ORCID Profile
0000-0001-5351-6957
Current Organisation
University of Tasmania
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Publisher: Springer Science and Business Media LLC
Date: 10-02-2013
DOI: 10.1007/S10529-013-1153-2
Abstract: A newly-synthesized cry2Ab gene was characterized in Nicotiana tabacum, before its further transformation in cotton. Synthetic cry2Ab gene was cloned in pGreen0029 and its expression was transiently analyzed at mRNA level through agroinfiltration in tobacco. The mRNA of cry2Ab was detected after 72 h agroinfiltration through PCR using total plant RNA. This construct was then transformed into N. tabacum through Agrobacterium. Insect bioassays were conducted on detached leaves using first instar Spodoptera exigua larvae after 96 h significant insect mortality was recorded. This newly synthesized gene was effective in controlling S. exigua first instar larvae. It can be used in combinations with other Bt genes like cry1Ac for developing resistance against major insect pests of cotton and further widening the insect control spectrum.
Publisher: Springer Science and Business Media LLC
Date: 28-02-2022
DOI: 10.1007/S00425-022-03844-Z
Abstract: Droughted sorghum had higher concentrations of ROS in both wildtype and dhurrin-lacking mutants. Dhurrin increased in wildtype genotypes with drought. Dhurrin does not appear to mitigate oxidative stress in sorghum. Sorghum bicolor is tolerant of high temperatures and prolonged droughts. During droughts, concentrations of dhurrin, a cyanogenic glucoside, increase posing a risk to livestock of hydrogen cyanide poisoning. Dhurrin can also be recycled without the release of hydrogen cyanide presenting the possibility that it may have functions other than defence. It has been hypothesised that dhurrin may be able to mitigate oxidative stress by scavenging reactive oxygen species (ROS) during biosynthesis and recycling. To test this, we compared the growth and chemical composition of S. bicolor in total cyanide deficient sorghum mutants ( tcd1 ) with wild-type plants that were either well-watered or left unwatered for 2 weeks. Plants from the adult cyanide deficient class of mutant ( acdc1 ) were also included. Foliar dhurrin increased in response to drought in all lines except tcd1 and acdc1 , but not in the roots or leaf sheaths. Foliar ROS concentration increased in drought-stressed plants in all genotypes. Phenolic concentrations were also measured but no differences were detected. The total amounts of dhurrin, ROS and phenolics on a whole plant basis were lower in droughted plants due to their smaller biomass, but there were no significant genotypic differences. Up until treatments began at the 3-leaf stage, tcd1 mutants grew more slowly than the other genotypes but after that they had higher relative growth rates, even when droughted. The findings presented here do not support the hypothesis that the increase in dhurrin commonly seen in drought-stressed sorghum plays a role in reducing oxidative stress by scavenging ROS.
Publisher: Springer Science and Business Media LLC
Date: 10-04-2012
DOI: 10.1007/S10529-012-0923-6
Abstract: Efficacy of two newly synthesized cry1Ac and cry2Ab genes was checked in tobacco before their expression in cotton. Both genes were artificially synthesized and codon optimized with respect to cotton-preferred codon usage. These genes were cloned in a plant expression vector and then transformed into tobacco. Fifty-eight putative transgenic plants were recovered from the selected explants. Successful integration of both genes in plant genome was confirmed by PCR lification. Expression of transgenes was confirmed by PCR lification from total plant RNA. Detached leaf insect bioassays were conducted with Helicoverpa armigera and Spodoptera exigua larvae. About 12 % of the transgenic plants showed significantly high resistance to S. exigua. Significant mortality (62 %) of H. armigera was recorded within 24 h of bioassays. Both toxins showed synergistic effect in tobacco and broadened the spectrum of plant activity against insects.
Publisher: MDPI AG
Date: 17-12-2020
Abstract: In plants, the production of secondary metabolites is considered to be at the expense of primary growth. Sorghum produces a cyanogenic glycoside (dhurrin) that is believed to act as its chemical defence. Studies have shown that acyanogenic plants are smaller in size compared to the wildtype. This study aimed to investigate whether the small plant size is due to delayed germination or due to the lack of dhurrin derived nitrogen. A novel plant system consisting of totally cyanide deficient class 1 (tcd1) and adult cyanide deficient 1 (acdc1) mutant lines was employed. The data for germination, plant height and developmental stage during seedling development and final plant reproductive fitness was recorded. The possible role of phytohormones in recovering the wildtype phenotype, especially in developmentally acyanogenic acdc1 line, was also investigated. The data on plant growth have shown that the lack of dhurrin is disadvantageous to growth, but only at the early developmental stage. The tcd1 plants also took longer to mature probably due to delayed flowering. None of the tested hormones were able to recover the wildtype phenotype. We conclude that the generation of dhurrin is advantageous for plant growth, especially at critical growth stages like germinating seed by providing a ready source of reduced nitrogen.
No related grants have been discovered for Muhammad Nouman Sohail.