Selective plant crossing? Plant genetics?

[ZinHead]

I used to work in a laboratory where we were genetically engineering tomato, brassica napens, vitis vinifera, strawberry and a few others.

We inserted a gene into the host plant's DNA by using Agrobacterium tumefacians.

The gene we inserted helped to delay ethylene synthesis in the plants as the fruit ripened.

Some fruits/vegetables give off ethylene gas as it ripens i.e. tomato, banana, strawberry and by stopping the production of ethylene, the fruit had a longer shelf life.

THAT is one way to modify plants, another method that has been used for centuries is by selecting certain traits in plants that present as desirable, and cross-pollinating that plant and selecting for the presentation of that trait.

Ethylene is the fruit ripening hormone which helps turn starch into sugar.
But it also helps ripen methoxypyrazines like in Sauvignon Blanc & many other species other than Vitis vinifera.
2-isopropyl-3-methoxypyrazine
2‐Alkyl‐3‐methoxypyrazines
2-sec-Butyl-3-methoxypyrazine
6-bromo-3-iodo-2-methoxypyrazine
4-methyl-5-vinylthiazole
2-isobutyl-3-methoxy-pyrazine
2-methyl-3-methoxypyrazine
2-methyl-6-methoxypyrazine
3,5-dimethyl-2-ethylpyrazin
dimethylpyrazine
2,3-diethyl-5-methylpyrazine
3-hydroxy-4,5-dimethyl-2(5H)-furanone.
Some species would increase in allergies due to this, or be more toxic as in Asimina triloba or retain undesirable tannins like in persimmons.
This is something which benefits the distributor, not the consumer.