and clinical examination to record probing pocket depth (PPD) and clinical attachment level (CAL). Only 21 defects revealed two-walled configuration on surgical debridement. These defects were selected and randomly allotted to the study groups. Group 1 defects were treated with TCP, group 2 with TCP+CA, and group 3 with TCP+CA+ORC. PPD, CAL, defect depth (DD), and level of alveolar crest (AC) were evaluated at the time of initial surgery and after 6 months at surgical re-entry. These measurements were utilized to calculate PPD reduction, CAL gain, defect fill (DF), %defect fill (%DF), and crestal resorption (CR). Statistical Analysis: A paired t-test was used for assessing changes in each group. Unpaired t-test was used for intergroup comparisons. Results: All three groups showed statistically significant PPD reduction, CAL gain, DF, and %DF, but insignificant CR at the end of 6 months. On intergroup comparison, no statistically significant differences were noted between the groups for all the parameters. Conclusion: Efficacy of combination techniques using TCP+CA; TCP+CA+ORC in treatment of periodontal infrabony defects is at least equal to that of TCP alone.