Looks like sunburn. If it was kept indoors and then put in the sun for hours, that's what will happen.

yep, sunburn - has happened to me before too....

mDog

Sunburn seems like an accurate diagnosis. Thanks to you both.

Now that the sunburn has happened, any suggestions about how to help the plant recover?

Plants without direct sunlight need to get gradually used to the direct sun. The burned parts will not recover, but dry out and the leaves will eventually fall off. The new leaves coming out in the sun will be ok automatically.

actually what papayas do, is steal minerals and nutrients from the bottom leaves to send to the top leaves when they are growing fast. (in lots of sun)

The bottom leaves drop normally after a time.
Often they go yellow or white first.

Im not saying that its NOT sunburn,
but i would keep that in mind.

Papaya LOVE the sun.
I live in New Orleans and am growing several.

I am looking for seeds of other varieties to grow.
We can trade if you like ?

Most of mine are Caribbean Red, (type of Maradol)
or just plain Maradol.

I have a few others but they are still small.

Brad

In my experience the more sun the better with papaya , but if your plant got used to the shade, then I can see this happening.

new leaves should be ok.

I have a couple growing, and actually placed one on the roof of a storage area, to maximize sun exposure.