Efficacy of Cry1Ac protein against gypsy moth and fall webworm in transgenic poplar (Populus davidiana × Populus bolleana) by bioassay

2018 ◽  
Vol 98 (4) ◽  
pp. 844-850 ◽  
Author(s):  
Liping Ding ◽  
Yajuan Chen ◽  
Hongzhi Wang ◽  
Jianhua Wei

A modified Bacillus thuringiensis (Bt) cry1Ac gene was introduced into poplar ‘Shanxin’ (Populus davidiana × Populus bolleana) by Agrobacterium-mediated transformation. Seventeen cry1Ac transgenic lines were regenerated. The integration and expression of the cry1Ac gene in these transgenic lines were analyzed by polymerase chain reaction (PCR) and reverse-transcription quantitative PCR, respectively. Variable amounts of cry1Ac mRNA accumulated in different transgenic plants. The expression of Cry1Ac toxin protein in transgenic plants was analyzed by enzyme-linked immunosorbent assay, the concentration ranged from 0.12 to 21.00 μg g−1. The concentration of Cry1Ac protein was highly consistent with mRNA amount in each transgenic line. Leaf section bioassays were conducted using the larvae of both gypsy moth (Lymantria dispar) and fall webworm (Hyphantria cunea). Those plants, except lines 10 and 11, caused rapid mortality of all gypsy moth and fall webworm larvae with almost no defoliation, while lines 10 and 11, with Cry1Ac protein concentrations of 0.12 and 0.76 μg g−1, respectively, provided relatively weak insect protection. Results of insect bioassays indicate that Cry1Ac protein expression over 1.3 μg g−1 consistently produced high insect mortality for both species of moths. The correlation between concentration of Cry1Ac protein and insect mortality is important to understand for managing insect pests with transgenic plants. Transgenic poplars with high insect resistance will be useful tools for managing Lepidoptera pests of these trees.

1997 ◽  
Vol 10 (5) ◽  
pp. 617-623 ◽  
Author(s):  
Y.-P. Duan ◽  
C. A. Powell ◽  
S. E. Webb ◽  
D. E. Purcifull ◽  
E. Hiebert

Tobacco explants were transformed by Agrobacterium-mediated transformation with sense and antisense constructs of the movement protein genes (BC1 and BV1) of tomato mottle geminivirus (TMoV). Transgenic plants were tested for virus resistance either by exposure to viruliferous whiteflies carrying TMoV or cabbage leaf curl geminivirus (CabLCV) for a 72-h inoculation period or by continuous exposure to TMoV during the life of the plants. The transgenic lines were scored for disease symptoms, and virus replication and distribution were determined by enzyme-linked immunosorbent assay and dot blot hybridizations. Transgenic plants which expressed a mutated form (identified in a previous study) of the BC1 gene showed TMoV and CabLCV resistance. Three resistant phenotypes were observed: a delay in symptom development, a recovery from early symptoms, and an absence of virus symptoms at all stages. Geminivirus was detected in inoculated leaves but was not readily detected in leaves beyond the inoculation sites in the highly resistant plants. The geminivirus resistance conferred by expression of the spontaneously mutated BC1 gene (detected after transformation) in transgenic tobacco may involve transdominant negative interference.


PLoS ONE ◽  
2017 ◽  
Vol 12 (6) ◽  
pp. e0178754 ◽  
Author(s):  
Liping Ding ◽  
Yajuan Chen ◽  
Xiaoli Wei ◽  
Mi Ni ◽  
Jiewei Zhang ◽  
...  

Author(s):  
Lvquan Zhao ◽  
Wei Wang ◽  
Ying Qiu ◽  
Alex S. Torson

Abstract The accumulation of nutrients during diapause preparation is crucial because any lack of nutrition will reduce the likelihood of insects completing diapause, thereby decreasing their chances of survival and reproduction. The fall webworm, Hyphantria cunea, diapause as overwintering pupae and their diapause incidence and diapause intensity are regulated by the photoperiod. In this study, we test the hypothesis that photoperiod influences energy reserve accumulation during diapause preparation in fall webworm. We found that the body size and mass, lipid and carbohydrate content of pupae with a short photoperiod during the diapause induction phase were significantly greater than those of pupae with a relatively short photoperiod, and the efficiency of converting digested food and ingested food into body matter was greater in the short-photoperiod diapause-destined larvae than the relatively short-photoperiod diapause-destined larvae. We also observed higher lipase and amylase activities in short-photoperiod diapause-destined larvae relative to the counterparts. However, no obvious difference was found in protein and protease in the pupae with a short photoperiod during the diapause induction phase and short-photoperiod diapause-destined larvae compared with the counterparts. Therefore, we conclude that the energy reserve patterns of diapausing fall webworm pupae are plastic and that short-photoperiod diapause-destined larvae increase their energy reserves by improving their feeding efficiency and increase their lipid and carbohydrate stores by increasing the lipase and amylase activities in the midgut.


2006 ◽  
Vol 33 (2) ◽  
pp. 153 ◽  
Author(s):  
Mohammad S. Hoque ◽  
Josette Masle ◽  
Michael K. Udvardi ◽  
Peter R. Ryan ◽  
Narayana M. Upadhyaya

A transgenic approach was undertaken to investigate the role of a rice ammonium transporter (OsAMT1-1) in ammonium uptake and consequent ammonium assimilation under different nitrogen regimes. Transgenic lines overexpressing OsAMT1-1 were produced by Agrobacterium-mediated transformation of two rice cultivars, Taipei 309 and Jarrah, with an OsAMT1-1 cDNA gene construct driven by the maize ubiquitin promoter. Transcript levels of OsAMT1-1 in both Taipei 309 and Jarrah transgenic lines correlated positively with transgene copy number. Shoot and root biomass of some transgenic lines decreased during seedling and early vegetative stage compared to the wild type, especially when grown under high (2 mm) ammonium nutrition. Transgenic plants, particularly those of cv. Jarrah recovered in the mid-vegetative stage under high ammonium nutrition. Roots of the transgenic plants showed increased ammonium uptake and ammonium content. We conclude that the decreased biomass of the transgenic lines at early stages of growth might be caused by the accumulation of ammonium in the roots owing to the inability of ammonium assimilation to match the greater ammonium uptake.


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