Status of DIMBOA and phenolic acids in transgenic Bt corn

2005 ◽  
Vol 56 (8) ◽  
pp. 833 ◽  
Author(s):  
C. R. Nie ◽  
S. M. Luo ◽  
C. X. Lin ◽  
R. S. Zeng ◽  
J. H. Huang ◽  
...  

Experiments were conducted to investigate the status of DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) and phenolic acids in leaves of some transgenic Bt corn hybrids. Comparison between Bt corn hybrids and their corresponding non-transgenic near-isogenic lines suggested that the introduction of the Bt gene has adverse effects on the biosynthesis and accumulation of DIMBOA and some phenolic acids, such as ferulic acid, in the corn plants. Under conditions of either water or nitrogen stress, the accumulation of DIMBOA in the leaves of the Bt corns could be enhanced. The results of this study suggest that caution must be taken when considering the introduction of Bt corns into China because Bt corns may have a weaker capacity, relative to traditional Chinese corn hybrids, to synthesise DIMBOA and some forms of phenolic acids in the leaves and, therefore, reduce the plant’s resistance to pathogens, diseases, and pests other than the targetted corn borer.

1999 ◽  
Vol 24 (1) ◽  
Author(s):  
R. Higgins ◽  
L. Buschman ◽  
P. Sloderbeck ◽  
V. Martin
Keyword(s):  
Bt Corn ◽  

2002 ◽  
Vol 95 (5) ◽  
pp. 878-892 ◽  
Author(s):  
Clinton D. Pilcher ◽  
Marlin E. Rice ◽  
Randall A. Higgins ◽  
Kevin L. Steffey ◽  
Richard L. Hellmich ◽  
...  

1997 ◽  
Vol 22 (1) ◽  
pp. 426-427
Author(s):  
J.T. Shaw ◽  
K.L. Steffey ◽  
M.E. Gray ◽  
J.W. Finger

Abstract Corn was planted at the University of Illinois Cruse Farm, Champaign, Illinois, on 24 May. The experimental design was a split plot with natural or manual infestation of ECB as the main plots and 5 different B/-corn hybrids and their non-Br isolines as the subplots. Each plot was 4 rows (30-inch) wide X 40 ft long with 35 plants per row (after thinning). Treatments were replicated 5 times. Manual ECB infestations to simulate the first-generation were made on 3 and 6 July at the V7 corn leaf stage by releasing approximately 50 neonate larvae in corn grit into the whorls of corn plants using a ‘bazooka’ applicator. Manual ECB infestations to simulate the second-generation were made at corn anthesis on 7 Aug by applying approximately 25 neonate larvae in corn grit to the leaf exiles above and below the ear node. On 8 Aug, 25 neonate larvae were applied to the ear node and the second leaf axil above the ear node. All manual infestations were made to all plants (70 total) in the middle 2 rows of each plot. On 31 Jul, 20 consecutive plants were rated for leaf feeding by first generation larvae by using the 1 to 10 Guthrie scale. On 9 and lOOct, 15 consecutive plants from 1 of the middle 2 rows were split with a corn knife for evaluation. The number of plants with cavities and the total length of cavities per plant were recorded. Also, the number of live larvae per plant was recorded. The mean percentage of plants with cavities, the mean length of stalk tunneling (in inches) per plant and the mean number of live larvae were determined for each plot. ECB damage to the ear and shank were analyzed separately from the stalk damage data. An ear rating scale of 1 to 3 was used, with 1 being tip damage only, 2 being side damage only, and 3 being tip + side damage on the same ear. Shelled grain weights (yields) were taken from the 15 dissected plants, corrected to 15.5% moisture, and added to the machine harvested weights (moisture corrected) for the remaining plants of the middle 2 rows in each plot.


2006 ◽  
Vol 41 (3) ◽  
pp. 221-231 ◽  
Author(s):  
Kerry C. Allen ◽  
Henry N. Pitre

A 2-yr study was conducted to measure the influence of transgenic corn, Zea mays L., expressing the CrylAb endotoxin of Bacillus thuringiensis (Berliner) (Bt) by means of Event MON810 on natural populations of Helicoverpa zea (Boddie) and Diatraea grandiosella (Dyar). The studies were conducted at Leland and Morgan City, MS, in 1999 and at Morgan City in 2000. Although total numbers of H. zea larvae were not significantly different on transgenic corn hybrids compared with their near-isogenic parent lines, fewer large larvae were found on the transgenic hybrids. Differences in H. zea larval growth were noticeable when larvae fed on Bt corn vs non-Bt corn. The delay in larval growth for insects within a single generation, which could possibly result in asynchronous mating between insecticide resistant and susceptible insects, was observed for larvae feeding on plants expressing the Bt toxin. Diatraea grandiosella caused limited damage to the transgenic corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with the near-isogenic, non-Bt corn parents; however, there was a trend toward higher yields for Bt hybrids compared with their near-isogenic non-Bt parents.


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