Inverse effects of Arabidopsis NPR1 gene on fusarium seedling blight and fusarium head blight in transgenic wheat     

C.‐S. Gao  X.‐J. Kou  H.‐P. Li  J.‐B. Zhang  A. S. I. Saad  Y.‐C. Liao 《Plant pathology》2013,62(2):383-392

In this study, the Arabidopsis thaliana NPR1 (non‐expressor of PR genes) gene was integrated into an elite wheat cultivar, and the response of the transgenic wheat expressing NPR1 to inoculation with Fusarium asiaticum was analysed. With seedling inoculation, the transgenic lines showed significantly increased fusarium seedling blight (FSB) susceptibility, whereas floret inoculation resulted in enhanced fusarium head blight (FHB) resistance. Quantitative real‐time PCR revealed that expression of two defence genes, PR3 and PR5, was associated with susceptible reactions to FSB and FHB, whereas the PR1 gene was activated in resistance responses. This inverse modulation by the constitutively expressed NPR1 gene suggests that NPR1 has a bifunctional role in regulating defence responses in plants. Therefore, it is unsuitable for improving overall resistance to FSB and FHB in wheat.  相似文献   

A Stable Synthetic Pyrethroid,NRDC 147, and the Control of Spodoptera littoralis     

A. S. A. Saad  A. A. El-Bahrawi  F. Amin 《国际虫害防治杂志》2013,59(3):278-281

Abstract

Pyrethrins, the botanical insecticides and their synthetic analogues are well known for their power of producing very rapid paralysis (knockdown) in treated insects. The use of pyrethrins or synthetic analogues in agriculture to combat insect pests on field crops has been rather limited. The main reason for this is their non-persistence in field conditions. A recently developed synthetic pyrethroid NRDC 147, which is 10–100 times more stable in light than previous pyrethroids was tested in the laboratory and field against the Egyptian cotton leafworm Spodoptera littoralis (Boisd). Results indicate higher efficiency (LC₅₀ 320 ppm), compared with 460, 422, 1250, 180, 2150 and 265 ppm for cyolane, chlorpyrifos, leptophos, methomyl, monocrotophos and methamidophos respectively. The residual effect (LT₅₀) is more than 7 days in the field for NRDC 147, while it was 5.8, 6.8 and 4.2 for cyolane, leptophos and methamidophos.  相似文献   

Stress combination: When two negatives may become antagonistic,synergistic or additive for plants?     

Hera NADEEM  Amir KHAN  Rishil GUPTA  Mohamed HASHEM  Saad ALAMRI  Mansoor Ahmad SIDDIQUI  Faheem AHMAD 《土壤圈》2023,33(2):287-300

Plants in their natural environment are constantly subjected to various abiotic and biotic stressors and, therefore, have developed several defense mechanisms to maintain fitness. Stress responses are intricate and require various physiological, biochemical, and cellular changes in plants. The reaction mechanisms in plants subjected to drought, salinity, or heat stress alone have been explained in numerous studies. However, the field conditions are significantly different from the controlled lab...  相似文献   

Seroprevalence of camel brucellosis (Camelus dromedarius) in Somaliland     

Ghanem  Yasser M.  El-Khodery  Sabry A.  Saad  Ashraf A.  Abdelkader  Ahemd H.  Heybe  Ahemd  Musse  Yasin A. 《Tropical animal health and production》2009,41(8):1779-1786

The present study was delineated to investigate the prevalence and risk factors of camel brucellosis in Northern Somalia (Somaliland). The study was carried out at three main districts of camel-rearing regions of Somaliland (Awdal, Waqoyi Galbed and Togdheer) in the period from July to November, 2008. A total of 1246 camel blood sera were randomly collected from 42 sporadic small scale camel herds. Two serological tests were used to screen all serum samples, Rose Bengal Plate Test (RBPT) and indirect ELISA (I-ELISA). Multivariate logistic regression was constructed to study the risk factors associated with Brucella seropositive cases. The overall prevalence of camel brucellosis in districts under investigation was 3.9% by RBPT and 3.1% by (I-ELISA). Multivariate logistic regression on animal level showed that locality (P < 0.05; OR: 6.254; CI, 1.186–32.976), herd size (P < 0.001; OR: 5.493; CI, 2.956-10–207), rearing with other ruminants (P < 0.001; OR: 12.433; CI, 3.957–39.060), and contact with other camels (P < 0.05; OR: 5.311; CI, 1.093–25.800) were the potential risk factors. However, herd size (P < 0.05; OR: 5.425; CI, 1.181–24.932), and rearing with other ruminants (P < 0.05; OR: 20.466; CI, 1.456–28.638) were recorded as risk factors on the herd level. The results of the present investigation indicate that the Brucella spp. exists within the camel herds in Somaliland. Further studies need to be done on Brucella infection in the other ruminants to determine which measure should be followed for control of brucellosis.  相似文献   

Evaluation of Cow Pea Seed Meal,Vigna sinensis,as a Dietary Protein Replacer for Nile tilapia,Oreochromis niloticus (L.), Fingerlings     

Deyab M. S. D EL‐Saidy  Aml S. Saad 《Journal of the World Aquaculture Society》2008,39(5):636-645

The main objectives of this study were to evaluate the effect of partial and total replacement of fish meal (FM) protein by cow pea seed meal (CPSM) protein in practical diets on growth performance, feed utilization, and body composition of Nile tilapia, Oreochromis niloticus (L.). Fish of an average initial weight of 4.6 ± 0.2 g were stocked in 15 glass aquariums (80 L each) at a rate of 15 fish per aquarium. FM protein (30% of the diet) was used as the sole source of animal protein in the control diet. Percent replacement of FM by CPSM on the basis of crude protein were as follows: 0% (control diet A), 25% (diet B), 50% (diet C), 75% (diet D), and 100% (diet E). Diets were fed to fish at a rate of 4% of the total fish biomass daily, for a period of 16 wk. The results of this study revealed that the fish fed control diet A (100% FM) had the best average final body weight, specific growth rate (SGR %/d), weight gain (g/fish), weight gain %, while the poorest results for all parameters were obtained with fish fed diet E (100% CPSM). The same parameters of fish fed diets B (25% CPSM) and C (50% CPSM) were not significantly different (P > 0.05) from those of fish fed the control diet A. Feed utilization parameters of fish fed diets A, B, C, and D were better than for diet E. Proximate composition of whole‐body moisture and ash contents were not significantly different (P > 0.05) among all experimental diets and control diet. Whole‐body protein contents for fish fed diets B and C were superior to the control diet A. Incorporation of CPSM in the diets significantly increased whole‐body fat content. Incorporation of CPSM in the diets significantly decreased apparent digestibility coefficient of crude protein crude fat and energy. Diets B and C were not significantly different from control diet A. Therefore, these findings suggest that up to 50% of FM protein can be replaced by CPSM protein in Nile tilapia diets without any adverse effects on growth performance, feed utilization, body composition, and digestibility.  相似文献