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1.
Improper timing of artificial insemination with respect to ovulation is one of the major factors hampering the conception rate in buffalo. The present study was an attempt to relate physio-chemical changes in estrual mucus to subsequent pregnancy status in order to find their optimal values for determining the time for artificial insemination (AI). Serum estradiol, total protein and dry matter contents of estrual mucus were evaluated to predict the subsequent pregnancy in 36 buffalo during October 1988 to February 1989. Serum estradiol was determined by radioimmunoassay (RIA); spinnbarkeit, dry matter and total protein were determined by standard methods. Multivariate probit analyses were carried out to relate these variables to subsequent pregnancy status. Elasticity and protein concentration were significantly related to prediction probability of pregnancy status, and they predicted the pregnancy status 86% of the times correctly (P < 0.05). The probability of pregnant animals being correctly classified was 0.76, whereas the corresponding value for non-pregnant animals was 0.95. The present study demonstrated the possibility of using such a statistical model on mucus characteristics for determining proper AI time for better conception rates in Nili-Ravi water buffalo. 相似文献
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Molecular cloning of fungal xylanases: an overview 总被引:1,自引:0,他引:1
Xylanases have received great attention in the development of environment-friendly technologies in the paper and pulp industry.
Their use could greatly improve the overall lignocellulosic materials for the generation of liquid fuels and chemicals. Fungi
are widely used as xylanase producers and are generally considered as more potent producers of xylanases than bacteria and
yeasts. Large-scale production of xylanases is facilitated with the advent of genetic engineering. Recent breakthroughs in
genomics have helped to overcome the problems such as limited enzyme availability, substrate scope, and operational stability.
Genes encoding xylanases have been cloned in homologous and heterologous hosts with the objectives of overproducing the enzyme
and altering its properties to suit commercial applications. Owing to the industrial importance of xylanases, a significant
number of studies are reported on cloning and expression of the enzymes during the last few years. We, therefore, have reviewed
recent knowledge regarding cloning of fungal xylanase genes into various hosts for heterologous production. This will bring
an insight into the current status of cloning and expression of the fungal xylanases for industrial applications. 相似文献
4.
Taiyu Chen Saba Riaz Philip Davey Ziyu Zhao Yaqi Sun Gregory F Dykes Fei Zhou James Hartwell Tracy Lawson Peter J Nixon Yongjun Lin Lu-Ning Liu 《The Plant cell》2023,35(2):795
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) performs most of the carbon fixation on Earth. However, plant Rubisco is an intrinsically inefficient enzyme given its low carboxylation rate, representing a major limitation to photosynthesis. Replacing endogenous plant Rubisco with a faster Rubisco is anticipated to enhance crop photosynthesis and productivity. However, the requirement of chaperones for Rubisco expression and assembly has obstructed the efficient production of functional foreign Rubisco in chloroplasts. Here, we report the engineering of a Form 1A Rubisco from the proteobacterium Halothiobacillus neapolitanus in Escherichia coli and tobacco (Nicotiana tabacum) chloroplasts without any cognate chaperones. The native tobacco gene encoding Rubisco large subunit was genetically replaced with H. neapolitanus Rubisco (HnRubisco) large and small subunit genes. We show that HnRubisco subunits can form functional L8S8 hexadecamers in tobacco chloroplasts at high efficiency, accounting for ∼40% of the wild-type tobacco Rubisco content. The chloroplast-expressed HnRubisco displayed a ∼2-fold greater carboxylation rate and supported a similar autotrophic growth rate of transgenic plants to that of wild-type in air supplemented with 1% CO2. This study represents a step toward the engineering of a fast and highly active Rubisco in chloroplasts to improve crop photosynthesis and growth.Introducing a proteobacterial Rubisco with a greater carboxylation rate and a higher content of active sites into tobacco chloroplasts supports photosynthesis and growth at high CO2 concentrations.IN A NUTSHELL Background: Rubisco is the key enzyme responsible for fixing CO2. However, due to its intrinsically low catalytic turnover rate, Rubisco represents the ultimate rate-limiting step in plant photosynthesis. Improving Rubisco carboxylation and assembly in plants has been a long-standing challenge in crop engineering to meet the pressing need for increased global food production. There is mounting interest in replacing endogenous plant Rubisco with active non-native Rubisco candidates from other organisms to enhance photosynthetic carbon fixation. Question: The folding and assembly of Rubisco in chloroplasts are intricate processes that usually require a series of ancillary factors. Seeking a new Rubisco variant that can be produced in chloroplasts with a high yield and high catalytic performance, without the requirement for cognate assembly factors and activases, could help improve carbon fixation in crop plants. Finding: In this work, we introduced a Rubisco from a proteobacterium into tobacco chloroplasts to replace native tobacco Rubisco. In the proteobacteria, Rubisco is naturally encapsulated at a high density within a CO2-fixing protein organelle, the carboxysome. The foreign Rubisco derived from bacteria formed efficiently and was functional in chloroplasts without the need for exogenous chaperones. Intriguingly, the chloroplast-expressed bacterial Rubisco supported the autotrophic growth of transgenic plants at a similar rate to wild-type plants at 1% CO2. Next Step: The successful production of functional bacterial Rubisco represents a step toward installing faster, highly active Rubisco, functional carboxysomes, and eventually active CO2 concentration mechanisms into chloroplasts to improve Rubisco carboxylation, with the intent of enhancing crop photosynthesis and crop yield on a global scale. 相似文献
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AbstractThe present study was conducted to assess the magnitude and health impacts of As in drinking water. Drinking water samples (n?=?60) were collected from twenty different sites of Shiekhupura District (Pakistan). Health risk assessment through average daily dose (ADD), hazard indices (HI), hazard quotient (HQ), carcinogenic risk (CR), and cancer indices (CI) for dermal and oral exposure were determined. Results revealed that As concentration ranged from 2 to 900?µg?L?1 in water samples, which was significantly greater than the safe limit of As (10?µg?L?1) in water. Health risk assessment of As showed that ADD (1.07E?02–9.85E?04), HQ (1.06E+01–9.85E+00), and CR (1.60E?02–9.85E?04) for oral exposure and ADD (1.03E?05–9.69E?06), HQ (1.19E?02–7.96E?03), and CR (1.11E?05–8.98E?05) for dermal exposure which were exceeded the toxic risk index value. Comparison of the two exposure pathways indicated that the oral exposure is much higher risk than the dermal contact. Both values of HI and CI were greater than WHO limit. It is concluded that residents of study area are at higher risk of As induced diseases and carcinogenicity. 相似文献
6.
