Plant science for plant people.

Pepper plants make their own pesticide. A single compound brewed in their roots does two things at once: it attacks the spores of the pathogen behind root rot, and it recruits helpful soil bacteria to mount a second line of defense. Resistant pepper varieties keep making it under attack; vulnerable ones stop. When researchers sprayed the compound onto sick plants in the lab, disease spread dropped sharply. One molecule, two jobs, and a possible rescue for next year's harvest.

Lift your eyes from the pepper row and the week's bigger story is what warming is doing to plant communication. The chemical bouquet flowers release to attract pollinators shifts with temperature, the recipe drifting in ways bees and butterflies may not recognize. And heat-wave damage doesn't end with the heat. It gets written into plants' DNA and passed to their seeds, so the next generation arrives carrying the mark of the stress their parents endured.

The plants we grow today are already being shaped by the summers we give them.