Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Quantification of Cry1ac Protein in Four Newly Released Bt Brinjal Varieties (2014-2015)

M. M. Khatun
Biotechnology Division, BARI, Joydebpur, Gazipur

M. K. Hasan
Biotechnology Division, BARI, Joydebpur, Gazipur

Abstract/ Executive Summary:

The cultivation of genetically engineered crops has been expanded rapidly worldwide in a very short span of time. Bt brinjal is transgenic brinjal created by inserting a crystal protein gene Cry1Ac from the soil bacterium Bacillus thuringiensis. Four Bt Brinjal varieties - BARI Bt Begun 1, BARI Bt Begun 2, BARI Bt Begun 3 and BARI Bt Begun 4 are started to cultivate in Bangladesh in 2014 as first genetically engineered crop in the country. In the present study, ELISA technique was adopted to quantify the Cry1Ac proteins in newly released four Bt brinjal varieties. The Cry1Ac expression was found to be variable among the varieties and varied from 29.53 to 33.99 µg g^-1.

Keywords: ELISA method, Brinjal, Transgenic

Location:

Start Date: 00-00-2014

End Date: 00-00-2015

Program Area: Variety and Species

Commodity: Brinjal

Objectives:

In the present study, ELISA method was validated for the quantitation of the Cry1Ac protein in the fruit tissues of the newly released transgenic brinjal plants.

Methodology:

The Cry 1Ac protein in brinjal (BARI Bt Begun 1, BARI Bt Begun 2, BARI Bt Begun 3 and BARI Bt Begun 4) fruits extracts was determined through Enzyme-Linked Immunosorbent Assay (ELISA) method. About one kg of edible fruits for each variety was collected from four different Bt brinjal plants. Plant tissue samples were frozen in a –80^oC freezer and subsequently lyophilized in a Christ Alpha 1-4 Lyo Display Freeze Dryer. After complete lyophilization, the dried samples were ground into a fine powder using a micro grinder and stored in sealed containers at –20^oC freezer. Cry1Ac content in fruit samples was quantified using a commercially available DesiGen Quan-T ELISA kit. SigmaPlot software was used to generate a 4-parameter sigmoidal standard curve and the Cry1Ac levels in the samples were derived from this plot.

Source of Information: Annual Research Report 2014-2015, Biotechnology Division, BARI, Joydebpur, Gazipur

Article Link (Online Journal):

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

The quantification result of Cry1Ac in the brinjal fruit tissue sample is shown. As per the protocol of the manufacturer, the assay was accepted. The mean absorbance of the buffer blank should be ≤ 0.246. Our mean absorbance of buffer blank was 0.238 which was correct. The mean absorbance of the highest standard should be ≥ 1.305. In that case, our mean absorbance of the highest standard was 3.501 which was also correct. Percent of residuals were also fitted the prescribed value. Moreover, the R² of the standard curve should be ≥ 0.98. In our case, we got the accepted R²value 0.99. The mean absorbencies of BARI Bt Begun 1, BARI Bt Begun 2, BARI Bt Begun 3 and BARI Bt Begun 4 for Cry1Ac clearly show the presence of Bt proteins in the samples. Moreover, the average absorbencies of the samples at 405 nm were higher than the positive control.

The highest amount of Bt protein (33.99 µg g^-1dry weight) was found in BARI Bt Begun 2 followed by BARI Bt Begun 4 (32.14 µg g^-1dry weight) and BARI Bt Begun 3 (31.78 µg g^-1dry weight) (Fig. 2). The lower amount of Bt protein was in BARI Bt Begun 1 (29.53 µg g^-1dry weight). Kranthi et al. (2005) observed variability amongst the cotton hybrids in the case of Cry1Ac expression. Although the critical value was not determined to control BFSB (brinjal fruit and shoot borer), the varieties were found free from the caught of BFSB whereas the counterparts were affected by the insects at the practical field. This indicated that the prevailing levels of Bt protein are effective to control the insect. On an average of different locations in India, Cry1Ac protein varied from 16.78 to 40.34 µg g^-1 and found effective to control BFSB (Mahyco, 2007). In the case of cotton, (in India), Kranthi et al. (2005) had calculated a critical level of Cry1Ab/c (1.9 μg g^-1) for effective control of Helicoverpa armigera, below which the target pest had higher chances of survival. Ullah et al. (2014) found the critical value of Cry1Ab/c at any given time is found to be 770 ± 25 ng g^-1 for the control of Pakistani population of H. armigera.

ELISA method was found effective to quantify the Cry1Ac protein in transgenic Bt brinjal varieties. This information may be used for further research.As a new transgenic crop in Bangladesh, post-release monitoring, as well as extensive research, should be carried out on Bt brinjal considering the influence of external environmental factors on the expression of Bt protein, optimization of minimum standard value of Bt protein, quantification of Bt protein is not only the fruit tissue but also the other plant parts, the study of Bt protein at molecular levels etc.

Knowledge Management: Report/Proceedings