ELISA Testing for Fruit Stems

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Questions and Answers

What are the two plant viruses investigated in the context of softening of pickles?

CGMMV and ZYMV

What symptoms were observed in fruits of ZYMV-infected plants?

Severe symptoms like deformations and discoloration

What alterations were observed in fruits of ZYMV-infected plants?

Histological alterations

What conclusion was drawn regarding the influence of plant viruses on the firmness and crunchiness of pickled cucumbers after pasteurization?

Plant viruses could have a considerable influence on the firmness and crunchiness of pickled cucumbers after pasteurization. Signup and view all the answers

What are the two plant viruses that affect cucurbit production and appearance mentioned in the text?

Zucchini yellow mosaic potyvirus (ZYMV) and Cucumber green mottle mosaic tobamovirus (CGMMV) Signup and view all the answers

What are the key factors that can impact the texture quality of cucumbers for pickling?

Preharvest and postharvest factors, including abiotic and biotic factors Signup and view all the answers

What were the process parameters investigated for in relation to pickle softening during manufacturing?

Pickle softening without success Signup and view all the answers

What were the conditions under which the cucumber plants were grown in the greenhouse?

16:8 h light:dark photoperiod, 26.8 °C, and 49.7% relative humidity using universal fertilizer Signup and view all the answers

What was the change in the ELISA test protocol compared to the standard procedure?

The ELISA test was performed with 100 µL aliquots per well instead of 200 µL and three replicates. Signup and view all the answers

What were the temperature ranges for storing the fruits before processing?

Fruits were stored at 10°C and 12°C for up to 24 hours before processing. Signup and view all the answers

Describe the processing steps for the cucumbers.

Processing included pasteurization in a water-filled automatic preserving cooker for 32 minutes, reaching a temperature of 82°C, and cooling in a water bath. Signup and view all the answers

What method was used to measure the texture of fresh and stored pickles, and how were the results reported?

Texture of fresh and stored pickles was measured using a texture analyzer TA.XT plus with a Warner Bratzler rectangular notch blade, and the results reported as maximum shear force (firmness, N/mm) and rise of graph (crunchiness, N/mm²). Signup and view all the answers

What are the characteristic virus symptoms observed in ZYMV-infected plants and fruits?

Deformations, blistering, chlorosis, mosaic on leaves; small leaves, reduced formation of side shoots, severe symptoms on fruits including deformations, pox-like growths, and discoloration. Signup and view all the answers

How did ZYMV infection affect the number of fruits per plant and weight per fruit compared to the control and CGMMV infection?

ZYMV infection significantly reduced the number of fruits per plant and weight per fruit. The fruits per plant were reduced to $6.31$ fruits/plant, a reduction of $53.6%$ in comparison to the control ($13.57$ fruits/plant) and of $59.8%$ in comparison to CGMMV ($15.68$ fruits/plant). Signup and view all the answers

What impact did CGMMV and ZYMV have on the number of fruits per plant and their weight, independent of the cultivar?

Both viruses had a significant influence on the number of fruits per plant and their weight, independent of the cultivar. ZYMV infection resulted in a significant reduction in fruit number per plant and weight per fruit in all cultivars. CGMMV-infected plants had an increased number of fruits per plant compared to the control. Signup and view all the answers

What was the result of the serological assay for plants infected with CGMMV and ZYMV, as well as the control plants?

All plants artificially inoculated with CGMMV and ZYMV tested positive three weeks after inoculation. The control plants tested negative for both viruses before and after harvest. For the entire period of the experiment, fruits from CGMMV and ZYMV infected plants serologically tested positive, confirming a systemic spread of the virus within the plants. Signup and view all the answers

What are the numbers of harvested fruits for CGMMV-infected plants per cultivar for 'Liszt', 'Platina', 'Profi', and 'Dirigent'?

For CGMMV-infected plants, the numbers of harvested fruits per cultivar were as follows: 'Liszt' n = 67, 'Platina' n = 75, 'Profi' n = 59, and 'Dirigent' n = 500. Signup and view all the answers

What were the texture measurements of freshly harvested cucumbers for the control, CGMMV-infection, and ZYMV-infection?

The texture measurements of freshly harvested cucumbers were carried out within 48 h of harvest. There were 60 fresh cucumbers analyzed for texture, with n = 15 for the control, n = 30 for CGMMV-infection, and n = 15 for ZYMV-infection. Signup and view all the answers

What differences were observed in the texture of pasteurized pickles infected with ZYMV compared to CGMMV and control pickles over a 12-month storage period?

The firmness and crunchiness of ZYMV-infected pickles were significantly reduced at all time points compared to CGMMV-infected and control pickles. The texture quality of ZYMV-infected cucumbers decreased by about 55% after six months and by another 20% compared to the control after 12 months. Signup and view all the answers

How many pasteurized ZYMV-infected fruits were measured after four months, six months, and 12 months of storage?

The numbers of measured ZYMV-infected fruits were as follows: after four months, n = 44, after six months n = 6, after 12 months n = 9. Signup and view all the answers

Study Notes

Fruit stems were tested for contamination using ELISA method with DSMZ's commercially available assays (RT-0190 and RT-0234).
The ELISA test was performed with 100 µL aliquots per well instead of 200 µL and three replicates.
Optical density was measured after 30 minutes and 60 minutes substrate incubation, with a cut-off value determined by mean and standard deviation of the control.
Cucumbers for processing were harvested every 2-3 days with a length of 6-9 cm, corresponding to industrial preservation sorting size.
Fruits were stored at 10°C and 12°C for up to 24 hours before processing.
Processing included pasteurization in a water-filled automatic preserving cooker for 32 minutes, reaching a temperature of 82°C, and cooling in a water bath.
Texture of fresh and stored pickles was measured using a texture analyzer TA.XT plus with a Warner Bratzler rectangular notch blade, and the results reported as maximum shear force (firmness, N/mm) and rise of graph (crunchiness, N/mm²).
Cucumber slices for microscopy were fixated in FAA fixative, dehydrated, infiltrated, and embedded in paraffin wax, then sectioned and mounted on microscope slides coated with protein glycerol.
Sections were deparaffinized, rehydrated, stained with fuchsin-chrysoidine-astra blue (FCA), cleared with Roti®-Histol, and mounted in Roti®Histokitt for imaging.

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Description

Test your knowledge of ELISA (Double Antibody Sandwich Enzyme-linked Immunosorbent Assay) procedures for analyzing fruit stem samples. Learn about deviations from standard protocols and factors affecting optical density measurements.