The most likely cause is not a disease but simple transplant shock. Plants need a dormant period in the shade after transplanting to recover.

Assuming you transplanted it to a large enough container and used a good soil-less mix in the container the plant will most likely recover. If you can move it out of the sun for a couple of days to the shade, do NOT overwater it, and just leave it alone, it should be fine.

But for future ref - in most of AZ this is not the time to be planting tomatoes. ;) Most AZ gardeners I communicate with planted in March or April so next year plan to get a 2-3 month head start with yours so that you can get some fruit. Once air temps exceed 90 degrees on a regular basis, tomatoes will not set any fruit - the blooms just die and fall off.

Check with your local county extension office as they can advise you on the correct planting dates for your area.

Good luck.

Dave