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Enhanced methanol production in plants provides broad spectrum insect resistance.

Dixit S, Upadhyay SK, Singh H, Sidhu OP, Verma PC, K C - PLoS ONE (2013)

Bottom Line: In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively.Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT.Cell wall enzyme transcript levels were comparable with WT.

View Article: PubMed Central - PubMed

Affiliation: CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow, Uttar Pradesh, India ; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2-Rafi Marg, New Delhi, India.

ABSTRACT
Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR) and spectra showed up to 16 fold higher methanol as compared to control wild type (WT) plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

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Transcript level of important cell wall enzyme in transgenic plant.Transcript level of all analysed genes [endo-1,4-ß-glucanases (Cel2, Cel4, Cel5, Cel7, Cel8), Cellulose synthase (celsyn), endo-xyloglucan transferase (Xytr), Expansin (NtExp1) and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH)] was up regulated in AtPME transgenic lines (At-5) over WT (NTPH) while AnPME transgenic plants (An-4) also showed expression pattern similar to AtPME except Cel4. Transcript level of housekeeping genes like GADPH was almost unaltered in transgenic plants.
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pone-0079664-g008: Transcript level of important cell wall enzyme in transgenic plant.Transcript level of all analysed genes [endo-1,4-ß-glucanases (Cel2, Cel4, Cel5, Cel7, Cel8), Cellulose synthase (celsyn), endo-xyloglucan transferase (Xytr), Expansin (NtExp1) and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH)] was up regulated in AtPME transgenic lines (At-5) over WT (NTPH) while AnPME transgenic plants (An-4) also showed expression pattern similar to AtPME except Cel4. Transcript level of housekeeping genes like GADPH was almost unaltered in transgenic plants.

Mentions: To observe the effect of over expression of PME on other important cell wall enzymes, we analysed the transcript level of certain important cell wall enzymes viz., endo-1,4-ß-glucanases (Cel2, Cel4, Cel5, Cel7, Cel8), Cellulose synthase (celsyn), endo-xyloglucan transferase (Xytr), Expansin (NtExp1) and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by real time PCR (Figure 8). Transcript level of all analysed genes was up regulated in AtPME transgenic lines over WT. AnPME transgenic plants also showed expression pattern similar to AtPME except Cel4 which was slightly down regulated (1.3 fold). Transcript level of Cel5, Celsyn and NtExp1 was drastically increased in both types of transgenic plants. Transcript level up-regulation of these genes was 25, 37 and 35 folds in AnPME plants, and 29, 29 and 30 folds in AtPME plants, respectively. mRNA level of Cel7 (AnPME, 6.5 fold; AtPME, 3.5 fold) and Xytr (AnPME, 6.8 fold; AtPME, 5.3 fold) were also significantly increased in both types of transgenic plants. Cel2 was 1.3 and 1.9 fold while Cel8 was 1.1 and 1.9 fold up-regulated in AnPME and AtPME transgenic lines, respectively. Transcript level of housekeeping genes like GADPH was almost unaltered in transgenic plants (Figure 8).


Enhanced methanol production in plants provides broad spectrum insect resistance.

Dixit S, Upadhyay SK, Singh H, Sidhu OP, Verma PC, K C - PLoS ONE (2013)

Transcript level of important cell wall enzyme in transgenic plant.Transcript level of all analysed genes [endo-1,4-ß-glucanases (Cel2, Cel4, Cel5, Cel7, Cel8), Cellulose synthase (celsyn), endo-xyloglucan transferase (Xytr), Expansin (NtExp1) and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH)] was up regulated in AtPME transgenic lines (At-5) over WT (NTPH) while AnPME transgenic plants (An-4) also showed expression pattern similar to AtPME except Cel4. Transcript level of housekeeping genes like GADPH was almost unaltered in transgenic plants.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3818224&req=5

pone-0079664-g008: Transcript level of important cell wall enzyme in transgenic plant.Transcript level of all analysed genes [endo-1,4-ß-glucanases (Cel2, Cel4, Cel5, Cel7, Cel8), Cellulose synthase (celsyn), endo-xyloglucan transferase (Xytr), Expansin (NtExp1) and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH)] was up regulated in AtPME transgenic lines (At-5) over WT (NTPH) while AnPME transgenic plants (An-4) also showed expression pattern similar to AtPME except Cel4. Transcript level of housekeeping genes like GADPH was almost unaltered in transgenic plants.
Mentions: To observe the effect of over expression of PME on other important cell wall enzymes, we analysed the transcript level of certain important cell wall enzymes viz., endo-1,4-ß-glucanases (Cel2, Cel4, Cel5, Cel7, Cel8), Cellulose synthase (celsyn), endo-xyloglucan transferase (Xytr), Expansin (NtExp1) and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by real time PCR (Figure 8). Transcript level of all analysed genes was up regulated in AtPME transgenic lines over WT. AnPME transgenic plants also showed expression pattern similar to AtPME except Cel4 which was slightly down regulated (1.3 fold). Transcript level of Cel5, Celsyn and NtExp1 was drastically increased in both types of transgenic plants. Transcript level up-regulation of these genes was 25, 37 and 35 folds in AnPME plants, and 29, 29 and 30 folds in AtPME plants, respectively. mRNA level of Cel7 (AnPME, 6.5 fold; AtPME, 3.5 fold) and Xytr (AnPME, 6.8 fold; AtPME, 5.3 fold) were also significantly increased in both types of transgenic plants. Cel2 was 1.3 and 1.9 fold while Cel8 was 1.1 and 1.9 fold up-regulated in AnPME and AtPME transgenic lines, respectively. Transcript level of housekeeping genes like GADPH was almost unaltered in transgenic plants (Figure 8).

Bottom Line: In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively.Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT.Cell wall enzyme transcript levels were comparable with WT.

View Article: PubMed Central - PubMed

Affiliation: CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow, Uttar Pradesh, India ; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2-Rafi Marg, New Delhi, India.

ABSTRACT
Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR) and spectra showed up to 16 fold higher methanol as compared to control wild type (WT) plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

Show MeSH
Related in: MedlinePlus