Devastating Disease Threatening the World’s Chocolate Supply: Scientists Found a Possible Answer

A small genetic change

The Penn State team combined genome sequencing, CRISPR gene editing and traditional crossbreeding to improve cacao’s natural defenses against black pod disease. The mold-like pathogen attacks cacao plants and can sharply cut harvests.

Researchers changed two bases in the plant’s genome, then bred out transgenic material, including foreign DNA linked to the editing machinery. Mark Guiltinan said the change reduced disease by about 42% in laboratory conditions; the plants retained the mutation without foreign DNA.

The research builds on decades of work by Guiltinan and Siela Maximova, both in Penn State’s Department of Plant Sciences. The study appeared in the Plant Biotechnology Journal.

Cacao faces growing pressures

Cacao originated beneath the Amazon rainforest canopy, where surrounding trees helped maintain stable conditions. It is now grown across tropical parts of Africa, Asia and Latin America, often in environments unlike its original habitat.

Field trials and commercial plans

Field evaluations are underway with the U.S. Department of Agriculture in Hawaii and Puerto Rico. The trials will test how the edited plants perform in real growing environments before broader cultivation is considered.

Penn State has licensed commercial rights to plants carrying the disease-tolerance mutation to AgroNetica, a biotechnology company focused on cacao. The company plans further testing, expanded production and eventual marketing of improved varieties to growers in cacao-producing countries.

Maximova said developing a crop variety for farmers takes millions of dollars and many years, making investment partnerships important. The article does not report that the newly licensed plants have yet succeeded in field trials or reached growers.

Other traits remain goals

AgroNetica is also pursuing possible cacao traits including heat and drought tolerance, reduced cadmium accumulation and more compact trees that could support greater mechanization. Other aims include earlier first harvests and caffeine-free cacao.

These are development objectives, not demonstrated benefits of the newly licensed disease-tolerant plants. The current evidence for the mutation’s effect comes from laboratory testing, with field results still to come.