Molybdenum supply increases root system growth of winter wheat by enhancing nitric oxide accumulation and expression of NRT genes 总被引:1,自引:0,他引:1
Imran Muhammad Sun Xuecheng Hussain Saddam Rana Muhammad Shoaib Saleem Muhammad Hamzah Riaz Muhammad Tang Xiangru Khan Imran Hu Chengxiao 《Plant and Soil》2021,462(1-2):235-244
Plant and Soil - Success in agronomic biofortification of maize and wheat is highly variable. This study aimed to elucidate the differences in uptake and translocation of foliar-applied zinc (Zn)... 相似文献
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Yousafi Qudsia Batool Jannat Khan Muhammad Saad Perveen Tamsila Sajid Muhammad Wasim Hussain Abrar Mehmood Asim Saleem Shahzad 《International journal of peptide research and therapeutics》2021,27(1):351-351
International Journal of Peptide Research and Therapeutics - The original version of the article unfortunately contained a typo in co-author name. 相似文献
9.
Muhammad Arslan Khan Hasan Riaz Muhammad Raheel Qaiser Shakeel Ummara Waheed Nadeem Ahmed Muhammad Bashair Waqas Ashraf Hafiz Tassawar Abbas Maria Siddique Maria Khan Ambreen Naz Musarrat Shaheen Asif Mahmood Arif Habib Ali Muhammad Nasir Mohammad Javed Ansari Hamed A. Ghramh Khalid Ali Khan 《Saudi Journal of Biological Sciences》2021,28(1):1-9
Root-knot nematodes Meloidogyne incognita (Kofoid and White) Chitwood and Rhizoctonia bataticola (Taub.) Butler, fungus, are very dangerous root damaging pathogens. Present study was planned to establish a chemical control of these root deteriorating pathogens under lab conditions as well as in field. Maximum death rate of nematode juveniles and minimum numbers of nematode eggs hatched were recorded in plates treated with Cadusafos (Rugby® 100G) @12 g/100 ml and Cartap® (4% G) @9g/100 ml. Chemical treatment of Rhizoctonia bataticola with Trifloxystrobin + Tebuconazole (Nativo®) @0.2 g/100 ml and Mancozeb + Matalaxyl (Axiom) @0.25 g/100 ml significantly controlled the mycelial growth in plates. The best treatments tested in laboratory were applied in field as protective and curative treatments. Results proved that chemical control of root-knot nematode and root rot fungi by tested chemicals at recommended time and dose is a significant management technique under field conditions. 相似文献
10.
Amjad Ullah Ivana Tlak Gajger Arnold Majoros Showket Ahmad Dar Sanaullah Khan Ayesha Haleem Shah Muhammad Nasir Khabir Riaz Hussain Hikmat Ullah Khan Mehwish Hameed Syed Ishtiaq Anjum 《Saudi Journal of Biological Sciences》2021,28(1):523-530
Honey bee is vital for pollination and ecological services, boosting crops productivity in terms of quality and quantity and production of colony products: wax, royal jelly, bee venom, honey, pollen and propolis. Honey bees are most important plant pollinators and almost one third of diet depends on bee’s pollination, worth billions of dollars. Hence the role that honey bees have in environment and their economic importance in food production, their health is of dominant significance. Honey bees can be infected by various pathogens like: viruses, bacteria, fungi, or infested by parasitic mites. At least more than 20 viruses have been identified to infect honey bees worldwide, generally from Dicistroviridae as well as Iflaviridae families, like ABPV (Acute Bee Paralysis Virus), BQCV (Black Queen Cell Virus), KBV (Kashmir Bee Virus), SBV (Sacbrood Virus), CBPV (Chronic bee paralysis virus), SBPV (Slow Bee Paralysis Virus) along with IAPV (Israeli acute paralysis virus), and DWV (Deformed Wing Virus) are prominent and cause infections harmful for honey bee colonies health. This issue about honey bee viruses demonstrates remarkably how diverse this field is, and considerable work has to be done to get a comprehensive interpretation of the bee virology. 相似文献